Merge tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

- VFIO direct character device (cdev) interface support. This extracts
the vfio device fd from the container and group model, and is
intended to be the native uAPI for use with IOMMUFD (Yi Liu)

- Enhancements to the PCI hot reset interface in support of cdev usage
(Yi Liu)

- Fix a potential race between registering and unregistering vfio files
in the kvm-vfio interface and extend use of a lock to avoid extra
drop and acquires (Dmitry Torokhov)

- A new vfio-pci variant driver for the AMD/Pensando Distributed
Services Card (PDS) Ethernet device, supporting live migration (Brett
Creeley)

- Cleanups to remove redundant owner setup in cdx and fsl bus drivers,
and simplify driver init/exit in fsl code (Li Zetao)

- Fix uninitialized hole in data structure and pad capability
structures for alignment (Stefan Hajnoczi)

* tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio: (53 commits)
vfio/pds: Send type for SUSPEND_STATUS command
vfio/pds: fix return value in pds_vfio_get_lm_file()
pds_core: Fix function header descriptions
vfio: align capability structures
vfio/type1: fix cap_migration information leak
vfio/fsl-mc: Use module_fsl_mc_driver macro to simplify the code
vfio/cdx: Remove redundant initialization owner in vfio_cdx_driver
vfio/pds: Add Kconfig and documentation
vfio/pds: Add support for firmware recovery
vfio/pds: Add support for dirty page tracking
vfio/pds: Add VFIO live migration support
vfio/pds: register with the pds_core PF
pds_core: Require callers of register/unregister to pass PF drvdata
vfio/pds: Initial support for pds VFIO driver
vfio: Commonize combine_ranges for use in other VFIO drivers
kvm/vfio: avoid bouncing the mutex when adding and deleting groups
kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add()
docs: vfio: Add vfio device cdev description
vfio: Compile vfio_group infrastructure optionally
vfio: Move the IOMMU_CAP_CACHE_COHERENCY check in __vfio_register_dev()
...

Documentation/driver-api/vfio.rst

···
 	/* Gratuitous device reset and go... */
 	ioctl(device, VFIO_DEVICE_RESET);
 
+IOMMUFD and vfio_iommu_type1
+----------------------------
+
+IOMMUFD is the new user API to manage I/O page tables from userspace.
+It intends to be the portal of delivering advanced userspace DMA
+features (nested translation [5]_, PASID [6]_, etc.) while also providing
+a backwards compatibility interface for existing VFIO_TYPE1v2_IOMMU use
+cases.  Eventually the vfio_iommu_type1 driver, as well as the legacy
+vfio container and group model is intended to be deprecated.
+
+The IOMMUFD backwards compatibility interface can be enabled two ways.
+In the first method, the kernel can be configured with
+CONFIG_IOMMUFD_VFIO_CONTAINER, in which case the IOMMUFD subsystem
+transparently provides the entire infrastructure for the VFIO
+container and IOMMU backend interfaces.  The compatibility mode can
+also be accessed if the VFIO container interface, ie. /dev/vfio/vfio is
+simply symlink'd to /dev/iommu.  Note that at the time of writing, the
+compatibility mode is not entirely feature complete relative to
+VFIO_TYPE1v2_IOMMU (ex. DMA mapping MMIO) and does not attempt to
+provide compatibility to the VFIO_SPAPR_TCE_IOMMU interface.  Therefore
+it is not generally advisable at this time to switch from native VFIO
+implementations to the IOMMUFD compatibility interfaces.
+
+Long term, VFIO users should migrate to device access through the cdev
+interface described below, and native access through the IOMMUFD
+provided interfaces.
+
+VFIO Device cdev
+----------------
+
+Traditionally user acquires a device fd via VFIO_GROUP_GET_DEVICE_FD
+in a VFIO group.
+
+With CONFIG_VFIO_DEVICE_CDEV=y the user can now acquire a device fd
+by directly opening a character device /dev/vfio/devices/vfioX where
+"X" is the number allocated uniquely by VFIO for registered devices.
+cdev interface does not support noiommu devices, so user should use
+the legacy group interface if noiommu is wanted.
+
+The cdev only works with IOMMUFD.  Both VFIO drivers and applications
+must adapt to the new cdev security model which requires using
+VFIO_DEVICE_BIND_IOMMUFD to claim DMA ownership before starting to
+actually use the device.  Once BIND succeeds then a VFIO device can
+be fully accessed by the user.
+
+VFIO device cdev doesn't rely on VFIO group/container/iommu drivers.
+Hence those modules can be fully compiled out in an environment
+where no legacy VFIO application exists.
+
+So far SPAPR does not support IOMMUFD yet.  So it cannot support device
+cdev either.
+
+vfio device cdev access is still bound by IOMMU group semantics, ie. there
+can be only one DMA owner for the group.  Devices belonging to the same
+group can not be bound to multiple iommufd_ctx or shared between native
+kernel and vfio bus driver or other driver supporting the driver_managed_dma
+flag.  A violation of this ownership requirement will fail at the
+VFIO_DEVICE_BIND_IOMMUFD ioctl, which gates full device access.
+
+Device cdev Example
+-------------------
+
+Assume user wants to access PCI device 0000:6a:01.0::
+
+	$ ls /sys/bus/pci/devices/0000:6a:01.0/vfio-dev/
+	vfio0
+
+This device is therefore represented as vfio0.  The user can verify
+its existence::
+
+	$ ls -l /dev/vfio/devices/vfio0
+	crw------- 1 root root 511, 0 Feb 16 01:22 /dev/vfio/devices/vfio0
+	$ cat /sys/bus/pci/devices/0000:6a:01.0/vfio-dev/vfio0/dev
+	511:0
+	$ ls -l /dev/char/511\:0
+	lrwxrwxrwx 1 root root 21 Feb 16 01:22 /dev/char/511:0 -> ../vfio/devices/vfio0
+
+Then provide the user with access to the device if unprivileged
+operation is desired::
+
+	$ chown user:user /dev/vfio/devices/vfio0
+
+Finally the user could get cdev fd by::
+
+	cdev_fd = open("/dev/vfio/devices/vfio0", O_RDWR);
+
+An opened cdev_fd doesn't give the user any permission of accessing
+the device except binding the cdev_fd to an iommufd.  After that point
+then the device is fully accessible including attaching it to an
+IOMMUFD IOAS/HWPT to enable userspace DMA::
+
+	struct vfio_device_bind_iommufd bind = {
+		.argsz = sizeof(bind),
+		.flags = 0,
+	};
+	struct iommu_ioas_alloc alloc_data  = {
+		.size = sizeof(alloc_data),
+		.flags = 0,
+	};
+	struct vfio_device_attach_iommufd_pt attach_data = {
+		.argsz = sizeof(attach_data),
+		.flags = 0,
+	};
+	struct iommu_ioas_map map = {
+		.size = sizeof(map),
+		.flags = IOMMU_IOAS_MAP_READABLE |
+			 IOMMU_IOAS_MAP_WRITEABLE |
+			 IOMMU_IOAS_MAP_FIXED_IOVA,
+		.__reserved = 0,
+	};
+
+	iommufd = open("/dev/iommu", O_RDWR);
+
+	bind.iommufd = iommufd;
+	ioctl(cdev_fd, VFIO_DEVICE_BIND_IOMMUFD, &bind);
+
+	ioctl(iommufd, IOMMU_IOAS_ALLOC, &alloc_data);
+	attach_data.pt_id = alloc_data.out_ioas_id;
+	ioctl(cdev_fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &attach_data);
+
+	/* Allocate some space and setup a DMA mapping */
+	map.user_va = (int64_t)mmap(0, 1024 * 1024, PROT_READ | PROT_WRITE,
+				    MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
+	map.iova = 0; /* 1MB starting at 0x0 from device view */
+	map.length = 1024 * 1024;
+	map.ioas_id = alloc_data.out_ioas_id;;
+
+	ioctl(iommufd, IOMMU_IOAS_MAP, &map);
+
+	/* Other device operations as stated in "VFIO Usage Example" */
+
 VFIO User API
 -------------------------------------------------------------------------------
 
···
 					struct iommufd_ctx *ictx, u32 *out_device_id);
 		void	(*unbind_iommufd)(struct vfio_device *vdev);
 		int	(*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
+		void	(*detach_ioas)(struct vfio_device *vdev);
 		int	(*open_device)(struct vfio_device *vdev);
 		void	(*close_device)(struct vfio_device *vdev);
 		ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
···
 	- The [un]bind_iommufd callbacks are issued when the device is bound to
 	  and unbound from iommufd.
 
-	- The attach_ioas callback is issued when the device is attached to an
-	  IOAS managed by the bound iommufd. The attached IOAS is automatically
-	  detached when the device is unbound from iommufd.
+	- The [de]attach_ioas callback is issued when the device is attached to
+	  and detached from an IOAS managed by the bound iommufd. However, the
+	  attached IOAS can also be automatically detached when the device is
+	  unbound from iommufd.
 
 	- The read/write/mmap callbacks implement the device region access defined
 	  by the device's own VFIO_DEVICE_GET_REGION_INFO ioctl.
···
 				\-0d.1
 
 	00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 90)
+
+.. [5] Nested translation is an IOMMU feature which supports two stage
+   address translations.  This improves the address translation efficiency
+   in IOMMU virtualization.
+
+.. [6] PASID stands for Process Address Space ID, introduced by PCI
+   Express.  It is a prerequisite for Shared Virtual Addressing (SVA)
+   and Scalable I/O Virtualization (Scalable IOV).

Documentation/networking/device_drivers/ethernet/amd/pds_vfio_pci.rst

···
+.. SPDX-License-Identifier: GPL-2.0+
+.. note: can be edited and viewed with /usr/bin/formiko-vim
+
+==========================================================
+PCI VFIO driver for the AMD/Pensando(R) DSC adapter family
+==========================================================
+
+AMD/Pensando Linux VFIO PCI Device Driver
+Copyright(c) 2023 Advanced Micro Devices, Inc.
+
+Overview
+========
+
+The ``pds-vfio-pci`` module is a PCI driver that supports Live Migration
+capable Virtual Function (VF) devices in the DSC hardware.
+
+Using the device
+================
+
+The pds-vfio-pci device is enabled via multiple configuration steps and
+depends on the ``pds_core`` driver to create and enable SR-IOV Virtual
+Function devices.
+
+Shown below are the steps to bind the driver to a VF and also to the
+associated auxiliary device created by the ``pds_core`` driver. This
+example assumes the pds_core and pds-vfio-pci modules are already
+loaded.
+
+.. code-block:: bash
+  :name: example-setup-script
+
+  #!/bin/bash
+
+  PF_BUS="0000:60"
+  PF_BDF="0000:60:00.0"
+  VF_BDF="0000:60:00.1"
+
+  # Prevent non-vfio VF driver from probing the VF device
+  echo 0 > /sys/class/pci_bus/$PF_BUS/device/$PF_BDF/sriov_drivers_autoprobe
+
+  # Create single VF for Live Migration via pds_core
+  echo 1 > /sys/bus/pci/drivers/pds_core/$PF_BDF/sriov_numvfs
+
+  # Allow the VF to be bound to the pds-vfio-pci driver
+  echo "pds-vfio-pci" > /sys/class/pci_bus/$PF_BUS/device/$VF_BDF/driver_override
+
+  # Bind the VF to the pds-vfio-pci driver
+  echo "$VF_BDF" > /sys/bus/pci/drivers/pds-vfio-pci/bind
+
+After performing the steps above, a file in /dev/vfio/<iommu_group>
+should have been created.
+
+
+Enabling the driver
+===================
+
+The driver is enabled via the standard kernel configuration system,
+using the make command::
+
+  make oldconfig/menuconfig/etc.
+
+The driver is located in the menu structure at:
+
+  -> Device Drivers
+    -> VFIO Non-Privileged userspace driver framework
+      -> VFIO support for PDS PCI devices
+
+Support
+=======
+
+For general Linux networking support, please use the netdev mailing
+list, which is monitored by Pensando personnel::
+
+  [e-mail]
+
+For more specific support needs, please use the Pensando driver support
+email::
+
+  [e-mail]

Documentation/networking/device_drivers/ethernet/index.rst

···
    altera/altera_tse
    amd/pds_core
    amd/pds_vdpa
+   amd/pds_vfio_pci
    aquantia/atlantic
    chelsio/cxgb
    cirrus/cs89x0

Documentation/virt/kvm/devices/vfio.rst

···
   - KVM_DEV_TYPE_VFIO
 
 Only one VFIO instance may be created per VM.  The created device
-tracks VFIO groups in use by the VM and features of those groups
-important to the correctness and acceleration of the VM.  As groups
-are enabled and disabled for use by the VM, KVM should be updated
-about their presence.  When registered with KVM, a reference to the
-VFIO-group is held by KVM.
+tracks VFIO files (group or device) in use by the VM and features
+of those groups/devices important to the correctness and acceleration
+of the VM.  As groups/devices are enabled and disabled for use by the
+VM, KVM should be updated about their presence.  When registered with
+KVM, a reference to the VFIO file is held by KVM.
 
 Groups:
-  KVM_DEV_VFIO_GROUP
+  KVM_DEV_VFIO_FILE
+	alias: KVM_DEV_VFIO_GROUP
 
-KVM_DEV_VFIO_GROUP attributes:
-  KVM_DEV_VFIO_GROUP_ADD: Add a VFIO group to VFIO-KVM device tracking
-	kvm_device_attr.addr points to an int32_t file descriptor
-	for the VFIO group.
-  KVM_DEV_VFIO_GROUP_DEL: Remove a VFIO group from VFIO-KVM device tracking
-	kvm_device_attr.addr points to an int32_t file descriptor
-	for the VFIO group.
+KVM_DEV_VFIO_FILE attributes:
+  KVM_DEV_VFIO_FILE_ADD: Add a VFIO file (group/device) to VFIO-KVM device
+	tracking
+
+	kvm_device_attr.addr points to an int32_t file descriptor for the
+	VFIO file.
+
+  KVM_DEV_VFIO_FILE_DEL: Remove a VFIO file (group/device) from VFIO-KVM
+	device tracking
+
+	kvm_device_attr.addr points to an int32_t file descriptor for the
+	VFIO file.
+
+KVM_DEV_VFIO_GROUP (legacy kvm device group restricted to the handling of VFIO group fd):
+  KVM_DEV_VFIO_GROUP_ADD: same as KVM_DEV_VFIO_FILE_ADD for group fd only
+
+  KVM_DEV_VFIO_GROUP_DEL: same as KVM_DEV_VFIO_FILE_DEL for group fd only
+
   KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: attaches a guest visible TCE table
 	allocated by sPAPR KVM.
 	kvm_device_attr.addr points to a struct::
···
 	- @tablefd is a file descriptor for a TCE table allocated via
 	  KVM_CREATE_SPAPR_TCE.
 
-The GROUP_ADD operation above should be invoked prior to accessing the
+The FILE/GROUP_ADD operation above should be invoked prior to accessing the
 device file descriptor via VFIO_GROUP_GET_DEVICE_FD in order to support
 drivers which require a kvm pointer to be set in their .open_device()
-callback.
+callback.  It is the same for device file descriptor via character device
+open which gets device access via VFIO_DEVICE_BIND_IOMMUFD.  For such file
+descriptors, FILE_ADD should be invoked before VFIO_DEVICE_BIND_IOMMUFD
+to support the drivers mentioned in prior sentence as well.

MAINTAINERS

···
 P:	Documentation/driver-api/vfio-pci-device-specific-driver-acceptance.rst
 F:	drivers/vfio/pci/*/
 
+VFIO PDS PCI DRIVER
+M:	Brett Creeley <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	Documentation/networking/device_drivers/ethernet/amd/pds_vfio_pci.rst
+F:	drivers/vfio/pci/pds/
+
 VFIO PLATFORM DRIVER
 M:	Eric Auger <[e-mail]>
 L:	[e-mail]

drivers/gpu/drm/i915/gvt/kvmgt.c

···
 	.bind_iommufd	= vfio_iommufd_emulated_bind,
 	.unbind_iommufd = vfio_iommufd_emulated_unbind,
 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
+	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
 };
 
 static int intel_vgpu_probe(struct mdev_device *mdev)

drivers/iommu/iommufd/Kconfig

···
 if IOMMUFD
 config IOMMUFD_VFIO_CONTAINER
 	bool "IOMMUFD provides the VFIO container /dev/vfio/vfio"
-	depends on VFIO && !VFIO_CONTAINER
-	default VFIO && !VFIO_CONTAINER
+	depends on VFIO_GROUP && !VFIO_CONTAINER
+	default VFIO_GROUP && !VFIO_CONTAINER
 	help
 	  IOMMUFD will provide /dev/vfio/vfio instead of VFIO. This relies on
 	  IOMMUFD providing compatibility emulation to give the same ioctls.

drivers/iommu/iommufd/device.c

···
 EXPORT_SYMBOL_NS_GPL(iommufd_device_bind, IOMMUFD);
 
 /**
+ * iommufd_ctx_has_group - True if any device within the group is bound
+ *                         to the ictx
+ * @ictx: iommufd file descriptor
+ * @group: Pointer to a physical iommu_group struct
+ *
+ * True if any device within the group has been bound to this ictx, ex. via
+ * iommufd_device_bind(), therefore implying ictx ownership of the group.
+ */
+bool iommufd_ctx_has_group(struct iommufd_ctx *ictx, struct iommu_group *group)
+{
+	struct iommufd_object *obj;
+	unsigned long index;
+
+	if (!ictx || !group)
+		return false;
+
+	xa_lock(&ictx->objects);
+	xa_for_each(&ictx->objects, index, obj) {
+		if (obj->type == IOMMUFD_OBJ_DEVICE &&
+		    container_of(obj, struct iommufd_device, obj)->group == group) {
+			xa_unlock(&ictx->objects);
+			return true;
+		}
+	}
+	xa_unlock(&ictx->objects);
+	return false;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_ctx_has_group, IOMMUFD);
+
+/**
  * iommufd_device_unbind - Undo iommufd_device_bind()
  * @idev: Device returned by iommufd_device_bind()
  *
···
 	iommufd_object_destroy_user(idev->ictx, &idev->obj);
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_device_unbind, IOMMUFD);
+
+struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev)
+{
+	return idev->ictx;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_device_to_ictx, IOMMUFD);
+
+u32 iommufd_device_to_id(struct iommufd_device *idev)
+{
+	return idev->obj.id;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, IOMMUFD);
 
 static int iommufd_device_setup_msi(struct iommufd_device *idev,
 				    struct iommufd_hw_pagetable *hwpt,
···
 	iommufd_ctx_get(ictx);
 	iommufd_object_finalize(ictx, &access->obj);
 	*id = access->obj.id;
+	mutex_init(&access->ioas_lock);
 	return access;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_create, IOMMUFD);
···
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_destroy, IOMMUFD);
 
+void iommufd_access_detach(struct iommufd_access *access)
+{
+	struct iommufd_ioas *cur_ioas = access->ioas;
+
+	mutex_lock(&access->ioas_lock);
+	if (WARN_ON(!access->ioas))
+		goto out;
+	/*
+	 * Set ioas to NULL to block any further iommufd_access_pin_pages().
+	 * iommufd_access_unpin_pages() can continue using access->ioas_unpin.
+	 */
+	access->ioas = NULL;
+
+	if (access->ops->unmap) {
+		mutex_unlock(&access->ioas_lock);
+		access->ops->unmap(access->data, 0, ULONG_MAX);
+		mutex_lock(&access->ioas_lock);
+	}
+	iopt_remove_access(&cur_ioas->iopt, access);
+	refcount_dec(&cur_ioas->obj.users);
+out:
+	access->ioas_unpin = NULL;
+	mutex_unlock(&access->ioas_lock);
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_access_detach, IOMMUFD);
+
 int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id)
 {
 	struct iommufd_ioas *new_ioas;
 	int rc = 0;
 
-	if (access->ioas)
+	mutex_lock(&access->ioas_lock);
+	if (WARN_ON(access->ioas || access->ioas_unpin)) {
+		mutex_unlock(&access->ioas_lock);
 		return -EINVAL;
+	}
 
 	new_ioas = iommufd_get_ioas(access->ictx, ioas_id);
-	if (IS_ERR(new_ioas))
+	if (IS_ERR(new_ioas)) {
+		mutex_unlock(&access->ioas_lock);
 		return PTR_ERR(new_ioas);
+	}
 
 	rc = iopt_add_access(&new_ioas->iopt, access);
 	if (rc) {
+		mutex_unlock(&access->ioas_lock);
 		iommufd_put_object(&new_ioas->obj);
 		return rc;
 	}
 	iommufd_ref_to_users(&new_ioas->obj);
 
 	access->ioas = new_ioas;
+	access->ioas_unpin = new_ioas;
+	mutex_unlock(&access->ioas_lock);
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_attach, IOMMUFD);
···
 void iommufd_access_unpin_pages(struct iommufd_access *access,
 				unsigned long iova, unsigned long length)
 {
-	struct io_pagetable *iopt = &access->ioas->iopt;
 	struct iopt_area_contig_iter iter;
+	struct io_pagetable *iopt;
 	unsigned long last_iova;
 	struct iopt_area *area;
 
 	if (WARN_ON(!length) ||
 	    WARN_ON(check_add_overflow(iova, length - 1, &last_iova)))
 		return;
+
+	mutex_lock(&access->ioas_lock);
+	/*
+	 * The driver must be doing something wrong if it calls this before an
+	 * iommufd_access_attach() or after an iommufd_access_detach().
+	 */
+	if (WARN_ON(!access->ioas_unpin)) {
+		mutex_unlock(&access->ioas_lock);
+		return;
+	}
+	iopt = &access->ioas_unpin->iopt;
 
 	down_read(&iopt->iova_rwsem);
 	iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova)
···
 				min(last_iova, iopt_area_last_iova(area))));
 	WARN_ON(!iopt_area_contig_done(&iter));
 	up_read(&iopt->iova_rwsem);
+	mutex_unlock(&access->ioas_lock);
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_unpin_pages, IOMMUFD);
 
···
 			     unsigned long length, struct page **out_pages,
 			     unsigned int flags)
 {
-	struct io_pagetable *iopt = &access->ioas->iopt;
 	struct iopt_area_contig_iter iter;
+	struct io_pagetable *iopt;
 	unsigned long last_iova;
 	struct iopt_area *area;
 	int rc;
···
 		return -EINVAL;
 	if (check_add_overflow(iova, length - 1, &last_iova))
 		return -EOVERFLOW;
+
+	mutex_lock(&access->ioas_lock);
+	if (!access->ioas) {
+		mutex_unlock(&access->ioas_lock);
+		return -ENOENT;
+	}
+	iopt = &access->ioas->iopt;
 
 	down_read(&iopt->iova_rwsem);
 	iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova) {
···
 	}
 
 	up_read(&iopt->iova_rwsem);
+	mutex_unlock(&access->ioas_lock);
 	return 0;
 
 err_remove:
···
 						  iopt_area_last_iova(area))));
 	}
 	up_read(&iopt->iova_rwsem);
+	mutex_unlock(&access->ioas_lock);
 	return rc;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_pin_pages, IOMMUFD);
···
 int iommufd_access_rw(struct iommufd_access *access, unsigned long iova,
 		      void *data, size_t length, unsigned int flags)
 {
-	struct io_pagetable *iopt = &access->ioas->iopt;
 	struct iopt_area_contig_iter iter;
+	struct io_pagetable *iopt;
 	struct iopt_area *area;
 	unsigned long last_iova;
 	int rc;
···
 		return -EINVAL;
 	if (check_add_overflow(iova, length - 1, &last_iova))
 		return -EOVERFLOW;
+
+	mutex_lock(&access->ioas_lock);
+	if (!access->ioas) {
+		mutex_unlock(&access->ioas_lock);
+		return -ENOENT;
+	}
+	iopt = &access->ioas->iopt;
 
 	down_read(&iopt->iova_rwsem);
 	iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova) {
···
 		rc = -ENOENT;
 err_out:
 	up_read(&iopt->iova_rwsem);
+	mutex_unlock(&access->ioas_lock);
 	return rc;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_rw, IOMMUFD);

drivers/iommu/iommufd/iommufd_private.h

···
 	struct iommufd_object obj;
 	struct iommufd_ctx *ictx;
 	struct iommufd_ioas *ioas;
+	struct iommufd_ioas *ioas_unpin;
+	struct mutex ioas_lock;
 	const struct iommufd_access_ops *ops;
 	void *data;
 	unsigned long iova_alignment;

drivers/iommu/iommufd/main.c

···
 	 * before calling iommufd_object_finalize().
 	 */
 	rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY,
-		      xa_limit_32b, GFP_KERNEL_ACCOUNT);
+		      xa_limit_31b, GFP_KERNEL_ACCOUNT);
 	if (rc)
 		goto out_free;
 	return obj;
···
 	return ictx;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_ctx_from_file, IOMMUFD);
+
+/**
+ * iommufd_ctx_from_fd - Acquires a reference to the iommufd context
+ * @fd: File descriptor to obtain the reference from
+ *
+ * Returns a pointer to the iommufd_ctx, otherwise ERR_PTR. On success
+ * the caller is responsible to call iommufd_ctx_put().
+ */
+struct iommufd_ctx *iommufd_ctx_from_fd(int fd)
+{
+	struct file *file;
+
+	file = fget(fd);
+	if (!file)
+		return ERR_PTR(-EBADF);
+
+	if (file->f_op != &iommufd_fops) {
+		fput(file);
+		return ERR_PTR(-EBADFD);
+	}
+	/* fget is the same as iommufd_ctx_get() */
+	return file->private_data;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_ctx_from_fd, IOMMUFD);
 
 /**
  * iommufd_ctx_put - Put back a reference

drivers/iommu/iommufd/vfio_compat.c

···
 			rc = cap_size;
 			goto out_put;
 		}
+		cap_size = ALIGN(cap_size, sizeof(u64));
+
 		if (last_cap && info.argsz >= total_cap_size &&
 		    put_user(total_cap_size, &last_cap->next)) {
 			rc = -EFAULT;

drivers/net/ethernet/amd/pds_core/auxbus.c

···
 
 /**
  * pds_client_register - Link the client to the firmware
- * @pf_pdev:	ptr to the PF driver struct
+ * @pf:		ptr to the PF driver's private data struct
  * @devname:	name that includes service into, e.g. pds_core.vDPA
  *
  * Return: positive client ID (ci) on success, or
  *         negative for error
  */
-int pds_client_register(struct pci_dev *pf_pdev, char *devname)
+int pds_client_register(struct pdsc *pf, char *devname)
 {
 	union pds_core_adminq_comp comp = {};
 	union pds_core_adminq_cmd cmd = {};
-	struct pdsc *pf;
 	int err;
 	u16 ci;
-
-	pf = pci_get_drvdata(pf_pdev);
-	if (pf->state)
-		return -ENXIO;
 
 	cmd.client_reg.opcode = PDS_AQ_CMD_CLIENT_REG;
 	strscpy(cmd.client_reg.devname, devname,
···
 
 /**
  * pds_client_unregister - Unlink the client from the firmware
- * @pf_pdev:	ptr to the PF driver struct
+ * @pf:		ptr to the PF driver's private data struct
  * @client_id:	id returned from pds_client_register()
  *
  * Return: 0 on success, or
  *         negative for error
  */
-int pds_client_unregister(struct pci_dev *pf_pdev, u16 client_id)
+int pds_client_unregister(struct pdsc *pf, u16 client_id)
 {
 	union pds_core_adminq_comp comp = {};
 	union pds_core_adminq_cmd cmd = {};
-	struct pdsc *pf;
 	int err;
-
-	pf = pci_get_drvdata(pf_pdev);
-	if (pf->state)
-		return -ENXIO;
 
 	cmd.client_unreg.opcode = PDS_AQ_CMD_CLIENT_UNREG;
 	cmd.client_unreg.client_id = cpu_to_le16(client_id);
···
 
 	padev = pf->vfs[cf->vf_id].padev;
 	if (padev) {
-		pds_client_unregister(pf->pdev, padev->client_id);
+		pds_client_unregister(pf, padev->client_id);
 		auxiliary_device_delete(&padev->aux_dev);
 		auxiliary_device_uninit(&padev->aux_dev);
 		padev->client_id = 0;
···
 	 */
 	snprintf(devname, sizeof(devname), "%s.%s.%d",
 		 PDS_CORE_DRV_NAME, pf->viftype_status[vt].name, cf->uid);
-	client_id = pds_client_register(pf->pdev, devname);
+	client_id = pds_client_register(pf, devname);
 	if (client_id < 0) {
 		err = client_id;
 		goto out_unlock;
···
 	padev = pdsc_auxbus_dev_register(cf, pf, client_id,
 					 pf->viftype_status[vt].name);
 	if (IS_ERR(padev)) {
-		pds_client_unregister(pf->pdev, client_id);
+		pds_client_unregister(pf, client_id);
 		err = PTR_ERR(padev);
 		goto out_unlock;
 	}

drivers/s390/cio/vfio_ccw_ops.c

···
 	.bind_iommufd = vfio_iommufd_emulated_bind,
 	.unbind_iommufd = vfio_iommufd_emulated_unbind,
 	.attach_ioas = vfio_iommufd_emulated_attach_ioas,
+	.detach_ioas = vfio_iommufd_emulated_detach_ioas,
 };
 
 struct mdev_driver vfio_ccw_mdev_driver = {

drivers/s390/crypto/vfio_ap_ops.c

···
 	.bind_iommufd = vfio_iommufd_emulated_bind,
 	.unbind_iommufd = vfio_iommufd_emulated_unbind,
 	.attach_ioas = vfio_iommufd_emulated_attach_ioas,
+	.detach_ioas = vfio_iommufd_emulated_detach_ioas,
 	.request = vfio_ap_mdev_request
 };
 

drivers/vfio/Kconfig

···
 	select IOMMU_API
 	depends on IOMMUFD || !IOMMUFD
 	select INTERVAL_TREE
+	select VFIO_GROUP if SPAPR_TCE_IOMMU || IOMMUFD=n
+	select VFIO_DEVICE_CDEV if !VFIO_GROUP
 	select VFIO_CONTAINER if IOMMUFD=n
 	help
 	  VFIO provides a framework for secure userspace device drivers.
···
 	  If you don't know what to do here, say N.
 
 if VFIO
+config VFIO_DEVICE_CDEV
+	bool "Support for the VFIO cdev /dev/vfio/devices/vfioX"
+	depends on IOMMUFD && !SPAPR_TCE_IOMMU
+	default !VFIO_GROUP
+	help
+	  The VFIO device cdev is another way for userspace to get device
+	  access. Userspace gets device fd by opening device cdev under
+	  /dev/vfio/devices/vfioX, and then bind the device fd with an iommufd
+	  to set up secure DMA context for device access.  This interface does
+	  not support noiommu.
+
+	  If you don't know what to do here, say N.
+
+config VFIO_GROUP
+	bool "Support for the VFIO group /dev/vfio/$group_id"
+	default y
+	help
+	   VFIO group support provides the traditional model for accessing
+	   devices through VFIO and is used by the majority of userspace
+	   applications and drivers making use of VFIO.
+
+	   If you don't know what to do here, say Y.
+
 config VFIO_CONTAINER
 	bool "Support for the VFIO container /dev/vfio/vfio"
 	select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
+	depends on VFIO_GROUP
 	default y
 	help
 	  The VFIO container is the classic interface to VFIO for establishing
···
 
 config VFIO_NOIOMMU
 	bool "VFIO No-IOMMU support"
+	depends on VFIO_GROUP
 	help
 	  VFIO is built on the ability to isolate devices using the IOMMU.
 	  Only with an IOMMU can userspace access to DMA capable devices be

drivers/vfio/Makefile

···
 obj-$(CONFIG_VFIO) += vfio.o
 
 vfio-y += vfio_main.o \
-	  group.o \
 	  iova_bitmap.o
+vfio-$(CONFIG_VFIO_DEVICE_CDEV) += device_cdev.o
+vfio-$(CONFIG_VFIO_GROUP) += group.o
 vfio-$(CONFIG_IOMMUFD) += iommufd.o
 vfio-$(CONFIG_VFIO_CONTAINER) += container.o
 vfio-$(CONFIG_VFIO_VIRQFD) += virqfd.o

drivers/vfio/cdx/main.c

···
 	.match_id_table	= vfio_cdx_table,
 	.driver	= {
 		.name	= "vfio-cdx",
-		.owner	= THIS_MODULE,
 	},
 	.driver_managed_dma = true,
 };

drivers/vfio/device_cdev.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023 Intel Corporation.
+ */
+#include <linux/vfio.h>
+#include <linux/iommufd.h>
+
+#include "vfio.h"
+
+static dev_t device_devt;
+
+void vfio_init_device_cdev(struct vfio_device *device)
+{
+	device->device.devt = MKDEV(MAJOR(device_devt), device->index);
+	cdev_init(&device->cdev, &vfio_device_fops);
+	device->cdev.owner = THIS_MODULE;
+}
+
+/*
+ * device access via the fd opened by this function is blocked until
+ * .open_device() is called successfully during BIND_IOMMUFD.
+ */
+int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep)
+{
+	struct vfio_device *device = container_of(inode->i_cdev,
+						  struct vfio_device, cdev);
+	struct vfio_device_file *df;
+	int ret;
+
+	/* Paired with the put in vfio_device_fops_release() */
+	if (!vfio_device_try_get_registration(device))
+		return -ENODEV;
+
+	df = vfio_allocate_device_file(device);
+	if (IS_ERR(df)) {
+		ret = PTR_ERR(df);
+		goto err_put_registration;
+	}
+
+	filep->private_data = df;
+
+	return 0;
+
+err_put_registration:
+	vfio_device_put_registration(device);
+	return ret;
+}
+
+static void vfio_df_get_kvm_safe(struct vfio_device_file *df)
+{
+	spin_lock(&df->kvm_ref_lock);
+	vfio_device_get_kvm_safe(df->device, df->kvm);
+	spin_unlock(&df->kvm_ref_lock);
+}
+
+long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
+				struct vfio_device_bind_iommufd __user *arg)
+{
+	struct vfio_device *device = df->device;
+	struct vfio_device_bind_iommufd bind;
+	unsigned long minsz;
+	int ret;
+
+	static_assert(__same_type(arg->out_devid, df->devid));
+
+	minsz = offsetofend(struct vfio_device_bind_iommufd, out_devid);
+
+	if (copy_from_user(&bind, arg, minsz))
+		return -EFAULT;
+
+	if (bind.argsz < minsz || bind.flags || bind.iommufd < 0)
+		return -EINVAL;
+
+	/* BIND_IOMMUFD only allowed for cdev fds */
+	if (df->group)
+		return -EINVAL;
+
+	ret = vfio_device_block_group(device);
+	if (ret)
+		return ret;
+
+	mutex_lock(&device->dev_set->lock);
+	/* one device cannot be bound twice */
+	if (df->access_granted) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	df->iommufd = iommufd_ctx_from_fd(bind.iommufd);
+	if (IS_ERR(df->iommufd)) {
+		ret = PTR_ERR(df->iommufd);
+		df->iommufd = NULL;
+		goto out_unlock;
+	}
+
+	/*
+	 * Before the device open, get the KVM pointer currently
+	 * associated with the device file (if there is) and obtain
+	 * a reference.  This reference is held until device closed.
+	 * Save the pointer in the device for use by drivers.
+	 */
+	vfio_df_get_kvm_safe(df);
+
+	ret = vfio_df_open(df);
+	if (ret)
+		goto out_put_kvm;
+
+	ret = copy_to_user(&arg->out_devid, &df->devid,
+			   sizeof(df->devid)) ? -EFAULT : 0;
+	if (ret)
+		goto out_close_device;
+
+	device->cdev_opened = true;
+	/*
+	 * Paired with smp_load_acquire() in vfio_device_fops::ioctl/
+	 * read/write/mmap
+	 */
+	smp_store_release(&df->access_granted, true);
+	mutex_unlock(&device->dev_set->lock);
+	return 0;
+
+out_close_device:
+	vfio_df_close(df);
+out_put_kvm:
+	vfio_device_put_kvm(device);
+	iommufd_ctx_put(df->iommufd);
+	df->iommufd = NULL;
+out_unlock:
+	mutex_unlock(&device->dev_set->lock);
+	vfio_device_unblock_group(device);
+	return ret;
+}
+
+void vfio_df_unbind_iommufd(struct vfio_device_file *df)
+{
+	struct vfio_device *device = df->device;
+
+	/*
+	 * In the time of close, there is no contention with another one
+	 * changing this flag.  So read df->access_granted without lock
+	 * and no smp_load_acquire() is ok.
+	 */
+	if (!df->access_granted)
+		return;
+
+	mutex_lock(&device->dev_set->lock);
+	vfio_df_close(df);
+	vfio_device_put_kvm(device);
+	iommufd_ctx_put(df->iommufd);
+	device->cdev_opened = false;
+	mutex_unlock(&device->dev_set->lock);
+	vfio_device_unblock_group(device);
+}
+
+int vfio_df_ioctl_attach_pt(struct vfio_device_file *df,
+			    struct vfio_device_attach_iommufd_pt __user *arg)
+{
+	struct vfio_device *device = df->device;
+	struct vfio_device_attach_iommufd_pt attach;
+	unsigned long minsz;
+	int ret;
+
+	minsz = offsetofend(struct vfio_device_attach_iommufd_pt, pt_id);
+
+	if (copy_from_user(&attach, arg, minsz))
+		return -EFAULT;
+
+	if (attach.argsz < minsz || attach.flags)
+		return -EINVAL;
+
+	mutex_lock(&device->dev_set->lock);
+	ret = device->ops->attach_ioas(device, &attach.pt_id);
+	if (ret)
+		goto out_unlock;
+
+	if (copy_to_user(&arg->pt_id, &attach.pt_id, sizeof(attach.pt_id))) {
+		ret = -EFAULT;
+		goto out_detach;
+	}
+	mutex_unlock(&device->dev_set->lock);
+
+	return 0;
+
+out_detach:
+	device->ops->detach_ioas(device);
+out_unlock:
+	mutex_unlock(&device->dev_set->lock);
+	return ret;
+}
+
+int vfio_df_ioctl_detach_pt(struct vfio_device_file *df,
+			    struct vfio_device_detach_iommufd_pt __user *arg)
+{
+	struct vfio_device *device = df->device;
+	struct vfio_device_detach_iommufd_pt detach;
+	unsigned long minsz;
+
+	minsz = offsetofend(struct vfio_device_detach_iommufd_pt, flags);
+
+	if (copy_from_user(&detach, arg, minsz))
+		return -EFAULT;
+
+	if (detach.argsz < minsz || detach.flags)
+		return -EINVAL;
+
+	mutex_lock(&device->dev_set->lock);
+	device->ops->detach_ioas(device);
+	mutex_unlock(&device->dev_set->lock);
+
+	return 0;
+}
+
+static char *vfio_device_devnode(const struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "vfio/devices/%s", dev_name(dev));
+}
+
+int vfio_cdev_init(struct class *device_class)
+{
+	device_class->devnode = vfio_device_devnode;
+	return alloc_chrdev_region(&device_devt, 0,
+				   MINORMASK + 1, "vfio-dev");
+}
+
+void vfio_cdev_cleanup(void)
+{
+	unregister_chrdev_region(device_devt, MINORMASK + 1);
+}

drivers/vfio/fsl-mc/vfio_fsl_mc.c

···
 	.bind_iommufd	= vfio_iommufd_physical_bind,
 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
+	.detach_ioas	= vfio_iommufd_physical_detach_ioas,
 };
 
 static struct fsl_mc_driver vfio_fsl_mc_driver = {
···
 	.remove		= vfio_fsl_mc_remove,
 	.driver	= {
 		.name	= "vfio-fsl-mc",
-		.owner	= THIS_MODULE,
 	},
 	.driver_managed_dma = true,
 };
 
-static int __init vfio_fsl_mc_driver_init(void)
-{
-	return fsl_mc_driver_register(&vfio_fsl_mc_driver);
-}
-
-static void __exit vfio_fsl_mc_driver_exit(void)
-{
-	fsl_mc_driver_unregister(&vfio_fsl_mc_driver);
-}
-
-module_init(vfio_fsl_mc_driver_init);
-module_exit(vfio_fsl_mc_driver_exit);
+module_fsl_mc_driver(vfio_fsl_mc_driver);
 
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_DESCRIPTION("VFIO for FSL-MC devices - User Level meta-driver");

drivers/vfio/group.c

···
 static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
 {
 	spin_lock(&device->group->kvm_ref_lock);
-	if (!device->group->kvm)
-		goto unlock;
-
-	_vfio_device_get_kvm_safe(device, device->group->kvm);
-
-unlock:
+	vfio_device_get_kvm_safe(device, device->group->kvm);
 	spin_unlock(&device->group->kvm_ref_lock);
 }
 
-static int vfio_device_group_open(struct vfio_device *device)
+static int vfio_df_group_open(struct vfio_device_file *df)
 {
+	struct vfio_device *device = df->device;
 	int ret;
 
 	mutex_lock(&device->group->group_lock);
···
 	if (device->open_count == 0)
 		vfio_device_group_get_kvm_safe(device);
 
-	ret = vfio_device_open(device, device->group->iommufd);
+	df->iommufd = device->group->iommufd;
+	if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) {
+		/*
+		 * Require no compat ioas to be assigned to proceed.  The basic
+		 * statement is that the user cannot have done something that
+		 * implies they expected translation to exist
+		 */
+		if (!capable(CAP_SYS_RAWIO) ||
+		    vfio_iommufd_device_has_compat_ioas(device, df->iommufd))
+			ret = -EPERM;
+		else
+			ret = 0;
+		goto out_put_kvm;
+	}
 
-	if (device->open_count == 0)
-		vfio_device_put_kvm(device);
+	ret = vfio_df_open(df);
+	if (ret)
+		goto out_put_kvm;
+
+	if (df->iommufd && device->open_count == 1) {
+		ret = vfio_iommufd_compat_attach_ioas(device, df->iommufd);
+		if (ret)
+			goto out_close_device;
+	}
+
+	/*
+	 * Paired with smp_load_acquire() in vfio_device_fops::ioctl/
+	 * read/write/mmap and vfio_file_has_device_access()
+	 */
+	smp_store_release(&df->access_granted, true);
 
 	mutex_unlock(&device->dev_set->lock);
+	mutex_unlock(&device->group->group_lock);
+	return 0;
 
+out_close_device:
+	vfio_df_close(df);
+out_put_kvm:
+	df->iommufd = NULL;
+	if (device->open_count == 0)
+		vfio_device_put_kvm(device);
+	mutex_unlock(&device->dev_set->lock);
 out_unlock:
 	mutex_unlock(&device->group->group_lock);
 	return ret;
 }
 
-void vfio_device_group_close(struct vfio_device *device)
+void vfio_df_group_close(struct vfio_device_file *df)
 {
+	struct vfio_device *device = df->device;
+
 	mutex_lock(&device->group->group_lock);
 	mutex_lock(&device->dev_set->lock);
 
-	vfio_device_close(device, device->group->iommufd);
+	vfio_df_close(df);
+	df->iommufd = NULL;
 
 	if (device->open_count == 0)
 		vfio_device_put_kvm(device);
···
 
 static struct file *vfio_device_open_file(struct vfio_device *device)
 {
+	struct vfio_device_file *df;
 	struct file *filep;
 	int ret;
 
-	ret = vfio_device_group_open(device);
-	if (ret)
+	df = vfio_allocate_device_file(device);
+	if (IS_ERR(df)) {
+		ret = PTR_ERR(df);
 		goto err_out;
+	}
+
+	df->group = device->group;
+
+	ret = vfio_df_group_open(df);
+	if (ret)
+		goto err_free;
 
 	/*
 	 * We can't use anon_inode_getfd() because we need to modify
 	 * the f_mode flags directly to allow more than just ioctls
 	 */
 	filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
-				   device, O_RDWR);
+				   df, O_RDWR);
 	if (IS_ERR(filep)) {
 		ret = PTR_ERR(filep);
 		goto err_close_device;
···
 	return filep;
 
 err_close_device:
-	vfio_device_group_close(device);
+	vfio_df_group_close(df);
+err_free:
+	kfree(df);
 err_out:
 	return ERR_PTR(ret);
 }
···
 	}
 }
 
+int vfio_device_block_group(struct vfio_device *device)
+{
+	struct vfio_group *group = device->group;
+	int ret = 0;
+
+	mutex_lock(&group->group_lock);
+	if (group->opened_file) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+
+	group->cdev_device_open_cnt++;
+
+out_unlock:
+	mutex_unlock(&group->group_lock);
+	return ret;
+}
+
+void vfio_device_unblock_group(struct vfio_device *device)
+{
+	struct vfio_group *group = device->group;
+
+	mutex_lock(&group->group_lock);
+	group->cdev_device_open_cnt--;
+	mutex_unlock(&group->group_lock);
+}
+
 static int vfio_group_fops_open(struct inode *inode, struct file *filep)
 {
 	struct vfio_group *group =
···
 
 	if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
 		ret = -EPERM;
+		goto out_unlock;
+	}
+
+	if (group->cdev_device_open_cnt) {
+		ret = -EBUSY;
 		goto out_unlock;
 	}
 
···
 	mutex_destroy(&group->device_lock);
 	mutex_destroy(&group->group_lock);
 	WARN_ON(group->iommu_group);
+	WARN_ON(group->cdev_device_open_cnt);
 	ida_free(&vfio.group_ida, MINOR(group->dev.devt));
 	kfree(group);
 }
···
 	if (!iommu_group)
 		return ERR_PTR(-EINVAL);
 
-	/*
-	 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
-	 * restore cache coherency. It has to be checked here because it is only
-	 * valid for cases where we are using iommu groups.
-	 */
-	if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) {
-		iommu_group_put(iommu_group);
-		return ERR_PTR(-EINVAL);
-	}
-
 	mutex_lock(&vfio.group_lock);
 	group = vfio_group_find_from_iommu(iommu_group);
 	if (group) {
···
 	return device->group->container;
 }
 
+struct vfio_group *vfio_group_from_file(struct file *file)
+{
+	struct vfio_group *group = file->private_data;
+
+	if (file->f_op != &vfio_group_fops)
+		return NULL;
+	return group;
+}
+
 /**
  * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
  * @file: VFIO group file
···
  */
 struct iommu_group *vfio_file_iommu_group(struct file *file)
 {
-	struct vfio_group *group = file->private_data;
+	struct vfio_group *group = vfio_group_from_file(file);
 	struct iommu_group *iommu_group = NULL;
 
 	if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
 		return NULL;
 
-	if (!vfio_file_is_group(file))
+	if (!group)
 		return NULL;
 
 	mutex_lock(&group->group_lock);
···
 EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
 
 /**
- * vfio_file_is_group - True if the file is usable with VFIO aPIS
+ * vfio_file_is_group - True if the file is a vfio group file
  * @file: VFIO group file
  */
 bool vfio_file_is_group(struct file *file)
 {
-	return file->f_op == &vfio_group_fops;
+	return vfio_group_from_file(file);
 }
 EXPORT_SYMBOL_GPL(vfio_file_is_group);
 
-/**
- * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
- *        is always CPU cache coherent
- * @file: VFIO group file
- *
- * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
- * bit in DMA transactions. A return of false indicates that the user has
- * rights to access additional instructions such as wbinvd on x86.
- */
-bool vfio_file_enforced_coherent(struct file *file)
+bool vfio_group_enforced_coherent(struct vfio_group *group)
 {
-	struct vfio_group *group = file->private_data;
 	struct vfio_device *device;
 	bool ret = true;
-
-	if (!vfio_file_is_group(file))
-		return true;
 
 	/*
 	 * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then
···
 	mutex_unlock(&group->device_lock);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
 
-/**
- * vfio_file_set_kvm - Link a kvm with VFIO drivers
- * @file: VFIO group file
- * @kvm: KVM to link
- *
- * When a VFIO device is first opened the KVM will be available in
- * device->kvm if one was associated with the group.
- */
-void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
 {
-	struct vfio_group *group = file->private_data;
-
-	if (!vfio_file_is_group(file))
-		return;
-
 	spin_lock(&group->kvm_ref_lock);
 	group->kvm = kvm;
 	spin_unlock(&group->kvm_ref_lock);
 }
-EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
 
 /**
  * vfio_file_has_dev - True if the VFIO file is a handle for device
···
  */
 bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
 {
-	struct vfio_group *group = file->private_data;
+	struct vfio_group *group = vfio_group_from_file(file);
 
-	if (!vfio_file_is_group(file))
+	if (!group)
 		return false;
 
 	return group == device->group;

drivers/vfio/iommufd.c

···
 MODULE_IMPORT_NS(IOMMUFD);
 MODULE_IMPORT_NS(IOMMUFD_VFIO);
 
-int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx)
+bool vfio_iommufd_device_has_compat_ioas(struct vfio_device *vdev,
+					 struct iommufd_ctx *ictx)
 {
 	u32 ioas_id;
-	u32 device_id;
+
+	return !iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id);
+}
+
+int vfio_df_iommufd_bind(struct vfio_device_file *df)
+{
+	struct vfio_device *vdev = df->device;
+	struct iommufd_ctx *ictx = df->iommufd;
+
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	return vdev->ops->bind_iommufd(vdev, ictx, &df->devid);
+}
+
+int vfio_iommufd_compat_attach_ioas(struct vfio_device *vdev,
+				    struct iommufd_ctx *ictx)
+{
+	u32 ioas_id;
 	int ret;
 
 	lockdep_assert_held(&vdev->dev_set->lock);
 
-	if (vfio_device_is_noiommu(vdev)) {
-		if (!capable(CAP_SYS_RAWIO))
-			return -EPERM;
-
-		/*
-		 * Require no compat ioas to be assigned to proceed. The basic
-		 * statement is that the user cannot have done something that
-		 * implies they expected translation to exist
-		 */
-		if (!iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id))
-			return -EPERM;
+	/* compat noiommu does not need to do ioas attach */
+	if (vfio_device_is_noiommu(vdev))
 		return 0;
-	}
-
-	ret = vdev->ops->bind_iommufd(vdev, ictx, &device_id);
-	if (ret)
-		return ret;
 
 	ret = iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id);
 	if (ret)
-		goto err_unbind;
-	ret = vdev->ops->attach_ioas(vdev, &ioas_id);
-	if (ret)
-		goto err_unbind;
+		return ret;
 
-	/*
-	 * The legacy path has no way to return the device id or the selected
-	 * pt_id
-	 */
-	return 0;
-
-err_unbind:
-	if (vdev->ops->unbind_iommufd)
-		vdev->ops->unbind_iommufd(vdev);
-	return ret;
+	/* The legacy path has no way to return the selected pt_id */
+	return vdev->ops->attach_ioas(vdev, &ioas_id);
 }
 
-void vfio_iommufd_unbind(struct vfio_device *vdev)
+void vfio_df_iommufd_unbind(struct vfio_device_file *df)
 {
+	struct vfio_device *vdev = df->device;
+
 	lockdep_assert_held(&vdev->dev_set->lock);
 
 	if (vfio_device_is_noiommu(vdev))
···
 	if (vdev->ops->unbind_iommufd)
 		vdev->ops->unbind_iommufd(vdev);
 }
+
+struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev)
+{
+	if (vdev->iommufd_device)
+		return iommufd_device_to_ictx(vdev->iommufd_device);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_device_ictx);
+
+static int vfio_iommufd_device_id(struct vfio_device *vdev)
+{
+	if (vdev->iommufd_device)
+		return iommufd_device_to_id(vdev->iommufd_device);
+	return -EINVAL;
+}
+
+/*
+ * Return devid for a device.
+ *  valid ID for the device that is owned by the ictx
+ *  -ENOENT = device is owned but there is no ID
+ *  -ENODEV or other error = device is not owned
+ */
+int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx)
+{
+	struct iommu_group *group;
+	int devid;
+
+	if (vfio_iommufd_device_ictx(vdev) == ictx)
+		return vfio_iommufd_device_id(vdev);
+
+	group = iommu_group_get(vdev->dev);
+	if (!group)
+		return -ENODEV;
+
+	if (iommufd_ctx_has_group(ictx, group))
+		devid = -ENOENT;
+	else
+		devid = -ENODEV;
+
+	iommu_group_put(group);
+
+	return devid;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_get_dev_id);
 
 /*
  * The physical standard ops mean that the iommufd_device is bound to the
···
 {
 	int rc;
 
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	if (WARN_ON(!vdev->iommufd_device))
+		return -EINVAL;
+
+	if (vdev->iommufd_attached)
+		return -EBUSY;
+
 	rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
 	if (rc)
 		return rc;
···
 	return 0;
 }
 EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas);
+
+void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev)
+{
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	if (WARN_ON(!vdev->iommufd_device) || !vdev->iommufd_attached)
+		return;
+
+	iommufd_device_detach(vdev->iommufd_device);
+	vdev->iommufd_attached = false;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_physical_detach_ioas);
 
 /*
  * The emulated standard ops mean that vfio_device is going to use the
···
 	return 0;
 }
 EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas);
+
+void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev)
+{
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	if (WARN_ON(!vdev->iommufd_access) ||
+	    !vdev->iommufd_attached)
+		return;
+
+	iommufd_access_detach(vdev->iommufd_access);
+	vdev->iommufd_attached = false;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_detach_ioas);

drivers/vfio/pci/Kconfig

···
 
 source "drivers/vfio/pci/hisilicon/Kconfig"
 
+source "drivers/vfio/pci/pds/Kconfig"
+
 endmenu

drivers/vfio/pci/Makefile

···
 obj-$(CONFIG_MLX5_VFIO_PCI)           += mlx5/
 
 obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisilicon/
+
+obj-$(CONFIG_PDS_VFIO_PCI) += pds/

drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c

···
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
+	.detach_ioas = vfio_iommufd_physical_detach_ioas,
 };
 
 static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
···
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
+	.detach_ioas = vfio_iommufd_physical_detach_ioas,
 };
 
 static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)

drivers/vfio/pci/mlx5/cmd.c

···
 	mlx5vf_cmd_dealloc_pd(migf);
 }
 
-static void combine_ranges(struct rb_root_cached *root, u32 cur_nodes,
-			   u32 req_nodes)
-{
-	struct interval_tree_node *prev, *curr, *comb_start, *comb_end;
-	unsigned long min_gap;
-	unsigned long curr_gap;
-
-	/* Special shortcut when a single range is required */
-	if (req_nodes == 1) {
-		unsigned long last;
-
-		curr = comb_start = interval_tree_iter_first(root, 0, ULONG_MAX);
-		while (curr) {
-			last = curr->last;
-			prev = curr;
-			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
-			if (prev != comb_start)
-				interval_tree_remove(prev, root);
-		}
-		comb_start->last = last;
-		return;
-	}
-
-	/* Combine ranges which have the smallest gap */
-	while (cur_nodes > req_nodes) {
-		prev = NULL;
-		min_gap = ULONG_MAX;
-		curr = interval_tree_iter_first(root, 0, ULONG_MAX);
-		while (curr) {
-			if (prev) {
-				curr_gap = curr->start - prev->last;
-				if (curr_gap < min_gap) {
-					min_gap = curr_gap;
-					comb_start = prev;
-					comb_end = curr;
-				}
-			}
-			prev = curr;
-			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
-		}
-		comb_start->last = comb_end->last;
-		interval_tree_remove(comb_end, root);
-		cur_nodes--;
-	}
-}
-
 static int mlx5vf_create_tracker(struct mlx5_core_dev *mdev,
 				 struct mlx5vf_pci_core_device *mvdev,
 				 struct rb_root_cached *ranges, u32 nnodes)
···
 	int i;
 
 	if (num_ranges > max_num_range) {
-		combine_ranges(ranges, nnodes, max_num_range);
+		vfio_combine_iova_ranges(ranges, nnodes, max_num_range);
 		num_ranges = max_num_range;
 	}
 

drivers/vfio/pci/mlx5/main.c

···
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
+	.detach_ioas = vfio_iommufd_physical_detach_ioas,
 };
 
 static int mlx5vf_pci_probe(struct pci_dev *pdev,

drivers/vfio/pci/pds/Kconfig

···
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2023 Advanced Micro Devices, Inc.
+
+config PDS_VFIO_PCI
+	tristate "VFIO support for PDS PCI devices"
+	depends on PDS_CORE
+	select VFIO_PCI_CORE
+	help
+	  This provides generic PCI support for PDS devices using the VFIO
+	  framework.
+
+	  More specific information on this driver can be
+	  found in
+	  <file:Documentation/networking/device_drivers/ethernet/amd/pds_vfio_pci.rst>.
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called pds-vfio-pci.
+
+	  If you don't know what to do here, say N.

drivers/vfio/pci/pds/Makefile

···
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2023 Advanced Micro Devices, Inc.
+
+obj-$(CONFIG_PDS_VFIO_PCI) += pds-vfio-pci.o
+
+pds-vfio-pci-y := \
+	cmds.o		\
+	dirty.o		\
+	lm.o		\
+	pci_drv.o	\
+	vfio_dev.o

drivers/vfio/pci/pds/cmds.c

···
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+
+#include <linux/pds/pds_common.h>
+#include <linux/pds/pds_core_if.h>
+#include <linux/pds/pds_adminq.h>
+
+#include "vfio_dev.h"
+#include "cmds.h"
+
+#define SUSPEND_TIMEOUT_S		5
+#define SUSPEND_CHECK_INTERVAL_MS	1
+
+static int pds_vfio_client_adminq_cmd(struct pds_vfio_pci_device *pds_vfio,
+				      union pds_core_adminq_cmd *req,
+				      union pds_core_adminq_comp *resp,
+				      bool fast_poll)
+{
+	struct pci_dev *pdev = pds_vfio_to_pci_dev(pds_vfio);
+	union pds_core_adminq_cmd cmd = {};
+	struct pdsc *pdsc;
+	int err;
+
+	/* Wrap the client request */
+	cmd.client_request.opcode = PDS_AQ_CMD_CLIENT_CMD;
+	cmd.client_request.client_id = cpu_to_le16(pds_vfio->client_id);
+	memcpy(cmd.client_request.client_cmd, req,
+	       sizeof(cmd.client_request.client_cmd));
+
+	pdsc = pdsc_get_pf_struct(pdev);
+	if (IS_ERR(pdsc))
+		return PTR_ERR(pdsc);
+
+	err = pdsc_adminq_post(pdsc, &cmd, resp, fast_poll);
+	if (err && err != -EAGAIN)
+		dev_err(pds_vfio_to_dev(pds_vfio),
+			"client admin cmd failed: %pe\n", ERR_PTR(err));
+
+	return err;
+}
+
+int pds_vfio_register_client_cmd(struct pds_vfio_pci_device *pds_vfio)
+{
+	struct pci_dev *pdev = pds_vfio_to_pci_dev(pds_vfio);
+	char devname[PDS_DEVNAME_LEN];
+	struct pdsc *pdsc;
+	int ci;
+
+	snprintf(devname, sizeof(devname), "%s.%d-%u", PDS_VFIO_LM_DEV_NAME,
+		 pci_domain_nr(pdev->bus),
+		 PCI_DEVID(pdev->bus->number, pdev->devfn));
+
+	pdsc = pdsc_get_pf_struct(pdev);
+	if (IS_ERR(pdsc))
+		return PTR_ERR(pdsc);
+
+	ci = pds_client_register(pdsc, devname);
+	if (ci < 0)
+		return ci;
+
+	pds_vfio->client_id = ci;
+
+	return 0;
+}
+
+void pds_vfio_unregister_client_cmd(struct pds_vfio_pci_device *pds_vfio)
+{
+	struct pci_dev *pdev = pds_vfio_to_pci_dev(pds_vfio);
+	struct pdsc *pdsc;
+	int err;
+
+	pdsc = pdsc_get_pf_struct(pdev);
+	if (IS_ERR(pdsc))
+		return;
+
+	err = pds_client_unregister(pdsc, pds_vfio->client_id);
+	if (err)
+		dev_err(&pdev->dev, "unregister from DSC failed: %pe\n",
+			ERR_PTR(err));
+
+	pds_vfio->client_id = 0;
+}
+
+static int
+pds_vfio_suspend_wait_device_cmd(struct pds_vfio_pci_device *pds_vfio, u8 type)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_suspend_status = {
+			.opcode = PDS_LM_CMD_SUSPEND_STATUS,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+			.type = type,
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	unsigned long time_limit;
+	unsigned long time_start;
+	unsigned long time_done;
+	int err;
+
+	time_start = jiffies;
+	time_limit = time_start + HZ * SUSPEND_TIMEOUT_S;
+	do {
+		err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, true);
+		if (err != -EAGAIN)
+			break;
+
+		msleep(SUSPEND_CHECK_INTERVAL_MS);
+	} while (time_before(jiffies, time_limit));
+
+	time_done = jiffies;
+	dev_dbg(dev, "%s: vf%u: Suspend comp received in %d msecs\n", __func__,
+		pds_vfio->vf_id, jiffies_to_msecs(time_done - time_start));
+
+	/* Check the results */
+	if (time_after_eq(time_done, time_limit)) {
+		dev_err(dev, "%s: vf%u: Suspend comp timeout\n", __func__,
+			pds_vfio->vf_id);
+		err = -ETIMEDOUT;
+	}
+
+	return err;
+}
+
+int pds_vfio_suspend_device_cmd(struct pds_vfio_pci_device *pds_vfio, u8 type)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_suspend = {
+			.opcode = PDS_LM_CMD_SUSPEND,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+			.type = type,
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	int err;
+
+	dev_dbg(dev, "vf%u: Suspend device\n", pds_vfio->vf_id);
+
+	/*
+	 * The initial suspend request to the firmware starts the device suspend
+	 * operation and the firmware returns success if it's started
+	 * successfully.
+	 */
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, true);
+	if (err) {
+		dev_err(dev, "vf%u: Suspend failed: %pe\n", pds_vfio->vf_id,
+			ERR_PTR(err));
+		return err;
+	}
+
+	/*
+	 * The subsequent suspend status request(s) check if the firmware has
+	 * completed the device suspend process.
+	 */
+	return pds_vfio_suspend_wait_device_cmd(pds_vfio, type);
+}
+
+int pds_vfio_resume_device_cmd(struct pds_vfio_pci_device *pds_vfio, u8 type)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_resume = {
+			.opcode = PDS_LM_CMD_RESUME,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+			.type = type,
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+
+	dev_dbg(dev, "vf%u: Resume device\n", pds_vfio->vf_id);
+
+	return pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, true);
+}
+
+int pds_vfio_get_lm_state_size_cmd(struct pds_vfio_pci_device *pds_vfio, u64 *size)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_state_size = {
+			.opcode = PDS_LM_CMD_STATE_SIZE,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	int err;
+
+	dev_dbg(dev, "vf%u: Get migration status\n", pds_vfio->vf_id);
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err)
+		return err;
+
+	*size = le64_to_cpu(comp.lm_state_size.size);
+	return 0;
+}
+
+static int pds_vfio_dma_map_lm_file(struct device *dev,
+				    enum dma_data_direction dir,
+				    struct pds_vfio_lm_file *lm_file)
+{
+	struct pds_lm_sg_elem *sgl, *sge;
+	struct scatterlist *sg;
+	dma_addr_t sgl_addr;
+	size_t sgl_size;
+	int err;
+	int i;
+
+	if (!lm_file)
+		return -EINVAL;
+
+	/* dma map file pages */
+	err = dma_map_sgtable(dev, &lm_file->sg_table, dir, 0);
+	if (err)
+		return err;
+
+	lm_file->num_sge = lm_file->sg_table.nents;
+
+	/* alloc sgl */
+	sgl_size = lm_file->num_sge * sizeof(struct pds_lm_sg_elem);
+	sgl = kzalloc(sgl_size, GFP_KERNEL);
+	if (!sgl) {
+		err = -ENOMEM;
+		goto out_unmap_sgtable;
+	}
+
+	/* fill sgl */
+	sge = sgl;
+	for_each_sgtable_dma_sg(&lm_file->sg_table, sg, i) {
+		sge->addr = cpu_to_le64(sg_dma_address(sg));
+		sge->len = cpu_to_le32(sg_dma_len(sg));
+		dev_dbg(dev, "addr = %llx, len = %u\n", sge->addr, sge->len);
+		sge++;
+	}
+
+	sgl_addr = dma_map_single(dev, sgl, sgl_size, DMA_TO_DEVICE);
+	if (dma_mapping_error(dev, sgl_addr)) {
+		err = -EIO;
+		goto out_free_sgl;
+	}
+
+	lm_file->sgl = sgl;
+	lm_file->sgl_addr = sgl_addr;
+
+	return 0;
+
+out_free_sgl:
+	kfree(sgl);
+out_unmap_sgtable:
+	lm_file->num_sge = 0;
+	dma_unmap_sgtable(dev, &lm_file->sg_table, dir, 0);
+	return err;
+}
+
+static void pds_vfio_dma_unmap_lm_file(struct device *dev,
+				       enum dma_data_direction dir,
+				       struct pds_vfio_lm_file *lm_file)
+{
+	if (!lm_file)
+		return;
+
+	/* free sgl */
+	if (lm_file->sgl) {
+		dma_unmap_single(dev, lm_file->sgl_addr,
+				 lm_file->num_sge * sizeof(*lm_file->sgl),
+				 DMA_TO_DEVICE);
+		kfree(lm_file->sgl);
+		lm_file->sgl = NULL;
+		lm_file->sgl_addr = DMA_MAPPING_ERROR;
+		lm_file->num_sge = 0;
+	}
+
+	/* dma unmap file pages */
+	dma_unmap_sgtable(dev, &lm_file->sg_table, dir, 0);
+}
+
+int pds_vfio_get_lm_state_cmd(struct pds_vfio_pci_device *pds_vfio)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_save = {
+			.opcode = PDS_LM_CMD_SAVE,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+		},
+	};
+	struct pci_dev *pdev = pds_vfio_to_pci_dev(pds_vfio);
+	struct device *pdsc_dev = &pci_physfn(pdev)->dev;
+	union pds_core_adminq_comp comp = {};
+	struct pds_vfio_lm_file *lm_file;
+	int err;
+
+	dev_dbg(&pdev->dev, "vf%u: Get migration state\n", pds_vfio->vf_id);
+
+	lm_file = pds_vfio->save_file;
+
+	err = pds_vfio_dma_map_lm_file(pdsc_dev, DMA_FROM_DEVICE, lm_file);
+	if (err) {
+		dev_err(&pdev->dev, "failed to map save migration file: %pe\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	cmd.lm_save.sgl_addr = cpu_to_le64(lm_file->sgl_addr);
+	cmd.lm_save.num_sge = cpu_to_le32(lm_file->num_sge);
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err)
+		dev_err(&pdev->dev, "failed to get migration state: %pe\n",
+			ERR_PTR(err));
+
+	pds_vfio_dma_unmap_lm_file(pdsc_dev, DMA_FROM_DEVICE, lm_file);
+
+	return err;
+}
+
+int pds_vfio_set_lm_state_cmd(struct pds_vfio_pci_device *pds_vfio)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_restore = {
+			.opcode = PDS_LM_CMD_RESTORE,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+		},
+	};
+	struct pci_dev *pdev = pds_vfio_to_pci_dev(pds_vfio);
+	struct device *pdsc_dev = &pci_physfn(pdev)->dev;
+	union pds_core_adminq_comp comp = {};
+	struct pds_vfio_lm_file *lm_file;
+	int err;
+
+	dev_dbg(&pdev->dev, "vf%u: Set migration state\n", pds_vfio->vf_id);
+
+	lm_file = pds_vfio->restore_file;
+
+	err = pds_vfio_dma_map_lm_file(pdsc_dev, DMA_TO_DEVICE, lm_file);
+	if (err) {
+		dev_err(&pdev->dev,
+			"failed to map restore migration file: %pe\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	cmd.lm_restore.sgl_addr = cpu_to_le64(lm_file->sgl_addr);
+	cmd.lm_restore.num_sge = cpu_to_le32(lm_file->num_sge);
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err)
+		dev_err(&pdev->dev, "failed to set migration state: %pe\n",
+			ERR_PTR(err));
+
+	pds_vfio_dma_unmap_lm_file(pdsc_dev, DMA_TO_DEVICE, lm_file);
+
+	return err;
+}
+
+void pds_vfio_send_host_vf_lm_status_cmd(struct pds_vfio_pci_device *pds_vfio,
+					 enum pds_lm_host_vf_status vf_status)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_host_vf_status = {
+			.opcode = PDS_LM_CMD_HOST_VF_STATUS,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+			.status = vf_status,
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	int err;
+
+	dev_dbg(dev, "vf%u: Set host VF LM status: %u", pds_vfio->vf_id,
+		vf_status);
+	if (vf_status != PDS_LM_STA_IN_PROGRESS &&
+	    vf_status != PDS_LM_STA_NONE) {
+		dev_warn(dev, "Invalid host VF migration status, %d\n",
+			 vf_status);
+		return;
+	}
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err)
+		dev_warn(dev, "failed to send host VF migration status: %pe\n",
+			 ERR_PTR(err));
+}
+
+int pds_vfio_dirty_status_cmd(struct pds_vfio_pci_device *pds_vfio,
+			      u64 regions_dma, u8 *max_regions, u8 *num_regions)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_dirty_status = {
+			.opcode = PDS_LM_CMD_DIRTY_STATUS,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	int err;
+
+	dev_dbg(dev, "vf%u: Dirty status\n", pds_vfio->vf_id);
+
+	cmd.lm_dirty_status.regions_dma = cpu_to_le64(regions_dma);
+	cmd.lm_dirty_status.max_regions = *max_regions;
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err) {
+		dev_err(dev, "failed to get dirty status: %pe\n", ERR_PTR(err));
+		return err;
+	}
+
+	/* only support seq_ack approach for now */
+	if (!(le32_to_cpu(comp.lm_dirty_status.bmp_type_mask) &
+	      BIT(PDS_LM_DIRTY_BMP_TYPE_SEQ_ACK))) {
+		dev_err(dev, "Dirty bitmap tracking SEQ_ACK not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	*num_regions = comp.lm_dirty_status.num_regions;
+	*max_regions = comp.lm_dirty_status.max_regions;
+
+	dev_dbg(dev,
+		"Page Tracking Status command successful, max_regions: %d, num_regions: %d, bmp_type: %s\n",
+		*max_regions, *num_regions, "PDS_LM_DIRTY_BMP_TYPE_SEQ_ACK");
+
+	return 0;
+}
+
+int pds_vfio_dirty_enable_cmd(struct pds_vfio_pci_device *pds_vfio,
+			      u64 regions_dma, u8 num_regions)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_dirty_enable = {
+			.opcode = PDS_LM_CMD_DIRTY_ENABLE,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+			.regions_dma = cpu_to_le64(regions_dma),
+			.bmp_type = PDS_LM_DIRTY_BMP_TYPE_SEQ_ACK,
+			.num_regions = num_regions,
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	int err;
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err) {
+		dev_err(dev, "failed dirty tracking enable: %pe\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	return 0;
+}
+
+int pds_vfio_dirty_disable_cmd(struct pds_vfio_pci_device *pds_vfio)
+{
+	union pds_core_adminq_cmd cmd = {
+		.lm_dirty_disable = {
+			.opcode = PDS_LM_CMD_DIRTY_DISABLE,
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	int err;
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err || comp.lm_dirty_status.num_regions != 0) {
+		/* in case num_regions is still non-zero after disable */
+		err = err ? err : -EIO;
+		dev_err(dev,
+			"failed dirty tracking disable: %pe, num_regions %d\n",
+			ERR_PTR(err), comp.lm_dirty_status.num_regions);
+		return err;
+	}
+
+	return 0;
+}
+
+int pds_vfio_dirty_seq_ack_cmd(struct pds_vfio_pci_device *pds_vfio,
+			       u64 sgl_dma, u16 num_sge, u32 offset,
+			       u32 total_len, bool read_seq)
+{
+	const char *cmd_type_str = read_seq ? "read_seq" : "write_ack";
+	union pds_core_adminq_cmd cmd = {
+		.lm_dirty_seq_ack = {
+			.vf_id = cpu_to_le16(pds_vfio->vf_id),
+			.len_bytes = cpu_to_le32(total_len),
+			.off_bytes = cpu_to_le32(offset),
+			.sgl_addr = cpu_to_le64(sgl_dma),
+			.num_sge = cpu_to_le16(num_sge),
+		},
+	};
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_adminq_comp comp = {};
+	int err;
+
+	if (read_seq)
+		cmd.lm_dirty_seq_ack.opcode = PDS_LM_CMD_DIRTY_READ_SEQ;
+	else
+		cmd.lm_dirty_seq_ack.opcode = PDS_LM_CMD_DIRTY_WRITE_ACK;
+
+	err = pds_vfio_client_adminq_cmd(pds_vfio, &cmd, &comp, false);
+	if (err) {
+		dev_err(dev, "failed cmd Page Tracking %s: %pe\n", cmd_type_str,
+			ERR_PTR(err));
+		return err;
+	}
+
+	return 0;
+}

drivers/vfio/pci/pds/cmds.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#ifndef _CMDS_H_
+#define _CMDS_H_
+
+int pds_vfio_register_client_cmd(struct pds_vfio_pci_device *pds_vfio);
+void pds_vfio_unregister_client_cmd(struct pds_vfio_pci_device *pds_vfio);
+int pds_vfio_suspend_device_cmd(struct pds_vfio_pci_device *pds_vfio, u8 type);
+int pds_vfio_resume_device_cmd(struct pds_vfio_pci_device *pds_vfio, u8 type);
+int pds_vfio_get_lm_state_size_cmd(struct pds_vfio_pci_device *pds_vfio, u64 *size);
+int pds_vfio_get_lm_state_cmd(struct pds_vfio_pci_device *pds_vfio);
+int pds_vfio_set_lm_state_cmd(struct pds_vfio_pci_device *pds_vfio);
+void pds_vfio_send_host_vf_lm_status_cmd(struct pds_vfio_pci_device *pds_vfio,
+					 enum pds_lm_host_vf_status vf_status);
+int pds_vfio_dirty_status_cmd(struct pds_vfio_pci_device *pds_vfio,
+			      u64 regions_dma, u8 *max_regions,
+			      u8 *num_regions);
+int pds_vfio_dirty_enable_cmd(struct pds_vfio_pci_device *pds_vfio,
+			      u64 regions_dma, u8 num_regions);
+int pds_vfio_dirty_disable_cmd(struct pds_vfio_pci_device *pds_vfio);
+int pds_vfio_dirty_seq_ack_cmd(struct pds_vfio_pci_device *pds_vfio,
+			       u64 sgl_dma, u16 num_sge, u32 offset,
+			       u32 total_len, bool read_seq);
+#endif /* _CMDS_H_ */

drivers/vfio/pci/pds/dirty.c

···
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#include <linux/interval_tree.h>
+#include <linux/vfio.h>
+
+#include <linux/pds/pds_common.h>
+#include <linux/pds/pds_core_if.h>
+#include <linux/pds/pds_adminq.h>
+
+#include "vfio_dev.h"
+#include "cmds.h"
+#include "dirty.h"
+
+#define READ_SEQ true
+#define WRITE_ACK false
+
+bool pds_vfio_dirty_is_enabled(struct pds_vfio_pci_device *pds_vfio)
+{
+	return pds_vfio->dirty.is_enabled;
+}
+
+void pds_vfio_dirty_set_enabled(struct pds_vfio_pci_device *pds_vfio)
+{
+	pds_vfio->dirty.is_enabled = true;
+}
+
+void pds_vfio_dirty_set_disabled(struct pds_vfio_pci_device *pds_vfio)
+{
+	pds_vfio->dirty.is_enabled = false;
+}
+
+static void
+pds_vfio_print_guest_region_info(struct pds_vfio_pci_device *pds_vfio,
+				 u8 max_regions)
+{
+	int len = max_regions * sizeof(struct pds_lm_dirty_region_info);
+	struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
+	struct device *pdsc_dev = &pci_physfn(pdev)->dev;
+	struct pds_lm_dirty_region_info *region_info;
+	dma_addr_t regions_dma;
+	u8 num_regions;
+	int err;
+
+	region_info = kcalloc(max_regions,
+			      sizeof(struct pds_lm_dirty_region_info),
+			      GFP_KERNEL);
+	if (!region_info)
+		return;
+
+	regions_dma =
+		dma_map_single(pdsc_dev, region_info, len, DMA_FROM_DEVICE);
+	if (dma_mapping_error(pdsc_dev, regions_dma))
+		goto out_free_region_info;
+
+	err = pds_vfio_dirty_status_cmd(pds_vfio, regions_dma, &max_regions,
+					&num_regions);
+	dma_unmap_single(pdsc_dev, regions_dma, len, DMA_FROM_DEVICE);
+	if (err)
+		goto out_free_region_info;
+
+	for (unsigned int i = 0; i < num_regions; i++)
+		dev_dbg(&pdev->dev,
+			"region_info[%d]: dma_base 0x%llx page_count %u page_size_log2 %u\n",
+			i, le64_to_cpu(region_info[i].dma_base),
+			le32_to_cpu(region_info[i].page_count),
+			region_info[i].page_size_log2);
+
+out_free_region_info:
+	kfree(region_info);
+}
+
+static int pds_vfio_dirty_alloc_bitmaps(struct pds_vfio_dirty *dirty,
+					unsigned long bytes)
+{
+	unsigned long *host_seq_bmp, *host_ack_bmp;
+
+	host_seq_bmp = vzalloc(bytes);
+	if (!host_seq_bmp)
+		return -ENOMEM;
+
+	host_ack_bmp = vzalloc(bytes);
+	if (!host_ack_bmp) {
+		bitmap_free(host_seq_bmp);
+		return -ENOMEM;
+	}
+
+	dirty->host_seq.bmp = host_seq_bmp;
+	dirty->host_ack.bmp = host_ack_bmp;
+
+	return 0;
+}
+
+static void pds_vfio_dirty_free_bitmaps(struct pds_vfio_dirty *dirty)
+{
+	vfree(dirty->host_seq.bmp);
+	vfree(dirty->host_ack.bmp);
+	dirty->host_seq.bmp = NULL;
+	dirty->host_ack.bmp = NULL;
+}
+
+static void __pds_vfio_dirty_free_sgl(struct pds_vfio_pci_device *pds_vfio,
+				      struct pds_vfio_bmp_info *bmp_info)
+{
+	struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
+	struct device *pdsc_dev = &pci_physfn(pdev)->dev;
+
+	dma_unmap_single(pdsc_dev, bmp_info->sgl_addr,
+			 bmp_info->num_sge * sizeof(struct pds_lm_sg_elem),
+			 DMA_BIDIRECTIONAL);
+	kfree(bmp_info->sgl);
+
+	bmp_info->num_sge = 0;
+	bmp_info->sgl = NULL;
+	bmp_info->sgl_addr = 0;
+}
+
+static void pds_vfio_dirty_free_sgl(struct pds_vfio_pci_device *pds_vfio)
+{
+	if (pds_vfio->dirty.host_seq.sgl)
+		__pds_vfio_dirty_free_sgl(pds_vfio, &pds_vfio->dirty.host_seq);
+	if (pds_vfio->dirty.host_ack.sgl)
+		__pds_vfio_dirty_free_sgl(pds_vfio, &pds_vfio->dirty.host_ack);
+}
+
+static int __pds_vfio_dirty_alloc_sgl(struct pds_vfio_pci_device *pds_vfio,
+				      struct pds_vfio_bmp_info *bmp_info,
+				      u32 page_count)
+{
+	struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
+	struct device *pdsc_dev = &pci_physfn(pdev)->dev;
+	struct pds_lm_sg_elem *sgl;
+	dma_addr_t sgl_addr;
+	size_t sgl_size;
+	u32 max_sge;
+
+	max_sge = DIV_ROUND_UP(page_count, PAGE_SIZE * 8);
+	sgl_size = max_sge * sizeof(struct pds_lm_sg_elem);
+
+	sgl = kzalloc(sgl_size, GFP_KERNEL);
+	if (!sgl)
+		return -ENOMEM;
+
+	sgl_addr = dma_map_single(pdsc_dev, sgl, sgl_size, DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(pdsc_dev, sgl_addr)) {
+		kfree(sgl);
+		return -EIO;
+	}
+
+	bmp_info->sgl = sgl;
+	bmp_info->num_sge = max_sge;
+	bmp_info->sgl_addr = sgl_addr;
+
+	return 0;
+}
+
+static int pds_vfio_dirty_alloc_sgl(struct pds_vfio_pci_device *pds_vfio,
+				    u32 page_count)
+{
+	struct pds_vfio_dirty *dirty = &pds_vfio->dirty;
+	int err;
+
+	err = __pds_vfio_dirty_alloc_sgl(pds_vfio, &dirty->host_seq,
+					 page_count);
+	if (err)
+		return err;
+
+	err = __pds_vfio_dirty_alloc_sgl(pds_vfio, &dirty->host_ack,
+					 page_count);
+	if (err) {
+		__pds_vfio_dirty_free_sgl(pds_vfio, &dirty->host_seq);
+		return err;
+	}
+
+	return 0;
+}
+
+static int pds_vfio_dirty_enable(struct pds_vfio_pci_device *pds_vfio,
+				 struct rb_root_cached *ranges, u32 nnodes,
+				 u64 *page_size)
+{
+	struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
+	struct device *pdsc_dev = &pci_physfn(pdev)->dev;
+	struct pds_vfio_dirty *dirty = &pds_vfio->dirty;
+	u64 region_start, region_size, region_page_size;
+	struct pds_lm_dirty_region_info *region_info;
+	struct interval_tree_node *node = NULL;
+	u8 max_regions = 0, num_regions;
+	dma_addr_t regions_dma = 0;
+	u32 num_ranges = nnodes;
+	u32 page_count;
+	u16 len;
+	int err;
+
+	dev_dbg(&pdev->dev, "vf%u: Start dirty page tracking\n",
+		pds_vfio->vf_id);
+
+	if (pds_vfio_dirty_is_enabled(pds_vfio))
+		return -EINVAL;
+
+	/* find if dirty tracking is disabled, i.e. num_regions == 0 */
+	err = pds_vfio_dirty_status_cmd(pds_vfio, 0, &max_regions,
+					&num_regions);
+	if (err < 0) {
+		dev_err(&pdev->dev, "Failed to get dirty status, err %pe\n",
+			ERR_PTR(err));
+		return err;
+	} else if (num_regions) {
+		dev_err(&pdev->dev,
+			"Dirty tracking already enabled for %d regions\n",
+			num_regions);
+		return -EEXIST;
+	} else if (!max_regions) {
+		dev_err(&pdev->dev,
+			"Device doesn't support dirty tracking, max_regions %d\n",
+			max_regions);
+		return -EOPNOTSUPP;
+	}
+
+	/*
+	 * Only support 1 region for now. If there are any large gaps in the
+	 * VM's address regions, then this would be a waste of memory as we are
+	 * generating 2 bitmaps (ack/seq) from the min address to the max
+	 * address of the VM's address regions. In the future, if we support
+	 * more than one region in the device/driver we can split the bitmaps
+	 * on the largest address region gaps. We can do this split up to the
+	 * max_regions times returned from the dirty_status command.
+	 */
+	max_regions = 1;
+	if (num_ranges > max_regions) {
+		vfio_combine_iova_ranges(ranges, nnodes, max_regions);
+		num_ranges = max_regions;
+	}
+
+	node = interval_tree_iter_first(ranges, 0, ULONG_MAX);
+	if (!node)
+		return -EINVAL;
+
+	region_size = node->last - node->start + 1;
+	region_start = node->start;
+	region_page_size = *page_size;
+
+	len = sizeof(*region_info);
+	region_info = kzalloc(len, GFP_KERNEL);
+	if (!region_info)
+		return -ENOMEM;
+
+	page_count = DIV_ROUND_UP(region_size, region_page_size);
+
+	region_info->dma_base = cpu_to_le64(region_start);
+	region_info->page_count = cpu_to_le32(page_count);
+	region_info->page_size_log2 = ilog2(region_page_size);
+
+	regions_dma = dma_map_single(pdsc_dev, (void *)region_info, len,
+				     DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(pdsc_dev, regions_dma)) {
+		err = -ENOMEM;
+		goto out_free_region_info;
+	}
+
+	err = pds_vfio_dirty_enable_cmd(pds_vfio, regions_dma, max_regions);
+	dma_unmap_single(pdsc_dev, regions_dma, len, DMA_BIDIRECTIONAL);
+	if (err)
+		goto out_free_region_info;
+
+	/*
+	 * page_count might be adjusted by the device,
+	 * update it before freeing region_info DMA
+	 */
+	page_count = le32_to_cpu(region_info->page_count);
+
+	dev_dbg(&pdev->dev,
+		"region_info: regions_dma 0x%llx dma_base 0x%llx page_count %u page_size_log2 %u\n",
+		regions_dma, region_start, page_count,
+		(u8)ilog2(region_page_size));
+
+	err = pds_vfio_dirty_alloc_bitmaps(dirty, page_count / BITS_PER_BYTE);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to alloc dirty bitmaps: %pe\n",
+			ERR_PTR(err));
+		goto out_free_region_info;
+	}
+
+	err = pds_vfio_dirty_alloc_sgl(pds_vfio, page_count);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to alloc dirty sg lists: %pe\n",
+			ERR_PTR(err));
+		goto out_free_bitmaps;
+	}
+
+	dirty->region_start = region_start;
+	dirty->region_size = region_size;
+	dirty->region_page_size = region_page_size;
+	pds_vfio_dirty_set_enabled(pds_vfio);
+
+	pds_vfio_print_guest_region_info(pds_vfio, max_regions);
+
+	kfree(region_info);
+
+	return 0;
+
+out_free_bitmaps:
+	pds_vfio_dirty_free_bitmaps(dirty);
+out_free_region_info:
+	kfree(region_info);
+	return err;
+}
+
+void pds_vfio_dirty_disable(struct pds_vfio_pci_device *pds_vfio, bool send_cmd)
+{
+	if (pds_vfio_dirty_is_enabled(pds_vfio)) {
+		pds_vfio_dirty_set_disabled(pds_vfio);
+		if (send_cmd)
+			pds_vfio_dirty_disable_cmd(pds_vfio);
+		pds_vfio_dirty_free_sgl(pds_vfio);
+		pds_vfio_dirty_free_bitmaps(&pds_vfio->dirty);
+	}
+
+	if (send_cmd)
+		pds_vfio_send_host_vf_lm_status_cmd(pds_vfio, PDS_LM_STA_NONE);
+}
+
+static int pds_vfio_dirty_seq_ack(struct pds_vfio_pci_device *pds_vfio,
+				  struct pds_vfio_bmp_info *bmp_info,
+				  u32 offset, u32 bmp_bytes, bool read_seq)
+{
+	const char *bmp_type_str = read_seq ? "read_seq" : "write_ack";
+	u8 dma_dir = read_seq ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
+	struct device *pdsc_dev = &pci_physfn(pdev)->dev;
+	unsigned long long npages;
+	struct sg_table sg_table;
+	struct scatterlist *sg;
+	struct page **pages;
+	u32 page_offset;
+	const void *bmp;
+	size_t size;
+	u16 num_sge;
+	int err;
+	int i;
+
+	bmp = (void *)((u64)bmp_info->bmp + offset);
+	page_offset = offset_in_page(bmp);
+	bmp -= page_offset;
+
+	/*
+	 * Start and end of bitmap section to seq/ack might not be page
+	 * aligned, so use the page_offset to account for that so there
+	 * will be enough pages to represent the bmp_bytes
+	 */
+	npages = DIV_ROUND_UP_ULL(bmp_bytes + page_offset, PAGE_SIZE);
+	pages = kmalloc_array(npages, sizeof(*pages), GFP_KERNEL);
+	if (!pages)
+		return -ENOMEM;
+
+	for (unsigned long long i = 0; i < npages; i++) {
+		struct page *page = vmalloc_to_page(bmp);
+
+		if (!page) {
+			err = -EFAULT;
+			goto out_free_pages;
+		}
+
+		pages[i] = page;
+		bmp += PAGE_SIZE;
+	}
+
+	err = sg_alloc_table_from_pages(&sg_table, pages, npages, page_offset,
+					bmp_bytes, GFP_KERNEL);
+	if (err)
+		goto out_free_pages;
+
+	err = dma_map_sgtable(pdsc_dev, &sg_table, dma_dir, 0);
+	if (err)
+		goto out_free_sg_table;
+
+	for_each_sgtable_dma_sg(&sg_table, sg, i) {
+		struct pds_lm_sg_elem *sg_elem = &bmp_info->sgl[i];
+
+		sg_elem->addr = cpu_to_le64(sg_dma_address(sg));
+		sg_elem->len = cpu_to_le32(sg_dma_len(sg));
+	}
+
+	num_sge = sg_table.nents;
+	size = num_sge * sizeof(struct pds_lm_sg_elem);
+	dma_sync_single_for_device(pdsc_dev, bmp_info->sgl_addr, size, dma_dir);
+	err = pds_vfio_dirty_seq_ack_cmd(pds_vfio, bmp_info->sgl_addr, num_sge,
+					 offset, bmp_bytes, read_seq);
+	if (err)
+		dev_err(&pdev->dev,
+			"Dirty bitmap %s failed offset %u bmp_bytes %u num_sge %u DMA 0x%llx: %pe\n",
+			bmp_type_str, offset, bmp_bytes,
+			num_sge, bmp_info->sgl_addr, ERR_PTR(err));
+	dma_sync_single_for_cpu(pdsc_dev, bmp_info->sgl_addr, size, dma_dir);
+
+	dma_unmap_sgtable(pdsc_dev, &sg_table, dma_dir, 0);
+out_free_sg_table:
+	sg_free_table(&sg_table);
+out_free_pages:
+	kfree(pages);
+
+	return err;
+}
+
+static int pds_vfio_dirty_write_ack(struct pds_vfio_pci_device *pds_vfio,
+				    u32 offset, u32 len)
+{
+	return pds_vfio_dirty_seq_ack(pds_vfio, &pds_vfio->dirty.host_ack,
+				      offset, len, WRITE_ACK);
+}
+
+static int pds_vfio_dirty_read_seq(struct pds_vfio_pci_device *pds_vfio,
+				   u32 offset, u32 len)
+{
+	return pds_vfio_dirty_seq_ack(pds_vfio, &pds_vfio->dirty.host_seq,
+				      offset, len, READ_SEQ);
+}
+
+static int pds_vfio_dirty_process_bitmaps(struct pds_vfio_pci_device *pds_vfio,
+					  struct iova_bitmap *dirty_bitmap,
+					  u32 bmp_offset, u32 len_bytes)
+{
+	u64 page_size = pds_vfio->dirty.region_page_size;
+	u64 region_start = pds_vfio->dirty.region_start;
+	u32 bmp_offset_bit;
+	__le64 *seq, *ack;
+	int dword_count;
+
+	dword_count = len_bytes / sizeof(u64);
+	seq = (__le64 *)((u64)pds_vfio->dirty.host_seq.bmp + bmp_offset);
+	ack = (__le64 *)((u64)pds_vfio->dirty.host_ack.bmp + bmp_offset);
+	bmp_offset_bit = bmp_offset * 8;
+
+	for (int i = 0; i < dword_count; i++) {
+		u64 xor = le64_to_cpu(seq[i]) ^ le64_to_cpu(ack[i]);
+
+		/* prepare for next write_ack call */
+		ack[i] = seq[i];
+
+		for (u8 bit_i = 0; bit_i < BITS_PER_TYPE(u64); ++bit_i) {
+			if (xor & BIT(bit_i)) {
+				u64 abs_bit_i = bmp_offset_bit +
+						i * BITS_PER_TYPE(u64) + bit_i;
+				u64 addr = abs_bit_i * page_size + region_start;
+
+				iova_bitmap_set(dirty_bitmap, addr, page_size);
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int pds_vfio_dirty_sync(struct pds_vfio_pci_device *pds_vfio,
+			       struct iova_bitmap *dirty_bitmap,
+			       unsigned long iova, unsigned long length)
+{
+	struct device *dev = &pds_vfio->vfio_coredev.pdev->dev;
+	struct pds_vfio_dirty *dirty = &pds_vfio->dirty;
+	u64 bmp_offset, bmp_bytes;
+	u64 bitmap_size, pages;
+	int err;
+
+	dev_dbg(dev, "vf%u: Get dirty page bitmap\n", pds_vfio->vf_id);
+
+	if (!pds_vfio_dirty_is_enabled(pds_vfio)) {
+		dev_err(dev, "vf%u: Sync failed, dirty tracking is disabled\n",
+			pds_vfio->vf_id);
+		return -EINVAL;
+	}
+
+	pages = DIV_ROUND_UP(length, pds_vfio->dirty.region_page_size);
+	bitmap_size =
+		round_up(pages, sizeof(u64) * BITS_PER_BYTE) / BITS_PER_BYTE;
+
+	dev_dbg(dev,
+		"vf%u: iova 0x%lx length %lu page_size %llu pages %llu bitmap_size %llu\n",
+		pds_vfio->vf_id, iova, length, pds_vfio->dirty.region_page_size,
+		pages, bitmap_size);
+
+	if (!length || ((dirty->region_start + iova + length) >
+			(dirty->region_start + dirty->region_size))) {
+		dev_err(dev, "Invalid iova 0x%lx and/or length 0x%lx to sync\n",
+			iova, length);
+		return -EINVAL;
+	}
+
+	/* bitmap is modified in 64 bit chunks */
+	bmp_bytes = ALIGN(DIV_ROUND_UP(length / dirty->region_page_size,
+				       sizeof(u64)),
+			  sizeof(u64));
+	if (bmp_bytes != bitmap_size) {
+		dev_err(dev,
+			"Calculated bitmap bytes %llu not equal to bitmap size %llu\n",
+			bmp_bytes, bitmap_size);
+		return -EINVAL;
+	}
+
+	bmp_offset = DIV_ROUND_UP(iova / dirty->region_page_size, sizeof(u64));
+
+	dev_dbg(dev,
+		"Syncing dirty bitmap, iova 0x%lx length 0x%lx, bmp_offset %llu bmp_bytes %llu\n",
+		iova, length, bmp_offset, bmp_bytes);
+
+	err = pds_vfio_dirty_read_seq(pds_vfio, bmp_offset, bmp_bytes);
+	if (err)
+		return err;
+
+	err = pds_vfio_dirty_process_bitmaps(pds_vfio, dirty_bitmap, bmp_offset,
+					     bmp_bytes);
+	if (err)
+		return err;
+
+	err = pds_vfio_dirty_write_ack(pds_vfio, bmp_offset, bmp_bytes);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+int pds_vfio_dma_logging_report(struct vfio_device *vdev, unsigned long iova,
+				unsigned long length, struct iova_bitmap *dirty)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+	int err;
+
+	mutex_lock(&pds_vfio->state_mutex);
+	err = pds_vfio_dirty_sync(pds_vfio, dirty, iova, length);
+	pds_vfio_state_mutex_unlock(pds_vfio);
+
+	return err;
+}
+
+int pds_vfio_dma_logging_start(struct vfio_device *vdev,
+			       struct rb_root_cached *ranges, u32 nnodes,
+			       u64 *page_size)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+	int err;
+
+	mutex_lock(&pds_vfio->state_mutex);
+	pds_vfio_send_host_vf_lm_status_cmd(pds_vfio, PDS_LM_STA_IN_PROGRESS);
+	err = pds_vfio_dirty_enable(pds_vfio, ranges, nnodes, page_size);
+	pds_vfio_state_mutex_unlock(pds_vfio);
+
+	return err;
+}
+
+int pds_vfio_dma_logging_stop(struct vfio_device *vdev)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+
+	mutex_lock(&pds_vfio->state_mutex);
+	pds_vfio_dirty_disable(pds_vfio, true);
+	pds_vfio_state_mutex_unlock(pds_vfio);
+
+	return 0;
+}

drivers/vfio/pci/pds/dirty.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#ifndef _DIRTY_H_
+#define _DIRTY_H_
+
+struct pds_vfio_bmp_info {
+	unsigned long *bmp;
+	u32 bmp_bytes;
+	struct pds_lm_sg_elem *sgl;
+	dma_addr_t sgl_addr;
+	u16 num_sge;
+};
+
+struct pds_vfio_dirty {
+	struct pds_vfio_bmp_info host_seq;
+	struct pds_vfio_bmp_info host_ack;
+	u64 region_size;
+	u64 region_start;
+	u64 region_page_size;
+	bool is_enabled;
+};
+
+struct pds_vfio_pci_device;
+
+bool pds_vfio_dirty_is_enabled(struct pds_vfio_pci_device *pds_vfio);
+void pds_vfio_dirty_set_enabled(struct pds_vfio_pci_device *pds_vfio);
+void pds_vfio_dirty_set_disabled(struct pds_vfio_pci_device *pds_vfio);
+void pds_vfio_dirty_disable(struct pds_vfio_pci_device *pds_vfio,
+			    bool send_cmd);
+
+int pds_vfio_dma_logging_report(struct vfio_device *vdev, unsigned long iova,
+				unsigned long length,
+				struct iova_bitmap *dirty);
+int pds_vfio_dma_logging_start(struct vfio_device *vdev,
+			       struct rb_root_cached *ranges, u32 nnodes,
+			       u64 *page_size);
+int pds_vfio_dma_logging_stop(struct vfio_device *vdev);
+#endif /* _DIRTY_H_ */

drivers/vfio/pci/pds/lm.c

···
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <linux/vfio.h>
+#include <linux/vfio_pci_core.h>
+
+#include "vfio_dev.h"
+#include "cmds.h"
+
+static struct pds_vfio_lm_file *
+pds_vfio_get_lm_file(const struct file_operations *fops, int flags, u64 size)
+{
+	struct pds_vfio_lm_file *lm_file = NULL;
+	unsigned long long npages;
+	struct page **pages;
+	void *page_mem;
+	const void *p;
+
+	if (!size)
+		return NULL;
+
+	/* Alloc file structure */
+	lm_file = kzalloc(sizeof(*lm_file), GFP_KERNEL);
+	if (!lm_file)
+		return NULL;
+
+	/* Create file */
+	lm_file->filep =
+		anon_inode_getfile("pds_vfio_lm", fops, lm_file, flags);
+	if (IS_ERR(lm_file->filep))
+		goto out_free_file;
+
+	stream_open(lm_file->filep->f_inode, lm_file->filep);
+	mutex_init(&lm_file->lock);
+
+	/* prevent file from being released before we are done with it */
+	get_file(lm_file->filep);
+
+	/* Allocate memory for file pages */
+	npages = DIV_ROUND_UP_ULL(size, PAGE_SIZE);
+	pages = kmalloc_array(npages, sizeof(*pages), GFP_KERNEL);
+	if (!pages)
+		goto out_put_file;
+
+	page_mem = kvzalloc(ALIGN(size, PAGE_SIZE), GFP_KERNEL);
+	if (!page_mem)
+		goto out_free_pages_array;
+
+	p = page_mem - offset_in_page(page_mem);
+	for (unsigned long long i = 0; i < npages; i++) {
+		if (is_vmalloc_addr(p))
+			pages[i] = vmalloc_to_page(p);
+		else
+			pages[i] = kmap_to_page((void *)p);
+		if (!pages[i])
+			goto out_free_page_mem;
+
+		p += PAGE_SIZE;
+	}
+
+	/* Create scatterlist of file pages to use for DMA mapping later */
+	if (sg_alloc_table_from_pages(&lm_file->sg_table, pages, npages, 0,
+				      size, GFP_KERNEL))
+		goto out_free_page_mem;
+
+	lm_file->size = size;
+	lm_file->pages = pages;
+	lm_file->npages = npages;
+	lm_file->page_mem = page_mem;
+	lm_file->alloc_size = npages * PAGE_SIZE;
+
+	return lm_file;
+
+out_free_page_mem:
+	kvfree(page_mem);
+out_free_pages_array:
+	kfree(pages);
+out_put_file:
+	fput(lm_file->filep);
+	mutex_destroy(&lm_file->lock);
+out_free_file:
+	kfree(lm_file);
+
+	return NULL;
+}
+
+static void pds_vfio_put_lm_file(struct pds_vfio_lm_file *lm_file)
+{
+	mutex_lock(&lm_file->lock);
+
+	lm_file->size = 0;
+	lm_file->alloc_size = 0;
+
+	/* Free scatter list of file pages */
+	sg_free_table(&lm_file->sg_table);
+
+	kvfree(lm_file->page_mem);
+	lm_file->page_mem = NULL;
+	kfree(lm_file->pages);
+	lm_file->pages = NULL;
+
+	mutex_unlock(&lm_file->lock);
+
+	/* allow file to be released since we are done with it */
+	fput(lm_file->filep);
+}
+
+void pds_vfio_put_save_file(struct pds_vfio_pci_device *pds_vfio)
+{
+	if (!pds_vfio->save_file)
+		return;
+
+	pds_vfio_put_lm_file(pds_vfio->save_file);
+	pds_vfio->save_file = NULL;
+}
+
+void pds_vfio_put_restore_file(struct pds_vfio_pci_device *pds_vfio)
+{
+	if (!pds_vfio->restore_file)
+		return;
+
+	pds_vfio_put_lm_file(pds_vfio->restore_file);
+	pds_vfio->restore_file = NULL;
+}
+
+static struct page *pds_vfio_get_file_page(struct pds_vfio_lm_file *lm_file,
+					   unsigned long offset)
+{
+	unsigned long cur_offset = 0;
+	struct scatterlist *sg;
+	unsigned int i;
+
+	/* All accesses are sequential */
+	if (offset < lm_file->last_offset || !lm_file->last_offset_sg) {
+		lm_file->last_offset = 0;
+		lm_file->last_offset_sg = lm_file->sg_table.sgl;
+		lm_file->sg_last_entry = 0;
+	}
+
+	cur_offset = lm_file->last_offset;
+
+	for_each_sg(lm_file->last_offset_sg, sg,
+		    lm_file->sg_table.orig_nents - lm_file->sg_last_entry, i) {
+		if (offset < sg->length + cur_offset) {
+			lm_file->last_offset_sg = sg;
+			lm_file->sg_last_entry += i;
+			lm_file->last_offset = cur_offset;
+			return nth_page(sg_page(sg),
+					(offset - cur_offset) / PAGE_SIZE);
+		}
+		cur_offset += sg->length;
+	}
+
+	return NULL;
+}
+
+static int pds_vfio_release_file(struct inode *inode, struct file *filp)
+{
+	struct pds_vfio_lm_file *lm_file = filp->private_data;
+
+	mutex_lock(&lm_file->lock);
+	lm_file->filep->f_pos = 0;
+	lm_file->size = 0;
+	mutex_unlock(&lm_file->lock);
+	mutex_destroy(&lm_file->lock);
+	kfree(lm_file);
+
+	return 0;
+}
+
+static ssize_t pds_vfio_save_read(struct file *filp, char __user *buf,
+				  size_t len, loff_t *pos)
+{
+	struct pds_vfio_lm_file *lm_file = filp->private_data;
+	ssize_t done = 0;
+
+	if (pos)
+		return -ESPIPE;
+	pos = &filp->f_pos;
+
+	mutex_lock(&lm_file->lock);
+	if (*pos > lm_file->size) {
+		done = -EINVAL;
+		goto out_unlock;
+	}
+
+	len = min_t(size_t, lm_file->size - *pos, len);
+	while (len) {
+		size_t page_offset;
+		struct page *page;
+		size_t page_len;
+		u8 *from_buff;
+		int err;
+
+		page_offset = (*pos) % PAGE_SIZE;
+		page = pds_vfio_get_file_page(lm_file, *pos - page_offset);
+		if (!page) {
+			if (done == 0)
+				done = -EINVAL;
+			goto out_unlock;
+		}
+
+		page_len = min_t(size_t, len, PAGE_SIZE - page_offset);
+		from_buff = kmap_local_page(page);
+		err = copy_to_user(buf, from_buff + page_offset, page_len);
+		kunmap_local(from_buff);
+		if (err) {
+			done = -EFAULT;
+			goto out_unlock;
+		}
+		*pos += page_len;
+		len -= page_len;
+		done += page_len;
+		buf += page_len;
+	}
+
+out_unlock:
+	mutex_unlock(&lm_file->lock);
+	return done;
+}
+
+static const struct file_operations pds_vfio_save_fops = {
+	.owner = THIS_MODULE,
+	.read = pds_vfio_save_read,
+	.release = pds_vfio_release_file,
+	.llseek = no_llseek,
+};
+
+static int pds_vfio_get_save_file(struct pds_vfio_pci_device *pds_vfio)
+{
+	struct device *dev = &pds_vfio->vfio_coredev.pdev->dev;
+	struct pds_vfio_lm_file *lm_file;
+	u64 size;
+	int err;
+
+	/* Get live migration state size in this state */
+	err = pds_vfio_get_lm_state_size_cmd(pds_vfio, &size);
+	if (err) {
+		dev_err(dev, "failed to get save status: %pe\n", ERR_PTR(err));
+		return err;
+	}
+
+	dev_dbg(dev, "save status, size = %lld\n", size);
+
+	if (!size) {
+		dev_err(dev, "invalid state size\n");
+		return -EIO;
+	}
+
+	lm_file = pds_vfio_get_lm_file(&pds_vfio_save_fops, O_RDONLY, size);
+	if (!lm_file) {
+		dev_err(dev, "failed to create save file\n");
+		return -ENOENT;
+	}
+
+	dev_dbg(dev, "size = %lld, alloc_size = %lld, npages = %lld\n",
+		lm_file->size, lm_file->alloc_size, lm_file->npages);
+
+	pds_vfio->save_file = lm_file;
+
+	return 0;
+}
+
+static ssize_t pds_vfio_restore_write(struct file *filp, const char __user *buf,
+				      size_t len, loff_t *pos)
+{
+	struct pds_vfio_lm_file *lm_file = filp->private_data;
+	loff_t requested_length;
+	ssize_t done = 0;
+
+	if (pos)
+		return -ESPIPE;
+
+	pos = &filp->f_pos;
+
+	if (*pos < 0 ||
+	    check_add_overflow((loff_t)len, *pos, &requested_length))
+		return -EINVAL;
+
+	mutex_lock(&lm_file->lock);
+
+	while (len) {
+		size_t page_offset;
+		struct page *page;
+		size_t page_len;
+		u8 *to_buff;
+		int err;
+
+		page_offset = (*pos) % PAGE_SIZE;
+		page = pds_vfio_get_file_page(lm_file, *pos - page_offset);
+		if (!page) {
+			if (done == 0)
+				done = -EINVAL;
+			goto out_unlock;
+		}
+
+		page_len = min_t(size_t, len, PAGE_SIZE - page_offset);
+		to_buff = kmap_local_page(page);
+		err = copy_from_user(to_buff + page_offset, buf, page_len);
+		kunmap_local(to_buff);
+		if (err) {
+			done = -EFAULT;
+			goto out_unlock;
+		}
+		*pos += page_len;
+		len -= page_len;
+		done += page_len;
+		buf += page_len;
+		lm_file->size += page_len;
+	}
+out_unlock:
+	mutex_unlock(&lm_file->lock);
+	return done;
+}
+
+static const struct file_operations pds_vfio_restore_fops = {
+	.owner = THIS_MODULE,
+	.write = pds_vfio_restore_write,
+	.release = pds_vfio_release_file,
+	.llseek = no_llseek,
+};
+
+static int pds_vfio_get_restore_file(struct pds_vfio_pci_device *pds_vfio)
+{
+	struct device *dev = &pds_vfio->vfio_coredev.pdev->dev;
+	struct pds_vfio_lm_file *lm_file;
+	u64 size;
+
+	size = sizeof(union pds_lm_dev_state);
+	dev_dbg(dev, "restore status, size = %lld\n", size);
+
+	if (!size) {
+		dev_err(dev, "invalid state size");
+		return -EIO;
+	}
+
+	lm_file = pds_vfio_get_lm_file(&pds_vfio_restore_fops, O_WRONLY, size);
+	if (!lm_file) {
+		dev_err(dev, "failed to create restore file");
+		return -ENOENT;
+	}
+	pds_vfio->restore_file = lm_file;
+
+	return 0;
+}
+
+struct file *
+pds_vfio_step_device_state_locked(struct pds_vfio_pci_device *pds_vfio,
+				  enum vfio_device_mig_state next)
+{
+	enum vfio_device_mig_state cur = pds_vfio->state;
+	int err;
+
+	if (cur == VFIO_DEVICE_STATE_STOP && next == VFIO_DEVICE_STATE_STOP_COPY) {
+		err = pds_vfio_get_save_file(pds_vfio);
+		if (err)
+			return ERR_PTR(err);
+
+		err = pds_vfio_get_lm_state_cmd(pds_vfio);
+		if (err) {
+			pds_vfio_put_save_file(pds_vfio);
+			return ERR_PTR(err);
+		}
+
+		return pds_vfio->save_file->filep;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_STOP_COPY && next == VFIO_DEVICE_STATE_STOP) {
+		pds_vfio_put_save_file(pds_vfio);
+		pds_vfio_dirty_disable(pds_vfio, true);
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_STOP && next == VFIO_DEVICE_STATE_RESUMING) {
+		err = pds_vfio_get_restore_file(pds_vfio);
+		if (err)
+			return ERR_PTR(err);
+
+		return pds_vfio->restore_file->filep;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_RESUMING && next == VFIO_DEVICE_STATE_STOP) {
+		err = pds_vfio_set_lm_state_cmd(pds_vfio);
+		if (err)
+			return ERR_PTR(err);
+
+		pds_vfio_put_restore_file(pds_vfio);
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_RUNNING && next == VFIO_DEVICE_STATE_RUNNING_P2P) {
+		pds_vfio_send_host_vf_lm_status_cmd(pds_vfio,
+						    PDS_LM_STA_IN_PROGRESS);
+		err = pds_vfio_suspend_device_cmd(pds_vfio,
+						  PDS_LM_SUSPEND_RESUME_TYPE_P2P);
+		if (err)
+			return ERR_PTR(err);
+
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_RUNNING_P2P && next == VFIO_DEVICE_STATE_RUNNING) {
+		err = pds_vfio_resume_device_cmd(pds_vfio,
+						 PDS_LM_SUSPEND_RESUME_TYPE_FULL);
+		if (err)
+			return ERR_PTR(err);
+
+		pds_vfio_send_host_vf_lm_status_cmd(pds_vfio, PDS_LM_STA_NONE);
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_STOP && next == VFIO_DEVICE_STATE_RUNNING_P2P) {
+		err = pds_vfio_resume_device_cmd(pds_vfio,
+						 PDS_LM_SUSPEND_RESUME_TYPE_P2P);
+		if (err)
+			return ERR_PTR(err);
+
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_RUNNING_P2P && next == VFIO_DEVICE_STATE_STOP) {
+		err = pds_vfio_suspend_device_cmd(pds_vfio,
+						  PDS_LM_SUSPEND_RESUME_TYPE_FULL);
+		if (err)
+			return ERR_PTR(err);
+		return NULL;
+	}
+
+	return ERR_PTR(-EINVAL);
+}

drivers/vfio/pci/pds/lm.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#ifndef _LM_H_
+#define _LM_H_
+
+#include <linux/fs.h>
+#include <linux/mutex.h>
+#include <linux/scatterlist.h>
+#include <linux/types.h>
+
+#include <linux/pds/pds_common.h>
+#include <linux/pds/pds_adminq.h>
+
+struct pds_vfio_lm_file {
+	struct file *filep;
+	struct mutex lock;	/* protect live migration data file */
+	u64 size;		/* Size with valid data */
+	u64 alloc_size;		/* Total allocated size. Always >= len */
+	void *page_mem;		/* memory allocated for pages */
+	struct page **pages;	/* Backing pages for file */
+	unsigned long long npages;
+	struct sg_table sg_table;	/* SG table for backing pages */
+	struct pds_lm_sg_elem *sgl;	/* DMA mapping */
+	dma_addr_t sgl_addr;
+	u16 num_sge;
+	struct scatterlist *last_offset_sg;	/* Iterator */
+	unsigned int sg_last_entry;
+	unsigned long last_offset;
+};
+
+struct pds_vfio_pci_device;
+
+struct file *
+pds_vfio_step_device_state_locked(struct pds_vfio_pci_device *pds_vfio,
+				  enum vfio_device_mig_state next);
+
+void pds_vfio_put_save_file(struct pds_vfio_pci_device *pds_vfio);
+void pds_vfio_put_restore_file(struct pds_vfio_pci_device *pds_vfio);
+
+#endif /* _LM_H_ */

drivers/vfio/pci/pds/pci_drv.c

···
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/vfio.h>
+
+#include <linux/pds/pds_common.h>
+#include <linux/pds/pds_core_if.h>
+#include <linux/pds/pds_adminq.h>
+
+#include "vfio_dev.h"
+#include "pci_drv.h"
+#include "cmds.h"
+
+#define PDS_VFIO_DRV_DESCRIPTION	"AMD/Pensando VFIO Device Driver"
+#define PCI_VENDOR_ID_PENSANDO		0x1dd8
+
+static void pds_vfio_recovery(struct pds_vfio_pci_device *pds_vfio)
+{
+	bool deferred_reset_needed = false;
+
+	/*
+	 * Documentation states that the kernel migration driver must not
+	 * generate asynchronous device state transitions outside of
+	 * manipulation by the user or the VFIO_DEVICE_RESET ioctl.
+	 *
+	 * Since recovery is an asynchronous event received from the device,
+	 * initiate a deferred reset. Issue a deferred reset in the following
+	 * situations:
+	 *   1. Migration is in progress, which will cause the next step of
+	 *	the migration to fail.
+	 *   2. If the device is in a state that will be set to
+	 *	VFIO_DEVICE_STATE_RUNNING on the next action (i.e. VM is
+	 *	shutdown and device is in VFIO_DEVICE_STATE_STOP).
+	 */
+	mutex_lock(&pds_vfio->state_mutex);
+	if ((pds_vfio->state != VFIO_DEVICE_STATE_RUNNING &&
+	     pds_vfio->state != VFIO_DEVICE_STATE_ERROR) ||
+	    (pds_vfio->state == VFIO_DEVICE_STATE_RUNNING &&
+	     pds_vfio_dirty_is_enabled(pds_vfio)))
+		deferred_reset_needed = true;
+	mutex_unlock(&pds_vfio->state_mutex);
+
+	/*
+	 * On the next user initiated state transition, the device will
+	 * transition to the VFIO_DEVICE_STATE_ERROR. At this point it's the user's
+	 * responsibility to reset the device.
+	 *
+	 * If a VFIO_DEVICE_RESET is requested post recovery and before the next
+	 * state transition, then the deferred reset state will be set to
+	 * VFIO_DEVICE_STATE_RUNNING.
+	 */
+	if (deferred_reset_needed) {
+		spin_lock(&pds_vfio->reset_lock);
+		pds_vfio->deferred_reset = true;
+		pds_vfio->deferred_reset_state = VFIO_DEVICE_STATE_ERROR;
+		spin_unlock(&pds_vfio->reset_lock);
+	}
+}
+
+static int pds_vfio_pci_notify_handler(struct notifier_block *nb,
+				       unsigned long ecode, void *data)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(nb, struct pds_vfio_pci_device, nb);
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	union pds_core_notifyq_comp *event = data;
+
+	dev_dbg(dev, "%s: event code %lu\n", __func__, ecode);
+
+	/*
+	 * We don't need to do anything for RESET state==0 as there is no notify
+	 * or feedback mechanism available, and it is possible that we won't
+	 * even see a state==0 event since the pds_core recovery is pending.
+	 *
+	 * Any requests from VFIO while state==0 will fail, which will return
+	 * error and may cause migration to fail.
+	 */
+	if (ecode == PDS_EVENT_RESET) {
+		dev_info(dev, "%s: PDS_EVENT_RESET event received, state==%d\n",
+			 __func__, event->reset.state);
+		/*
+		 * pds_core device finished recovery and sent us the
+		 * notification (state == 1) to allow us to recover
+		 */
+		if (event->reset.state == 1)
+			pds_vfio_recovery(pds_vfio);
+	}
+
+	return 0;
+}
+
+static int
+pds_vfio_pci_register_event_handler(struct pds_vfio_pci_device *pds_vfio)
+{
+	struct device *dev = pds_vfio_to_dev(pds_vfio);
+	struct notifier_block *nb = &pds_vfio->nb;
+	int err;
+
+	if (!nb->notifier_call) {
+		nb->notifier_call = pds_vfio_pci_notify_handler;
+		err = pdsc_register_notify(nb);
+		if (err) {
+			nb->notifier_call = NULL;
+			dev_err(dev,
+				"failed to register pds event handler: %pe\n",
+				ERR_PTR(err));
+			return -EINVAL;
+		}
+		dev_dbg(dev, "pds event handler registered\n");
+	}
+
+	return 0;
+}
+
+static void
+pds_vfio_pci_unregister_event_handler(struct pds_vfio_pci_device *pds_vfio)
+{
+	if (pds_vfio->nb.notifier_call) {
+		pdsc_unregister_notify(&pds_vfio->nb);
+		pds_vfio->nb.notifier_call = NULL;
+	}
+}
+
+static int pds_vfio_pci_probe(struct pci_dev *pdev,
+			      const struct pci_device_id *id)
+{
+	struct pds_vfio_pci_device *pds_vfio;
+	int err;
+
+	pds_vfio = vfio_alloc_device(pds_vfio_pci_device, vfio_coredev.vdev,
+				     &pdev->dev, pds_vfio_ops_info());
+	if (IS_ERR(pds_vfio))
+		return PTR_ERR(pds_vfio);
+
+	dev_set_drvdata(&pdev->dev, &pds_vfio->vfio_coredev);
+
+	err = vfio_pci_core_register_device(&pds_vfio->vfio_coredev);
+	if (err)
+		goto out_put_vdev;
+
+	err = pds_vfio_register_client_cmd(pds_vfio);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register as client: %pe\n",
+			ERR_PTR(err));
+		goto out_unregister_coredev;
+	}
+
+	err = pds_vfio_pci_register_event_handler(pds_vfio);
+	if (err)
+		goto out_unregister_client;
+
+	return 0;
+
+out_unregister_client:
+	pds_vfio_unregister_client_cmd(pds_vfio);
+out_unregister_coredev:
+	vfio_pci_core_unregister_device(&pds_vfio->vfio_coredev);
+out_put_vdev:
+	vfio_put_device(&pds_vfio->vfio_coredev.vdev);
+	return err;
+}
+
+static void pds_vfio_pci_remove(struct pci_dev *pdev)
+{
+	struct pds_vfio_pci_device *pds_vfio = pds_vfio_pci_drvdata(pdev);
+
+	pds_vfio_pci_unregister_event_handler(pds_vfio);
+	pds_vfio_unregister_client_cmd(pds_vfio);
+	vfio_pci_core_unregister_device(&pds_vfio->vfio_coredev);
+	vfio_put_device(&pds_vfio->vfio_coredev.vdev);
+}
+
+static const struct pci_device_id pds_vfio_pci_table[] = {
+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_PENSANDO, 0x1003) }, /* Ethernet VF */
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, pds_vfio_pci_table);
+
+static void pds_vfio_pci_aer_reset_done(struct pci_dev *pdev)
+{
+	struct pds_vfio_pci_device *pds_vfio = pds_vfio_pci_drvdata(pdev);
+
+	pds_vfio_reset(pds_vfio);
+}
+
+static const struct pci_error_handlers pds_vfio_pci_err_handlers = {
+	.reset_done = pds_vfio_pci_aer_reset_done,
+	.error_detected = vfio_pci_core_aer_err_detected,
+};
+
+static struct pci_driver pds_vfio_pci_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = pds_vfio_pci_table,
+	.probe = pds_vfio_pci_probe,
+	.remove = pds_vfio_pci_remove,
+	.err_handler = &pds_vfio_pci_err_handlers,
+	.driver_managed_dma = true,
+};
+
+module_pci_driver(pds_vfio_pci_driver);
+
+MODULE_DESCRIPTION(PDS_VFIO_DRV_DESCRIPTION);
+MODULE_AUTHOR("Brett Creeley <[e-mail]>");
+MODULE_LICENSE("GPL");

drivers/vfio/pci/pds/pci_drv.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#ifndef _PCI_DRV_H
+#define _PCI_DRV_H
+
+#include <linux/pci.h>
+
+#endif /* _PCI_DRV_H */

drivers/vfio/pci/pds/vfio_dev.c

···
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#include <linux/vfio.h>
+#include <linux/vfio_pci_core.h>
+
+#include "lm.h"
+#include "dirty.h"
+#include "vfio_dev.h"
+
+struct pci_dev *pds_vfio_to_pci_dev(struct pds_vfio_pci_device *pds_vfio)
+{
+	return pds_vfio->vfio_coredev.pdev;
+}
+
+struct device *pds_vfio_to_dev(struct pds_vfio_pci_device *pds_vfio)
+{
+	return &pds_vfio_to_pci_dev(pds_vfio)->dev;
+}
+
+struct pds_vfio_pci_device *pds_vfio_pci_drvdata(struct pci_dev *pdev)
+{
+	struct vfio_pci_core_device *core_device = dev_get_drvdata(&pdev->dev);
+
+	return container_of(core_device, struct pds_vfio_pci_device,
+			    vfio_coredev);
+}
+
+void pds_vfio_state_mutex_unlock(struct pds_vfio_pci_device *pds_vfio)
+{
+again:
+	spin_lock(&pds_vfio->reset_lock);
+	if (pds_vfio->deferred_reset) {
+		pds_vfio->deferred_reset = false;
+		if (pds_vfio->state == VFIO_DEVICE_STATE_ERROR) {
+			pds_vfio_put_restore_file(pds_vfio);
+			pds_vfio_put_save_file(pds_vfio);
+			pds_vfio_dirty_disable(pds_vfio, false);
+		}
+		pds_vfio->state = pds_vfio->deferred_reset_state;
+		pds_vfio->deferred_reset_state = VFIO_DEVICE_STATE_RUNNING;
+		spin_unlock(&pds_vfio->reset_lock);
+		goto again;
+	}
+	mutex_unlock(&pds_vfio->state_mutex);
+	spin_unlock(&pds_vfio->reset_lock);
+}
+
+void pds_vfio_reset(struct pds_vfio_pci_device *pds_vfio)
+{
+	spin_lock(&pds_vfio->reset_lock);
+	pds_vfio->deferred_reset = true;
+	pds_vfio->deferred_reset_state = VFIO_DEVICE_STATE_RUNNING;
+	if (!mutex_trylock(&pds_vfio->state_mutex)) {
+		spin_unlock(&pds_vfio->reset_lock);
+		return;
+	}
+	spin_unlock(&pds_vfio->reset_lock);
+	pds_vfio_state_mutex_unlock(pds_vfio);
+}
+
+static struct file *
+pds_vfio_set_device_state(struct vfio_device *vdev,
+			  enum vfio_device_mig_state new_state)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+	struct file *res = NULL;
+
+	mutex_lock(&pds_vfio->state_mutex);
+	/*
+	 * only way to transition out of VFIO_DEVICE_STATE_ERROR is via
+	 * VFIO_DEVICE_RESET, so prevent the state machine from running since
+	 * vfio_mig_get_next_state() will throw a WARN_ON() when transitioning
+	 * from VFIO_DEVICE_STATE_ERROR to any other state
+	 */
+	while (pds_vfio->state != VFIO_DEVICE_STATE_ERROR &&
+	       new_state != pds_vfio->state) {
+		enum vfio_device_mig_state next_state;
+
+		int err = vfio_mig_get_next_state(vdev, pds_vfio->state,
+						  new_state, &next_state);
+		if (err) {
+			res = ERR_PTR(err);
+			break;
+		}
+
+		res = pds_vfio_step_device_state_locked(pds_vfio, next_state);
+		if (IS_ERR(res))
+			break;
+
+		pds_vfio->state = next_state;
+
+		if (WARN_ON(res && new_state != pds_vfio->state)) {
+			res = ERR_PTR(-EINVAL);
+			break;
+		}
+	}
+	pds_vfio_state_mutex_unlock(pds_vfio);
+	/* still waiting on a deferred_reset */
+	if (pds_vfio->state == VFIO_DEVICE_STATE_ERROR)
+		res = ERR_PTR(-EIO);
+
+	return res;
+}
+
+static int pds_vfio_get_device_state(struct vfio_device *vdev,
+				     enum vfio_device_mig_state *current_state)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+
+	mutex_lock(&pds_vfio->state_mutex);
+	*current_state = pds_vfio->state;
+	pds_vfio_state_mutex_unlock(pds_vfio);
+	return 0;
+}
+
+static int pds_vfio_get_device_state_size(struct vfio_device *vdev,
+					  unsigned long *stop_copy_length)
+{
+	*stop_copy_length = PDS_LM_DEVICE_STATE_LENGTH;
+	return 0;
+}
+
+static const struct vfio_migration_ops pds_vfio_lm_ops = {
+	.migration_set_state = pds_vfio_set_device_state,
+	.migration_get_state = pds_vfio_get_device_state,
+	.migration_get_data_size = pds_vfio_get_device_state_size
+};
+
+static const struct vfio_log_ops pds_vfio_log_ops = {
+	.log_start = pds_vfio_dma_logging_start,
+	.log_stop = pds_vfio_dma_logging_stop,
+	.log_read_and_clear = pds_vfio_dma_logging_report,
+};
+
+static int pds_vfio_init_device(struct vfio_device *vdev)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+	struct pci_dev *pdev = to_pci_dev(vdev->dev);
+	int err, vf_id, pci_id;
+
+	vf_id = pci_iov_vf_id(pdev);
+	if (vf_id < 0)
+		return vf_id;
+
+	err = vfio_pci_core_init_dev(vdev);
+	if (err)
+		return err;
+
+	pds_vfio->vf_id = vf_id;
+
+	vdev->migration_flags = VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P;
+	vdev->mig_ops = &pds_vfio_lm_ops;
+	vdev->log_ops = &pds_vfio_log_ops;
+
+	pci_id = PCI_DEVID(pdev->bus->number, pdev->devfn);
+	dev_dbg(&pdev->dev,
+		"%s: PF %#04x VF %#04x vf_id %d domain %d pds_vfio %p\n",
+		__func__, pci_dev_id(pdev->physfn), pci_id, vf_id,
+		pci_domain_nr(pdev->bus), pds_vfio);
+
+	return 0;
+}
+
+static int pds_vfio_open_device(struct vfio_device *vdev)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+	int err;
+
+	err = vfio_pci_core_enable(&pds_vfio->vfio_coredev);
+	if (err)
+		return err;
+
+	mutex_init(&pds_vfio->state_mutex);
+	pds_vfio->state = VFIO_DEVICE_STATE_RUNNING;
+	pds_vfio->deferred_reset_state = VFIO_DEVICE_STATE_RUNNING;
+
+	vfio_pci_core_finish_enable(&pds_vfio->vfio_coredev);
+
+	return 0;
+}
+
+static void pds_vfio_close_device(struct vfio_device *vdev)
+{
+	struct pds_vfio_pci_device *pds_vfio =
+		container_of(vdev, struct pds_vfio_pci_device,
+			     vfio_coredev.vdev);
+
+	mutex_lock(&pds_vfio->state_mutex);
+	pds_vfio_put_restore_file(pds_vfio);
+	pds_vfio_put_save_file(pds_vfio);
+	pds_vfio_dirty_disable(pds_vfio, true);
+	mutex_unlock(&pds_vfio->state_mutex);
+	mutex_destroy(&pds_vfio->state_mutex);
+	vfio_pci_core_close_device(vdev);
+}
+
+static const struct vfio_device_ops pds_vfio_ops = {
+	.name = "pds-vfio",
+	.init = pds_vfio_init_device,
+	.release = vfio_pci_core_release_dev,
+	.open_device = pds_vfio_open_device,
+	.close_device = pds_vfio_close_device,
+	.ioctl = vfio_pci_core_ioctl,
+	.device_feature = vfio_pci_core_ioctl_feature,
+	.read = vfio_pci_core_read,
+	.write = vfio_pci_core_write,
+	.mmap = vfio_pci_core_mmap,
+	.request = vfio_pci_core_request,
+	.match = vfio_pci_core_match,
+	.bind_iommufd = vfio_iommufd_physical_bind,
+	.unbind_iommufd = vfio_iommufd_physical_unbind,
+	.attach_ioas = vfio_iommufd_physical_attach_ioas,
+};
+
+const struct vfio_device_ops *pds_vfio_ops_info(void)
+{
+	return &pds_vfio_ops;
+}

drivers/vfio/pci/pds/vfio_dev.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
+
+#ifndef _VFIO_DEV_H_
+#define _VFIO_DEV_H_
+
+#include <linux/pci.h>
+#include <linux/vfio_pci_core.h>
+
+#include "dirty.h"
+#include "lm.h"
+
+struct pds_vfio_pci_device {
+	struct vfio_pci_core_device vfio_coredev;
+
+	struct pds_vfio_lm_file *save_file;
+	struct pds_vfio_lm_file *restore_file;
+	struct pds_vfio_dirty dirty;
+	struct mutex state_mutex; /* protect migration state */
+	enum vfio_device_mig_state state;
+	spinlock_t reset_lock; /* protect reset_done flow */
+	u8 deferred_reset;
+	enum vfio_device_mig_state deferred_reset_state;
+	struct notifier_block nb;
+
+	int vf_id;
+	u16 client_id;
+};
+
+void pds_vfio_state_mutex_unlock(struct pds_vfio_pci_device *pds_vfio);
+
+const struct vfio_device_ops *pds_vfio_ops_info(void);
+struct pds_vfio_pci_device *pds_vfio_pci_drvdata(struct pci_dev *pdev);
+void pds_vfio_reset(struct pds_vfio_pci_device *pds_vfio);
+
+struct pci_dev *pds_vfio_to_pci_dev(struct pds_vfio_pci_device *pds_vfio);
+struct device *pds_vfio_to_dev(struct pds_vfio_pci_device *pds_vfio);
+
+#endif /* _VFIO_DEV_H_ */

drivers/vfio/pci/vfio_pci.c

···
 	.bind_iommufd	= vfio_iommufd_physical_bind,
 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
+	.detach_ioas	= vfio_iommufd_physical_detach_ioas,
 };
 
 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)

drivers/vfio/pci/vfio_pci_core.c

···
 #include <linux/vgaarb.h>
 #include <linux/nospec.h>
 #include <linux/sched/mm.h>
+#include <linux/iommufd.h>
 #if IS_ENABLED(CONFIG_EEH)
 #include <asm/eeh.h>
 #endif
···
 struct vfio_pci_group_info;
 static void vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set);
 static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
-				      struct vfio_pci_group_info *groups);
+				      struct vfio_pci_group_info *groups,
+				      struct iommufd_ctx *iommufd_ctx);
 
 /*
  * INTx masking requires the ability to disable INTx signaling via PCI_COMMAND
···
 }
 
 struct vfio_pci_fill_info {
-	int max;
-	int cur;
-	struct vfio_pci_dependent_device *devices;
+	struct vfio_pci_dependent_device __user *devices;
+	struct vfio_pci_dependent_device __user *devices_end;
+	struct vfio_device *vdev;
+	u32 count;
+	u32 flags;
 };
 
 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
 {
+	struct vfio_pci_dependent_device info = {
+		.segment = pci_domain_nr(pdev->bus),
+		.bus = pdev->bus->number,
+		.devfn = pdev->devfn,
+	};
 	struct vfio_pci_fill_info *fill = data;
-	struct iommu_group *iommu_group;
 
-	if (fill->cur == fill->max)
-		return -EAGAIN; /* Something changed, try again */
+	fill->count++;
+	if (fill->devices >= fill->devices_end)
+		return 0;
 
-	iommu_group = iommu_group_get(&pdev->dev);
-	if (!iommu_group)
-		return -EPERM; /* Cannot reset non-isolated devices */
+	if (fill->flags & VFIO_PCI_HOT_RESET_FLAG_DEV_ID) {
+		struct iommufd_ctx *iommufd = vfio_iommufd_device_ictx(fill->vdev);
+		struct vfio_device_set *dev_set = fill->vdev->dev_set;
+		struct vfio_device *vdev;
 
-	fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
-	fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
-	fill->devices[fill->cur].bus = pdev->bus->number;
-	fill->devices[fill->cur].devfn = pdev->devfn;
-	fill->cur++;
-	iommu_group_put(iommu_group);
+		/*
+		 * hot-reset requires all affected devices be represented in
+		 * the dev_set.
+		 */
+		vdev = vfio_find_device_in_devset(dev_set, &pdev->dev);
+		if (!vdev) {
+			info.devid = VFIO_PCI_DEVID_NOT_OWNED;
+		} else {
+			int id = vfio_iommufd_get_dev_id(vdev, iommufd);
+
+			if (id > 0)
+				info.devid = id;
+			else if (id == -ENOENT)
+				info.devid = VFIO_PCI_DEVID_OWNED;
+			else
+				info.devid = VFIO_PCI_DEVID_NOT_OWNED;
+		}
+		/* If devid is VFIO_PCI_DEVID_NOT_OWNED, clear owned flag. */
+		if (info.devid == VFIO_PCI_DEVID_NOT_OWNED)
+			fill->flags &= ~VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED;
+	} else {
+		struct iommu_group *iommu_group;
+
+		iommu_group = iommu_group_get(&pdev->dev);
+		if (!iommu_group)
+			return -EPERM; /* Cannot reset non-isolated devices */
+
+		info.group_id = iommu_group_id(iommu_group);
+		iommu_group_put(iommu_group);
+	}
+
+	if (copy_to_user(fill->devices, &info, sizeof(info)))
+		return -EFAULT;
+	fill->devices++;
 	return 0;
 }
 
···
 				   struct vfio_device_info __user *arg)
 {
 	unsigned long minsz = offsetofend(struct vfio_device_info, num_irqs);
-	struct vfio_device_info info;
+	struct vfio_device_info info = {};
 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
-	unsigned long capsz;
 	int ret;
-
-	/* For backward compatibility, cannot require this */
-	capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
 
 	if (copy_from_user(&info, arg, minsz))
 		return -EFAULT;
···
 	if (info.argsz < minsz)
 		return -EINVAL;
 
-	if (info.argsz >= capsz) {
-		minsz = capsz;
-		info.cap_offset = 0;
-	}
+	minsz = min_t(size_t, info.argsz, sizeof(info));
 
 	info.flags = VFIO_DEVICE_FLAGS_PCI;
 
···
 	unsigned long minsz =
 		offsetofend(struct vfio_pci_hot_reset_info, count);
 	struct vfio_pci_hot_reset_info hdr;
-	struct vfio_pci_fill_info fill = { 0 };
-	struct vfio_pci_dependent_device *devices = NULL;
+	struct vfio_pci_fill_info fill = {};
 	bool slot = false;
 	int ret = 0;
 
···
 	else if (pci_probe_reset_bus(vdev->pdev->bus))
 		return -ENODEV;
 
-	/* How many devices are affected? */
-	ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
-					    &fill.max, slot);
+	fill.devices = arg->devices;
+	fill.devices_end = arg->devices +
+			   (hdr.argsz - sizeof(hdr)) / sizeof(arg->devices[0]);
+	fill.vdev = &vdev->vdev;
+
+	if (vfio_device_cdev_opened(&vdev->vdev))
+		fill.flags |= VFIO_PCI_HOT_RESET_FLAG_DEV_ID |
+			     VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED;
+
+	mutex_lock(&vdev->vdev.dev_set->lock);
+	ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_fill_devs,
+					    &fill, slot);
+	mutex_unlock(&vdev->vdev.dev_set->lock);
 	if (ret)
 		return ret;
 
-	WARN_ON(!fill.max); /* Should always be at least one */
-
-	/*
-	 * If there's enough space, fill it now, otherwise return -ENOSPC and
-	 * the number of devices affected.
-	 */
-	if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
-		ret = -ENOSPC;
-		hdr.count = fill.max;
-		goto reset_info_exit;
-	}
-
-	devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
-	if (!devices)
-		return -ENOMEM;
-
-	fill.devices = devices;
-
-	ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_fill_devs,
-					    &fill, slot);
-
-	/*
-	 * If a device was removed between counting and filling, we may come up
-	 * short of fill.max.  If a device was added, we'll have a return of
-	 * -EAGAIN above.
-	 */
-	if (!ret)
-		hdr.count = fill.cur;
-
-reset_info_exit:
+	hdr.count = fill.count;
+	hdr.flags = fill.flags;
 	if (copy_to_user(arg, &hdr, minsz))
-		ret = -EFAULT;
+		return -EFAULT;
 
-	if (!ret) {
-		if (copy_to_user(&arg->devices, devices,
-				 hdr.count * sizeof(*devices)))
-			ret = -EFAULT;
-	}
-
-	kfree(devices);
-	return ret;
+	if (fill.count > fill.devices - arg->devices)
+		return -ENOSPC;
+	return 0;
 }
 
-static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
-					struct vfio_pci_hot_reset __user *arg)
+static int
+vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev,
+				    int array_count, bool slot,
+				    struct vfio_pci_hot_reset __user *arg)
 {
-	unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count);
-	struct vfio_pci_hot_reset hdr;
 	int32_t *group_fds;
 	struct file **files;
 	struct vfio_pci_group_info info;
-	bool slot = false;
 	int file_idx, count = 0, ret = 0;
-
-	if (copy_from_user(&hdr, arg, minsz))
-		return -EFAULT;
-
-	if (hdr.argsz < minsz || hdr.flags)
-		return -EINVAL;
-
-	/* Can we do a slot or bus reset or neither? */
-	if (!pci_probe_reset_slot(vdev->pdev->slot))
-		slot = true;
-	else if (pci_probe_reset_bus(vdev->pdev->bus))
-		return -ENODEV;
 
 	/*
 	 * We can't let userspace give us an arbitrarily large buffer to copy,
···
 	if (ret)
 		return ret;
 
-	/* Somewhere between 1 and count is OK */
-	if (!hdr.count || hdr.count > count)
+	if (array_count > count)
 		return -EINVAL;
 
-	group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
-	files = kcalloc(hdr.count, sizeof(*files), GFP_KERNEL);
+	group_fds = kcalloc(array_count, sizeof(*group_fds), GFP_KERNEL);
+	files = kcalloc(array_count, sizeof(*files), GFP_KERNEL);
 	if (!group_fds || !files) {
 		kfree(group_fds);
 		kfree(files);
···
 	}
 
 	if (copy_from_user(group_fds, arg->group_fds,
-			   hdr.count * sizeof(*group_fds))) {
+			   array_count * sizeof(*group_fds))) {
 		kfree(group_fds);
 		kfree(files);
 		return -EFAULT;
 	}
 
 	/*
-	 * For each group_fd, get the group through the vfio external user
-	 * interface and store the group and iommu ID.  This ensures the group
-	 * is held across the reset.
+	 * Get the group file for each fd to ensure the group is held across
+	 * the reset
 	 */
-	for (file_idx = 0; file_idx < hdr.count; file_idx++) {
+	for (file_idx = 0; file_idx < array_count; file_idx++) {
 		struct file *file = fget(group_fds[file_idx]);
 
 		if (!file) {
···
 	if (ret)
 		goto hot_reset_release;
 
-	info.count = hdr.count;
+	info.count = array_count;
 	info.files = files;
 
-	ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info);
+	ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info, NULL);
 
 hot_reset_release:
 	for (file_idx--; file_idx >= 0; file_idx--)
···
 
 	kfree(files);
 	return ret;
+}
+
+static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
+					struct vfio_pci_hot_reset __user *arg)
+{
+	unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count);
+	struct vfio_pci_hot_reset hdr;
+	bool slot = false;
+
+	if (copy_from_user(&hdr, arg, minsz))
+		return -EFAULT;
+
+	if (hdr.argsz < minsz || hdr.flags)
+		return -EINVAL;
+
+	/* zero-length array is only for cdev opened devices */
+	if (!!hdr.count == vfio_device_cdev_opened(&vdev->vdev))
+		return -EINVAL;
+
+	/* Can we do a slot or bus reset or neither? */
+	if (!pci_probe_reset_slot(vdev->pdev->slot))
+		slot = true;
+	else if (pci_probe_reset_bus(vdev->pdev->bus))
+		return -ENODEV;
+
+	if (hdr.count)
+		return vfio_pci_ioctl_pci_hot_reset_groups(vdev, hdr.count, slot, arg);
+
+	return vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, NULL,
+					  vfio_iommufd_device_ictx(&vdev->vdev));
 }
 
 static int vfio_pci_ioctl_ioeventfd(struct vfio_pci_core_device *vdev,
···
 };
 EXPORT_SYMBOL_GPL(vfio_pci_core_err_handlers);
 
-static bool vfio_dev_in_groups(struct vfio_pci_core_device *vdev,
+static bool vfio_dev_in_groups(struct vfio_device *vdev,
 			       struct vfio_pci_group_info *groups)
 {
 	unsigned int i;
 
+	if (!groups)
+		return false;
+
 	for (i = 0; i < groups->count; i++)
-		if (vfio_file_has_dev(groups->files[i], &vdev->vdev))
+		if (vfio_file_has_dev(groups->files[i], vdev))
 			return true;
 	return false;
 }
···
 static int vfio_pci_is_device_in_set(struct pci_dev *pdev, void *data)
 {
 	struct vfio_device_set *dev_set = data;
-	struct vfio_device *cur;
 
-	list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
-		if (cur->dev == &pdev->dev)
-			return 0;
-	return -EBUSY;
+	return vfio_find_device_in_devset(dev_set, &pdev->dev) ? 0 : -ENODEV;
 }
 
 /*
···
  * get each memory_lock.
  */
 static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
-				      struct vfio_pci_group_info *groups)
+				      struct vfio_pci_group_info *groups,
+				      struct iommufd_ctx *iommufd_ctx)
 {
 	struct vfio_pci_core_device *cur_mem;
 	struct vfio_pci_core_device *cur_vma;
···
 		goto err_unlock;
 
 	list_for_each_entry(cur_vma, &dev_set->device_list, vdev.dev_set_list) {
+		bool owned;
+
 		/*
-		 * Test whether all the affected devices are contained by the
-		 * set of groups provided by the user.
+		 * Test whether all the affected devices can be reset by the
+		 * user.
+		 *
+		 * If called from a group opened device and the user provides
+		 * a set of groups, all the devices in the dev_set should be
+		 * contained by the set of groups provided by the user.
+		 *
+		 * If called from a cdev opened device and the user provides
+		 * a zero-length array, all the devices in the dev_set must
+		 * be bound to the same iommufd_ctx as the input iommufd_ctx.
+		 * If there is any device that has not been bound to any
+		 * iommufd_ctx yet, check if its iommu_group has any device
+		 * bound to the input iommufd_ctx.  Such devices can be
+		 * considered owned by the input iommufd_ctx as the device
+		 * cannot be owned by another iommufd_ctx when its iommu_group
+		 * is owned.
+		 *
+		 * Otherwise, reset is not allowed.
 		 */
-		if (!vfio_dev_in_groups(cur_vma, groups)) {
+		if (iommufd_ctx) {
+			int devid = vfio_iommufd_get_dev_id(&cur_vma->vdev,
+							    iommufd_ctx);
+
+			owned = (devid > 0 || devid == -ENOENT);
+		} else {
+			owned = vfio_dev_in_groups(&cur_vma->vdev, groups);
+		}
+
+		if (!owned) {
 			ret = -EINVAL;
 			goto err_undo;
 		}

drivers/vfio/platform/vfio_amba.c

···
 	.bind_iommufd	= vfio_iommufd_physical_bind,
 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
+	.detach_ioas	= vfio_iommufd_physical_detach_ioas,
 };
 
 static const struct amba_id pl330_ids[] = {

drivers/vfio/platform/vfio_platform.c

···
 	.bind_iommufd	= vfio_iommufd_physical_bind,
 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
+	.detach_ioas	= vfio_iommufd_physical_detach_ioas,
 };
 
 static struct platform_driver vfio_platform_driver = {

drivers/vfio/vfio.h

···
 struct iommu_group;
 struct vfio_container;
 
+struct vfio_device_file {
+	struct vfio_device *device;
+	struct vfio_group *group;
+
+	u8 access_granted;
+	u32 devid; /* only valid when iommufd is valid */
+	spinlock_t kvm_ref_lock; /* protect kvm field */
+	struct kvm *kvm;
+	struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */
+};
+
 void vfio_device_put_registration(struct vfio_device *device);
 bool vfio_device_try_get_registration(struct vfio_device *device);
-int vfio_device_open(struct vfio_device *device, struct iommufd_ctx *iommufd);
-void vfio_device_close(struct vfio_device *device,
-		       struct iommufd_ctx *iommufd);
+int vfio_df_open(struct vfio_device_file *df);
+void vfio_df_close(struct vfio_device_file *df);
+struct vfio_device_file *
+vfio_allocate_device_file(struct vfio_device *device);
 
 extern const struct file_operations vfio_device_fops;
+
+#ifdef CONFIG_VFIO_NOIOMMU
+extern bool vfio_noiommu __read_mostly;
+#else
+enum { vfio_noiommu = false };
+#endif
 
 enum vfio_group_type {
 	/*
···
 	VFIO_NO_IOMMU,
 };
 
+#if IS_ENABLED(CONFIG_VFIO_GROUP)
 struct vfio_group {
 	struct device 			dev;
 	struct cdev			cdev;
···
 	struct blocking_notifier_head	notifier;
 	struct iommufd_ctx		*iommufd;
 	spinlock_t			kvm_ref_lock;
+	unsigned int			cdev_device_open_cnt;
 };
 
+int vfio_device_block_group(struct vfio_device *device);
+void vfio_device_unblock_group(struct vfio_device *device);
 int vfio_device_set_group(struct vfio_device *device,
 			  enum vfio_group_type type);
 void vfio_device_remove_group(struct vfio_device *device);
···
 void vfio_device_group_unregister(struct vfio_device *device);
 int vfio_device_group_use_iommu(struct vfio_device *device);
 void vfio_device_group_unuse_iommu(struct vfio_device *device);
-void vfio_device_group_close(struct vfio_device *device);
+void vfio_df_group_close(struct vfio_device_file *df);
+struct vfio_group *vfio_group_from_file(struct file *file);
+bool vfio_group_enforced_coherent(struct vfio_group *group);
+void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
 bool vfio_device_has_container(struct vfio_device *device);
 int __init vfio_group_init(void);
 void vfio_group_cleanup(void);
···
 	return IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
 	       vdev->group->type == VFIO_NO_IOMMU;
 }
+#else
+struct vfio_group;
+
+static inline int vfio_device_block_group(struct vfio_device *device)
+{
+	return 0;
+}
+
+static inline void vfio_device_unblock_group(struct vfio_device *device)
+{
+}
+
+static inline int vfio_device_set_group(struct vfio_device *device,
+					enum vfio_group_type type)
+{
+	return 0;
+}
+
+static inline void vfio_device_remove_group(struct vfio_device *device)
+{
+}
+
+static inline void vfio_device_group_register(struct vfio_device *device)
+{
+}
+
+static inline void vfio_device_group_unregister(struct vfio_device *device)
+{
+}
+
+static inline int vfio_device_group_use_iommu(struct vfio_device *device)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void vfio_device_group_unuse_iommu(struct vfio_device *device)
+{
+}
+
+static inline void vfio_df_group_close(struct vfio_device_file *df)
+{
+}
+
+static inline struct vfio_group *vfio_group_from_file(struct file *file)
+{
+	return NULL;
+}
+
+static inline bool vfio_group_enforced_coherent(struct vfio_group *group)
+{
+	return true;
+}
+
+static inline void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
+{
+}
+
+static inline bool vfio_device_has_container(struct vfio_device *device)
+{
+	return false;
+}
+
+static inline int __init vfio_group_init(void)
+{
+	return 0;
+}
+
+static inline void vfio_group_cleanup(void)
+{
+}
+
+static inline bool vfio_device_is_noiommu(struct vfio_device *vdev)
+{
+	return false;
+}
+#endif /* CONFIG_VFIO_GROUP */
 
 #if IS_ENABLED(CONFIG_VFIO_CONTAINER)
 /**
···
 #endif
 
 #if IS_ENABLED(CONFIG_IOMMUFD)
-int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);
-void vfio_iommufd_unbind(struct vfio_device *device);
+bool vfio_iommufd_device_has_compat_ioas(struct vfio_device *vdev,
+					 struct iommufd_ctx *ictx);
+int vfio_df_iommufd_bind(struct vfio_device_file *df);
+void vfio_df_iommufd_unbind(struct vfio_device_file *df);
+int vfio_iommufd_compat_attach_ioas(struct vfio_device *device,
+				    struct iommufd_ctx *ictx);
 #else
-static inline int vfio_iommufd_bind(struct vfio_device *device,
+static inline bool
+vfio_iommufd_device_has_compat_ioas(struct vfio_device *vdev,
 				    struct iommufd_ctx *ictx)
+{
+	return false;
+}
+
+static inline int vfio_df_iommufd_bind(struct vfio_device_file *fd)
 {
 	return -EOPNOTSUPP;
 }
 
-static inline void vfio_iommufd_unbind(struct vfio_device *device)
+static inline void vfio_df_iommufd_unbind(struct vfio_device_file *df)
 {
 }
+
+static inline int
+vfio_iommufd_compat_attach_ioas(struct vfio_device *device,
+				struct iommufd_ctx *ictx)
+{
+	return -EOPNOTSUPP;
+}
 #endif
+
+int vfio_df_ioctl_attach_pt(struct vfio_device_file *df,
+			    struct vfio_device_attach_iommufd_pt __user *arg);
+int vfio_df_ioctl_detach_pt(struct vfio_device_file *df,
+			    struct vfio_device_detach_iommufd_pt __user *arg);
+
+#if IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV)
+void vfio_init_device_cdev(struct vfio_device *device);
+
+static inline int vfio_device_add(struct vfio_device *device)
+{
+	/* cdev does not support noiommu device */
+	if (vfio_device_is_noiommu(device))
+		return device_add(&device->device);
+	vfio_init_device_cdev(device);
+	return cdev_device_add(&device->cdev, &device->device);
+}
+
+static inline void vfio_device_del(struct vfio_device *device)
+{
+	if (vfio_device_is_noiommu(device))
+		device_del(&device->device);
+	else
+		cdev_device_del(&device->cdev, &device->device);
+}
+
+int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep);
+long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
+				struct vfio_device_bind_iommufd __user *arg);
+void vfio_df_unbind_iommufd(struct vfio_device_file *df);
+int vfio_cdev_init(struct class *device_class);
+void vfio_cdev_cleanup(void);
+#else
+static inline void vfio_init_device_cdev(struct vfio_device *device)
+{
+}
+
+static inline int vfio_device_add(struct vfio_device *device)
+{
+	return device_add(&device->device);
+}
+
+static inline void vfio_device_del(struct vfio_device *device)
+{
+	device_del(&device->device);
+}
+
+static inline int vfio_device_fops_cdev_open(struct inode *inode,
+					     struct file *filep)
+{
+	return 0;
+}
+
+static inline long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
+					      struct vfio_device_bind_iommufd __user *arg)
+{
+	return -ENOTTY;
+}
+
+static inline void vfio_df_unbind_iommufd(struct vfio_device_file *df)
+{
+}
+
+static inline int vfio_cdev_init(struct class *device_class)
+{
+	return 0;
+}
+
+static inline void vfio_cdev_cleanup(void)
+{
+}
+#endif /* CONFIG_VFIO_DEVICE_CDEV */
 
 #if IS_ENABLED(CONFIG_VFIO_VIRQFD)
 int __init vfio_virqfd_init(void);
···
 }
 #endif
 
-#ifdef CONFIG_VFIO_NOIOMMU
-extern bool vfio_noiommu __read_mostly;
-#else
-enum { vfio_noiommu = false };
-#endif
-
 #ifdef CONFIG_HAVE_KVM
-void _vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
+void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
 void vfio_device_put_kvm(struct vfio_device *device);
 #else
-static inline void _vfio_device_get_kvm_safe(struct vfio_device *device,
-					     struct kvm *kvm)
+static inline void vfio_device_get_kvm_safe(struct vfio_device *device,
+					    struct kvm *kvm)
 {
 }
 

drivers/vfio/vfio_iommu_type1.c

···
 static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
 					   struct vfio_info_cap *caps)
 {
-	struct vfio_iommu_type1_info_cap_migration cap_mig;
+	struct vfio_iommu_type1_info_cap_migration cap_mig = {};
 
 	cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION;
 	cap_mig.header.version = 1;
···
 static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
 				     unsigned long arg)
 {
-	struct vfio_iommu_type1_info info;
+	struct vfio_iommu_type1_info info = {};
 	unsigned long minsz;
 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
-	unsigned long capsz;
 	int ret;
 
 	minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
-
-	/* For backward compatibility, cannot require this */
-	capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
 
 	if (copy_from_user(&info, (void __user *)arg, minsz))
 		return -EFAULT;
···
 	if (info.argsz < minsz)
 		return -EINVAL;
 
-	if (info.argsz >= capsz) {
-		minsz = capsz;
-		info.cap_offset = 0; /* output, no-recopy necessary */
-	}
+	minsz = min_t(size_t, info.argsz, sizeof(info));
 
 	mutex_lock(&iommu->lock);
 	info.flags = VFIO_IOMMU_INFO_PGSIZES;

drivers/vfio/vfio_main.c

···
 }
 EXPORT_SYMBOL_GPL(vfio_device_set_open_count);
 
+struct vfio_device *
+vfio_find_device_in_devset(struct vfio_device_set *dev_set,
+			   struct device *dev)
+{
+	struct vfio_device *cur;
+
+	lockdep_assert_held(&dev_set->lock);
+
+	list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
+		if (cur->dev == dev)
+			return cur;
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_find_device_in_devset);
+
 /*
  * Device objects - create, release, get, put, search
  */
···
 	if (WARN_ON(IS_ENABLED(CONFIG_IOMMUFD) &&
 		    (!device->ops->bind_iommufd ||
 		     !device->ops->unbind_iommufd ||
-		     !device->ops->attach_ioas)))
+		     !device->ops->attach_ioas ||
+		     !device->ops->detach_ioas)))
 		return -EINVAL;
 
 	/*
···
 	if (ret)
 		return ret;
 
-	ret = device_add(&device->device);
+	/*
+	 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
+	 * restore cache coherency. It has to be checked here because it is only
+	 * valid for cases where we are using iommu groups.
+	 */
+	if (type == VFIO_IOMMU && !vfio_device_is_noiommu(device) &&
+	    !device_iommu_capable(device->dev, IOMMU_CAP_CACHE_COHERENCY)) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	ret = vfio_device_add(device);
 	if (ret)
 		goto err_out;
 
···
 	bool interrupted = false;
 	long rc;
 
+	/*
+	 * Prevent new device opened by userspace via the
+	 * VFIO_GROUP_GET_DEVICE_FD in the group path.
+	 */
+	vfio_device_group_unregister(device);
+
+	/*
+	 * Balances vfio_device_add() in register path, also prevents
+	 * new device opened by userspace in the cdev path.
+	 */
+	vfio_device_del(device);
+
 	vfio_device_put_registration(device);
 	rc = try_wait_for_completion(&device->comp);
 	while (rc <= 0) {
···
 		}
 	}
 
-	vfio_device_group_unregister(device);
-
-	/* Balances device_add in register path */
-	device_del(&device->device);
-
 	/* Balances vfio_device_set_group in register path */
 	vfio_device_remove_group(device);
 }
 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
 
 #ifdef CONFIG_HAVE_KVM
-void _vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
+void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
 {
 	void (*pfn)(struct kvm *kvm);
 	bool (*fn)(struct kvm *kvm);
 	bool ret;
 
 	lockdep_assert_held(&device->dev_set->lock);
+
+	if (!kvm)
+		return;
 
 	pfn = symbol_get(kvm_put_kvm);
 	if (WARN_ON(!pfn))
···
 	return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
 }
 
-static int vfio_device_first_open(struct vfio_device *device,
-				  struct iommufd_ctx *iommufd)
+struct vfio_device_file *
+vfio_allocate_device_file(struct vfio_device *device)
 {
+	struct vfio_device_file *df;
+
+	df = kzalloc(sizeof(*df), GFP_KERNEL_ACCOUNT);
+	if (!df)
+		return ERR_PTR(-ENOMEM);
+
+	df->device = device;
+	spin_lock_init(&df->kvm_ref_lock);
+
+	return df;
+}
+
+static int vfio_df_device_first_open(struct vfio_device_file *df)
+{
+	struct vfio_device *device = df->device;
+	struct iommufd_ctx *iommufd = df->iommufd;
 	int ret;
 
 	lockdep_assert_held(&device->dev_set->lock);
···
 		return -ENODEV;
 
 	if (iommufd)
-		ret = vfio_iommufd_bind(device, iommufd);
+		ret = vfio_df_iommufd_bind(df);
 	else
 		ret = vfio_device_group_use_iommu(device);
 	if (ret)
···
 
 err_unuse_iommu:
 	if (iommufd)
-		vfio_iommufd_unbind(device);
+		vfio_df_iommufd_unbind(df);
 	else
 		vfio_device_group_unuse_iommu(device);
 err_module_put:
···
 	return ret;
 }
 
-static void vfio_device_last_close(struct vfio_device *device,
-				   struct iommufd_ctx *iommufd)
+static void vfio_df_device_last_close(struct vfio_device_file *df)
 {
+	struct vfio_device *device = df->device;
+	struct iommufd_ctx *iommufd = df->iommufd;
+
 	lockdep_assert_held(&device->dev_set->lock);
 
 	if (device->ops->close_device)
 		device->ops->close_device(device);
 	if (iommufd)
-		vfio_iommufd_unbind(device);
+		vfio_df_iommufd_unbind(df);
 	else
 		vfio_device_group_unuse_iommu(device);
 	module_put(device->dev->driver->owner);
 }
 
-int vfio_device_open(struct vfio_device *device, struct iommufd_ctx *iommufd)
+int vfio_df_open(struct vfio_device_file *df)
 {
+	struct vfio_device *device = df->device;
 	int ret = 0;
 
 	lockdep_assert_held(&device->dev_set->lock);
 
+	/*
+	 * Only the group path allows the device to be opened multiple
+	 * times.  The device cdev path doesn't have a secure way for it.
+	 */
+	if (device->open_count != 0 && !df->group)
+		return -EINVAL;
+
 	device->open_count++;
 	if (device->open_count == 1) {
-		ret = vfio_device_first_open(device, iommufd);
+		ret = vfio_df_device_first_open(df);
 		if (ret)
 			device->open_count--;
 	}
···
 	return ret;
 }
 
-void vfio_device_close(struct vfio_device *device,
-		       struct iommufd_ctx *iommufd)
+void vfio_df_close(struct vfio_device_file *df)
 {
+	struct vfio_device *device = df->device;
+
 	lockdep_assert_held(&device->dev_set->lock);
 
 	vfio_assert_device_open(device);
 	if (device->open_count == 1)
-		vfio_device_last_close(device, iommufd);
+		vfio_df_device_last_close(df);
 	device->open_count--;
 }
 
···
  */
 static int vfio_device_fops_release(struct inode *inode, struct file *filep)
 {
-	struct vfio_device *device = filep->private_data;
+	struct vfio_device_file *df = filep->private_data;
+	struct vfio_device *device = df->device;
 
-	vfio_device_group_close(device);
+	if (df->group)
+		vfio_df_group_close(df);
+	else
+		vfio_df_unbind_iommufd(df);
 
 	vfio_device_put_registration(device);
+
+	kfree(df);
 
 	return 0;
 }
···
 	return 0;
 }
 
+void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
+			      u32 req_nodes)
+{
+	struct interval_tree_node *prev, *curr, *comb_start, *comb_end;
+	unsigned long min_gap, curr_gap;
+
+	/* Special shortcut when a single range is required */
+	if (req_nodes == 1) {
+		unsigned long last;
+
+		comb_start = interval_tree_iter_first(root, 0, ULONG_MAX);
+		curr = comb_start;
+		while (curr) {
+			last = curr->last;
+			prev = curr;
+			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
+			if (prev != comb_start)
+				interval_tree_remove(prev, root);
+		}
+		comb_start->last = last;
+		return;
+	}
+
+	/* Combine ranges which have the smallest gap */
+	while (cur_nodes > req_nodes) {
+		prev = NULL;
+		min_gap = ULONG_MAX;
+		curr = interval_tree_iter_first(root, 0, ULONG_MAX);
+		while (curr) {
+			if (prev) {
+				curr_gap = curr->start - prev->last;
+				if (curr_gap < min_gap) {
+					min_gap = curr_gap;
+					comb_start = prev;
+					comb_end = curr;
+				}
+			}
+			prev = curr;
+			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
+		}
+		comb_start->last = comb_end->last;
+		interval_tree_remove(comb_end, root);
+		cur_nodes--;
+	}
+}
+EXPORT_SYMBOL_GPL(vfio_combine_iova_ranges);
+
 /* Ranges should fit into a single kernel page */
 #define LOG_MAX_RANGES \
 	(PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range))
···
 static long vfio_device_fops_unl_ioctl(struct file *filep,
 				       unsigned int cmd, unsigned long arg)
 {
-	struct vfio_device *device = filep->private_data;
+	struct vfio_device_file *df = filep->private_data;
+	struct vfio_device *device = df->device;
+	void __user *uptr = (void __user *)arg;
 	int ret;
+
+	if (cmd == VFIO_DEVICE_BIND_IOMMUFD)
+		return vfio_df_ioctl_bind_iommufd(df, uptr);
+
+	/* Paired with smp_store_release() following vfio_df_open() */
+	if (!smp_load_acquire(&df->access_granted))
+		return -EINVAL;
 
 	ret = vfio_device_pm_runtime_get(device);
 	if (ret)
 		return ret;
 
+	/* cdev only ioctls */
+	if (IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV) && !df->group) {
+		switch (cmd) {
+		case VFIO_DEVICE_ATTACH_IOMMUFD_PT:
+			ret = vfio_df_ioctl_attach_pt(df, uptr);
+			goto out;
+
+		case VFIO_DEVICE_DETACH_IOMMUFD_PT:
+			ret = vfio_df_ioctl_detach_pt(df, uptr);
+			goto out;
+		}
+	}
+
 	switch (cmd) {
 	case VFIO_DEVICE_FEATURE:
-		ret = vfio_ioctl_device_feature(device, (void __user *)arg);
+		ret = vfio_ioctl_device_feature(device, uptr);
 		break;
 
 	default:
···
 			ret = device->ops->ioctl(device, cmd, arg);
 		break;
 	}
-
+out:
 	vfio_device_pm_runtime_put(device);
 	return ret;
 }
···
 static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
 				     size_t count, loff_t *ppos)
 {
-	struct vfio_device *device = filep->private_data;
+	struct vfio_device_file *df = filep->private_data;
+	struct vfio_device *device = df->device;
+
+	/* Paired with smp_store_release() following vfio_df_open() */
+	if (!smp_load_acquire(&df->access_granted))
+		return -EINVAL;
 
 	if (unlikely(!device->ops->read))
 		return -EINVAL;
···
 				      const char __user *buf,
 				      size_t count, loff_t *ppos)
 {
-	struct vfio_device *device = filep->private_data;
+	struct vfio_device_file *df = filep->private_data;
+	struct vfio_device *device = df->device;
+
+	/* Paired with smp_store_release() following vfio_df_open() */
+	if (!smp_load_acquire(&df->access_granted))
+		return -EINVAL;
 
 	if (unlikely(!device->ops->write))
 		return -EINVAL;
···
 
 static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
 {
-	struct vfio_device *device = filep->private_data;
+	struct vfio_device_file *df = filep->private_data;
+	struct vfio_device *device = df->device;
+
+	/* Paired with smp_store_release() following vfio_df_open() */
+	if (!smp_load_acquire(&df->access_granted))
+		return -EINVAL;
 
 	if (unlikely(!device->ops->mmap))
 		return -EINVAL;
···
 
 const struct file_operations vfio_device_fops = {
 	.owner		= THIS_MODULE,
+	.open		= vfio_device_fops_cdev_open,
 	.release	= vfio_device_fops_release,
 	.read		= vfio_device_fops_read,
 	.write		= vfio_device_fops_write,
···
 	.compat_ioctl	= compat_ptr_ioctl,
 	.mmap		= vfio_device_fops_mmap,
 };
+
+static struct vfio_device *vfio_device_from_file(struct file *file)
+{
+	struct vfio_device_file *df = file->private_data;
+
+	if (file->f_op != &vfio_device_fops)
+		return NULL;
+	return df->device;
+}
+
+/**
+ * vfio_file_is_valid - True if the file is valid vfio file
+ * @file: VFIO group file or VFIO device file
+ */
+bool vfio_file_is_valid(struct file *file)
+{
+	return vfio_group_from_file(file) ||
+	       vfio_device_from_file(file);
+}
+EXPORT_SYMBOL_GPL(vfio_file_is_valid);
+
+/**
+ * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
+ *        is always CPU cache coherent
+ * @file: VFIO group file or VFIO device file
+ *
+ * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
+ * bit in DMA transactions. A return of false indicates that the user has
+ * rights to access additional instructions such as wbinvd on x86.
+ */
+bool vfio_file_enforced_coherent(struct file *file)
+{
+	struct vfio_device *device;
+	struct vfio_group *group;
+
+	group = vfio_group_from_file(file);
+	if (group)
+		return vfio_group_enforced_coherent(group);
+
+	device = vfio_device_from_file(file);
+	if (device)
+		return device_iommu_capable(device->dev,
+					    IOMMU_CAP_ENFORCE_CACHE_COHERENCY);
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
+
+static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
+{
+	struct vfio_device_file *df = file->private_data;
+
+	/*
+	 * The kvm is first recorded in the vfio_device_file, and will
+	 * be propagated to vfio_device::kvm when the file is bound to
+	 * iommufd successfully in the vfio device cdev path.
+	 */
+	spin_lock(&df->kvm_ref_lock);
+	df->kvm = kvm;
+	spin_unlock(&df->kvm_ref_lock);
+}
+
+/**
+ * vfio_file_set_kvm - Link a kvm with VFIO drivers
+ * @file: VFIO group file or VFIO device file
+ * @kvm: KVM to link
+ *
+ * When a VFIO device is first opened the KVM will be available in
+ * device->kvm if one was associated with the file.
+ */
+void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+{
+	struct vfio_group *group;
+
+	group = vfio_group_from_file(file);
+	if (group)
+		vfio_group_set_kvm(group, kvm);
+
+	if (vfio_device_from_file(file))
+		vfio_device_file_set_kvm(file, kvm);
+}
+EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
 
 /*
  * Sub-module support
···
 {
 	void *buf;
 	struct vfio_info_cap_header *header, *tmp;
+
+	/* Ensure that the next capability struct will be aligned */
+	size = ALIGN(size, sizeof(u64));
 
 	buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
 	if (!buf) {
···
 {
 	struct vfio_info_cap_header *tmp;
 	void *buf = (void *)caps->buf;
+
+	/* Capability structs should start with proper alignment */
+	WARN_ON(!IS_ALIGNED(offset, sizeof(u64)));
 
 	for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset)
 		tmp->next += offset;
···
 		goto err_dev_class;
 	}
 
+	ret = vfio_cdev_init(vfio.device_class);
+	if (ret)
+		goto err_alloc_dev_chrdev;
+
 	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 	return 0;
 
+err_alloc_dev_chrdev:
+	class_destroy(vfio.device_class);
+	vfio.device_class = NULL;
 err_dev_class:
 	vfio_virqfd_exit();
 err_virqfd:
···
 static void __exit vfio_cleanup(void)
 {
 	ida_destroy(&vfio.device_ida);
+	vfio_cdev_cleanup();
 	class_destroy(vfio.device_class);
 	vfio.device_class = NULL;
 	vfio_virqfd_exit();

include/linux/iommufd.h

···
 struct iommufd_ctx;
 struct iommufd_access;
 struct file;
+struct iommu_group;
 
 struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
 					   struct device *dev, u32 *id);
···
 
 int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id);
 void iommufd_device_detach(struct iommufd_device *idev);
+
+struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev);
+u32 iommufd_device_to_id(struct iommufd_device *idev);
 
 struct iommufd_access_ops {
 	u8 needs_pin_pages : 1;
···
 		      const struct iommufd_access_ops *ops, void *data, u32 *id);
 void iommufd_access_destroy(struct iommufd_access *access);
 int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id);
+void iommufd_access_detach(struct iommufd_access *access);
 
 void iommufd_ctx_get(struct iommufd_ctx *ictx);
 
 #if IS_ENABLED(CONFIG_IOMMUFD)
 struct iommufd_ctx *iommufd_ctx_from_file(struct file *file);
+struct iommufd_ctx *iommufd_ctx_from_fd(int fd);
 void iommufd_ctx_put(struct iommufd_ctx *ictx);
+bool iommufd_ctx_has_group(struct iommufd_ctx *ictx, struct iommu_group *group);
 
 int iommufd_access_pin_pages(struct iommufd_access *access, unsigned long iova,
 			     unsigned long length, struct page **out_pages,

include/linux/pds/pds_adminq.h

···
 	__le64 features;
 };
 
+#define PDS_LM_DEVICE_STATE_LENGTH		65536
+#define PDS_LM_CHECK_DEVICE_STATE_LENGTH(X) \
+			PDS_CORE_SIZE_CHECK(union, PDS_LM_DEVICE_STATE_LENGTH, X)
+
+/*
+ * enum pds_lm_cmd_opcode - Live Migration Device commands
+ */
+enum pds_lm_cmd_opcode {
+	PDS_LM_CMD_HOST_VF_STATUS  = 1,
+
+	/* Device state commands */
+	PDS_LM_CMD_STATE_SIZE	   = 16,
+	PDS_LM_CMD_SUSPEND         = 18,
+	PDS_LM_CMD_SUSPEND_STATUS  = 19,
+	PDS_LM_CMD_RESUME          = 20,
+	PDS_LM_CMD_SAVE            = 21,
+	PDS_LM_CMD_RESTORE         = 22,
+
+	/* Dirty page tracking commands */
+	PDS_LM_CMD_DIRTY_STATUS    = 32,
+	PDS_LM_CMD_DIRTY_ENABLE    = 33,
+	PDS_LM_CMD_DIRTY_DISABLE   = 34,
+	PDS_LM_CMD_DIRTY_READ_SEQ  = 35,
+	PDS_LM_CMD_DIRTY_WRITE_ACK = 36,
+};
+
+/**
+ * struct pds_lm_cmd - generic command
+ * @opcode:	Opcode
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @rsvd2:	Structure padding to 60 Bytes
+ */
+struct pds_lm_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     rsvd2[56];
+};
+
+/**
+ * struct pds_lm_state_size_cmd - STATE_SIZE command
+ * @opcode:	Opcode
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ */
+struct pds_lm_state_size_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+};
+
+/**
+ * struct pds_lm_state_size_comp - STATE_SIZE command completion
+ * @status:		Status of the command (enum pds_core_status_code)
+ * @rsvd:		Word boundary padding
+ * @comp_index:		Index in the desc ring for which this is the completion
+ * @size:		Size of the device state
+ * @rsvd2:		Word boundary padding
+ * @color:		Color bit
+ */
+struct pds_lm_state_size_comp {
+	u8     status;
+	u8     rsvd;
+	__le16 comp_index;
+	union {
+		__le64 size;
+		u8     rsvd2[11];
+	} __packed;
+	u8     color;
+};
+
+enum pds_lm_suspend_resume_type {
+	PDS_LM_SUSPEND_RESUME_TYPE_FULL = 0,
+	PDS_LM_SUSPEND_RESUME_TYPE_P2P = 1,
+};
+
+/**
+ * struct pds_lm_suspend_cmd - SUSPEND command
+ * @opcode:	Opcode PDS_LM_CMD_SUSPEND
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @type:	Type of suspend (enum pds_lm_suspend_resume_type)
+ */
+struct pds_lm_suspend_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     type;
+};
+
+/**
+ * struct pds_lm_suspend_status_cmd - SUSPEND status command
+ * @opcode:	Opcode PDS_AQ_CMD_LM_SUSPEND_STATUS
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @type:	Type of suspend (enum pds_lm_suspend_resume_type)
+ */
+struct pds_lm_suspend_status_cmd {
+	u8 opcode;
+	u8 rsvd;
+	__le16 vf_id;
+	u8 type;
+};
+
+/**
+ * struct pds_lm_resume_cmd - RESUME command
+ * @opcode:	Opcode PDS_LM_CMD_RESUME
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @type:	Type of resume (enum pds_lm_suspend_resume_type)
+ */
+struct pds_lm_resume_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     type;
+};
+
+/**
+ * struct pds_lm_sg_elem - Transmit scatter-gather (SG) descriptor element
+ * @addr:	DMA address of SG element data buffer
+ * @len:	Length of SG element data buffer, in bytes
+ * @rsvd:	Word boundary padding
+ */
+struct pds_lm_sg_elem {
+	__le64 addr;
+	__le32 len;
+	__le16 rsvd[2];
+};
+
+/**
+ * struct pds_lm_save_cmd - SAVE command
+ * @opcode:	Opcode PDS_LM_CMD_SAVE
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @rsvd2:	Word boundary padding
+ * @sgl_addr:	IOVA address of the SGL to dma the device state
+ * @num_sge:	Total number of SG elements
+ */
+struct pds_lm_save_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     rsvd2[4];
+	__le64 sgl_addr;
+	__le32 num_sge;
+} __packed;
+
+/**
+ * struct pds_lm_restore_cmd - RESTORE command
+ * @opcode:	Opcode PDS_LM_CMD_RESTORE
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @rsvd2:	Word boundary padding
+ * @sgl_addr:	IOVA address of the SGL to dma the device state
+ * @num_sge:	Total number of SG elements
+ */
+struct pds_lm_restore_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     rsvd2[4];
+	__le64 sgl_addr;
+	__le32 num_sge;
+} __packed;
+
+/**
+ * union pds_lm_dev_state - device state information
+ * @words:	Device state words
+ */
+union pds_lm_dev_state {
+	__le32 words[PDS_LM_DEVICE_STATE_LENGTH / sizeof(__le32)];
+};
+
+enum pds_lm_host_vf_status {
+	PDS_LM_STA_NONE = 0,
+	PDS_LM_STA_IN_PROGRESS,
+	PDS_LM_STA_MAX,
+};
+
+/**
+ * struct pds_lm_dirty_region_info - Memory region info for STATUS and ENABLE
+ * @dma_base:		Base address of the DMA-contiguous memory region
+ * @page_count:		Number of pages in the memory region
+ * @page_size_log2:	Log2 page size in the memory region
+ * @rsvd:		Word boundary padding
+ */
+struct pds_lm_dirty_region_info {
+	__le64 dma_base;
+	__le32 page_count;
+	u8     page_size_log2;
+	u8     rsvd[3];
+};
+
+/**
+ * struct pds_lm_dirty_status_cmd - DIRTY_STATUS command
+ * @opcode:		Opcode PDS_LM_CMD_DIRTY_STATUS
+ * @rsvd:		Word boundary padding
+ * @vf_id:		VF id
+ * @max_regions:	Capacity of the region info buffer
+ * @rsvd2:		Word boundary padding
+ * @regions_dma:	DMA address of the region info buffer
+ *
+ * The minimum of max_regions (from the command) and num_regions (from the
+ * completion) of struct pds_lm_dirty_region_info will be written to
+ * regions_dma.
+ *
+ * The max_regions may be zero, in which case regions_dma is ignored.  In that
+ * case, the completion will only report the maximum number of regions
+ * supported by the device, and the number of regions currently enabled.
+ */
+struct pds_lm_dirty_status_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     max_regions;
+	u8     rsvd2[3];
+	__le64 regions_dma;
+} __packed;
+
+/**
+ * enum pds_lm_dirty_bmp_type - Type of dirty page bitmap
+ * @PDS_LM_DIRTY_BMP_TYPE_NONE: No bitmap / disabled
+ * @PDS_LM_DIRTY_BMP_TYPE_SEQ_ACK: Seq/Ack bitmap representation
+ */
+enum pds_lm_dirty_bmp_type {
+	PDS_LM_DIRTY_BMP_TYPE_NONE     = 0,
+	PDS_LM_DIRTY_BMP_TYPE_SEQ_ACK  = 1,
+};
+
+/**
+ * struct pds_lm_dirty_status_comp - STATUS command completion
+ * @status:		Status of the command (enum pds_core_status_code)
+ * @rsvd:		Word boundary padding
+ * @comp_index:		Index in the desc ring for which this is the completion
+ * @max_regions:	Maximum number of regions supported by the device
+ * @num_regions:	Number of regions currently enabled
+ * @bmp_type:		Type of dirty bitmap representation
+ * @rsvd2:		Word boundary padding
+ * @bmp_type_mask:	Mask of supported bitmap types, bit index per type
+ * @rsvd3:		Word boundary padding
+ * @color:		Color bit
+ *
+ * This completion descriptor is used for STATUS, ENABLE, and DISABLE.
+ */
+struct pds_lm_dirty_status_comp {
+	u8     status;
+	u8     rsvd;
+	__le16 comp_index;
+	u8     max_regions;
+	u8     num_regions;
+	u8     bmp_type;
+	u8     rsvd2;
+	__le32 bmp_type_mask;
+	u8     rsvd3[3];
+	u8     color;
+};
+
+/**
+ * struct pds_lm_dirty_enable_cmd - DIRTY_ENABLE command
+ * @opcode:		Opcode PDS_LM_CMD_DIRTY_ENABLE
+ * @rsvd:		Word boundary padding
+ * @vf_id:		VF id
+ * @bmp_type:		Type of dirty bitmap representation
+ * @num_regions:	Number of entries in the region info buffer
+ * @rsvd2:		Word boundary padding
+ * @regions_dma:	DMA address of the region info buffer
+ *
+ * The num_regions must be nonzero, and less than or equal to the maximum
+ * number of regions supported by the device.
+ *
+ * The memory regions should not overlap.
+ *
+ * The information should be initialized by the driver.  The device may modify
+ * the information on successful completion, such as by size-aligning the
+ * number of pages in a region.
+ *
+ * The modified number of pages will be greater than or equal to the page count
+ * given in the enable command, and at least as coarsly aligned as the given
+ * value.  For example, the count might be aligned to a multiple of 64, but
+ * if the value is already a multiple of 128 or higher, it will not change.
+ * If the driver requires its own minimum alignment of the number of pages, the
+ * driver should account for that already in the region info of this command.
+ *
+ * This command uses struct pds_lm_dirty_status_comp for its completion.
+ */
+struct pds_lm_dirty_enable_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     bmp_type;
+	u8     num_regions;
+	u8     rsvd2[2];
+	__le64 regions_dma;
+} __packed;
+
+/**
+ * struct pds_lm_dirty_disable_cmd - DIRTY_DISABLE command
+ * @opcode:	Opcode PDS_LM_CMD_DIRTY_DISABLE
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ *
+ * Dirty page tracking will be disabled.  This may be called in any state, as
+ * long as dirty page tracking is supported by the device, to ensure that dirty
+ * page tracking is disabled.
+ *
+ * This command uses struct pds_lm_dirty_status_comp for its completion.  On
+ * success, num_regions will be zero.
+ */
+struct pds_lm_dirty_disable_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+};
+
+/**
+ * struct pds_lm_dirty_seq_ack_cmd - DIRTY_READ_SEQ or _WRITE_ACK command
+ * @opcode:	Opcode PDS_LM_CMD_DIRTY_[READ_SEQ|WRITE_ACK]
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @off_bytes:	Byte offset in the bitmap
+ * @len_bytes:	Number of bytes to transfer
+ * @num_sge:	Number of DMA scatter gather elements
+ * @rsvd2:	Word boundary padding
+ * @sgl_addr:	DMA address of scatter gather list
+ *
+ * Read bytes from the SEQ bitmap, or write bytes into the ACK bitmap.
+ *
+ * This command treats the entire bitmap as a byte buffer.  It does not
+ * distinguish between guest memory regions.  The driver should refer to the
+ * number of pages in each region, according to PDS_LM_CMD_DIRTY_STATUS, to
+ * determine the region boundaries in the bitmap.  Each region will be
+ * represented by exactly the number of bits as the page count for that region,
+ * immediately following the last bit of the previous region.
+ */
+struct pds_lm_dirty_seq_ack_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	__le32 off_bytes;
+	__le32 len_bytes;
+	__le16 num_sge;
+	u8     rsvd2[2];
+	__le64 sgl_addr;
+} __packed;
+
+/**
+ * struct pds_lm_host_vf_status_cmd - HOST_VF_STATUS command
+ * @opcode:	Opcode PDS_LM_CMD_HOST_VF_STATUS
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @status:	Current LM status of host VF driver (enum pds_lm_host_status)
+ */
+struct pds_lm_host_vf_status_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     status;
+};
+
 union pds_core_adminq_cmd {
 	u8     opcode;
 	u8     bytes[64];
···
 	struct pds_vdpa_vq_init_cmd	  vdpa_vq_init;
 	struct pds_vdpa_vq_reset_cmd	  vdpa_vq_reset;
 
+	struct pds_lm_suspend_cmd	  lm_suspend;
+	struct pds_lm_suspend_status_cmd  lm_suspend_status;
+	struct pds_lm_resume_cmd	  lm_resume;
+	struct pds_lm_state_size_cmd	  lm_state_size;
+	struct pds_lm_save_cmd		  lm_save;
+	struct pds_lm_restore_cmd	  lm_restore;
+	struct pds_lm_host_vf_status_cmd  lm_host_vf_status;
+	struct pds_lm_dirty_status_cmd	  lm_dirty_status;
+	struct pds_lm_dirty_enable_cmd	  lm_dirty_enable;
+	struct pds_lm_dirty_disable_cmd	  lm_dirty_disable;
+	struct pds_lm_dirty_seq_ack_cmd	  lm_dirty_seq_ack;
 };
 
 union pds_core_adminq_comp {
···
 
 	struct pds_vdpa_vq_init_comp	  vdpa_vq_init;
 	struct pds_vdpa_vq_reset_comp	  vdpa_vq_reset;
+
+	struct pds_lm_state_size_comp	  lm_state_size;
+	struct pds_lm_dirty_status_comp	  lm_dirty_status;
 };
 
 #ifndef __CHECKER__

include/linux/pds/pds_common.h

···
 
 #define PDS_DEV_TYPE_CORE_STR	"Core"
 #define PDS_DEV_TYPE_VDPA_STR	"vDPA"
-#define PDS_DEV_TYPE_VFIO_STR	"VFio"
+#define PDS_DEV_TYPE_VFIO_STR	"vfio"
 #define PDS_DEV_TYPE_ETH_STR	"Eth"
 #define PDS_DEV_TYPE_RDMA_STR	"RDMA"
 #define PDS_DEV_TYPE_LM_STR	"LM"
 
 #define PDS_VDPA_DEV_NAME	PDS_CORE_DRV_NAME "." PDS_DEV_TYPE_VDPA_STR
+#define PDS_VFIO_LM_DEV_NAME	PDS_CORE_DRV_NAME "." PDS_DEV_TYPE_LM_STR "." PDS_DEV_TYPE_VFIO_STR
+
+struct pdsc;
 
 int pdsc_register_notify(struct notifier_block *nb);
 void pdsc_unregister_notify(struct notifier_block *nb);
 void *pdsc_get_pf_struct(struct pci_dev *vf_pdev);
-int pds_client_register(struct pci_dev *pf_pdev, char *devname);
-int pds_client_unregister(struct pci_dev *pf_pdev, u16 client_id);
+int pds_client_register(struct pdsc *pf, char *devname);
+int pds_client_unregister(struct pdsc *pf, u16 client_id);
 #endif /* _PDS_COMMON_H_ */

include/linux/vfio.h

···
 #include <linux/mm.h>
 #include <linux/workqueue.h>
 #include <linux/poll.h>
+#include <linux/cdev.h>
 #include <uapi/linux/vfio.h>
 #include <linux/iova_bitmap.h>
 
···
 	 */
 	const struct vfio_migration_ops *mig_ops;
 	const struct vfio_log_ops *log_ops;
+#if IS_ENABLED(CONFIG_VFIO_GROUP)
 	struct vfio_group *group;
+	struct list_head group_next;
+	struct list_head iommu_entry;
+#endif
 	struct vfio_device_set *dev_set;
 	struct list_head dev_set_list;
 	unsigned int migration_flags;
···
 	/* Members below here are private, not for driver use */
 	unsigned int index;
 	struct device device;	/* device.kref covers object life circle */
+#if IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV)
+	struct cdev cdev;
+#endif
 	refcount_t refcount;	/* user count on registered device*/
 	unsigned int open_count;
 	struct completion comp;
-	struct list_head group_next;
-	struct list_head iommu_entry;
 	struct iommufd_access *iommufd_access;
 	void (*put_kvm)(struct kvm *kvm);
 #if IS_ENABLED(CONFIG_IOMMUFD)
 	struct iommufd_device *iommufd_device;
-	bool iommufd_attached;
+	u8 iommufd_attached:1;
 #endif
+	u8 cdev_opened:1;
 };
 
 /**
···
  * @bind_iommufd: Called when binding the device to an iommufd
  * @unbind_iommufd: Opposite of bind_iommufd
  * @attach_ioas: Called when attaching device to an IOAS/HWPT managed by the
- *		 bound iommufd. Undo in unbind_iommufd.
+ *		 bound iommufd. Undo in unbind_iommufd if @detach_ioas is not
+ *		 called.
+ * @detach_ioas: Opposite of attach_ioas
  * @open_device: Called when the first file descriptor is opened for this device
  * @close_device: Opposite of open_device
  * @read: Perform read(2) on device file descriptor
···
 				struct iommufd_ctx *ictx, u32 *out_device_id);
 	void	(*unbind_iommufd)(struct vfio_device *vdev);
 	int	(*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
+	void	(*detach_ioas)(struct vfio_device *vdev);
 	int	(*open_device)(struct vfio_device *vdev);
 	void	(*close_device)(struct vfio_device *vdev);
 	ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
···
 };
 
 #if IS_ENABLED(CONFIG_IOMMUFD)
+struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev);
+int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx);
 int vfio_iommufd_physical_bind(struct vfio_device *vdev,
 			       struct iommufd_ctx *ictx, u32 *out_device_id);
 void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
 int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
+void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev);
 int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
 			       struct iommufd_ctx *ictx, u32 *out_device_id);
 void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
 int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
+void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev);
 #else
+static inline struct iommufd_ctx *
+vfio_iommufd_device_ictx(struct vfio_device *vdev)
+{
+	return NULL;
+}
+
+static inline int
+vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx)
+{
+	return VFIO_PCI_DEVID_NOT_OWNED;
+}
+
 #define vfio_iommufd_physical_bind                                      \
 	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
 		  u32 *out_device_id)) NULL)
···
 	((void (*)(struct vfio_device *vdev)) NULL)
 #define vfio_iommufd_physical_attach_ioas \
 	((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
+#define vfio_iommufd_physical_detach_ioas \
+	((void (*)(struct vfio_device *vdev)) NULL)
 #define vfio_iommufd_emulated_bind                                      \
 	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
 		  u32 *out_device_id)) NULL)
···
 	((void (*)(struct vfio_device *vdev)) NULL)
 #define vfio_iommufd_emulated_attach_ioas \
 	((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
+#define vfio_iommufd_emulated_detach_ioas \
+	((void (*)(struct vfio_device *vdev)) NULL)
 #endif
+
+static inline bool vfio_device_cdev_opened(struct vfio_device *device)
+{
+	return device->cdev_opened;
+}
 
 /**
  * struct vfio_migration_ops - VFIO bus device driver migration callbacks
···
 
 int vfio_assign_device_set(struct vfio_device *device, void *set_id);
 unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set);
+struct vfio_device *
+vfio_find_device_in_devset(struct vfio_device_set *dev_set,
+			   struct device *dev);
 
 int vfio_mig_get_next_state(struct vfio_device *device,
 			    enum vfio_device_mig_state cur_fsm,
 			    enum vfio_device_mig_state new_fsm,
 			    enum vfio_device_mig_state *next_fsm);
 
+void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
+			      u32 req_nodes);
+
 /*
  * External user API
  */
+#if IS_ENABLED(CONFIG_VFIO_GROUP)
 struct iommu_group *vfio_file_iommu_group(struct file *file);
 bool vfio_file_is_group(struct file *file);
+bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
+#else
+static inline struct iommu_group *vfio_file_iommu_group(struct file *file)
+{
+	return NULL;
+}
+
+static inline bool vfio_file_is_group(struct file *file)
+{
+	return false;
+}
+
+static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
+{
+	return false;
+}
+#endif
+bool vfio_file_is_valid(struct file *file);
 bool vfio_file_enforced_coherent(struct file *file);
 void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
-bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
 
 #define VFIO_PIN_PAGES_MAX_ENTRIES	(PAGE_SIZE/sizeof(unsigned long))
 

include/uapi/linux/kvm.h

···
 	__u64	addr;		/* userspace address of attr data */
 };
 
-#define  KVM_DEV_VFIO_GROUP			1
-#define   KVM_DEV_VFIO_GROUP_ADD			1
-#define   KVM_DEV_VFIO_GROUP_DEL			2
+#define  KVM_DEV_VFIO_FILE			1
+
+#define   KVM_DEV_VFIO_FILE_ADD			1
+#define   KVM_DEV_VFIO_FILE_DEL			2
+
+/* KVM_DEV_VFIO_GROUP aliases are for compile time uapi compatibility */
+#define  KVM_DEV_VFIO_GROUP	KVM_DEV_VFIO_FILE
+
+#define   KVM_DEV_VFIO_GROUP_ADD	KVM_DEV_VFIO_FILE_ADD
+#define   KVM_DEV_VFIO_GROUP_DEL	KVM_DEV_VFIO_FILE_DEL
 #define   KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE		3
 
 enum kvm_device_type {

include/uapi/linux/vfio.h

···
 	__u32	num_regions;	/* Max region index + 1 */
 	__u32	num_irqs;	/* Max IRQ index + 1 */
 	__u32   cap_offset;	/* Offset within info struct of first cap */
+	__u32   pad;
 };
 #define VFIO_DEVICE_GET_INFO		_IO(VFIO_TYPE, VFIO_BASE + 7)
 
···
  * VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 12,
  *					      struct vfio_pci_hot_reset_info)
  *
+ * This command is used to query the affected devices in the hot reset for
+ * a given device.
+ *
+ * This command always reports the segment, bus, and devfn information for
+ * each affected device, and selectively reports the group_id or devid per
+ * the way how the calling device is opened.
+ *
+ *	- If the calling device is opened via the traditional group/container
+ *	  API, group_id is reported.  User should check if it has owned all
+ *	  the affected devices and provides a set of group fds to prove the
+ *	  ownership in VFIO_DEVICE_PCI_HOT_RESET ioctl.
+ *
+ *	- If the calling device is opened as a cdev, devid is reported.
+ *	  Flag VFIO_PCI_HOT_RESET_FLAG_DEV_ID is set to indicate this
+ *	  data type.  All the affected devices should be represented in
+ *	  the dev_set, ex. bound to a vfio driver, and also be owned by
+ *	  this interface which is determined by the following conditions:
+ *	  1) Has a valid devid within the iommufd_ctx of the calling device.
+ *	     Ownership cannot be determined across separate iommufd_ctx and
+ *	     the cdev calling conventions do not support a proof-of-ownership
+ *	     model as provided in the legacy group interface.  In this case
+ *	     valid devid with value greater than zero is provided in the return
+ *	     structure.
+ *	  2) Does not have a valid devid within the iommufd_ctx of the calling
+ *	     device, but belongs to the same IOMMU group as the calling device
+ *	     or another opened device that has a valid devid within the
+ *	     iommufd_ctx of the calling device.  This provides implicit ownership
+ *	     for devices within the same DMA isolation context.  In this case
+ *	     the devid value of VFIO_PCI_DEVID_OWNED is provided in the return
+ *	     structure.
+ *
+ *	  A devid value of VFIO_PCI_DEVID_NOT_OWNED is provided in the return
+ *	  structure for affected devices where device is NOT represented in the
+ *	  dev_set or ownership is not available.  Such devices prevent the use
+ *	  of VFIO_DEVICE_PCI_HOT_RESET ioctl outside of the proof-of-ownership
+ *	  calling conventions (ie. via legacy group accessed devices).  Flag
+ *	  VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED would be set when all the
+ *	  affected devices are represented in the dev_set and also owned by
+ *	  the user.  This flag is available only when
+ *	  flag VFIO_PCI_HOT_RESET_FLAG_DEV_ID is set, otherwise reserved.
+ *	  When set, user could invoke VFIO_DEVICE_PCI_HOT_RESET with a zero
+ *	  length fd array on the calling device as the ownership is validated
+ *	  by iommufd_ctx.
+ *
  * Return: 0 on success, -errno on failure:
  *	-enospc = insufficient buffer, -enodev = unsupported for device.
  */
 struct vfio_pci_dependent_device {
-	__u32	group_id;
+	union {
+		__u32   group_id;
+		__u32	devid;
+#define VFIO_PCI_DEVID_OWNED		0
+#define VFIO_PCI_DEVID_NOT_OWNED	-1
+	};
 	__u16	segment;
 	__u8	bus;
 	__u8	devfn; /* Use PCI_SLOT/PCI_FUNC */
···
 struct vfio_pci_hot_reset_info {
 	__u32	argsz;
 	__u32	flags;
+#define VFIO_PCI_HOT_RESET_FLAG_DEV_ID		(1 << 0)
+#define VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED	(1 << 1)
 	__u32	count;
 	struct vfio_pci_dependent_device	devices[];
 };
···
 /**
  * VFIO_DEVICE_PCI_HOT_RESET - _IOW(VFIO_TYPE, VFIO_BASE + 13,
  *				    struct vfio_pci_hot_reset)
+ *
+ * A PCI hot reset results in either a bus or slot reset which may affect
+ * other devices sharing the bus/slot.  The calling user must have
+ * ownership of the full set of affected devices as determined by the
+ * VFIO_DEVICE_GET_PCI_HOT_RESET_INFO ioctl.
+ *
+ * When called on a device file descriptor acquired through the vfio
+ * group interface, the user is required to provide proof of ownership
+ * of those affected devices via the group_fds array in struct
+ * vfio_pci_hot_reset.
+ *
+ * When called on a direct cdev opened vfio device, the flags field of
+ * struct vfio_pci_hot_reset_info reports the ownership status of the
+ * affected devices and this ioctl must be called with an empty group_fds
+ * array.  See above INFO ioctl definition for ownership requirements.
+ *
+ * Mixed usage of legacy groups and cdevs across the set of affected
+ * devices is not supported.
  *
  * Return: 0 on success, -errno on failure.
  */
···
 };
 
 #define VFIO_DEVICE_FEATURE		_IO(VFIO_TYPE, VFIO_BASE + 17)
+
+/*
+ * VFIO_DEVICE_BIND_IOMMUFD - _IOR(VFIO_TYPE, VFIO_BASE + 18,
+ *				   struct vfio_device_bind_iommufd)
+ * @argsz:	 User filled size of this data.
+ * @flags:	 Must be 0.
+ * @iommufd:	 iommufd to bind.
+ * @out_devid:	 The device id generated by this bind. devid is a handle for
+ *		 this device/iommufd bond and can be used in IOMMUFD commands.
+ *
+ * Bind a vfio_device to the specified iommufd.
+ *
+ * User is restricted from accessing the device before the binding operation
+ * is completed.  Only allowed on cdev fds.
+ *
+ * Unbind is automatically conducted when device fd is closed.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+struct vfio_device_bind_iommufd {
+	__u32		argsz;
+	__u32		flags;
+	__s32		iommufd;
+	__u32		out_devid;
+};
+
+#define VFIO_DEVICE_BIND_IOMMUFD	_IO(VFIO_TYPE, VFIO_BASE + 18)
+
+/*
+ * VFIO_DEVICE_ATTACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 19,
+ *					struct vfio_device_attach_iommufd_pt)
+ * @argsz:	User filled size of this data.
+ * @flags:	Must be 0.
+ * @pt_id:	Input the target id which can represent an ioas or a hwpt
+ *		allocated via iommufd subsystem.
+ *		Output the input ioas id or the attached hwpt id which could
+ *		be the specified hwpt itself or a hwpt automatically created
+ *		for the specified ioas by kernel during the attachment.
+ *
+ * Associate the device with an address space within the bound iommufd.
+ * Undo by VFIO_DEVICE_DETACH_IOMMUFD_PT or device fd close.  This is only
+ * allowed on cdev fds.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+struct vfio_device_attach_iommufd_pt {
+	__u32	argsz;
+	__u32	flags;
+	__u32	pt_id;
+};
+
+#define VFIO_DEVICE_ATTACH_IOMMUFD_PT		_IO(VFIO_TYPE, VFIO_BASE + 19)
+
+/*
+ * VFIO_DEVICE_DETACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 20,
+ *					struct vfio_device_detach_iommufd_pt)
+ * @argsz:	User filled size of this data.
+ * @flags:	Must be 0.
+ *
+ * Remove the association of the device and its current associated address
+ * space.  After it, the device should be in a blocking DMA state.  This is only
+ * allowed on cdev fds.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+struct vfio_device_detach_iommufd_pt {
+	__u32	argsz;
+	__u32	flags;
+};
+
+#define VFIO_DEVICE_DETACH_IOMMUFD_PT		_IO(VFIO_TYPE, VFIO_BASE + 20)
 
 /*
  * Provide support for setting a PCI VF Token, which is used as a shared
···
 #define VFIO_IOMMU_INFO_CAPS	(1 << 1)	/* Info supports caps */
 	__u64	iova_pgsizes;	/* Bitmap of supported page sizes */
 	__u32   cap_offset;	/* Offset within info struct of first cap */
+	__u32   pad;
 };
 
 /*

samples/vfio-mdev/mbochs.c

···
 	.bind_iommufd	= vfio_iommufd_emulated_bind,
 	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
+	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
 };
 
 static struct mdev_driver mbochs_driver = {

samples/vfio-mdev/mdpy.c

···
 	.bind_iommufd	= vfio_iommufd_emulated_bind,
 	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
+	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
 };
 
 static struct mdev_driver mdpy_driver = {

samples/vfio-mdev/mtty.c

···
 	.bind_iommufd	= vfio_iommufd_emulated_bind,
 	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
+	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
 };
 
 static struct mdev_driver mtty_driver = {

virt/kvm/vfio.c

···
 #include <asm/kvm_ppc.h>
 #endif
 
-struct kvm_vfio_group {
+struct kvm_vfio_file {
 	struct list_head node;
 	struct file *file;
 #ifdef CONFIG_SPAPR_TCE_IOMMU
···
 };
 
 struct kvm_vfio {
-	struct list_head group_list;
+	struct list_head file_list;
 	struct mutex lock;
 	bool noncoherent;
 };
···
 	return ret;
 }
 
-static bool kvm_vfio_file_is_group(struct file *file)
+static bool kvm_vfio_file_is_valid(struct file *file)
 {
 	bool (*fn)(struct file *file);
 	bool ret;
 
-	fn = symbol_get(vfio_file_is_group);
+	fn = symbol_get(vfio_file_is_valid);
 	if (!fn)
 		return false;
 
 	ret = fn(file);
 
-	symbol_put(vfio_file_is_group);
+	symbol_put(vfio_file_is_valid);
 
 	return ret;
 }
···
 }
 
 static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm,
-					     struct kvm_vfio_group *kvg)
+					     struct kvm_vfio_file *kvf)
 {
-	if (WARN_ON_ONCE(!kvg->iommu_group))
+	if (WARN_ON_ONCE(!kvf->iommu_group))
 		return;
 
-	kvm_spapr_tce_release_iommu_group(kvm, kvg->iommu_group);
-	iommu_group_put(kvg->iommu_group);
-	kvg->iommu_group = NULL;
+	kvm_spapr_tce_release_iommu_group(kvm, kvf->iommu_group);
+	iommu_group_put(kvf->iommu_group);
+	kvf->iommu_group = NULL;
 }
 #endif
 
 /*
- * Groups can use the same or different IOMMU domains.  If the same then
- * adding a new group may change the coherency of groups we've previously
- * been told about.  We don't want to care about any of that so we retest
- * each group and bail as soon as we find one that's noncoherent.  This
- * means we only ever [un]register_noncoherent_dma once for the whole device.
+ * Groups/devices can use the same or different IOMMU domains. If the same
+ * then adding a new group/device may change the coherency of groups/devices
+ * we've previously been told about. We don't want to care about any of
+ * that so we retest each group/device and bail as soon as we find one that's
+ * noncoherent.  This means we only ever [un]register_noncoherent_dma once
+ * for the whole device.
  */
 static void kvm_vfio_update_coherency(struct kvm_device *dev)
 {
 	struct kvm_vfio *kv = dev->private;
 	bool noncoherent = false;
-	struct kvm_vfio_group *kvg;
+	struct kvm_vfio_file *kvf;
 
-	mutex_lock(&kv->lock);
-
-	list_for_each_entry(kvg, &kv->group_list, node) {
-		if (!kvm_vfio_file_enforced_coherent(kvg->file)) {
+	list_for_each_entry(kvf, &kv->file_list, node) {
+		if (!kvm_vfio_file_enforced_coherent(kvf->file)) {
 			noncoherent = true;
 			break;
 		}
···
 		else
 			kvm_arch_unregister_noncoherent_dma(dev->kvm);
 	}
-
-	mutex_unlock(&kv->lock);
 }
 
-static int kvm_vfio_group_add(struct kvm_device *dev, unsigned int fd)
+static int kvm_vfio_file_add(struct kvm_device *dev, unsigned int fd)
 {
 	struct kvm_vfio *kv = dev->private;
-	struct kvm_vfio_group *kvg;
+	struct kvm_vfio_file *kvf;
 	struct file *filp;
-	int ret;
+	int ret = 0;
 
 	filp = fget(fd);
 	if (!filp)
 		return -EBADF;
 
-	/* Ensure the FD is a vfio group FD.*/
-	if (!kvm_vfio_file_is_group(filp)) {
+	/* Ensure the FD is a vfio FD. */
+	if (!kvm_vfio_file_is_valid(filp)) {
 		ret = -EINVAL;
-		goto err_fput;
+		goto out_fput;
 	}
 
 	mutex_lock(&kv->lock);
 
-	list_for_each_entry(kvg, &kv->group_list, node) {
-		if (kvg->file == filp) {
+	list_for_each_entry(kvf, &kv->file_list, node) {
+		if (kvf->file == filp) {
 			ret = -EEXIST;
-			goto err_unlock;
+			goto out_unlock;
 		}
 	}
 
-	kvg = kzalloc(sizeof(*kvg), GFP_KERNEL_ACCOUNT);
-	if (!kvg) {
+	kvf = kzalloc(sizeof(*kvf), GFP_KERNEL_ACCOUNT);
+	if (!kvf) {
 		ret = -ENOMEM;
-		goto err_unlock;
+		goto out_unlock;
 	}
 
-	kvg->file = filp;
-	list_add_tail(&kvg->node, &kv->group_list);
+	kvf->file = get_file(filp);
+	list_add_tail(&kvf->node, &kv->file_list);
 
 	kvm_arch_start_assignment(dev->kvm);
-
-	mutex_unlock(&kv->lock);
-
-	kvm_vfio_file_set_kvm(kvg->file, dev->kvm);
+	kvm_vfio_file_set_kvm(kvf->file, dev->kvm);
 	kvm_vfio_update_coherency(dev);
 
-	return 0;
-err_unlock:
+out_unlock:
 	mutex_unlock(&kv->lock);
-err_fput:
+out_fput:
 	fput(filp);
 	return ret;
 }
 
-static int kvm_vfio_group_del(struct kvm_device *dev, unsigned int fd)
+static int kvm_vfio_file_del(struct kvm_device *dev, unsigned int fd)
 {
 	struct kvm_vfio *kv = dev->private;
-	struct kvm_vfio_group *kvg;
+	struct kvm_vfio_file *kvf;
 	struct fd f;
 	int ret;
 
···
 
 	mutex_lock(&kv->lock);
 
-	list_for_each_entry(kvg, &kv->group_list, node) {
-		if (kvg->file != f.file)
+	list_for_each_entry(kvf, &kv->file_list, node) {
+		if (kvf->file != f.file)
 			continue;
 
-		list_del(&kvg->node);
+		list_del(&kvf->node);
 		kvm_arch_end_assignment(dev->kvm);
 #ifdef CONFIG_SPAPR_TCE_IOMMU
-		kvm_spapr_tce_release_vfio_group(dev->kvm, kvg);
+		kvm_spapr_tce_release_vfio_group(dev->kvm, kvf);
 #endif
-		kvm_vfio_file_set_kvm(kvg->file, NULL);
-		fput(kvg->file);
-		kfree(kvg);
+		kvm_vfio_file_set_kvm(kvf->file, NULL);
+		fput(kvf->file);
+		kfree(kvf);
 		ret = 0;
 		break;
 	}
+
+	kvm_vfio_update_coherency(dev);
 
 	mutex_unlock(&kv->lock);
 
 	fdput(f);
 
-	kvm_vfio_update_coherency(dev);
-
 	return ret;
 }
 
 #ifdef CONFIG_SPAPR_TCE_IOMMU
-static int kvm_vfio_group_set_spapr_tce(struct kvm_device *dev,
-					void __user *arg)
+static int kvm_vfio_file_set_spapr_tce(struct kvm_device *dev,
+				       void __user *arg)
 {
 	struct kvm_vfio_spapr_tce param;
 	struct kvm_vfio *kv = dev->private;
-	struct kvm_vfio_group *kvg;
+	struct kvm_vfio_file *kvf;
 	struct fd f;
 	int ret;
 
···
 
 	mutex_lock(&kv->lock);
 
-	list_for_each_entry(kvg, &kv->group_list, node) {
-		if (kvg->file != f.file)
+	list_for_each_entry(kvf, &kv->file_list, node) {
+		if (kvf->file != f.file)
 			continue;
 
-		if (!kvg->iommu_group) {
-			kvg->iommu_group = kvm_vfio_file_iommu_group(kvg->file);
-			if (WARN_ON_ONCE(!kvg->iommu_group)) {
+		if (!kvf->iommu_group) {
+			kvf->iommu_group = kvm_vfio_file_iommu_group(kvf->file);
+			if (WARN_ON_ONCE(!kvf->iommu_group)) {
 				ret = -EIO;
 				goto err_fdput;
 			}
 		}
 
 		ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
-						       kvg->iommu_group);
+						       kvf->iommu_group);
 		break;
 	}
 
···
 }
 #endif
 
-static int kvm_vfio_set_group(struct kvm_device *dev, long attr,
-			      void __user *arg)
+static int kvm_vfio_set_file(struct kvm_device *dev, long attr,
+			     void __user *arg)
 {
 	int32_t __user *argp = arg;
 	int32_t fd;
 
 	switch (attr) {
-	case KVM_DEV_VFIO_GROUP_ADD:
+	case KVM_DEV_VFIO_FILE_ADD:
 		if (get_user(fd, argp))
 			return -EFAULT;
-		return kvm_vfio_group_add(dev, fd);
+		return kvm_vfio_file_add(dev, fd);
 
-	case KVM_DEV_VFIO_GROUP_DEL:
+	case KVM_DEV_VFIO_FILE_DEL:
 		if (get_user(fd, argp))
 			return -EFAULT;
-		return kvm_vfio_group_del(dev, fd);
+		return kvm_vfio_file_del(dev, fd);
 
 #ifdef CONFIG_SPAPR_TCE_IOMMU
 	case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE:
-		return kvm_vfio_group_set_spapr_tce(dev, arg);
+		return kvm_vfio_file_set_spapr_tce(dev, arg);
 #endif
 	}
 
···
 			     struct kvm_device_attr *attr)
 {
 	switch (attr->group) {
-	case KVM_DEV_VFIO_GROUP:
-		return kvm_vfio_set_group(dev, attr->attr,
-					  u64_to_user_ptr(attr->addr));
+	case KVM_DEV_VFIO_FILE:
+		return kvm_vfio_set_file(dev, attr->attr,
+					 u64_to_user_ptr(attr->addr));
 	}
 
 	return -ENXIO;
···
 			     struct kvm_device_attr *attr)
 {
 	switch (attr->group) {
-	case KVM_DEV_VFIO_GROUP:
+	case KVM_DEV_VFIO_FILE:
 		switch (attr->attr) {
-		case KVM_DEV_VFIO_GROUP_ADD:
-		case KVM_DEV_VFIO_GROUP_DEL:
+		case KVM_DEV_VFIO_FILE_ADD:
+		case KVM_DEV_VFIO_FILE_DEL:
 #ifdef CONFIG_SPAPR_TCE_IOMMU
 		case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE:
 #endif
···
 static void kvm_vfio_release(struct kvm_device *dev)
 {
 	struct kvm_vfio *kv = dev->private;
-	struct kvm_vfio_group *kvg, *tmp;
+	struct kvm_vfio_file *kvf, *tmp;
 
-	list_for_each_entry_safe(kvg, tmp, &kv->group_list, node) {
+	list_for_each_entry_safe(kvf, tmp, &kv->file_list, node) {
 #ifdef CONFIG_SPAPR_TCE_IOMMU
-		kvm_spapr_tce_release_vfio_group(dev->kvm, kvg);
+		kvm_spapr_tce_release_vfio_group(dev->kvm, kvf);
 #endif
-		kvm_vfio_file_set_kvm(kvg->file, NULL);
-		fput(kvg->file);
-		list_del(&kvg->node);
-		kfree(kvg);
+		kvm_vfio_file_set_kvm(kvf->file, NULL);
+		fput(kvf->file);
+		list_del(&kvf->node);
+		kfree(kvf);
 		kvm_arch_end_assignment(dev->kvm);
 	}
 
···
 	if (!kv)
 		return -ENOMEM;
 
-	INIT_LIST_HEAD(&kv->group_list);
+	INIT_LIST_HEAD(&kv->file_list);
 	mutex_init(&kv->lock);
 
 	dev->private = kv;