Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

- Rework copy_oldmem_page() callback to take an iov_iter.

This includes a few prerequisite updates and fixes to the oldmem
reading code.

- Rework cpufeature implementation to allow for various CPU feature
indications, which is not only limited to hardware capabilities, but
also allows CPU facilities.

- Use the cpufeature rework to autoload Ultravisor module when CPU
facility 158 is available.

- Add ELF note type for encrypted CPU state of a protected virtual CPU.
The zgetdump tool from s390-tools package will decrypt the CPU state
using a Customer Communication Key and overwrite respective notes to
make the data accessible for crash and other debugging tools.

- Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto
test.

- Fix incorrect recovery of kretprobe modified return address in
stacktrace.

- Switch the NMI handler to use generic irqentry_nmi_enter() and
irqentry_nmi_exit() helper functions.

- Rework the cryptographic Adjunct Processors (AP) pass-through design
to support dynamic changes to the AP matrix of a running guest as
well as to implement more of the AP architecture.

- Minor boot code cleanups.

- Grammar and typo fixes to hmcdrv and tape drivers.

* tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
Revert "s390/smp: enforce lowcore protection on CPU restart"
Revert "s390/smp: rework absolute lowcore access"
Revert "s390/smp,ptdump: add absolute lowcore markers"
s390/unwind: fix fgraph return address recovery
s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit()
s390: add ELF note type for encrypted CPU state of a PV VCPU
s390/smp,ptdump: add absolute lowcore markers
s390/smp: rework absolute lowcore access
s390/setup: rearrange absolute lowcore initialization
s390/boot: cleanup adjust_to_uv_max() function
s390/smp: enforce lowcore protection on CPU restart
s390/tape: fix comment typo
s390/hmcdrv: fix Kconfig "its" grammar
s390/docs: fix warnings for vfio_ap driver doc
s390/docs: fix warnings for vfio_ap driver lock usage doc
s390/crash: support multi-segment iterators
s390/crash: use static swap buffer for copy_to_user_real()
s390/crash: move copy_to_user_real() to crash_dump.c
s390/zcore: fix race when reading from hardware system area
s390/crash: fix incorrect number of bytes to copy to user space
...

Documentation/s390/index.rst

···
     qeth
     s390dbf
     vfio-ap
+    vfio-ap-locking
     vfio-ccw
     zfcpdump
     common_io

Documentation/s390/vfio-ap-locking.rst

···
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+VFIO AP Locks Overview
+======================
+This document describes the locks that are pertinent to the secure operation
+of the vfio_ap device driver. Throughout this document, the following variables
+will be used to denote instances of the structures herein described:
+
+.. code-block:: c
+
+  struct ap_matrix_dev *matrix_dev;
+  struct ap_matrix_mdev *matrix_mdev;
+  struct kvm *kvm;
+
+The Matrix Devices Lock (drivers/s390/crypto/vfio_ap_private.h)
+---------------------------------------------------------------
+
+.. code-block:: c
+
+  struct ap_matrix_dev {
+  	...
+  	struct list_head mdev_list;
+  	struct mutex mdevs_lock;
+  	...
+  }
+
+The Matrix Devices Lock (matrix_dev->mdevs_lock) is implemented as a global
+mutex contained within the single object of struct ap_matrix_dev. This lock
+controls access to all fields contained within each matrix_mdev
+(matrix_dev->mdev_list). This lock must be held while reading from, writing to
+or using the data from a field contained within a matrix_mdev instance
+representing one of the vfio_ap device driver's mediated devices.
+
+The KVM Lock (include/linux/kvm_host.h)
+---------------------------------------
+
+.. code-block:: c
+
+  struct kvm {
+  	...
+  	struct mutex lock;
+  	...
+  }
+
+The KVM Lock (kvm->lock) controls access to the state data for a KVM guest. This
+lock must be held by the vfio_ap device driver while one or more AP adapters,
+domains or control domains are being plugged into or unplugged from the guest.
+
+The KVM pointer is stored in the in the matrix_mdev instance
+(matrix_mdev->kvm = kvm) containing the state of the mediated device that has
+been attached to the KVM guest.
+
+The Guests Lock (drivers/s390/crypto/vfio_ap_private.h)
+-----------------------------------------------------------
+
+.. code-block:: c
+
+  struct ap_matrix_dev {
+  	...
+  	struct list_head mdev_list;
+  	struct mutex guests_lock;
+  	...
+  }
+
+The Guests Lock (matrix_dev->guests_lock) controls access to the
+matrix_mdev instances (matrix_dev->mdev_list) that represent mediated devices
+that hold the state for the mediated devices that have been attached to a
+KVM guest. This lock must be held:
+
+1. To control access to the KVM pointer (matrix_mdev->kvm) while the vfio_ap
+   device driver is using it to plug/unplug AP devices passed through to the KVM
+   guest.
+
+2. To add matrix_mdev instances to or remove them from matrix_dev->mdev_list.
+   This is necessary to ensure the proper locking order when the list is perused
+   to find an ap_matrix_mdev instance for the purpose of plugging/unplugging
+   AP devices passed through to a KVM guest.
+
+   For example, when a queue device is removed from the vfio_ap device driver,
+   if the adapter is passed through to a KVM guest, it will have to be
+   unplugged. In order to figure out whether the adapter is passed through,
+   the matrix_mdev object to which the queue is assigned will have to be
+   found. The KVM pointer (matrix_mdev->kvm) can then be used to determine if
+   the mediated device is passed through (matrix_mdev->kvm != NULL) and if so,
+   to unplug the adapter.
+
+It is not necessary to take the Guests Lock to access the KVM pointer if the
+pointer is not used to plug/unplug devices passed through to the KVM guest;
+however, in this case, the Matrix Devices Lock (matrix_dev->mdevs_lock) must be
+held in order to access the KVM pointer since it is set and cleared under the
+protection of the Matrix Devices Lock. A case in point is the function that
+handles interception of the PQAP(AQIC) instruction sub-function. This handler
+needs to access the KVM pointer only for the purposes of setting or clearing IRQ
+resources, so only the matrix_dev->mdevs_lock needs to be held.
+
+The PQAP Hook Lock (arch/s390/include/asm/kvm_host.h)
+-----------------------------------------------------
+
+.. code-block:: c
+
+  typedef int (*crypto_hook)(struct kvm_vcpu *vcpu);
+
+  struct kvm_s390_crypto {
+  	...
+  	struct rw_semaphore pqap_hook_rwsem;
+  	crypto_hook *pqap_hook;
+  	...
+  };
+
+The PQAP Hook Lock is a r/w semaphore that controls access to the function
+pointer of the handler ``(*kvm->arch.crypto.pqap_hook)`` to invoke when the
+PQAP(AQIC) instruction sub-function is intercepted by the host. The lock must be
+held in write mode when pqap_hook value is set, and in read mode when the
+pqap_hook function is called.

Documentation/s390/vfio-ap.rst

···
 by the hardware.
 
 A satellite control block called the Crypto Control Block (CRYCB) is attached to
-our main hardware virtualization control block. The CRYCB contains three fields
-to identify the adapters, usage domains and control domains assigned to the KVM
-guest:
+our main hardware virtualization control block. The CRYCB contains an AP Control
+Block (APCB) that has three fields to identify the adapters, usage domains and
+control domains assigned to the KVM guest:
 
 * The AP Mask (APM) field is a bit mask that identifies the AP adapters assigned
-  to the KVM guest. Each bit in the mask, from left to right (i.e. from most
-  significant to least significant bit in big endian order), corresponds to
+  to the KVM guest. Each bit in the mask, from left to right, corresponds to
   an APID from 0-255. If a bit is set, the corresponding adapter is valid for
   use by the KVM guest.
 
 * The AP Queue Mask (AQM) field is a bit mask identifying the AP usage domains
-  assigned to the KVM guest. Each bit in the mask, from left to right (i.e. from
-  most significant to least significant bit in big endian order), corresponds to
-  an AP queue index (APQI) from 0-255. If a bit is set, the corresponding queue
-  is valid for use by the KVM guest.
+  assigned to the KVM guest. Each bit in the mask, from left to right,
+  corresponds to an AP queue index (APQI) from 0-255. If a bit is set, the
+  corresponding queue is valid for use by the KVM guest.
 
 * The AP Domain Mask field is a bit mask that identifies the AP control domains
   assigned to the KVM guest. The ADM bit mask controls which domains can be
   changed by an AP command-request message sent to a usage domain from the
-  guest. Each bit in the mask, from left to right (i.e. from most significant to
-  least significant bit in big endian order), corresponds to a domain from
+  guest. Each bit in the mask, from left to right, corresponds to a domain from
   0-255. If a bit is set, the corresponding domain can be modified by an AP
   command-request message sent to a usage domain.
 
···
 an APQN to identify the AP queue to which an AP command-request message is to be
 sent (NQAP and PQAP instructions), or from which a command-reply message is to
 be received (DQAP instruction). The validity of an APQN is defined by the matrix
-calculated from the APM and AQM; it is the cross product of all assigned adapter
-numbers (APM) with all assigned queue indexes (AQM). For example, if adapters 1
-and 2 and usage domains 5 and 6 are assigned to a guest, the APQNs (1,5), (1,6),
-(2,5) and (2,6) will be valid for the guest.
+calculated from the APM and AQM; it is the Cartesian product of all assigned
+adapter numbers (APM) with all assigned queue indexes (AQM). For example, if
+adapters 1 and 2 and usage domains 5 and 6 are assigned to a guest, the APQNs
+(1,5), (1,6), (2,5) and (2,6) will be valid for the guest.
 
 The APQNs can provide secure key functionality - i.e., a private key is stored
 on the adapter card for each of its domains - so each APQN must be assigned to
···
 
 1. AP matrix device
 2. VFIO AP device driver (vfio_ap.ko)
-3. VFIO AP mediated matrix pass-through device
+3. VFIO AP mediated pass-through device
 
 The VFIO AP device driver
 -------------------------
···
 
 1. Provides the interfaces to secure APQNs for exclusive use of KVM guests.
 
-2. Sets up the VFIO mediated device interfaces to manage a mediated matrix
+2. Sets up the VFIO mediated device interfaces to manage a vfio_ap mediated
    device and creates the sysfs interfaces for assigning adapters, usage
    domains, and control domains comprising the matrix for a KVM guest.
 
-3. Configures the APM, AQM and ADM in the CRYCB referenced by a KVM guest's
-   SIE state description to grant the guest access to a matrix of AP devices
+3. Configures the APM, AQM and ADM in the APCB contained in the CRYCB referenced
+   by a KVM guest's SIE state description to grant the guest access to a matrix
+   of AP devices
 
 Reserve APQNs for exclusive use of KVM guests
 ---------------------------------------------
···
   |                  |       8 probe        |                  |
   +--------^---------+                      +--^--^------------+
   6 edit   |                                   |  |
-    apmask |     +-----------------------------+  | 9 mdev create
+    apmask |     +-----------------------------+  | 11 mdev create
     aqmask |     |           1 modprobe           |
   +--------+-----+---+           +----------------+-+         +----------------+
-  |                  |           |                  |8 create |     mediated   |
+  |                  |           |                  |10 create|     mediated   |
   |      admin       |           | VFIO device core |--------->     matrix     |
   |                  +           |                  |         |     device     |
   +------+-+---------+           +--------^---------+         +--------^-------+
···
 	 | | 9 create vfio_ap-passthrough |                            |
 	 | +------------------------------+                            |
 	 +-------------------------------------------------------------+
-		     10  assign adapter/domain/control domain
+		     12  assign adapter/domain/control domain
 
 The process for reserving an AP queue for use by a KVM guest is:
 
 1. The administrator loads the vfio_ap device driver
 2. The vfio-ap driver during its initialization will register a single 'matrix'
    device with the device core. This will serve as the parent device for
-   all mediated matrix devices used to configure an AP matrix for a guest.
+   all vfio_ap mediated devices used to configure an AP matrix for a guest.
 3. The /sys/devices/vfio_ap/matrix device is created by the device core
 4. The vfio_ap device driver will register with the AP bus for AP queue devices
    of type 10 and higher (CEX4 and newer). The driver will provide the vfio_ap
···
    default zcrypt cex4queue driver.
 8. The AP bus probes the vfio_ap device driver to bind the queues reserved for
    it.
-9. The administrator creates a passthrough type mediated matrix device to be
+9. The administrator creates a passthrough type vfio_ap mediated device to be
    used by a guest
 10. The administrator assigns the adapters, usage domains and control domains
     to be exclusively used by a guest.
 
 Set up the VFIO mediated device interfaces
 ------------------------------------------
-The VFIO AP device driver utilizes the common interface of the VFIO mediated
+The VFIO AP device driver utilizes the common interfaces of the VFIO mediated
 device core driver to:
 
-* Register an AP mediated bus driver to add a mediated matrix device to and
+* Register an AP mediated bus driver to add a vfio_ap mediated device to and
   remove it from a VFIO group.
-* Create and destroy a mediated matrix device
-* Add a mediated matrix device to and remove it from the AP mediated bus driver
-* Add a mediated matrix device to and remove it from an IOMMU group
+* Create and destroy a vfio_ap mediated device
+* Add a vfio_ap mediated device to and remove it from the AP mediated bus driver
+* Add a vfio_ap mediated device to and remove it from an IOMMU group
 
 The following high-level block diagram shows the main components and interfaces
-of the VFIO AP mediated matrix device driver::
+of the VFIO AP mediated device driver::
 
    +-------------+
    |             |
···
 	* device_api:
 	    the mediated device type's API
 	* available_instances:
-	    the number of mediated matrix passthrough devices
+	    the number of vfio_ap mediated passthrough devices
 	    that can be created
 	* device_api:
 	    specifies the VFIO API
···
     This attribute group identifies the user-defined sysfs attributes of the
     mediated device. When a device is registered with the VFIO mediated device
     framework, the sysfs attribute files identified in the 'mdev_attr_groups'
-    structure will be created in the mediated matrix device's directory. The
-    sysfs attributes for a mediated matrix device are:
+    structure will be created in the vfio_ap mediated device's directory. The
+    sysfs attributes for a vfio_ap mediated device are:
 
     assign_adapter / unassign_adapter:
       Write-only attributes for assigning/unassigning an AP adapter to/from the
-      mediated matrix device. To assign/unassign an adapter, the APID of the
-      adapter is echoed to the respective attribute file.
+      vfio_ap mediated device. To assign/unassign an adapter, the APID of the
+      adapter is echoed into the respective attribute file.
     assign_domain / unassign_domain:
       Write-only attributes for assigning/unassigning an AP usage domain to/from
-      the mediated matrix device. To assign/unassign a domain, the domain
-      number of the usage domain is echoed to the respective attribute
+      the vfio_ap mediated device. To assign/unassign a domain, the domain
+      number of the usage domain is echoed into the respective attribute
       file.
     matrix:
-      A read-only file for displaying the APQNs derived from the cross product
-      of the adapter and domain numbers assigned to the mediated matrix device.
+      A read-only file for displaying the APQNs derived from the Cartesian
+      product of the adapter and domain numbers assigned to the vfio_ap mediated
+      device.
+    guest_matrix:
+      A read-only file for displaying the APQNs derived from the Cartesian
+      product of the adapter and domain numbers assigned to the APM and AQM
+      fields respectively of the KVM guest's CRYCB. This may differ from the
+      the APQNs assigned to the vfio_ap mediated device if any APQN does not
+      reference a queue device bound to the vfio_ap device driver (i.e., the
+      queue is not in the host's AP configuration).
     assign_control_domain / unassign_control_domain:
       Write-only attributes for assigning/unassigning an AP control domain
-      to/from the mediated matrix device. To assign/unassign a control domain,
-      the ID of the domain to be assigned/unassigned is echoed to the respective
-      attribute file.
+      to/from the vfio_ap mediated device. To assign/unassign a control domain,
+      the ID of the domain to be assigned/unassigned is echoed into the
+      respective attribute file.
     control_domains:
       A read-only file for displaying the control domain numbers assigned to the
-      mediated matrix device.
+      vfio_ap mediated device.
 
 * functions:
 
···
     * Store the reference to the KVM structure for the guest using the mdev
     * Store the AP matrix configuration for the adapters, domains, and control
       domains assigned via the corresponding sysfs attributes files
+    * Store the AP matrix configuration for the adapters, domains and control
+      domains available to a guest. A guest may not be provided access to APQNs
+      referencing queue devices that do not exist, or are not bound to the
+      vfio_ap device driver.
 
   remove:
-    deallocates the mediated matrix device's ap_matrix_mdev structure. This will
-    be allowed only if a running guest is not using the mdev.
+    deallocates the vfio_ap mediated device's ap_matrix_mdev structure.
+    This will be allowed only if a running guest is not using the mdev.
 
 * callback interfaces
 
-  open:
+  open_device:
     The vfio_ap driver uses this callback to register a
-    VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the mdev matrix
-    device. The open is invoked when QEMU connects the VFIO iommu group
-    for the mdev matrix device to the MDEV bus. Access to the KVM structure used
-    to configure the KVM guest is provided via this callback. The KVM structure,
-    is used to configure the guest's access to the AP matrix defined via the
-    mediated matrix device's sysfs attribute files.
-  release:
-    unregisters the VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the
-    mdev matrix device and deconfigures the guest's AP matrix.
+    VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the matrix mdev
+    devices. The open_device callback is invoked by userspace to connect the
+    VFIO iommu group for the matrix mdev device to the MDEV bus. Access to the
+    KVM structure used to configure the KVM guest is provided via this callback.
+    The KVM structure, is used to configure the guest's access to the AP matrix
+    defined via the vfio_ap mediated device's sysfs attribute files.
 
-Configure the APM, AQM and ADM in the CRYCB
--------------------------------------------
-Configuring the AP matrix for a KVM guest will be performed when the
+  close_device:
+    unregisters the VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the
+    matrix mdev device and deconfigures the guest's AP matrix.
+
+  ioctl:
+    this callback handles the VFIO_DEVICE_GET_INFO and VFIO_DEVICE_RESET ioctls
+    defined by the vfio framework.
+
+Configure the guest's AP resources
+----------------------------------
+Configuring the AP resources for a KVM guest will be performed when the
 VFIO_GROUP_NOTIFY_SET_KVM notifier callback is invoked. The notifier
-function is called when QEMU connects to KVM. The guest's AP matrix is
-configured via it's CRYCB by:
+function is called when userspace connects to KVM. The guest's AP resources are
+configured via it's APCB by:
 
 * Setting the bits in the APM corresponding to the APIDs assigned to the
-  mediated matrix device via its 'assign_adapter' interface.
+  vfio_ap mediated device via its 'assign_adapter' interface.
 * Setting the bits in the AQM corresponding to the domains assigned to the
-  mediated matrix device via its 'assign_domain' interface.
+  vfio_ap mediated device via its 'assign_domain' interface.
 * Setting the bits in the ADM corresponding to the domain dIDs assigned to the
-  mediated matrix device via its 'assign_control_domains' interface.
+  vfio_ap mediated device via its 'assign_control_domains' interface.
+
+The linux device model precludes passing a device through to a KVM guest that
+is not bound to the device driver facilitating its pass-through. Consequently,
+an APQN that does not reference a queue device bound to the vfio_ap device
+driver will not be assigned to a KVM guest's matrix. The AP architecture,
+however, does not provide a means to filter individual APQNs from the guest's
+matrix, so the adapters, domains and control domains assigned to vfio_ap
+mediated device via its sysfs 'assign_adapter', 'assign_domain' and
+'assign_control_domain' interfaces will be filtered before providing the AP
+configuration to a guest:
+
+* The APIDs of the adapters, the APQIs of the domains and the domain numbers of
+  the control domains assigned to the matrix mdev that are not also assigned to
+  the host's AP configuration will be filtered.
+
+* Each APQN derived from the Cartesian product of the APIDs and APQIs assigned
+  to the vfio_ap mdev is examined and if any one of them does not reference a
+  queue device bound to the vfio_ap device driver, the adapter will not be
+  plugged into the guest (i.e., the bit corresponding to its APID will not be
+  set in the APM of the guest's APCB).
 
 The CPU model features for AP
 -----------------------------
-The AP stack relies on the presence of the AP instructions as well as two
-facilities: The AP Facilities Test (APFT) facility; and the AP Query
-Configuration Information (QCI) facility. These features/facilities are made
-available to a KVM guest via the following CPU model features:
+The AP stack relies on the presence of the AP instructions as well as three
+facilities: The AP Facilities Test (APFT) facility; the AP Query
+Configuration Information (QCI) facility; and the AP Queue Interruption Control
+facility. These features/facilities are made available to a KVM guest via the
+following CPU model features:
 
 1. ap: Indicates whether the AP instructions are installed on the guest. This
    feature will be enabled by KVM only if the AP instructions are installed
···
    can be made available to the guest only if it is available on the host (i.e.,
    facility bit 12 is set).
 
+4. apqi: Indicates AP Queue Interruption Control faclity is available on the
+   guest. This facility can be made available to the guest only if it is
+   available on the host (i.e., facility bit 65 is set).
+
 Note: If the user chooses to specify a CPU model different than the 'host'
 model to QEMU, the CPU model features and facilities need to be turned on
 explicitly; for example::
 
-     /usr/bin/qemu-system-s390x ... -cpu z13,ap=on,apqci=on,apft=on
+     /usr/bin/qemu-system-s390x ... -cpu z13,ap=on,apqci=on,apft=on,apqi=on
 
 A guest can be precluded from using AP features/facilities by turning them off
 explicitly; for example::
 
-     /usr/bin/qemu-system-s390x ... -cpu host,ap=off,apqci=off,apft=off
+     /usr/bin/qemu-system-s390x ... -cpu host,ap=off,apqci=off,apft=off,apqi=off
 
 Note: If the APFT facility is turned off (apft=off) for the guest, the guest
-will not see any AP devices. The zcrypt device drivers that register for type 10
-and newer AP devices - i.e., the cex4card and cex4queue device drivers - need
-the APFT facility to ascertain the facilities installed on a given AP device. If
-the APFT facility is not installed on the guest, then the probe of device
-drivers will fail since only type 10 and newer devices can be configured for
-guest use.
+will not see any AP devices. The zcrypt device drivers on the guest that
+register for type 10 and newer AP devices - i.e., the cex4card and cex4queue
+device drivers - need the APFT facility to ascertain the facilities installed on
+a given AP device. If the APFT facility is not installed on the guest, then no
+adapter or domain devices will get created by the AP bus running on the
+guest because only type 10 and newer devices can be configured for guest use.
 
 Example
 =======
···
 05.00ab     CEX5C CCA-Coproc
 06          CEX5A Accelerator
 06.0004     CEX5A Accelerator
-06.00ab     CEX5C CCA-Coproc
+06.00ab     CEX5A Accelerator
 =========== ===== ============
 
 Guest2
···
 =========== ===== ============
 CARD.DOMAIN TYPE  MODE
 =========== ===== ============
-05          CEX5A Accelerator
-05.0047     CEX5A Accelerator
-05.00ff     CEX5A Accelerator
+05          CEX5C CCA-Coproc
+05.0047     CEX5C CCA-Coproc
+05.00ff     CEX5C CCA-Coproc
 =========== ===== ============
 
 Guest3
···
 
 2. Secure the AP queues to be used by the three guests so that the host can not
    access them. To secure them, there are two sysfs files that specify
-   bitmasks marking a subset of the APQN range as 'usable by the default AP
-   queue device drivers' or 'not usable by the default device drivers' and thus
-   available for use by the vfio_ap device driver'. The location of the sysfs
-   files containing the masks are::
+   bitmasks marking a subset of the APQN range as usable only by the default AP
+   queue device drivers. All remaining APQNs are available for use by
+   any other device driver. The vfio_ap device driver is currently the only
+   non-default device driver. The location of the sysfs files containing the
+   masks are::
 
      /sys/bus/ap/apmask
      /sys/bus/ap/aqmask
 
    The 'apmask' is a 256-bit mask that identifies a set of AP adapter IDs
-   (APID). Each bit in the mask, from left to right (i.e., from most significant
-   to least significant bit in big endian order), corresponds to an APID from
-   0-255. If a bit is set, the APID is marked as usable only by the default AP
-   queue device drivers; otherwise, the APID is usable by the vfio_ap
-   device driver.
+   (APID). Each bit in the mask, from left to right, corresponds to an APID from
+   0-255. If a bit is set, the APID belongs to the subset of APQNs marked as
+   available only to the default AP queue device drivers.
 
    The 'aqmask' is a 256-bit mask that identifies a set of AP queue indexes
-   (APQI). Each bit in the mask, from left to right (i.e., from most significant
-   to least significant bit in big endian order), corresponds to an APQI from
-   0-255. If a bit is set, the APQI is marked as usable only by the default AP
-   queue device drivers; otherwise, the APQI is usable by the vfio_ap device
-   driver.
+   (APQI). Each bit in the mask, from left to right, corresponds to an APQI from
+   0-255. If a bit is set, the APQI belongs to the subset of APQNs marked as
+   available only to the default AP queue device drivers.
 
-   Take, for example, the following mask::
+   The Cartesian product of the APIDs corresponding to the bits set in the
+   apmask and the APQIs corresponding to the bits set in the aqmask comprise
+   the subset of APQNs that can be used only by the host default device drivers.
+   All other APQNs are available to the non-default device drivers such as the
+   vfio_ap driver.
 
-      0x7dffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
+   Take, for example, the following masks::
 
-    It indicates:
+      apmask:
+      0x7d00000000000000000000000000000000000000000000000000000000000000
 
-      1, 2, 3, 4, 5, and 7-255 belong to the default drivers' pool, and 0 and 6
-      belong to the vfio_ap device driver's pool.
+      aqmask:
+      0x8000000000000000000000000000000000000000000000000000000000000000
+
+   The masks indicate:
+
+   * Adapters 1, 2, 3, 4, 5, and 7 are available for use by the host default
+     device drivers.
+
+   * Domain 0 is available for use by the host default device drivers
+
+   * The subset of APQNs available for use only by the default host device
+     drivers are:
+
+     (1,0), (2,0), (3,0), (4.0), (5,0) and (7,0)
+
+   * All other APQNs are available for use by the non-default device drivers.
 
    The APQN of each AP queue device assigned to the linux host is checked by the
-   AP bus against the set of APQNs derived from the cross product of APIDs
-   and APQIs marked as usable only by the default AP queue device drivers. If a
+   AP bus against the set of APQNs derived from the Cartesian product of APIDs
+   and APQIs marked as available to the default AP queue device drivers. If a
    match is detected,  only the default AP queue device drivers will be probed;
    otherwise, the vfio_ap device driver will be probed.
 
···
 
 	   0x4100000000000000000000000000000000000000000000000000000000000000
 
-	Keep in mind that the mask reads from left to right (i.e., most
-	significant to least significant bit in big endian order), so the mask
+	Keep in mind that the mask reads from left to right, so the mask
 	above identifies device numbers 1 and 7 (01000001).
 
 	If the string is longer than the mask, the operation is terminated with
···
 	    default drivers pool:    adapter 0-15, domain 1
 	    alternate drivers pool:  adapter 16-255, domains 0, 2-255
 
+   **Note:**
+   Changing a mask such that one or more APQNs will be taken from a vfio_ap
+   mediated device (see below) will fail with an error (EBUSY). A message
+   is logged to the kernel ring buffer which can be viewed with the 'dmesg'
+   command. The output identifies each APQN flagged as 'in use' and identifies
+   the vfio_ap mediated device to which it is assigned; for example:
+
+   Userspace may not re-assign queue 05.0054 already assigned to 62177883-f1bb-47f0-914d-32a22e3a8804
+   Userspace may not re-assign queue 04.0054 already assigned to cef03c3c-903d-4ecc-9a83-40694cb8aee4
+
 Securing the APQNs for our example
 ----------------------------------
    To secure the AP queues 05.0004, 05.0047, 05.00ab, 05.00ff, 06.0004, 06.0047,
    06.00ab, and 06.00ff for use by the vfio_ap device driver, the corresponding
-   APQNs can either be removed from the default masks::
+   APQNs can be removed from the default masks using either of the following
+   commands::
 
       echo -5,-6 > /sys/bus/ap/apmask
 
···
 
      /sys/devices/vfio_ap/matrix/
      --- [mdev_supported_types]
-     ------ [vfio_ap-passthrough] (passthrough mediated matrix device type)
+     ------ [vfio_ap-passthrough] (passthrough vfio_ap mediated device type)
      --------- create
      --------- [devices]
 
···
      ----------------unassign_control_domain
      ----------------unassign_domain
 
+   Note *****: The vfio_ap mdevs do not persist across reboots unless the
+               mdevctl tool is used to create and persist them.
+
 4. The administrator now needs to configure the matrixes for the mediated
    devices $uuid1 (for Guest1), $uuid2 (for Guest2) and $uuid3 (for Guest3).
 
···
 
 	 cat matrix
 
+   To display the matrix that is or will be assigned to Guest1::
+
+	 cat guest_matrix
+
    This is how the matrix is configured for Guest2::
 
       echo 5 > assign_adapter
···
      higher than the maximum is specified, the operation will terminate with
      an error (ENODEV).
 
-   * All APQNs that can be derived from the adapter ID and the IDs of
-     the previously assigned domains must be bound to the vfio_ap device
-     driver. If no domains have yet been assigned, then there must be at least
-     one APQN with the specified APID bound to the vfio_ap driver. If no such
-     APQNs are bound to the driver, the operation will terminate with an
-     error (EADDRNOTAVAIL).
+     Note: The maximum adapter number can be obtained via the sysfs
+	   /sys/bus/ap/ap_max_adapter_id attribute file.
 
-     No APQN that can be derived from the adapter ID and the IDs of the
-     previously assigned domains can be assigned to another mediated matrix
-     device. If an APQN is assigned to another mediated matrix device, the
-     operation will terminate with an error (EADDRINUSE).
+   * Each APQN derived from the Cartesian product of the APID of the adapter
+     being assigned and the APQIs of the domains previously assigned:
+
+     - Must only be available to the vfio_ap device driver as specified in the
+       sysfs /sys/bus/ap/apmask and /sys/bus/ap/aqmask attribute files. If even
+       one APQN is reserved for use by the host device driver, the operation
+       will terminate with an error (EADDRNOTAVAIL).
+
+     - Must NOT be assigned to another vfio_ap mediated device. If even one APQN
+       is assigned to another vfio_ap mediated device, the operation will
+       terminate with an error (EBUSY).
+
+     - Must NOT be assigned while the sysfs /sys/bus/ap/apmask and
+       sys/bus/ap/aqmask attribute files are being edited or the operation may
+       terminate with an error (EBUSY).
 
    In order to successfully assign a domain:
 
···
      higher than the maximum is specified, the operation will terminate with
      an error (ENODEV).
 
-   * All APQNs that can be derived from the domain ID and the IDs of
-     the previously assigned adapters must be bound to the vfio_ap device
-     driver. If no domains have yet been assigned, then there must be at least
-     one APQN with the specified APQI bound to the vfio_ap driver. If no such
-     APQNs are bound to the driver, the operation will terminate with an
-     error (EADDRNOTAVAIL).
+     Note: The maximum domain number can be obtained via the sysfs
+	   /sys/bus/ap/ap_max_domain_id attribute file.
 
-     No APQN that can be derived from the domain ID and the IDs of the
-     previously assigned adapters can be assigned to another mediated matrix
-     device. If an APQN is assigned to another mediated matrix device, the
-     operation will terminate with an error (EADDRINUSE).
+    * Each APQN derived from the Cartesian product of the APQI of the domain
+      being assigned and the APIDs of the adapters previously assigned:
 
-   In order to successfully assign a control domain, the domain number
-   specified must represent a value from 0 up to the maximum domain number
-   configured for the system. If a control domain number higher than the maximum
-   is specified, the operation will terminate with an error (ENODEV).
+     - Must only be available to the vfio_ap device driver as specified in the
+       sysfs /sys/bus/ap/apmask and /sys/bus/ap/aqmask attribute files. If even
+       one APQN is reserved for use by the host device driver, the operation
+       will terminate with an error (EADDRNOTAVAIL).
+
+     - Must NOT be assigned to another vfio_ap mediated device. If even one APQN
+       is assigned to another vfio_ap mediated device, the operation will
+       terminate with an error (EBUSY).
+
+     - Must NOT be assigned while the sysfs /sys/bus/ap/apmask and
+       sys/bus/ap/aqmask attribute files are being edited or the operation may
+       terminate with an error (EBUSY).
+
+   In order to successfully assign a control domain:
+
+   * The domain number specified must represent a value from 0 up to the maximum
+     domain number configured for the system. If a control domain number higher
+     than the maximum is specified, the operation will terminate with an
+     error (ENODEV).
 
 5. Start Guest1::
 
-     /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
+     /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on,apqi=on \
 	-device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid1 ...
 
 7. Start Guest2::
 
-     /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
+     /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on,apqi=on \
 	-device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid2 ...
 
 7. Start Guest3::
 
-     /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
+     /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on,apqi=on \
 	-device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid3 ...
 
-When the guest is shut down, the mediated matrix devices may be removed.
+When the guest is shut down, the vfio_ap mediated devices may be removed.
 
-Using our example again, to remove the mediated matrix device $uuid1::
+Using our example again, to remove the vfio_ap mediated device $uuid1::
 
    /sys/devices/vfio_ap/matrix/
       --- [mdev_supported_types]
···
 
    echo 1 > remove
 
-This will remove all of the mdev matrix device's sysfs structures including
-the mdev device itself. To recreate and reconfigure the mdev matrix device,
+This will remove all of the matrix mdev device's sysfs structures including
+the mdev device itself. To recreate and reconfigure the matrix mdev device,
 all of the steps starting with step 3 will have to be performed again. Note
-that the remove will fail if a guest using the mdev is still running.
+that the remove will fail if a guest using the vfio_ap mdev is still running.
 
-It is not necessary to remove an mdev matrix device, but one may want to
+It is not necessary to remove a vfio_ap mdev, but one may want to
 remove it if no guest will use it during the remaining lifetime of the linux
-host. If the mdev matrix device is removed, one may want to also reconfigure
+host. If the vfio_ap mdev is removed, one may want to also reconfigure
 the pool of adapters and queues reserved for use by the default drivers.
+
+Hot plug/unplug support:
+========================
+An adapter, domain or control domain may be hot plugged into a running KVM
+guest by assigning it to the vfio_ap mediated device being used by the guest if
+the following conditions are met:
+
+* The adapter, domain or control domain must also be assigned to the host's
+  AP configuration.
+
+* Each APQN derived from the Cartesian product comprised of the APID of the
+  adapter being assigned and the APQIs of the domains assigned must reference a
+  queue device bound to the vfio_ap device driver.
+
+* To hot plug a domain, each APQN derived from the Cartesian product
+  comprised of the APQI of the domain being assigned and the APIDs of the
+  adapters assigned must reference a queue device bound to the vfio_ap device
+  driver.
+
+An adapter, domain or control domain may be hot unplugged from a running KVM
+guest by unassigning it from the vfio_ap mediated device being used by the
+guest.
+
+Over-provisioning of AP queues for a KVM guest:
+===============================================
+Over-provisioning is defined herein as the assignment of adapters or domains to
+a vfio_ap mediated device that do not reference AP devices in the host's AP
+configuration. The idea here is that when the adapter or domain becomes
+available, it will be automatically hot-plugged into the KVM guest using
+the vfio_ap mediated device to which it is assigned as long as each new APQN
+resulting from plugging it in references a queue device bound to the vfio_ap
+device driver.
 
 Limitations
 ===========
-* The KVM/kernel interfaces do not provide a way to prevent restoring an APQN
-  to the default drivers pool of a queue that is still assigned to a mediated
-  device in use by a guest. It is incumbent upon the administrator to
-  ensure there is no mediated device in use by a guest to which the APQN is
-  assigned lest the host be given access to the private data of the AP queue
-  device such as a private key configured specifically for the guest.
+Live guest migration is not supported for guests using AP devices without
+intervention by a system administrator. Before a KVM guest can be migrated,
+the vfio_ap mediated device must be removed. Unfortunately, it can not be
+removed manually (i.e., echo 1 > /sys/devices/vfio_ap/matrix/$UUID/remove) while
+the mdev is in use by a KVM guest. If the guest is being emulated by QEMU,
+its mdev can be hot unplugged from the guest in one of two ways:
 
-* Dynamically modifying the AP matrix for a running guest (which would amount to
-  hot(un)plug of AP devices for the guest) is currently not supported
+1. If the KVM guest was started with libvirt, you can hot unplug the mdev via
+   the following commands:
 
-* Live guest migration is not supported for guests using AP devices.
+      virsh detach-device <guestname> <path-to-device-xml>
+
+      For example, to hot unplug mdev 62177883-f1bb-47f0-914d-32a22e3a8804 from
+      the guest named 'my-guest':
+
+         virsh detach-device my-guest ~/config/my-guest-hostdev.xml
+
+            The contents of my-guest-hostdev.xml:
+
+.. code-block:: xml
+
+            <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-ap'>
+              <source>
+                <address uuid='62177883-f1bb-47f0-914d-32a22e3a8804'/>
+              </source>
+            </hostdev>
+
+
+      virsh qemu-monitor-command <guest-name> --hmp "device-del <device-id>"
+
+      For example, to hot unplug the vfio_ap mediated device identified on the
+      qemu command line with 'id=hostdev0' from the guest named 'my-guest':
+
+.. code-block:: sh
+
+         virsh qemu-monitor-command my-guest --hmp "device_del hostdev0"
+
+2. A vfio_ap mediated device can be hot unplugged by attaching the qemu monitor
+   to the guest and using the following qemu monitor command:
+
+      (QEMU) device-del id=<device-id>
+
+      For example, to hot unplug the vfio_ap mediated device that was specified
+      on the qemu command line with 'id=hostdev0' when the guest was started:
+
+         (QEMU) device-del id=hostdev0
+
+After live migration of the KVM guest completes, an AP configuration can be
+restored to the KVM guest by hot plugging a vfio_ap mediated device on the target
+system into the guest in one of two ways:
+
+1. If the KVM guest was started with libvirt, you can hot plug a matrix mediated
+   device into the guest via the following virsh commands:
+
+   virsh attach-device <guestname> <path-to-device-xml>
+
+      For example, to hot plug mdev 62177883-f1bb-47f0-914d-32a22e3a8804 into
+      the guest named 'my-guest':
+
+         virsh attach-device my-guest ~/config/my-guest-hostdev.xml
+
+            The contents of my-guest-hostdev.xml:
+
+.. code-block:: xml
+
+            <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-ap'>
+              <source>
+                <address uuid='62177883-f1bb-47f0-914d-32a22e3a8804'/>
+              </source>
+            </hostdev>
+
+
+   virsh qemu-monitor-command <guest-name> --hmp \
+   "device_add vfio-ap,sysfsdev=<path-to-mdev>,id=<device-id>"
+
+      For example, to hot plug the vfio_ap mediated device
+      62177883-f1bb-47f0-914d-32a22e3a8804 into the guest named 'my-guest' with
+      device-id hostdev0:
+
+      virsh qemu-monitor-command my-guest --hmp \
+      "device_add vfio-ap,\
+      sysfsdev=/sys/devices/vfio_ap/matrix/62177883-f1bb-47f0-914d-32a22e3a8804,\
+      id=hostdev0"
+
+2. A vfio_ap mediated device can be hot plugged by attaching the qemu monitor
+   to the guest and using the following qemu monitor command:
+
+      (qemu) device_add "vfio-ap,sysfsdev=<path-to-mdev>,id=<device-id>"
+
+      For example, to plug the vfio_ap mediated device
+      62177883-f1bb-47f0-914d-32a22e3a8804 into the guest with the device-id
+      hostdev0:
+
+         (QEMU) device-add "vfio-ap,\
+         sysfsdev=/sys/devices/vfio_ap/matrix/62177883-f1bb-47f0-914d-32a22e3a8804,\
+         id=hostdev0"

MAINTAINERS

···
 L:	[e-mail]
 S:	Supported
 W:	http://www.ibm.com/developerworks/linux/linux390/
-F:	Documentation/s390/vfio-ap.rst
+F:	Documentation/s390/vfio-ap*
 F:	drivers/s390/crypto/vfio_ap*
 
 S390 VFIO-CCW DRIVER

arch/s390/boot/startup.c

···
 	unsigned long vmemmap_start;
 	unsigned long rte_size;
 	unsigned long pages;
+	unsigned long vmax;
 
 	pages = ident_map_size / PAGE_SIZE;
 	/* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
···
 	    vmalloc_size > _REGION2_SIZE ||
 	    vmemmap_start + vmemmap_size + vmalloc_size + MODULES_LEN >
 		    _REGION2_SIZE) {
-		MODULES_END = _REGION1_SIZE;
+		vmax = _REGION1_SIZE;
 		rte_size = _REGION2_SIZE;
 	} else {
-		MODULES_END = _REGION2_SIZE;
+		vmax = _REGION2_SIZE;
 		rte_size = _REGION3_SIZE;
 	}
 	/*
···
 	 * secure storage limit, so that any vmalloc allocation
 	 * we do could be used to back secure guest storage.
 	 */
-	adjust_to_uv_max(&MODULES_END);
+	vmax = adjust_to_uv_max(vmax);
 #ifdef CONFIG_KASAN
 	/* force vmalloc and modules below kasan shadow */
-	MODULES_END = min(MODULES_END, KASAN_SHADOW_START);
+	vmax = min(vmax, KASAN_SHADOW_START);
 #endif
+	MODULES_END = vmax;
 	MODULES_VADDR = MODULES_END - MODULES_LEN;
 	VMALLOC_END = MODULES_VADDR;
 

arch/s390/boot/uv.c

···
 }
 
 #if IS_ENABLED(CONFIG_KVM)
-void adjust_to_uv_max(unsigned long *vmax)
+unsigned long adjust_to_uv_max(unsigned long limit)
 {
 	if (is_prot_virt_host() && uv_info.max_sec_stor_addr)
-		*vmax = min_t(unsigned long, *vmax, uv_info.max_sec_stor_addr);
+		limit = min_t(unsigned long, limit, uv_info.max_sec_stor_addr);
+	return limit;
 }
 
 static int is_prot_virt_host_capable(void)

arch/s390/boot/uv.h

···
 #define BOOT_UV_H
 
 #if IS_ENABLED(CONFIG_KVM)
-void adjust_to_uv_max(unsigned long *vmax);
+unsigned long adjust_to_uv_max(unsigned long limit);
 void sanitize_prot_virt_host(void);
 #else
-static inline void adjust_to_uv_max(unsigned long *vmax) {}
+static inline unsigned long adjust_to_uv_max(unsigned long limit)
+{
+	return limit;
+}
 static inline void sanitize_prot_virt_host(void) {}
 #endif
 

arch/s390/crypto/aes_s390.c

···
 	return ret;
 }
 
-module_cpu_feature_match(MSA, aes_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init);
 module_exit(aes_s390_fini);
 
 MODULE_ALIAS_CRYPTO("aes-all");

arch/s390/crypto/chacha-glue.c

···
 		crypto_unregister_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs));
 }
 
-module_cpu_feature_match(VXRS, chacha_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_VXRS, chacha_mod_init);
 module_exit(chacha_mod_fini);
 
 MODULE_DESCRIPTION("ChaCha20 stream cipher");

arch/s390/crypto/crc32-vx.c

···
 	crypto_unregister_shashes(crc32_vx_algs, ARRAY_SIZE(crc32_vx_algs));
 }
 
-module_cpu_feature_match(VXRS, crc_vx_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_VXRS, crc_vx_mod_init);
 module_exit(crc_vx_mod_exit);
 
 MODULE_AUTHOR("Hendrik Brueckner <[e-mail]>");

arch/s390/crypto/des_s390.c

···
 	return ret;
 }
 
-module_cpu_feature_match(MSA, des_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, des_s390_init);
 module_exit(des_s390_exit);
 
 MODULE_ALIAS_CRYPTO("des");

arch/s390/crypto/ghash_s390.c

···
 	crypto_unregister_shash(&ghash_alg);
 }
 
-module_cpu_feature_match(MSA, ghash_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, ghash_mod_init);
 module_exit(ghash_mod_exit);
 
 MODULE_ALIAS_CRYPTO("ghash");

arch/s390/crypto/prng.c

···
 	}
 }
 
-module_cpu_feature_match(MSA, prng_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, prng_init);
 module_exit(prng_exit);

arch/s390/crypto/sha1_s390.c

···
 	crypto_unregister_shash(&alg);
 }
 
-module_cpu_feature_match(MSA, sha1_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha1_s390_init);
 module_exit(sha1_s390_fini);
 
 MODULE_ALIAS_CRYPTO("sha1");

arch/s390/crypto/sha256_s390.c

···
 	crypto_unregister_shash(&sha256_alg);
 }
 
-module_cpu_feature_match(MSA, sha256_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha256_s390_init);
 module_exit(sha256_s390_fini);
 
 MODULE_ALIAS_CRYPTO("sha256");

arch/s390/crypto/sha3_256_s390.c

···
 	crypto_unregister_shash(&sha3_256_alg);
 }
 
-module_cpu_feature_match(MSA, sha3_256_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha3_256_s390_init);
 module_exit(sha3_256_s390_fini);
 
 MODULE_ALIAS_CRYPTO("sha3-256");

arch/s390/crypto/sha3_512_s390.c

···
 	crypto_unregister_shash(&sha3_384_alg);
 }
 
-module_cpu_feature_match(MSA, init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, init);
 module_exit(fini);
 
 MODULE_LICENSE("GPL");

arch/s390/crypto/sha512_s390.c

···
 	crypto_unregister_shash(&sha384_alg);
 }
 
-module_cpu_feature_match(MSA, init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, init);
 module_exit(fini);
 
 MODULE_LICENSE("GPL");

arch/s390/include/asm/cpufeature.h

···
 /*
  * Module interface for CPU features
  *
- * Copyright IBM Corp. 2015
+ * Copyright IBM Corp. 2015, 2022
  * Author(s): Hendrik Brueckner <[e-mail]>
  */
 
 #ifndef __ASM_S390_CPUFEATURE_H
 #define __ASM_S390_CPUFEATURE_H
 
-#include <asm/elf.h>
+enum {
+	S390_CPU_FEATURE_MSA,
+	S390_CPU_FEATURE_VXRS,
+	S390_CPU_FEATURE_UV,
+	MAX_CPU_FEATURES
+};
 
-/* Hardware features on Linux on z Systems are indicated by facility bits that
- * are mapped to the so-called machine flags.  Particular machine flags are
- * then used to define ELF hardware capabilities; most notably hardware flags
- * that are essential for user space / glibc.
- *
- * Restrict the set of exposed CPU features to ELF hardware capabilities for
- * now.  Additional machine flags can be indicated by values larger than
- * MAX_ELF_HWCAP_FEATURES.
- */
-#define MAX_ELF_HWCAP_FEATURES	(8 * sizeof(elf_hwcap))
-#define MAX_CPU_FEATURES	MAX_ELF_HWCAP_FEATURES
-
-#define cpu_feature(feat)	ilog2(HWCAP_ ## feat)
+#define cpu_feature(feature)	(feature)
 
 int cpu_have_feature(unsigned int nr);
 

arch/s390/include/asm/mmu.h

···
 	.context.pgtable_list = LIST_HEAD_INIT(name.context.pgtable_list), \
 	.context.gmap_list = LIST_HEAD_INIT(name.context.gmap_list),
 
-static inline int tprot(unsigned long addr)
-{
-	int rc = -EFAULT;
-
-	asm volatile(
-		"	tprot	0(%1),0\n"
-		"0:	ipm	%0\n"
-		"	srl	%0,28\n"
-		"1:\n"
-		EX_TABLE(0b,1b)
-		: "+d" (rc) : "a" (addr) : "cc");
-	return rc;
-}
-
 #endif

arch/s390/include/asm/os_info.h

···
 #ifndef _ASM_S390_OS_INFO_H
 #define _ASM_S390_OS_INFO_H
 
+#include <linux/uio.h>
+
 #define OS_INFO_VERSION_MAJOR	1
 #define OS_INFO_VERSION_MINOR	1
 #define OS_INFO_MAGIC		0x4f53494e464f535aULL /* OSINFOSZ */
···
 
 #ifdef CONFIG_CRASH_DUMP
 void *os_info_old_entry(int nr, unsigned long *size);
-int copy_oldmem_kernel(void *dst, unsigned long src, size_t count);
+size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count);
+
+static inline int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
+{
+	struct iov_iter iter;
+	struct kvec kvec;
+
+	kvec.iov_base = dst;
+	kvec.iov_len = count;
+	iov_iter_kvec(&iter, WRITE, &kvec, 1, count);
+	if (copy_oldmem_iter(&iter, src, count) < count)
+		return -EFAULT;
+	return 0;
+}
 #else
 static inline void *os_info_old_entry(int nr, unsigned long *size)
 {

arch/s390/include/asm/sclp.h

···
 #define EXT_SCCB_READ_CPU	(3 * PAGE_SIZE)
 
 #ifndef __ASSEMBLY__
+#include <linux/uio.h>
 #include <asm/chpid.h>
 #include <asm/cpu.h>
 
···
 int sclp_ap_configure(u32 apid);
 int sclp_ap_deconfigure(u32 apid);
 int sclp_pci_report(struct zpci_report_error_header *report, u32 fh, u32 fid);
-int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count);
-int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count);
+size_t memcpy_hsa_iter(struct iov_iter *iter, unsigned long src, size_t count);
 void sclp_ocf_cpc_name_copy(char *dst);
 
 static inline int sclp_get_core_info(struct sclp_core_info *info, int early)

arch/s390/include/asm/uaccess.h

···
 	return __clear_user(to, n);
 }
 
-int copy_to_user_real(void __user *dest, unsigned long src, unsigned long count);
 void *s390_kernel_write(void *dst, const void *src, size_t size);
 
 int __noreturn __put_kernel_bad(void);

arch/s390/include/asm/unwind.h

···
 static inline unsigned long unwind_recover_ret_addr(struct unwind_state *state,
 						    unsigned long ip)
 {
-	ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, NULL);
+	ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, (void *)state->sp);
 	if (is_kretprobe_trampoline(ip))
 		ip = kretprobe_find_ret_addr(state->task, (void *)state->sp, &state->kr_cur);
 	return ip;

arch/s390/kernel/Makefile

···
 
 obj-y	:= traps.o time.o process.o earlypgm.o early.o setup.o idle.o vtime.o
 obj-y	+= processor.o syscall.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
-obj-y	+= debug.o irq.o ipl.o dis.o diag.o vdso.o
+obj-y	+= debug.o irq.o ipl.o dis.o diag.o vdso.o cpufeature.o
 obj-y	+= sysinfo.o lgr.o os_info.o machine_kexec.o
 obj-y	+= runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
 obj-y	+= entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o

arch/s390/kernel/cpufeature.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2022
+ */
+
+#include <linux/cpufeature.h>
+#include <linux/bug.h>
+#include <asm/elf.h>
+
+enum {
+	TYPE_HWCAP,
+	TYPE_FACILITY,
+};
+
+struct s390_cpu_feature {
+	unsigned int type	: 4;
+	unsigned int num	: 28;
+};
+
+static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
+	[S390_CPU_FEATURE_MSA]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
+	[S390_CPU_FEATURE_VXRS]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
+	[S390_CPU_FEATURE_UV]	= {.type = TYPE_FACILITY, .num = 158},
+};
+
+/*
+ * cpu_have_feature - Test CPU features on module initialization
+ */
+int cpu_have_feature(unsigned int num)
+{
+	struct s390_cpu_feature *feature;
+
+	if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES))
+		return 0;
+	feature = &s390_cpu_features[num];
+	switch (feature->type) {
+	case TYPE_HWCAP:
+		return !!(elf_hwcap & BIT(feature->num));
+	case TYPE_FACILITY:
+		return test_facility(feature->num);
+	default:
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+}
+EXPORT_SYMBOL(cpu_have_feature);

arch/s390/kernel/crash_dump.c

···
 };
 
 static LIST_HEAD(dump_save_areas);
+static DEFINE_MUTEX(memcpy_real_mutex);
+static char memcpy_real_buf[PAGE_SIZE];
 
 /*
  * Allocate a save area
···
 
 	sa = memblock_alloc(sizeof(*sa), 8);
 	if (!sa)
-		panic("Failed to allocate save area\n");
+		return NULL;
 
 	if (is_boot_cpu)
 		list_add(&sa->list, &dump_save_areas);
···
 	memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
 }
 
-/*
- * Return physical address for virtual address
- */
-static inline void *load_real_addr(void *addr)
+static size_t copy_to_iter_real(struct iov_iter *iter, unsigned long src, size_t count)
 {
-	unsigned long real_addr;
+	size_t len, copied, res = 0;
 
-	asm volatile(
-		   "	lra     %0,0(%1)\n"
-		   "	jz	0f\n"
-		   "	la	%0,0\n"
-		   "0:"
-		   : "=a" (real_addr) : "a" (addr) : "cc");
-	return (void *)real_addr;
+	mutex_lock(&memcpy_real_mutex);
+	while (count) {
+		len = min(PAGE_SIZE, count);
+		if (memcpy_real(memcpy_real_buf, src, len))
+			break;
+		copied = copy_to_iter(memcpy_real_buf, len, iter);
+		count -= copied;
+		src += copied;
+		res += copied;
+		if (copied < len)
+			break;
+	}
+	mutex_unlock(&memcpy_real_mutex);
+	return res;
 }
 
-/*
- * Copy memory of the old, dumped system to a kernel space virtual address
- */
-int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
+size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
 {
-	unsigned long len;
-	void *ra;
-	int rc;
+	size_t len, copied, res = 0;
 
 	while (count) {
 		if (!oldmem_data.start && src < sclp.hsa_size) {
 			/* Copy from zfcp/nvme dump HSA area */
 			len = min(count, sclp.hsa_size - src);
-			rc = memcpy_hsa_kernel(dst, src, len);
-			if (rc)
-				return rc;
+			copied = memcpy_hsa_iter(iter, src, len);
 		} else {
 			/* Check for swapped kdump oldmem areas */
 			if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) {
···
 			} else {
 				len = count;
 			}
-			if (is_vmalloc_or_module_addr(dst)) {
-				ra = load_real_addr(dst);
-				len = min(PAGE_SIZE - offset_in_page(ra), len);
-			} else {
-				ra = dst;
-			}
-			if (memcpy_real(ra, src, len))
-				return -EFAULT;
+			copied = copy_to_iter_real(iter, src, len);
 		}
-		dst += len;
-		src += len;
-		count -= len;
+		count -= copied;
+		src += copied;
+		res += copied;
+		if (copied < len)
+			break;
 	}
-	return 0;
-}
-
-/*
- * Copy memory of the old, dumped system to a user space virtual address
- */
-static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count)
-{
-	unsigned long len;
-	int rc;
-
-	while (count) {
-		if (!oldmem_data.start && src < sclp.hsa_size) {
-			/* Copy from zfcp/nvme dump HSA area */
-			len = min(count, sclp.hsa_size - src);
-			rc = memcpy_hsa_user(dst, src, len);
-			if (rc)
-				return rc;
-		} else {
-			/* Check for swapped kdump oldmem areas */
-			if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) {
-				src -= oldmem_data.start;
-				len = min(count, oldmem_data.size - src);
-			} else if (oldmem_data.start && src < oldmem_data.size) {
-				len = min(count, oldmem_data.size - src);
-				src += oldmem_data.start;
-			} else {
-				len = count;
-			}
-			rc = copy_to_user_real(dst, src, count);
-			if (rc)
-				return rc;
-		}
-		dst += len;
-		src += len;
-		count -= len;
-	}
-	return 0;
+	return res;
 }
 
 /*
···
 			 unsigned long offset)
 {
 	unsigned long src;
-	int rc;
 
-	if (!(iter_is_iovec(iter) || iov_iter_is_kvec(iter)))
-		return -EINVAL;
-	/* Multi-segment iterators are not supported */
-	if (iter->nr_segs > 1)
-		return -EINVAL;
-	if (!csize)
-		return 0;
 	src = pfn_to_phys(pfn) + offset;
-
-	/* XXX: pass the iov_iter down to a common function */
-	if (iter_is_iovec(iter))
-		rc = copy_oldmem_user(iter->iov->iov_base, src, csize);
-	else
-		rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize);
-	if (rc < 0)
-		return rc;
-	iov_iter_advance(iter, csize);
-	return csize;
+	return copy_oldmem_iter(iter, src, csize);
 }
 
 /*

arch/s390/kernel/nmi.c

···
 #include <linux/kernel_stat.h>
 #include <linux/init.h>
 #include <linux/errno.h>
+#include <linux/entry-common.h>
 #include <linux/hardirq.h>
 #include <linux/log2.h>
 #include <linux/kprobes.h>
···
 	static unsigned long long last_ipd;
 	struct mcck_struct *mcck;
 	unsigned long long tmp;
+	irqentry_state_t irq_state;
 	union mci mci;
 	unsigned long mcck_dam_code;
 	int mcck_pending = 0;
 
-	nmi_enter();
+	irq_state = irqentry_nmi_enter(regs);
 
 	if (user_mode(regs))
 		update_timer_mcck();
···
 	clear_cpu_flag(CIF_MCCK_GUEST);
 
 	if (user_mode(regs) && mcck_pending) {
-		nmi_exit();
+		irqentry_nmi_exit(regs, irq_state);
 		return 1;
 	}
 
 	if (mcck_pending)
 		schedule_mcck_handler();
 
-	nmi_exit();
+	irqentry_nmi_exit(regs, irq_state);
 	return 0;
 }
 NOKPROBE_SYMBOL(s390_do_machine_check);

arch/s390/kernel/processor.c

···
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/stop_machine.h>
-#include <linux/cpufeature.h>
 #include <linux/bitops.h>
 #include <linux/kernel.h>
 #include <linux/random.h>
···
 	BUG_ON(current->mm);
 	enter_lazy_tlb(&init_mm, current);
 }
-
-/*
- * cpu_have_feature - Test CPU features on module initialization
- */
-int cpu_have_feature(unsigned int num)
-{
-	return elf_hwcap & (1UL << num);
-}
-EXPORT_SYMBOL(cpu_have_feature);
 
 static void show_facilities(struct seq_file *m)
 {

arch/s390/kernel/setup.c

···
 	lc->restart_data = 0;
 	lc->restart_source = -1U;
 
-	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
-	if (!mcck_stack)
-		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
-		      __func__, THREAD_SIZE, THREAD_SIZE);
-	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
-
-	/* Setup absolute zero lowcore */
 	put_abs_lowcore(restart_stack, lc->restart_stack);
 	put_abs_lowcore(restart_fn, lc->restart_fn);
 	put_abs_lowcore(restart_data, lc->restart_data);
 	put_abs_lowcore(restart_source, lc->restart_source);
 	put_abs_lowcore(restart_psw, lc->restart_psw);
+
+	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
+	if (!mcck_stack)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, THREAD_SIZE, THREAD_SIZE);
+	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
 
 	lc->spinlock_lockval = arch_spin_lockval(0);
 	lc->spinlock_index = 0;

arch/s390/mm/maccess.c

···
 }
 
 /*
- * Copy memory from kernel (real) to user (virtual)
- */
-int copy_to_user_real(void __user *dest, unsigned long src, unsigned long count)
-{
-	int offs = 0, size, rc;
-	char *buf;
-
-	buf = (char *) __get_free_page(GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-	rc = -EFAULT;
-	while (offs < count) {
-		size = min(PAGE_SIZE, count - offs);
-		if (memcpy_real(buf, src + offs, size))
-			goto out;
-		if (copy_to_user(dest + offs, buf, size))
-			goto out;
-		offs += size;
-	}
-	rc = 0;
-out:
-	free_page((unsigned long) buf);
-	return rc;
-}
-
-/*
  * Check if physical address is within prefix or zero page
  */
 static int is_swapped(phys_addr_t addr)

drivers/char/hw_random/s390-trng.c

···
 	trng_debug_exit();
 }
 
-module_cpu_feature_match(MSA, trng_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, trng_init);
 module_exit(trng_exit);

drivers/s390/char/Kconfig

···
 	  Management Console (HMC) drive CD/DVD-ROM. It is available as a
 	  module, called 'hmcdrv', and also as kernel built-in. There is one
 	  optional parameter for this module: cachesize=N, which modifies the
-	  transfer cache size from it's default value 0.5MB to N bytes. If N
+	  transfer cache size from its default value 0.5MB to N bytes. If N
 	  is zero, then no caching is performed.
 
 config SCLP_OFB

drivers/s390/char/tape_34xx.c

···
 	case 0x2e:
 		/*
 		 * Not capable. This indicates either that the drive fails
-		 * reading the format id mark or that that format specified
+		 * reading the format id mark or that format specified
 		 * is not supported by the drive.
 		 */
 		dev_warn (&device->cdev->dev, "The tape unit cannot process "

drivers/s390/char/uvdevice.c

···
 #include <linux/stddef.h>
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
+#include <linux/cpufeature.h>
 
 #include <asm/uvdevice.h>
 #include <asm/uv.h>
···
 
 static int __init uvio_dev_init(void)
 {
-	if (!test_facility(158))
-		return -ENXIO;
 	return misc_register(&uvio_dev_miscdev);
 }
 
-module_init(uvio_dev_init);
+module_cpu_feature_match(S390_CPU_FEATURE_UV, uvio_dev_init);
 module_exit(uvio_dev_exit);
 
 MODULE_AUTHOR("IBM Corporation");

drivers/s390/char/zcore.c

···
 #include <linux/debugfs.h>
 #include <linux/panic_notifier.h>
 #include <linux/reboot.h>
+#include <linux/uio.h>
 
 #include <asm/asm-offsets.h>
 #include <asm/ipl.h>
···
 static struct dentry *zcore_hsa_file;
 static struct ipl_parameter_block *zcore_ipl_block;
 
+static DEFINE_MUTEX(hsa_buf_mutex);
 static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE);
 
 /*
- * Copy memory from HSA to user memory (not reentrant):
+ * Copy memory from HSA to iterator (not reentrant):
  *
- * @dest:  User buffer where memory should be copied to
+ * @iter:  Iterator where memory should be copied to
  * @src:   Start address within HSA where data should be copied
  * @count: Size of buffer, which should be copied
  */
-int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
+size_t memcpy_hsa_iter(struct iov_iter *iter, unsigned long src, size_t count)
 {
-	unsigned long offset, bytes;
+	size_t bytes, copied, res = 0;
+	unsigned long offset;
 
 	if (!hsa_available)
-		return -ENODATA;
+		return 0;
 
+	mutex_lock(&hsa_buf_mutex);
 	while (count) {
 		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
 			TRACE("sclp_sdias_copy() failed\n");
-			return -EIO;
+			break;
 		}
 		offset = src % PAGE_SIZE;
 		bytes = min(PAGE_SIZE - offset, count);
-		if (copy_to_user(dest, hsa_buf + offset, bytes))
-			return -EFAULT;
-		src += bytes;
-		dest += bytes;
-		count -= bytes;
+		copied = copy_to_iter(hsa_buf + offset, bytes, iter);
+		count -= copied;
+		src += copied;
+		res += copied;
+		if (copied < bytes)
+			break;
 	}
-	return 0;
+	mutex_unlock(&hsa_buf_mutex);
+	return res;
 }
 
 /*
···
  * @src:   Start address within HSA where data should be copied
  * @count: Size of buffer, which should be copied
  */
-int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
+static inline int memcpy_hsa_kernel(void *dst, unsigned long src, size_t count)
 {
-	unsigned long offset, bytes;
+	struct iov_iter iter;
+	struct kvec kvec;
 
-	if (!hsa_available)
-		return -ENODATA;
-
-	while (count) {
-		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
-			TRACE("sclp_sdias_copy() failed\n");
-			return -EIO;
-		}
-		offset = src % PAGE_SIZE;
-		bytes = min(PAGE_SIZE - offset, count);
-		memcpy(dest, hsa_buf + offset, bytes);
-		src += bytes;
-		dest += bytes;
-		count -= bytes;
-	}
+	kvec.iov_base = dst;
+	kvec.iov_len = count;
+	iov_iter_kvec(&iter, WRITE, &kvec, 1, count);
+	if (memcpy_hsa_iter(&iter, src, count) < count)
+		return -EIO;
 	return 0;
 }
 

drivers/s390/crypto/ap_bus.c

···
 	bus_for_each_dev(&ap_bus_type, NULL, NULL, __ap_revise_reserved);
 }
 
+/**
+ * ap_owned_by_def_drv: indicates whether an AP adapter is reserved for the
+ *			default host driver or not.
+ * @card: the APID of the adapter card to check
+ * @queue: the APQI of the queue to check
+ *
+ * Note: the ap_perms_mutex must be locked by the caller of this function.
+ *
+ * Return: an int specifying whether the AP adapter is reserved for the host (1)
+ *	   or not (0).
+ */
 int ap_owned_by_def_drv(int card, int queue)
 {
 	int rc = 0;
···
 	if (card < 0 || card >= AP_DEVICES || queue < 0 || queue >= AP_DOMAINS)
 		return -EINVAL;
 
-	mutex_lock(&ap_perms_mutex);
-
 	if (test_bit_inv(card, ap_perms.apm) &&
 	    test_bit_inv(queue, ap_perms.aqm))
 		rc = 1;
-
-	mutex_unlock(&ap_perms_mutex);
 
 	return rc;
 }
 EXPORT_SYMBOL(ap_owned_by_def_drv);
 
+/**
+ * ap_apqn_in_matrix_owned_by_def_drv: indicates whether every APQN contained in
+ *				       a set is reserved for the host drivers
+ *				       or not.
+ * @apm: a bitmap specifying a set of APIDs comprising the APQNs to check
+ * @aqm: a bitmap specifying a set of APQIs comprising the APQNs to check
+ *
+ * Note: the ap_perms_mutex must be locked by the caller of this function.
+ *
+ * Return: an int specifying whether each APQN is reserved for the host (1) or
+ *	   not (0)
+ */
 int ap_apqn_in_matrix_owned_by_def_drv(unsigned long *apm,
 				       unsigned long *aqm)
 {
 	int card, queue, rc = 0;
-
-	mutex_lock(&ap_perms_mutex);
 
 	for (card = 0; !rc && card < AP_DEVICES; card++)
 		if (test_bit_inv(card, apm) &&
···
 				if (test_bit_inv(queue, aqm) &&
 				    test_bit_inv(queue, ap_perms.aqm))
 					rc = 1;
-
-	mutex_unlock(&ap_perms_mutex);
 
 	return rc;
 }

drivers/s390/crypto/pkey_api.c

···
 	pkey_debug_exit();
 }
 
-module_cpu_feature_match(MSA, pkey_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, pkey_init);
 module_exit(pkey_exit);

drivers/s390/crypto/vfio_ap_drv.c

···
 
 #define VFIO_AP_ROOT_NAME "vfio_ap"
 #define VFIO_AP_DEV_NAME "matrix"
-#define AP_QUEUE_ASSIGNED "assigned"
-#define AP_QUEUE_UNASSIGNED "unassigned"
-#define AP_QUEUE_IN_USE "in use"
 
 MODULE_AUTHOR("IBM Corporation");
 MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
···
 	{ /* end of sibling */ },
 };
 
-static struct ap_matrix_mdev *vfio_ap_mdev_for_queue(struct vfio_ap_queue *q)
-{
-	struct ap_matrix_mdev *matrix_mdev;
-	unsigned long apid = AP_QID_CARD(q->apqn);
-	unsigned long apqi = AP_QID_QUEUE(q->apqn);
-
-	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
-		if (test_bit_inv(apid, matrix_mdev->matrix.apm) &&
-		    test_bit_inv(apqi, matrix_mdev->matrix.aqm))
-			return matrix_mdev;
-	}
-
-	return NULL;
-}
-
-static ssize_t status_show(struct device *dev,
-			   struct device_attribute *attr,
-			   char *buf)
-{
-	ssize_t nchars = 0;
-	struct vfio_ap_queue *q;
-	struct ap_matrix_mdev *matrix_mdev;
-	struct ap_device *apdev = to_ap_dev(dev);
-
-	mutex_lock(&matrix_dev->lock);
-	q = dev_get_drvdata(&apdev->device);
-	matrix_mdev = vfio_ap_mdev_for_queue(q);
-
-	if (matrix_mdev) {
-		if (matrix_mdev->kvm)
-			nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
-					   AP_QUEUE_IN_USE);
-		else
-			nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
-					   AP_QUEUE_ASSIGNED);
-	} else {
-		nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
-				   AP_QUEUE_UNASSIGNED);
-	}
-
-	mutex_unlock(&matrix_dev->lock);
-
-	return nchars;
-}
-
-static DEVICE_ATTR_RO(status);
-
-static struct attribute *vfio_queue_attrs[] = {
-	&dev_attr_status.attr,
-	NULL,
-};
-
-static const struct attribute_group vfio_queue_attr_group = {
-	.attrs = vfio_queue_attrs,
-};
-
-/**
- * vfio_ap_queue_dev_probe: Allocate a vfio_ap_queue structure and associate it
- *			    with the device as driver_data.
- *
- * @apdev: the AP device being probed
- *
- * Return: returns 0 if the probe succeeded; otherwise, returns an error if
- *	   storage could not be allocated for a vfio_ap_queue object or the
- *	   sysfs 'status' attribute could not be created for the queue device.
- */
-static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
-{
-	int ret;
-	struct vfio_ap_queue *q;
-
-	q = kzalloc(sizeof(*q), GFP_KERNEL);
-	if (!q)
-		return -ENOMEM;
-
-	mutex_lock(&matrix_dev->lock);
-	dev_set_drvdata(&apdev->device, q);
-	q->apqn = to_ap_queue(&apdev->device)->qid;
-	q->saved_isc = VFIO_AP_ISC_INVALID;
-
-	ret = sysfs_create_group(&apdev->device.kobj, &vfio_queue_attr_group);
-	if (ret) {
-		dev_set_drvdata(&apdev->device, NULL);
-		kfree(q);
-	}
-
-	mutex_unlock(&matrix_dev->lock);
-
-	return ret;
-}
-
-/**
- * vfio_ap_queue_dev_remove: Free the associated vfio_ap_queue structure.
- *
- * @apdev: the AP device being removed
- *
- * Takes the matrix lock to avoid actions on this device while doing the remove.
- */
-static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
-{
-	struct vfio_ap_queue *q;
-
-	mutex_lock(&matrix_dev->lock);
-	sysfs_remove_group(&apdev->device.kobj, &vfio_queue_attr_group);
-	q = dev_get_drvdata(&apdev->device);
-	vfio_ap_mdev_reset_queue(q, 1);
-	dev_set_drvdata(&apdev->device, NULL);
-	kfree(q);
-	mutex_unlock(&matrix_dev->lock);
-}
-
 static struct ap_driver vfio_ap_drv = {
-	.probe = vfio_ap_queue_dev_probe,
-	.remove = vfio_ap_queue_dev_remove,
+	.probe = vfio_ap_mdev_probe_queue,
+	.remove = vfio_ap_mdev_remove_queue,
+	.in_use = vfio_ap_mdev_resource_in_use,
+	.on_config_changed = vfio_ap_on_cfg_changed,
+	.on_scan_complete = vfio_ap_on_scan_complete,
 	.ids = ap_queue_ids,
 };
 
···
 			goto matrix_alloc_err;
 	}
 
-	mutex_init(&matrix_dev->lock);
+	mutex_init(&matrix_dev->mdevs_lock);
 	INIT_LIST_HEAD(&matrix_dev->mdev_list);
+	mutex_init(&matrix_dev->guests_lock);
 
 	dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
 	matrix_dev->device.parent = root_device;

drivers/s390/crypto/vfio_ap_ops.c

···
 #define VFIO_AP_MDEV_TYPE_HWVIRT "passthrough"
 #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
 
-static int vfio_ap_mdev_reset_queues(struct ap_matrix_mdev *matrix_mdev);
+#define AP_QUEUE_ASSIGNED "assigned"
+#define AP_QUEUE_UNASSIGNED "unassigned"
+#define AP_QUEUE_IN_USE "in use"
+
+static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable);
 static struct vfio_ap_queue *vfio_ap_find_queue(int apqn);
 static const struct vfio_device_ops vfio_ap_matrix_dev_ops;
+static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q, unsigned int retry);
 
-static int match_apqn(struct device *dev, const void *data)
+/**
+ * get_update_locks_for_kvm: Acquire the locks required to dynamically update a
+ *			     KVM guest's APCB in the proper order.
+ *
+ * @kvm: a pointer to a struct kvm object containing the KVM guest's APCB.
+ *
+ * The proper locking order is:
+ * 1. matrix_dev->guests_lock: required to use the KVM pointer to update a KVM
+ *			       guest's APCB.
+ * 2. kvm->lock:	       required to update a guest's APCB
+ * 3. matrix_dev->mdevs_lock:  required to access data stored in a matrix_mdev
+ *
+ * Note: If @kvm is NULL, the KVM lock will not be taken.
+ */
+static inline void get_update_locks_for_kvm(struct kvm *kvm)
 {
-	struct vfio_ap_queue *q = dev_get_drvdata(dev);
-
-	return (q->apqn == *(int *)(data)) ? 1 : 0;
+	mutex_lock(&matrix_dev->guests_lock);
+	if (kvm)
+		mutex_lock(&kvm->lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
 }
 
 /**
- * vfio_ap_get_queue - retrieve a queue with a specific APQN from a list
- * @matrix_mdev: the associated mediated matrix
- * @apqn: The queue APQN
+ * release_update_locks_for_kvm: Release the locks used to dynamically update a
+ *				 KVM guest's APCB in the proper order.
  *
- * Retrieve a queue with a specific APQN from the list of the
- * devices of the vfio_ap_drv.
- * Verify that the APID and the APQI are set in the matrix.
+ * @kvm: a pointer to a struct kvm object containing the KVM guest's APCB.
  *
- * Return: the pointer to the associated vfio_ap_queue
+ * The proper unlocking order is:
+ * 1. matrix_dev->mdevs_lock
+ * 2. kvm->lock
+ * 3. matrix_dev->guests_lock
+ *
+ * Note: If @kvm is NULL, the KVM lock will not be released.
  */
-static struct vfio_ap_queue *vfio_ap_get_queue(
+static inline void release_update_locks_for_kvm(struct kvm *kvm)
+{
+	mutex_unlock(&matrix_dev->mdevs_lock);
+	if (kvm)
+		mutex_unlock(&kvm->lock);
+	mutex_unlock(&matrix_dev->guests_lock);
+}
+
+/**
+ * get_update_locks_for_mdev: Acquire the locks required to dynamically update a
+ *			      KVM guest's APCB in the proper order.
+ *
+ * @matrix_mdev: a pointer to a struct ap_matrix_mdev object containing the AP
+ *		 configuration data to use to update a KVM guest's APCB.
+ *
+ * The proper locking order is:
+ * 1. matrix_dev->guests_lock: required to use the KVM pointer to update a KVM
+ *			       guest's APCB.
+ * 2. matrix_mdev->kvm->lock:  required to update a guest's APCB
+ * 3. matrix_dev->mdevs_lock:  required to access data stored in a matrix_mdev
+ *
+ * Note: If @matrix_mdev is NULL or is not attached to a KVM guest, the KVM
+ *	 lock will not be taken.
+ */
+static inline void get_update_locks_for_mdev(struct ap_matrix_mdev *matrix_mdev)
+{
+	mutex_lock(&matrix_dev->guests_lock);
+	if (matrix_mdev && matrix_mdev->kvm)
+		mutex_lock(&matrix_mdev->kvm->lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
+}
+
+/**
+ * release_update_locks_for_mdev: Release the locks used to dynamically update a
+ *				  KVM guest's APCB in the proper order.
+ *
+ * @matrix_mdev: a pointer to a struct ap_matrix_mdev object containing the AP
+ *		 configuration data to use to update a KVM guest's APCB.
+ *
+ * The proper unlocking order is:
+ * 1. matrix_dev->mdevs_lock
+ * 2. matrix_mdev->kvm->lock
+ * 3. matrix_dev->guests_lock
+ *
+ * Note: If @matrix_mdev is NULL or is not attached to a KVM guest, the KVM
+ *	 lock will not be released.
+ */
+static inline void release_update_locks_for_mdev(struct ap_matrix_mdev *matrix_mdev)
+{
+	mutex_unlock(&matrix_dev->mdevs_lock);
+	if (matrix_mdev && matrix_mdev->kvm)
+		mutex_unlock(&matrix_mdev->kvm->lock);
+	mutex_unlock(&matrix_dev->guests_lock);
+}
+
+/**
+ * get_update_locks_by_apqn: Find the mdev to which an APQN is assigned and
+ *			     acquire the locks required to update the APCB of
+ *			     the KVM guest to which the mdev is attached.
+ *
+ * @apqn: the APQN of a queue device.
+ *
+ * The proper locking order is:
+ * 1. matrix_dev->guests_lock: required to use the KVM pointer to update a KVM
+ *			       guest's APCB.
+ * 2. matrix_mdev->kvm->lock:  required to update a guest's APCB
+ * 3. matrix_dev->mdevs_lock:  required to access data stored in a matrix_mdev
+ *
+ * Note: If @apqn is not assigned to a matrix_mdev, the matrix_mdev->kvm->lock
+ *	 will not be taken.
+ *
+ * Return: the ap_matrix_mdev object to which @apqn is assigned or NULL if @apqn
+ *	   is not assigned to an ap_matrix_mdev.
+ */
+static struct ap_matrix_mdev *get_update_locks_by_apqn(int apqn)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+
+	mutex_lock(&matrix_dev->guests_lock);
+
+	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+		if (test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm) &&
+		    test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm)) {
+			if (matrix_mdev->kvm)
+				mutex_lock(&matrix_mdev->kvm->lock);
+
+			mutex_lock(&matrix_dev->mdevs_lock);
+
+			return matrix_mdev;
+		}
+	}
+
+	mutex_lock(&matrix_dev->mdevs_lock);
+
+	return NULL;
+}
+
+/**
+ * get_update_locks_for_queue: get the locks required to update the APCB of the
+ *			       KVM guest to which the matrix mdev linked to a
+ *			       vfio_ap_queue object is attached.
+ *
+ * @q: a pointer to a vfio_ap_queue object.
+ *
+ * The proper locking order is:
+ * 1. q->matrix_dev->guests_lock: required to use the KVM pointer to update a
+ *				  KVM guest's APCB.
+ * 2. q->matrix_mdev->kvm->lock:  required to update a guest's APCB
+ * 3. matrix_dev->mdevs_lock:	  required to access data stored in matrix_mdev
+ *
+ * Note: if @queue is not linked to an ap_matrix_mdev object, the KVM lock
+ *	  will not be taken.
+ */
+static inline void get_update_locks_for_queue(struct vfio_ap_queue *q)
+{
+	mutex_lock(&matrix_dev->guests_lock);
+	if (q->matrix_mdev && q->matrix_mdev->kvm)
+		mutex_lock(&q->matrix_mdev->kvm->lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
+}
+
+/**
+ * vfio_ap_mdev_get_queue - retrieve a queue with a specific APQN from a
+ *			    hash table of queues assigned to a matrix mdev
+ * @matrix_mdev: the matrix mdev
+ * @apqn: The APQN of a queue device
+ *
+ * Return: the pointer to the vfio_ap_queue struct representing the queue or
+ *	   NULL if the queue is not assigned to @matrix_mdev
+ */
+static struct vfio_ap_queue *vfio_ap_mdev_get_queue(
 					struct ap_matrix_mdev *matrix_mdev,
 					int apqn)
 {
 	struct vfio_ap_queue *q;
 
-	if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm))
-		return NULL;
-	if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm))
-		return NULL;
+	hash_for_each_possible(matrix_mdev->qtable.queues, q, mdev_qnode,
+			       apqn) {
+		if (q && q->apqn == apqn)
+			return q;
+	}
 
-	q = vfio_ap_find_queue(apqn);
-	if (q)
-		q->matrix_mdev = matrix_mdev;
-
-	return q;
+	return NULL;
 }
 
 /**
···
 		  status.response_code);
 end_free:
 	vfio_ap_free_aqic_resources(q);
-	q->matrix_mdev = NULL;
 	return status;
 }
 
···
 		return -EOPNOTSUPP;
 	}
 
-	mutex_lock(&matrix_dev->lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
+
 	if (!vcpu->kvm->arch.crypto.pqap_hook) {
 		VFIO_AP_DBF_WARN("%s: PQAP(AQIC) hook not registered with the vfio_ap driver: apqn=0x%04x\n",
 				 __func__, apqn);
+
 		goto out_unlock;
 	}
 
···
 		goto out_unlock;
 	}
 
-	q = vfio_ap_get_queue(matrix_mdev, apqn);
+	q = vfio_ap_mdev_get_queue(matrix_mdev, apqn);
 	if (!q) {
 		VFIO_AP_DBF_WARN("%s: Queue %02x.%04x not bound to the vfio_ap driver\n",
 				 __func__, AP_QID_CARD(apqn),
···
 out_unlock:
 	memcpy(&vcpu->run->s.regs.gprs[1], &qstatus, sizeof(qstatus));
 	vcpu->run->s.regs.gprs[1] >>= 32;
-	mutex_unlock(&matrix_dev->lock);
+	mutex_unlock(&matrix_dev->mdevs_lock);
 	return 0;
 }
 
···
 	matrix->apm_max = info->apxa ? info->Na : 63;
 	matrix->aqm_max = info->apxa ? info->Nd : 15;
 	matrix->adm_max = info->apxa ? info->Nd : 15;
+}
+
+static void vfio_ap_mdev_update_guest_apcb(struct ap_matrix_mdev *matrix_mdev)
+{
+	if (matrix_mdev->kvm)
+		kvm_arch_crypto_set_masks(matrix_mdev->kvm,
+					  matrix_mdev->shadow_apcb.apm,
+					  matrix_mdev->shadow_apcb.aqm,
+					  matrix_mdev->shadow_apcb.adm);
+}
+
+static bool vfio_ap_mdev_filter_cdoms(struct ap_matrix_mdev *matrix_mdev)
+{
+	DECLARE_BITMAP(prev_shadow_adm, AP_DOMAINS);
+
+	bitmap_copy(prev_shadow_adm, matrix_mdev->shadow_apcb.adm, AP_DOMAINS);
+	bitmap_and(matrix_mdev->shadow_apcb.adm, matrix_mdev->matrix.adm,
+		   (unsigned long *)matrix_dev->info.adm, AP_DOMAINS);
+
+	return !bitmap_equal(prev_shadow_adm, matrix_mdev->shadow_apcb.adm,
+			     AP_DOMAINS);
+}
+
+/*
+ * vfio_ap_mdev_filter_matrix - filter the APQNs assigned to the matrix mdev
+ *				to ensure no queue devices are passed through to
+ *				the guest that are not bound to the vfio_ap
+ *				device driver.
+ *
+ * @matrix_mdev: the matrix mdev whose matrix is to be filtered.
+ *
+ * Note: If an APQN referencing a queue device that is not bound to the vfio_ap
+ *	 driver, its APID will be filtered from the guest's APCB. The matrix
+ *	 structure precludes filtering an individual APQN, so its APID will be
+ *	 filtered.
+ *
+ * Return: a boolean value indicating whether the KVM guest's APCB was changed
+ *	   by the filtering or not.
+ */
+static bool vfio_ap_mdev_filter_matrix(unsigned long *apm, unsigned long *aqm,
+				       struct ap_matrix_mdev *matrix_mdev)
+{
+	unsigned long apid, apqi, apqn;
+	DECLARE_BITMAP(prev_shadow_apm, AP_DEVICES);
+	DECLARE_BITMAP(prev_shadow_aqm, AP_DOMAINS);
+	struct vfio_ap_queue *q;
+
+	bitmap_copy(prev_shadow_apm, matrix_mdev->shadow_apcb.apm, AP_DEVICES);
+	bitmap_copy(prev_shadow_aqm, matrix_mdev->shadow_apcb.aqm, AP_DOMAINS);
+	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
+
+	/*
+	 * Copy the adapters, domains and control domains to the shadow_apcb
+	 * from the matrix mdev, but only those that are assigned to the host's
+	 * AP configuration.
+	 */
+	bitmap_and(matrix_mdev->shadow_apcb.apm, matrix_mdev->matrix.apm,
+		   (unsigned long *)matrix_dev->info.apm, AP_DEVICES);
+	bitmap_and(matrix_mdev->shadow_apcb.aqm, matrix_mdev->matrix.aqm,
+		   (unsigned long *)matrix_dev->info.aqm, AP_DOMAINS);
+
+	for_each_set_bit_inv(apid, apm, AP_DEVICES) {
+		for_each_set_bit_inv(apqi, aqm, AP_DOMAINS) {
+			/*
+			 * If the APQN is not bound to the vfio_ap device
+			 * driver, then we can't assign it to the guest's
+			 * AP configuration. The AP architecture won't
+			 * allow filtering of a single APQN, so let's filter
+			 * the APID since an adapter represents a physical
+			 * hardware device.
+			 */
+			apqn = AP_MKQID(apid, apqi);
+			q = vfio_ap_mdev_get_queue(matrix_mdev, apqn);
+			if (!q || q->reset_rc) {
+				clear_bit_inv(apid,
+					      matrix_mdev->shadow_apcb.apm);
+				break;
+			}
+		}
+	}
+
+	return !bitmap_equal(prev_shadow_apm, matrix_mdev->shadow_apcb.apm,
+			     AP_DEVICES) ||
+	       !bitmap_equal(prev_shadow_aqm, matrix_mdev->shadow_apcb.aqm,
+			     AP_DOMAINS);
 }
 
 static int vfio_ap_mdev_probe(struct mdev_device *mdev)
···
 	matrix_mdev->mdev = mdev;
 	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
 	matrix_mdev->pqap_hook = handle_pqap;
-	mutex_lock(&matrix_dev->lock);
-	list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
-	mutex_unlock(&matrix_dev->lock);
+	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
+	hash_init(matrix_mdev->qtable.queues);
 
 	ret = vfio_register_emulated_iommu_dev(&matrix_mdev->vdev);
 	if (ret)
 		goto err_list;
 	dev_set_drvdata(&mdev->dev, matrix_mdev);
+	mutex_lock(&matrix_dev->mdevs_lock);
+	list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
+	mutex_unlock(&matrix_dev->mdevs_lock);
 	return 0;
 
 err_list:
-	mutex_lock(&matrix_dev->lock);
-	list_del(&matrix_mdev->node);
-	mutex_unlock(&matrix_dev->lock);
 	vfio_uninit_group_dev(&matrix_mdev->vdev);
 	kfree(matrix_mdev);
 err_dec_available:
 	atomic_inc(&matrix_dev->available_instances);
 	return ret;
+}
+
+static void vfio_ap_mdev_link_queue(struct ap_matrix_mdev *matrix_mdev,
+				    struct vfio_ap_queue *q)
+{
+	if (q) {
+		q->matrix_mdev = matrix_mdev;
+		hash_add(matrix_mdev->qtable.queues, &q->mdev_qnode, q->apqn);
+	}
+}
+
+static void vfio_ap_mdev_link_apqn(struct ap_matrix_mdev *matrix_mdev, int apqn)
+{
+	struct vfio_ap_queue *q;
+
+	q = vfio_ap_find_queue(apqn);
+	vfio_ap_mdev_link_queue(matrix_mdev, q);
+}
+
+static void vfio_ap_unlink_queue_fr_mdev(struct vfio_ap_queue *q)
+{
+	hash_del(&q->mdev_qnode);
+}
+
+static void vfio_ap_unlink_mdev_fr_queue(struct vfio_ap_queue *q)
+{
+	q->matrix_mdev = NULL;
+}
+
+static void vfio_ap_mdev_unlink_fr_queues(struct ap_matrix_mdev *matrix_mdev)
+{
+	struct vfio_ap_queue *q;
+	unsigned long apid, apqi;
+
+	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES) {
+		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
+				     AP_DOMAINS) {
+			q = vfio_ap_mdev_get_queue(matrix_mdev,
+						   AP_MKQID(apid, apqi));
+			if (q)
+				q->matrix_mdev = NULL;
+		}
+	}
 }
 
 static void vfio_ap_mdev_remove(struct mdev_device *mdev)
···
 
 	vfio_unregister_group_dev(&matrix_mdev->vdev);
 
-	mutex_lock(&matrix_dev->lock);
-	vfio_ap_mdev_reset_queues(matrix_mdev);
+	mutex_lock(&matrix_dev->guests_lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
+	vfio_ap_mdev_reset_queues(&matrix_mdev->qtable);
+	vfio_ap_mdev_unlink_fr_queues(matrix_mdev);
 	list_del(&matrix_mdev->node);
-	mutex_unlock(&matrix_dev->lock);
+	mutex_unlock(&matrix_dev->mdevs_lock);
+	mutex_unlock(&matrix_dev->guests_lock);
 	vfio_uninit_group_dev(&matrix_mdev->vdev);
 	kfree(matrix_mdev);
 	atomic_inc(&matrix_dev->available_instances);
···
 	NULL,
 };
 
-struct vfio_ap_queue_reserved {
-	unsigned long *apid;
-	unsigned long *apqi;
-	bool reserved;
-};
+#define MDEV_SHARING_ERR "Userspace may not re-assign queue %02lx.%04lx " \
+			 "already assigned to %s"
 
-/**
- * vfio_ap_has_queue - determines if the AP queue containing the target in @data
- *
- * @dev: an AP queue device
- * @data: a struct vfio_ap_queue_reserved reference
- *
- * Flags whether the AP queue device (@dev) has a queue ID containing the APQN,
- * apid or apqi specified in @data:
- *
- * - If @data contains both an apid and apqi value, then @data will be flagged
- *   as reserved if the APID and APQI fields for the AP queue device matches
- *
- * - If @data contains only an apid value, @data will be flagged as
- *   reserved if the APID field in the AP queue device matches
- *
- * - If @data contains only an apqi value, @data will be flagged as
- *   reserved if the APQI field in the AP queue device matches
- *
- * Return: 0 to indicate the input to function succeeded. Returns -EINVAL if
- * @data does not contain either an apid or apqi.
- */
-static int vfio_ap_has_queue(struct device *dev, void *data)
+static void vfio_ap_mdev_log_sharing_err(struct ap_matrix_mdev *matrix_mdev,
+					 unsigned long *apm,
+					 unsigned long *aqm)
 {
-	struct vfio_ap_queue_reserved *qres = data;
-	struct ap_queue *ap_queue = to_ap_queue(dev);
-	ap_qid_t qid;
-	unsigned long id;
+	unsigned long apid, apqi;
+	const struct device *dev = mdev_dev(matrix_mdev->mdev);
+	const char *mdev_name = dev_name(dev);
 
-	if (qres->apid && qres->apqi) {
-		qid = AP_MKQID(*qres->apid, *qres->apqi);
-		if (qid == ap_queue->qid)
-			qres->reserved = true;
-	} else if (qres->apid && !qres->apqi) {
-		id = AP_QID_CARD(ap_queue->qid);
-		if (id == *qres->apid)
-			qres->reserved = true;
-	} else if (!qres->apid && qres->apqi) {
-		id = AP_QID_QUEUE(ap_queue->qid);
-		if (id == *qres->apqi)
-			qres->reserved = true;
-	} else {
-		return -EINVAL;
-	}
-
-	return 0;
+	for_each_set_bit_inv(apid, apm, AP_DEVICES)
+		for_each_set_bit_inv(apqi, aqm, AP_DOMAINS)
+			dev_warn(dev, MDEV_SHARING_ERR, apid, apqi, mdev_name);
 }
 
 /**
- * vfio_ap_verify_queue_reserved - verifies that the AP queue containing
- * @apid or @aqpi is reserved
+ * vfio_ap_mdev_verify_no_sharing - verify APQNs are not shared by matrix mdevs
  *
- * @apid: an AP adapter ID
- * @apqi: an AP queue index
+ * @mdev_apm: mask indicating the APIDs of the APQNs to be verified
+ * @mdev_aqm: mask indicating the APQIs of the APQNs to be verified
  *
- * Verifies that the AP queue with @apid/@apqi is reserved by the VFIO AP device
- * driver according to the following rules:
- *
- * - If both @apid and @apqi are not NULL, then there must be an AP queue
- *   device bound to the vfio_ap driver with the APQN identified by @apid and
- *   @apqi
- *
- * - If only @apid is not NULL, then there must be an AP queue device bound
- *   to the vfio_ap driver with an APQN containing @apid
- *
- * - If only @apqi is not NULL, then there must be an AP queue device bound
- *   to the vfio_ap driver with an APQN containing @apqi
- *
- * Return: 0 if the AP queue is reserved; otherwise, returns -EADDRNOTAVAIL.
- */
-static int vfio_ap_verify_queue_reserved(unsigned long *apid,
-					 unsigned long *apqi)
-{
-	int ret;
-	struct vfio_ap_queue_reserved qres;
-
-	qres.apid = apid;
-	qres.apqi = apqi;
-	qres.reserved = false;
-
-	ret = driver_for_each_device(&matrix_dev->vfio_ap_drv->driver, NULL,
-				     &qres, vfio_ap_has_queue);
-	if (ret)
-		return ret;
-
-	if (qres.reserved)
-		return 0;
-
-	return -EADDRNOTAVAIL;
-}
-
-static int
-vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev,
-					     unsigned long apid)
-{
-	int ret;
-	unsigned long apqi;
-	unsigned long nbits = matrix_mdev->matrix.aqm_max + 1;
-
-	if (find_first_bit_inv(matrix_mdev->matrix.aqm, nbits) >= nbits)
-		return vfio_ap_verify_queue_reserved(&apid, NULL);
-
-	for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, nbits) {
-		ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-
-/**
- * vfio_ap_mdev_verify_no_sharing - verifies that the AP matrix is not configured
- *
- * @matrix_mdev: the mediated matrix device
- *
- * Verifies that the APQNs derived from the cross product of the AP adapter IDs
- * and AP queue indexes comprising the AP matrix are not configured for another
+ * Verifies that each APQN derived from the Cartesian product of a bitmap of
+ * AP adapter IDs and AP queue indexes is not configured for any matrix
  * mediated device. AP queue sharing is not allowed.
  *
- * Return: 0 if the APQNs are not shared; otherwise returns -EADDRINUSE.
+ * Return: 0 if the APQNs are not shared; otherwise return -EADDRINUSE.
  */
-static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
+static int vfio_ap_mdev_verify_no_sharing(unsigned long *mdev_apm,
+					  unsigned long *mdev_aqm)
 {
-	struct ap_matrix_mdev *lstdev;
+	struct ap_matrix_mdev *matrix_mdev;
 	DECLARE_BITMAP(apm, AP_DEVICES);
 	DECLARE_BITMAP(aqm, AP_DOMAINS);
 
-	list_for_each_entry(lstdev, &matrix_dev->mdev_list, node) {
-		if (matrix_mdev == lstdev)
+	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+		/*
+		 * If the input apm and aqm are fields of the matrix_mdev
+		 * object, then move on to the next matrix_mdev.
+		 */
+		if (mdev_apm == matrix_mdev->matrix.apm &&
+		    mdev_aqm == matrix_mdev->matrix.aqm)
 			continue;
 
 		memset(apm, 0, sizeof(apm));
···
 		 * We work on full longs, as we can only exclude the leftover
 		 * bits in non-inverse order. The leftover is all zeros.
 		 */
-		if (!bitmap_and(apm, matrix_mdev->matrix.apm,
-				lstdev->matrix.apm, AP_DEVICES))
+		if (!bitmap_and(apm, mdev_apm, matrix_mdev->matrix.apm,
+				AP_DEVICES))
 			continue;
 
-		if (!bitmap_and(aqm, matrix_mdev->matrix.aqm,
-				lstdev->matrix.aqm, AP_DOMAINS))
+		if (!bitmap_and(aqm, mdev_aqm, matrix_mdev->matrix.aqm,
+				AP_DOMAINS))
 			continue;
+
+		vfio_ap_mdev_log_sharing_err(matrix_mdev, apm, aqm);
 
 		return -EADDRINUSE;
 	}
 
 	return 0;
+}
+
+/**
+ * vfio_ap_mdev_validate_masks - verify that the APQNs assigned to the mdev are
+ *				 not reserved for the default zcrypt driver and
+ *				 are not assigned to another mdev.
+ *
+ * @matrix_mdev: the mdev to which the APQNs being validated are assigned.
+ *
+ * Return: One of the following values:
+ * o the error returned from the ap_apqn_in_matrix_owned_by_def_drv() function,
+ *   most likely -EBUSY indicating the ap_perms_mutex lock is already held.
+ * o EADDRNOTAVAIL if an APQN assigned to @matrix_mdev is reserved for the
+ *		   zcrypt default driver.
+ * o EADDRINUSE if an APQN assigned to @matrix_mdev is assigned to another mdev
+ * o A zero indicating validation succeeded.
+ */
+static int vfio_ap_mdev_validate_masks(struct ap_matrix_mdev *matrix_mdev)
+{
+	if (ap_apqn_in_matrix_owned_by_def_drv(matrix_mdev->matrix.apm,
+					       matrix_mdev->matrix.aqm))
+		return -EADDRNOTAVAIL;
+
+	return vfio_ap_mdev_verify_no_sharing(matrix_mdev->matrix.apm,
+					      matrix_mdev->matrix.aqm);
+}
+
+static void vfio_ap_mdev_link_adapter(struct ap_matrix_mdev *matrix_mdev,
+				      unsigned long apid)
+{
+	unsigned long apqi;
+
+	for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, AP_DOMAINS)
+		vfio_ap_mdev_link_apqn(matrix_mdev,
+				       AP_MKQID(apid, apqi));
 }
 
 /**
···
  *	   An APQN derived from the cross product of the APID being assigned
  *	   and the APQIs previously assigned is being used by another mediated
  *	   matrix device
+ *
+ *	5. -EAGAIN
+ *	   A lock required to validate the mdev's AP configuration could not
+ *	   be obtained.
  */
 static ssize_t assign_adapter_store(struct device *dev,
 				    struct device_attribute *attr,
···
 {
 	int ret;
 	unsigned long apid;
+	DECLARE_BITMAP(apm_delta, AP_DEVICES);
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 
-	mutex_lock(&matrix_dev->lock);
-
-	/* If the KVM guest is running, disallow assignment of adapter */
-	if (matrix_mdev->kvm) {
-		ret = -EBUSY;
-		goto done;
-	}
+	mutex_lock(&ap_perms_mutex);
+	get_update_locks_for_mdev(matrix_mdev);
 
 	ret = kstrtoul(buf, 0, &apid);
 	if (ret)
···
 		goto done;
 	}
 
-	/*
-	 * Set the bit in the AP mask (APM) corresponding to the AP adapter
-	 * number (APID). The bits in the mask, from most significant to least
-	 * significant bit, correspond to APIDs 0-255.
-	 */
-	ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);
-	if (ret)
-		goto done;
-
 	set_bit_inv(apid, matrix_mdev->matrix.apm);
 
-	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
-	if (ret)
-		goto share_err;
+	ret = vfio_ap_mdev_validate_masks(matrix_mdev);
+	if (ret) {
+		clear_bit_inv(apid, matrix_mdev->matrix.apm);
+		goto done;
+	}
+
+	vfio_ap_mdev_link_adapter(matrix_mdev, apid);
+	memset(apm_delta, 0, sizeof(apm_delta));
+	set_bit_inv(apid, apm_delta);
+
+	if (vfio_ap_mdev_filter_matrix(apm_delta,
+				       matrix_mdev->matrix.aqm, matrix_mdev))
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
 
 	ret = count;
-	goto done;
-
-share_err:
-	clear_bit_inv(apid, matrix_mdev->matrix.apm);
 done:
-	mutex_unlock(&matrix_dev->lock);
+	release_update_locks_for_mdev(matrix_mdev);
+	mutex_unlock(&ap_perms_mutex);
 
 	return ret;
 }
 static DEVICE_ATTR_WO(assign_adapter);
+
+static struct vfio_ap_queue
+*vfio_ap_unlink_apqn_fr_mdev(struct ap_matrix_mdev *matrix_mdev,
+			     unsigned long apid, unsigned long apqi)
+{
+	struct vfio_ap_queue *q = NULL;
+
+	q = vfio_ap_mdev_get_queue(matrix_mdev, AP_MKQID(apid, apqi));
+	/* If the queue is assigned to the matrix mdev, unlink it. */
+	if (q)
+		vfio_ap_unlink_queue_fr_mdev(q);
+
+	return q;
+}
+
+/**
+ * vfio_ap_mdev_unlink_adapter - unlink all queues associated with unassigned
+ *				 adapter from the matrix mdev to which the
+ *				 adapter was assigned.
+ * @matrix_mdev: the matrix mediated device to which the adapter was assigned.
+ * @apid: the APID of the unassigned adapter.
+ * @qtable: table for storing queues associated with unassigned adapter.
+ */
+static void vfio_ap_mdev_unlink_adapter(struct ap_matrix_mdev *matrix_mdev,
+					unsigned long apid,
+					struct ap_queue_table *qtable)
+{
+	unsigned long apqi;
+	struct vfio_ap_queue *q;
+
+	for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, AP_DOMAINS) {
+		q = vfio_ap_unlink_apqn_fr_mdev(matrix_mdev, apid, apqi);
+
+		if (q && qtable) {
+			if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm) &&
+			    test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm))
+				hash_add(qtable->queues, &q->mdev_qnode,
+					 q->apqn);
+		}
+	}
+}
+
+static void vfio_ap_mdev_hot_unplug_adapter(struct ap_matrix_mdev *matrix_mdev,
+					    unsigned long apid)
+{
+	int loop_cursor;
+	struct vfio_ap_queue *q;
+	struct ap_queue_table *qtable = kzalloc(sizeof(*qtable), GFP_KERNEL);
+
+	hash_init(qtable->queues);
+	vfio_ap_mdev_unlink_adapter(matrix_mdev, apid, qtable);
+
+	if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm)) {
+		clear_bit_inv(apid, matrix_mdev->shadow_apcb.apm);
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+	}
+
+	vfio_ap_mdev_reset_queues(qtable);
+
+	hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {
+		vfio_ap_unlink_mdev_fr_queue(q);
+		hash_del(&q->mdev_qnode);
+	}
+
+	kfree(qtable);
+}
 
 /**
  * unassign_adapter_store - parses the APID from @buf and clears the
···
 	unsigned long apid;
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 
-	mutex_lock(&matrix_dev->lock);
-
-	/* If the KVM guest is running, disallow unassignment of adapter */
-	if (matrix_mdev->kvm) {
-		ret = -EBUSY;
-		goto done;
-	}
+	get_update_locks_for_mdev(matrix_mdev);
 
 	ret = kstrtoul(buf, 0, &apid);
 	if (ret)
···
 	}
 
 	clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+	vfio_ap_mdev_hot_unplug_adapter(matrix_mdev, apid);
 	ret = count;
 done:
-	mutex_unlock(&matrix_dev->lock);
+	release_update_locks_for_mdev(matrix_mdev);
 	return ret;
 }
 static DEVICE_ATTR_WO(unassign_adapter);
 
-static int
-vfio_ap_mdev_verify_queues_reserved_for_apqi(struct ap_matrix_mdev *matrix_mdev,
-					     unsigned long apqi)
+static void vfio_ap_mdev_link_domain(struct ap_matrix_mdev *matrix_mdev,
+				     unsigned long apqi)
 {
-	int ret;
 	unsigned long apid;
-	unsigned long nbits = matrix_mdev->matrix.apm_max + 1;
 
-	if (find_first_bit_inv(matrix_mdev->matrix.apm, nbits) >= nbits)
-		return vfio_ap_verify_queue_reserved(NULL, &apqi);
-
-	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, nbits) {
-		ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
+	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES)
+		vfio_ap_mdev_link_apqn(matrix_mdev,
+				       AP_MKQID(apid, apqi));
 }
 
 /**
···
  *	   An APQN derived from the cross product of the APQI being assigned
  *	   and the APIDs previously assigned is being used by another mediated
  *	   matrix device
+ *
+ *	5. -EAGAIN
+ *	   The lock required to validate the mdev's AP configuration could not
+ *	   be obtained.
  */
 static ssize_t assign_domain_store(struct device *dev,
 				   struct device_attribute *attr,
···
 {
 	int ret;
 	unsigned long apqi;
+	DECLARE_BITMAP(aqm_delta, AP_DOMAINS);
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
-	unsigned long max_apqi = matrix_mdev->matrix.aqm_max;
 
-	mutex_lock(&matrix_dev->lock);
-
-	/* If the KVM guest is running, disallow assignment of domain */
-	if (matrix_mdev->kvm) {
-		ret = -EBUSY;
-		goto done;
-	}
+	mutex_lock(&ap_perms_mutex);
+	get_update_locks_for_mdev(matrix_mdev);
 
 	ret = kstrtoul(buf, 0, &apqi);
 	if (ret)
 		goto done;
-	if (apqi > max_apqi) {
+
+	if (apqi > matrix_mdev->matrix.aqm_max) {
 		ret = -ENODEV;
 		goto done;
 	}
 
-	ret = vfio_ap_mdev_verify_queues_reserved_for_apqi(matrix_mdev, apqi);
-	if (ret)
-		goto done;
-
 	set_bit_inv(apqi, matrix_mdev->matrix.aqm);
 
-	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
-	if (ret)
-		goto share_err;
+	ret = vfio_ap_mdev_validate_masks(matrix_mdev);
+	if (ret) {
+		clear_bit_inv(apqi, matrix_mdev->matrix.aqm);
+		goto done;
+	}
+
+	vfio_ap_mdev_link_domain(matrix_mdev, apqi);
+	memset(aqm_delta, 0, sizeof(aqm_delta));
+	set_bit_inv(apqi, aqm_delta);
+
+	if (vfio_ap_mdev_filter_matrix(matrix_mdev->matrix.apm, aqm_delta,
+				       matrix_mdev))
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
 
 	ret = count;
-	goto done;
-
-share_err:
-	clear_bit_inv(apqi, matrix_mdev->matrix.aqm);
 done:
-	mutex_unlock(&matrix_dev->lock);
+	release_update_locks_for_mdev(matrix_mdev);
+	mutex_unlock(&ap_perms_mutex);
 
 	return ret;
 }
 static DEVICE_ATTR_WO(assign_domain);
 
+static void vfio_ap_mdev_unlink_domain(struct ap_matrix_mdev *matrix_mdev,
+				       unsigned long apqi,
+				       struct ap_queue_table *qtable)
+{
+	unsigned long apid;
+	struct vfio_ap_queue *q;
+
+	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES) {
+		q = vfio_ap_unlink_apqn_fr_mdev(matrix_mdev, apid, apqi);
+
+		if (q && qtable) {
+			if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm) &&
+			    test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm))
+				hash_add(qtable->queues, &q->mdev_qnode,
+					 q->apqn);
+		}
+	}
+}
+
+static void vfio_ap_mdev_hot_unplug_domain(struct ap_matrix_mdev *matrix_mdev,
+					   unsigned long apqi)
+{
+	int loop_cursor;
+	struct vfio_ap_queue *q;
+	struct ap_queue_table *qtable = kzalloc(sizeof(*qtable), GFP_KERNEL);
+
+	hash_init(qtable->queues);
+	vfio_ap_mdev_unlink_domain(matrix_mdev, apqi, qtable);
+
+	if (test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm)) {
+		clear_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm);
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+	}
+
+	vfio_ap_mdev_reset_queues(qtable);
+
+	hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {
+		vfio_ap_unlink_mdev_fr_queue(q);
+		hash_del(&q->mdev_qnode);
+	}
+
+	kfree(qtable);
+}
 
 /**
  * unassign_domain_store - parses the APQI from @buf and clears the
···
 	unsigned long apqi;
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 
-	mutex_lock(&matrix_dev->lock);
-
-	/* If the KVM guest is running, disallow unassignment of domain */
-	if (matrix_mdev->kvm) {
-		ret = -EBUSY;
-		goto done;
-	}
+	get_update_locks_for_mdev(matrix_mdev);
 
 	ret = kstrtoul(buf, 0, &apqi);
 	if (ret)
···
 	}
 
 	clear_bit_inv((unsigned long)apqi, matrix_mdev->matrix.aqm);
+	vfio_ap_mdev_hot_unplug_domain(matrix_mdev, apqi);
 	ret = count;
 
 done:
-	mutex_unlock(&matrix_dev->lock);
+	release_update_locks_for_mdev(matrix_mdev);
 	return ret;
 }
 static DEVICE_ATTR_WO(unassign_domain);
···
 	unsigned long id;
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 
-	mutex_lock(&matrix_dev->lock);
-
-	/* If the KVM guest is running, disallow assignment of control domain */
-	if (matrix_mdev->kvm) {
-		ret = -EBUSY;
-		goto done;
-	}
+	get_update_locks_for_mdev(matrix_mdev);
 
 	ret = kstrtoul(buf, 0, &id);
 	if (ret)
···
 	 * number of control domains that can be assigned.
 	 */
 	set_bit_inv(id, matrix_mdev->matrix.adm);
+	if (vfio_ap_mdev_filter_cdoms(matrix_mdev))
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+
 	ret = count;
 done:
-	mutex_unlock(&matrix_dev->lock);
+	release_update_locks_for_mdev(matrix_mdev);
 	return ret;
 }
 static DEVICE_ATTR_WO(assign_control_domain);
···
 	int ret;
 	unsigned long domid;
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
-	unsigned long max_domid =  matrix_mdev->matrix.adm_max;
 
-	mutex_lock(&matrix_dev->lock);
-
-	/* If a KVM guest is running, disallow unassignment of control domain */
-	if (matrix_mdev->kvm) {
-		ret = -EBUSY;
-		goto done;
-	}
+	get_update_locks_for_mdev(matrix_mdev);
 
 	ret = kstrtoul(buf, 0, &domid);
 	if (ret)
 		goto done;
-	if (domid > max_domid) {
+
+	if (domid > matrix_mdev->matrix.adm_max) {
 		ret = -ENODEV;
 		goto done;
 	}
 
 	clear_bit_inv(domid, matrix_mdev->matrix.adm);
+
+	if (test_bit_inv(domid, matrix_mdev->shadow_apcb.adm)) {
+		clear_bit_inv(domid, matrix_mdev->shadow_apcb.adm);
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+	}
+
 	ret = count;
 done:
-	mutex_unlock(&matrix_dev->lock);
+	release_update_locks_for_mdev(matrix_mdev);
 	return ret;
 }
 static DEVICE_ATTR_WO(unassign_control_domain);
···
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 	unsigned long max_domid = matrix_mdev->matrix.adm_max;
 
-	mutex_lock(&matrix_dev->lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
 	for_each_set_bit_inv(id, matrix_mdev->matrix.adm, max_domid + 1) {
 		n = sprintf(bufpos, "%04lx\n", id);
 		bufpos += n;
 		nchars += n;
 	}
-	mutex_unlock(&matrix_dev->lock);
+	mutex_unlock(&matrix_dev->mdevs_lock);
 
 	return nchars;
 }
 static DEVICE_ATTR_RO(control_domains);
 
-static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
-			   char *buf)
+static ssize_t vfio_ap_mdev_matrix_show(struct ap_matrix *matrix, char *buf)
 {
-	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 	char *bufpos = buf;
 	unsigned long apid;
 	unsigned long apqi;
 	unsigned long apid1;
 	unsigned long apqi1;
-	unsigned long napm_bits = matrix_mdev->matrix.apm_max + 1;
-	unsigned long naqm_bits = matrix_mdev->matrix.aqm_max + 1;
+	unsigned long napm_bits = matrix->apm_max + 1;
+	unsigned long naqm_bits = matrix->aqm_max + 1;
 	int nchars = 0;
 	int n;
 
-	apid1 = find_first_bit_inv(matrix_mdev->matrix.apm, napm_bits);
-	apqi1 = find_first_bit_inv(matrix_mdev->matrix.aqm, naqm_bits);
-
-	mutex_lock(&matrix_dev->lock);
+	apid1 = find_first_bit_inv(matrix->apm, napm_bits);
+	apqi1 = find_first_bit_inv(matrix->aqm, naqm_bits);
 
 	if ((apid1 < napm_bits) && (apqi1 < naqm_bits)) {
-		for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
-			for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
+		for_each_set_bit_inv(apid, matrix->apm, napm_bits) {
+			for_each_set_bit_inv(apqi, matrix->aqm,
 					     naqm_bits) {
 				n = sprintf(bufpos, "%02lx.%04lx\n", apid,
 					    apqi);
···
 			}
 		}
 	} else if (apid1 < napm_bits) {
-		for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
+		for_each_set_bit_inv(apid, matrix->apm, napm_bits) {
 			n = sprintf(bufpos, "%02lx.\n", apid);
 			bufpos += n;
 			nchars += n;
 		}
 	} else if (apqi1 < naqm_bits) {
-		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, naqm_bits) {
+		for_each_set_bit_inv(apqi, matrix->aqm, naqm_bits) {
 			n = sprintf(bufpos, ".%04lx\n", apqi);
 			bufpos += n;
 			nchars += n;
 		}
 	}
 
-	mutex_unlock(&matrix_dev->lock);
+	return nchars;
+}
+
+static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	ssize_t nchars;
+	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
+
+	mutex_lock(&matrix_dev->mdevs_lock);
+	nchars = vfio_ap_mdev_matrix_show(&matrix_mdev->matrix, buf);
+	mutex_unlock(&matrix_dev->mdevs_lock);
 
 	return nchars;
 }
 static DEVICE_ATTR_RO(matrix);
+
+static ssize_t guest_matrix_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	ssize_t nchars;
+	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
+
+	mutex_lock(&matrix_dev->mdevs_lock);
+	nchars = vfio_ap_mdev_matrix_show(&matrix_mdev->shadow_apcb, buf);
+	mutex_unlock(&matrix_dev->mdevs_lock);
+
+	return nchars;
+}
+static DEVICE_ATTR_RO(guest_matrix);
 
 static struct attribute *vfio_ap_mdev_attrs[] = {
 	&dev_attr_assign_adapter.attr,
···
 	&dev_attr_unassign_control_domain.attr,
 	&dev_attr_control_domains.attr,
 	&dev_attr_matrix.attr,
+	&dev_attr_guest_matrix.attr,
 	NULL,
 };
 
···
 		kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
 		up_write(&kvm->arch.crypto.pqap_hook_rwsem);
 
-		mutex_lock(&kvm->lock);
-		mutex_lock(&matrix_dev->lock);
+		get_update_locks_for_kvm(kvm);
 
 		list_for_each_entry(m, &matrix_dev->mdev_list, node) {
 			if (m != matrix_mdev && m->kvm == kvm) {
-				mutex_unlock(&kvm->lock);
-				mutex_unlock(&matrix_dev->lock);
+				release_update_locks_for_kvm(kvm);
 				return -EPERM;
 			}
 		}
 
 		kvm_get_kvm(kvm);
 		matrix_mdev->kvm = kvm;
-		kvm_arch_crypto_set_masks(kvm,
-					  matrix_mdev->matrix.apm,
-					  matrix_mdev->matrix.aqm,
-					  matrix_mdev->matrix.adm);
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
 
-		mutex_unlock(&kvm->lock);
-		mutex_unlock(&matrix_dev->lock);
+		release_update_locks_for_kvm(kvm);
 	}
 
 	return 0;
···
 		kvm->arch.crypto.pqap_hook = NULL;
 		up_write(&kvm->arch.crypto.pqap_hook_rwsem);
 
-		mutex_lock(&kvm->lock);
-		mutex_lock(&matrix_dev->lock);
+		get_update_locks_for_kvm(kvm);
 
 		kvm_arch_crypto_clear_masks(kvm);
-		vfio_ap_mdev_reset_queues(matrix_mdev);
+		vfio_ap_mdev_reset_queues(&matrix_mdev->qtable);
 		kvm_put_kvm(kvm);
 		matrix_mdev->kvm = NULL;
 
-		mutex_unlock(&kvm->lock);
-		mutex_unlock(&matrix_dev->lock);
+		release_update_locks_for_kvm(kvm);
 	}
 }
 
 static struct vfio_ap_queue *vfio_ap_find_queue(int apqn)
 {
-	struct device *dev;
+	struct ap_queue *queue;
 	struct vfio_ap_queue *q = NULL;
 
-	dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
-				 &apqn, match_apqn);
-	if (dev) {
-		q = dev_get_drvdata(dev);
-		put_device(dev);
-	}
+	queue = ap_get_qdev(apqn);
+	if (!queue)
+		return NULL;
+
+	if (queue->ap_dev.device.driver == &matrix_dev->vfio_ap_drv->driver)
+		q = dev_get_drvdata(&queue->ap_dev.device);
+
+	put_device(&queue->ap_dev.device);
 
 	return q;
 }
 
-int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
-			     unsigned int retry)
+static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
+				    unsigned int retry)
 {
 	struct ap_queue_status status;
 	int ret;
···
 
 	if (!q)
 		return 0;
-
 retry_zapq:
 	status = ap_zapq(q->apqn);
+	q->reset_rc = status.response_code;
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		ret = 0;
···
 	case AP_RESPONSE_Q_NOT_AVAIL:
 	case AP_RESPONSE_DECONFIGURED:
 	case AP_RESPONSE_CHECKSTOPPED:
-		WARN_ON_ONCE(status.irq_enabled);
+		WARN_ONCE(status.irq_enabled,
+			  "PQAP/ZAPQ for %02x.%04x failed with rc=%u while IRQ enabled",
+			  AP_QID_CARD(q->apqn), AP_QID_QUEUE(q->apqn),
+			  status.response_code);
 		ret = -EBUSY;
 		goto free_resources;
 	default:
 		/* things are really broken, give up */
-		WARN(true, "PQAP/ZAPQ completed with invalid rc (%x)\n",
+		WARN(true,
+		     "PQAP/ZAPQ for %02x.%04x failed with invalid rc=%u\n",
+		     AP_QID_CARD(q->apqn), AP_QID_QUEUE(q->apqn),
 		     status.response_code);
 		return -EIO;
 	}
···
 		msleep(20);
 		status = ap_tapq(q->apqn, NULL);
 	}
-	WARN_ON_ONCE(retry2 <= 0);
+	WARN_ONCE(retry2 <= 0, "unable to verify reset of queue %02x.%04x",
+		  AP_QID_CARD(q->apqn), AP_QID_QUEUE(q->apqn));
 
 free_resources:
 	vfio_ap_free_aqic_resources(q);
···
 	return ret;
 }
 
-static int vfio_ap_mdev_reset_queues(struct ap_matrix_mdev *matrix_mdev)
+static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable)
 {
-	int ret;
-	int rc = 0;
-	unsigned long apid, apqi;
+	int ret, loop_cursor, rc = 0;
 	struct vfio_ap_queue *q;
 
-	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm,
-			     matrix_mdev->matrix.apm_max + 1) {
-		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
-				     matrix_mdev->matrix.aqm_max + 1) {
-			q = vfio_ap_find_queue(AP_MKQID(apid, apqi));
-			ret = vfio_ap_mdev_reset_queue(q, 1);
-			/*
-			 * Regardless whether a queue turns out to be busy, or
-			 * is not operational, we need to continue resetting
-			 * the remaining queues.
-			 */
-			if (ret)
-				rc = ret;
-		}
+	hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {
+		ret = vfio_ap_mdev_reset_queue(q, 1);
+		/*
+		 * Regardless whether a queue turns out to be busy, or
+		 * is not operational, we need to continue resetting
+		 * the remaining queues.
+		 */
+		if (ret)
+			rc = ret;
 	}
 
 	return rc;
···
 		container_of(vdev, struct ap_matrix_mdev, vdev);
 	int ret;
 
-	mutex_lock(&matrix_dev->lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
 	switch (cmd) {
 	case VFIO_DEVICE_GET_INFO:
 		ret = vfio_ap_mdev_get_device_info(arg);
 		break;
 	case VFIO_DEVICE_RESET:
-		ret = vfio_ap_mdev_reset_queues(matrix_mdev);
+		ret = vfio_ap_mdev_reset_queues(&matrix_mdev->qtable);
 		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;
 	}
-	mutex_unlock(&matrix_dev->lock);
+	mutex_unlock(&matrix_dev->mdevs_lock);
 
 	return ret;
 }
+
+static struct ap_matrix_mdev *vfio_ap_mdev_for_queue(struct vfio_ap_queue *q)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+	unsigned long apid = AP_QID_CARD(q->apqn);
+	unsigned long apqi = AP_QID_QUEUE(q->apqn);
+
+	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+		if (test_bit_inv(apid, matrix_mdev->matrix.apm) &&
+		    test_bit_inv(apqi, matrix_mdev->matrix.aqm))
+			return matrix_mdev;
+	}
+
+	return NULL;
+}
+
+static ssize_t status_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	ssize_t nchars = 0;
+	struct vfio_ap_queue *q;
+	struct ap_matrix_mdev *matrix_mdev;
+	struct ap_device *apdev = to_ap_dev(dev);
+
+	mutex_lock(&matrix_dev->mdevs_lock);
+	q = dev_get_drvdata(&apdev->device);
+	matrix_mdev = vfio_ap_mdev_for_queue(q);
+
+	if (matrix_mdev) {
+		if (matrix_mdev->kvm)
+			nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
+					   AP_QUEUE_IN_USE);
+		else
+			nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
+					   AP_QUEUE_ASSIGNED);
+	} else {
+		nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
+				   AP_QUEUE_UNASSIGNED);
+	}
+
+	mutex_unlock(&matrix_dev->mdevs_lock);
+
+	return nchars;
+}
+
+static DEVICE_ATTR_RO(status);
+
+static struct attribute *vfio_queue_attrs[] = {
+	&dev_attr_status.attr,
+	NULL,
+};
+
+static const struct attribute_group vfio_queue_attr_group = {
+	.attrs = vfio_queue_attrs,
+};
 
 static const struct vfio_device_ops vfio_ap_matrix_dev_ops = {
 	.open_device = vfio_ap_mdev_open_device,
···
 {
 	mdev_unregister_device(&matrix_dev->device);
 	mdev_unregister_driver(&vfio_ap_matrix_driver);
+}
+
+int vfio_ap_mdev_probe_queue(struct ap_device *apdev)
+{
+	int ret;
+	struct vfio_ap_queue *q;
+	struct ap_matrix_mdev *matrix_mdev;
+
+	ret = sysfs_create_group(&apdev->device.kobj, &vfio_queue_attr_group);
+	if (ret)
+		return ret;
+
+	q = kzalloc(sizeof(*q), GFP_KERNEL);
+	if (!q)
+		return -ENOMEM;
+
+	q->apqn = to_ap_queue(&apdev->device)->qid;
+	q->saved_isc = VFIO_AP_ISC_INVALID;
+	matrix_mdev = get_update_locks_by_apqn(q->apqn);
+
+	if (matrix_mdev) {
+		vfio_ap_mdev_link_queue(matrix_mdev, q);
+
+		if (vfio_ap_mdev_filter_matrix(matrix_mdev->matrix.apm,
+					       matrix_mdev->matrix.aqm,
+					       matrix_mdev))
+			vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+	}
+	dev_set_drvdata(&apdev->device, q);
+	release_update_locks_for_mdev(matrix_mdev);
+
+	return 0;
+}
+
+void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
+{
+	unsigned long apid, apqi;
+	struct vfio_ap_queue *q;
+	struct ap_matrix_mdev *matrix_mdev;
+
+	sysfs_remove_group(&apdev->device.kobj, &vfio_queue_attr_group);
+	q = dev_get_drvdata(&apdev->device);
+	get_update_locks_for_queue(q);
+	matrix_mdev = q->matrix_mdev;
+
+	if (matrix_mdev) {
+		vfio_ap_unlink_queue_fr_mdev(q);
+
+		apid = AP_QID_CARD(q->apqn);
+		apqi = AP_QID_QUEUE(q->apqn);
+
+		/*
+		 * If the queue is assigned to the guest's APCB, then remove
+		 * the adapter's APID from the APCB and hot it into the guest.
+		 */
+		if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm) &&
+		    test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm)) {
+			clear_bit_inv(apid, matrix_mdev->shadow_apcb.apm);
+			vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+		}
+	}
+
+	vfio_ap_mdev_reset_queue(q, 1);
+	dev_set_drvdata(&apdev->device, NULL);
+	kfree(q);
+	release_update_locks_for_mdev(matrix_mdev);
+}
+
+/**
+ * vfio_ap_mdev_resource_in_use: check whether any of a set of APQNs is
+ *				 assigned to a mediated device under the control
+ *				 of the vfio_ap device driver.
+ *
+ * @apm: a bitmap specifying a set of APIDs comprising the APQNs to check.
+ * @aqm: a bitmap specifying a set of APQIs comprising the APQNs to check.
+ *
+ * Return:
+ *	* -EADDRINUSE if one or more of the APQNs specified via @apm/@aqm are
+ *	  assigned to a mediated device under the control of the vfio_ap
+ *	  device driver.
+ *	* Otherwise, return 0.
+ */
+int vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm)
+{
+	int ret;
+
+	mutex_lock(&matrix_dev->guests_lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
+	ret = vfio_ap_mdev_verify_no_sharing(apm, aqm);
+	mutex_unlock(&matrix_dev->mdevs_lock);
+	mutex_unlock(&matrix_dev->guests_lock);
+
+	return ret;
+}
+
+/**
+ * vfio_ap_mdev_hot_unplug_cfg - hot unplug the adapters, domains and control
+ *				 domains that have been removed from the host's
+ *				 AP configuration from a guest.
+ *
+ * @matrix_mdev: an ap_matrix_mdev object attached to a KVM guest.
+ * @aprem: the adapters that have been removed from the host's AP configuration
+ * @aqrem: the domains that have been removed from the host's AP configuration
+ * @cdrem: the control domains that have been removed from the host's AP
+ *	   configuration.
+ */
+static void vfio_ap_mdev_hot_unplug_cfg(struct ap_matrix_mdev *matrix_mdev,
+					unsigned long *aprem,
+					unsigned long *aqrem,
+					unsigned long *cdrem)
+{
+	int do_hotplug = 0;
+
+	if (!bitmap_empty(aprem, AP_DEVICES)) {
+		do_hotplug |= bitmap_andnot(matrix_mdev->shadow_apcb.apm,
+					    matrix_mdev->shadow_apcb.apm,
+					    aprem, AP_DEVICES);
+	}
+
+	if (!bitmap_empty(aqrem, AP_DOMAINS)) {
+		do_hotplug |= bitmap_andnot(matrix_mdev->shadow_apcb.aqm,
+					    matrix_mdev->shadow_apcb.aqm,
+					    aqrem, AP_DEVICES);
+	}
+
+	if (!bitmap_empty(cdrem, AP_DOMAINS))
+		do_hotplug |= bitmap_andnot(matrix_mdev->shadow_apcb.adm,
+					    matrix_mdev->shadow_apcb.adm,
+					    cdrem, AP_DOMAINS);
+
+	if (do_hotplug)
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+}
+
+/**
+ * vfio_ap_mdev_cfg_remove - determines which guests are using the adapters,
+ *			     domains and control domains that have been removed
+ *			     from the host AP configuration and unplugs them
+ *			     from those guests.
+ *
+ * @ap_remove:	bitmap specifying which adapters have been removed from the host
+ *		config.
+ * @aq_remove:	bitmap specifying which domains have been removed from the host
+ *		config.
+ * @cd_remove:	bitmap specifying which control domains have been removed from
+ *		the host config.
+ */
+static void vfio_ap_mdev_cfg_remove(unsigned long *ap_remove,
+				    unsigned long *aq_remove,
+				    unsigned long *cd_remove)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+	DECLARE_BITMAP(aprem, AP_DEVICES);
+	DECLARE_BITMAP(aqrem, AP_DOMAINS);
+	DECLARE_BITMAP(cdrem, AP_DOMAINS);
+	int do_remove = 0;
+
+	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+		mutex_lock(&matrix_mdev->kvm->lock);
+		mutex_lock(&matrix_dev->mdevs_lock);
+
+		do_remove |= bitmap_and(aprem, ap_remove,
+					  matrix_mdev->matrix.apm,
+					  AP_DEVICES);
+		do_remove |= bitmap_and(aqrem, aq_remove,
+					  matrix_mdev->matrix.aqm,
+					  AP_DOMAINS);
+		do_remove |= bitmap_andnot(cdrem, cd_remove,
+					     matrix_mdev->matrix.adm,
+					     AP_DOMAINS);
+
+		if (do_remove)
+			vfio_ap_mdev_hot_unplug_cfg(matrix_mdev, aprem, aqrem,
+						    cdrem);
+
+		mutex_unlock(&matrix_dev->mdevs_lock);
+		mutex_unlock(&matrix_mdev->kvm->lock);
+	}
+}
+
+/**
+ * vfio_ap_mdev_on_cfg_remove - responds to the removal of adapters, domains and
+ *				control domains from the host AP configuration
+ *				by unplugging them from the guests that are
+ *				using them.
+ * @cur_config_info: the current host AP configuration information
+ * @prev_config_info: the previous host AP configuration information
+ */
+static void vfio_ap_mdev_on_cfg_remove(struct ap_config_info *cur_config_info,
+				       struct ap_config_info *prev_config_info)
+{
+	int do_remove;
+	DECLARE_BITMAP(aprem, AP_DEVICES);
+	DECLARE_BITMAP(aqrem, AP_DOMAINS);
+	DECLARE_BITMAP(cdrem, AP_DOMAINS);
+
+	do_remove = bitmap_andnot(aprem,
+				  (unsigned long *)prev_config_info->apm,
+				  (unsigned long *)cur_config_info->apm,
+				  AP_DEVICES);
+	do_remove |= bitmap_andnot(aqrem,
+				   (unsigned long *)prev_config_info->aqm,
+				   (unsigned long *)cur_config_info->aqm,
+				   AP_DEVICES);
+	do_remove |= bitmap_andnot(cdrem,
+				   (unsigned long *)prev_config_info->adm,
+				   (unsigned long *)cur_config_info->adm,
+				   AP_DEVICES);
+
+	if (do_remove)
+		vfio_ap_mdev_cfg_remove(aprem, aqrem, cdrem);
+}
+
+/**
+ * vfio_ap_filter_apid_by_qtype: filter APIDs from an AP mask for adapters that
+ *				 are older than AP type 10 (CEX4).
+ * @apm: a bitmap of the APIDs to examine
+ * @aqm: a bitmap of the APQIs of the queues to query for the AP type.
+ */
+static void vfio_ap_filter_apid_by_qtype(unsigned long *apm, unsigned long *aqm)
+{
+	bool apid_cleared;
+	struct ap_queue_status status;
+	unsigned long apid, apqi, info;
+	int qtype, qtype_mask = 0xff000000;
+
+	for_each_set_bit_inv(apid, apm, AP_DEVICES) {
+		apid_cleared = false;
+
+		for_each_set_bit_inv(apqi, aqm, AP_DOMAINS) {
+			status = ap_test_queue(AP_MKQID(apid, apqi), 1, &info);
+			switch (status.response_code) {
+			/*
+			 * According to the architecture in each case
+			 * below, the queue's info should be filled.
+			 */
+			case AP_RESPONSE_NORMAL:
+			case AP_RESPONSE_RESET_IN_PROGRESS:
+			case AP_RESPONSE_DECONFIGURED:
+			case AP_RESPONSE_CHECKSTOPPED:
+			case AP_RESPONSE_BUSY:
+				qtype = info & qtype_mask;
+
+				/*
+				 * The vfio_ap device driver only
+				 * supports CEX4 and newer adapters, so
+				 * remove the APID if the adapter is
+				 * older than a CEX4.
+				 */
+				if (qtype < AP_DEVICE_TYPE_CEX4) {
+					clear_bit_inv(apid, apm);
+					apid_cleared = true;
+				}
+
+				break;
+
+			default:
+				/*
+				 * If we don't know the adapter type,
+				 * clear its APID since it can't be
+				 * determined whether the vfio_ap
+				 * device driver supports it.
+				 */
+				clear_bit_inv(apid, apm);
+				apid_cleared = true;
+				break;
+			}
+
+			/*
+			 * If we've already cleared the APID from the apm, there
+			 * is no need to continue examining the remainin AP
+			 * queues to determine the type of the adapter.
+			 */
+			if (apid_cleared)
+				continue;
+		}
+	}
+}
+
+/**
+ * vfio_ap_mdev_cfg_add - store bitmaps specifying the adapters, domains and
+ *			  control domains that have been added to the host's
+ *			  AP configuration for each matrix mdev to which they
+ *			  are assigned.
+ *
+ * @apm_add: a bitmap specifying the adapters that have been added to the AP
+ *	     configuration.
+ * @aqm_add: a bitmap specifying the domains that have been added to the AP
+ *	     configuration.
+ * @adm_add: a bitmap specifying the control domains that have been added to the
+ *	     AP configuration.
+ */
+static void vfio_ap_mdev_cfg_add(unsigned long *apm_add, unsigned long *aqm_add,
+				 unsigned long *adm_add)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+
+	if (list_empty(&matrix_dev->mdev_list))
+		return;
+
+	vfio_ap_filter_apid_by_qtype(apm_add, aqm_add);
+
+	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+		bitmap_and(matrix_mdev->apm_add,
+			   matrix_mdev->matrix.apm, apm_add, AP_DEVICES);
+		bitmap_and(matrix_mdev->aqm_add,
+			   matrix_mdev->matrix.aqm, aqm_add, AP_DOMAINS);
+		bitmap_and(matrix_mdev->adm_add,
+			   matrix_mdev->matrix.adm, adm_add, AP_DEVICES);
+	}
+}
+
+/**
+ * vfio_ap_mdev_on_cfg_add - responds to the addition of adapters, domains and
+ *			     control domains to the host AP configuration
+ *			     by updating the bitmaps that specify what adapters,
+ *			     domains and control domains have been added so they
+ *			     can be hot plugged into the guest when the AP bus
+ *			     scan completes (see vfio_ap_on_scan_complete
+ *			     function).
+ * @cur_config_info: the current AP configuration information
+ * @prev_config_info: the previous AP configuration information
+ */
+static void vfio_ap_mdev_on_cfg_add(struct ap_config_info *cur_config_info,
+				    struct ap_config_info *prev_config_info)
+{
+	bool do_add;
+	DECLARE_BITMAP(apm_add, AP_DEVICES);
+	DECLARE_BITMAP(aqm_add, AP_DOMAINS);
+	DECLARE_BITMAP(adm_add, AP_DOMAINS);
+
+	do_add = bitmap_andnot(apm_add,
+			       (unsigned long *)cur_config_info->apm,
+			       (unsigned long *)prev_config_info->apm,
+			       AP_DEVICES);
+	do_add |= bitmap_andnot(aqm_add,
+				(unsigned long *)cur_config_info->aqm,
+				(unsigned long *)prev_config_info->aqm,
+				AP_DOMAINS);
+	do_add |= bitmap_andnot(adm_add,
+				(unsigned long *)cur_config_info->adm,
+				(unsigned long *)prev_config_info->adm,
+				AP_DOMAINS);
+
+	if (do_add)
+		vfio_ap_mdev_cfg_add(apm_add, aqm_add, adm_add);
+}
+
+/**
+ * vfio_ap_on_cfg_changed - handles notification of changes to the host AP
+ *			    configuration.
+ *
+ * @cur_cfg_info: the current host AP configuration
+ * @prev_cfg_info: the previous host AP configuration
+ */
+void vfio_ap_on_cfg_changed(struct ap_config_info *cur_cfg_info,
+			    struct ap_config_info *prev_cfg_info)
+{
+	if (!cur_cfg_info || !prev_cfg_info)
+		return;
+
+	mutex_lock(&matrix_dev->guests_lock);
+
+	vfio_ap_mdev_on_cfg_remove(cur_cfg_info, prev_cfg_info);
+	vfio_ap_mdev_on_cfg_add(cur_cfg_info, prev_cfg_info);
+	memcpy(&matrix_dev->info, cur_cfg_info, sizeof(*cur_cfg_info));
+
+	mutex_unlock(&matrix_dev->guests_lock);
+}
+
+static void vfio_ap_mdev_hot_plug_cfg(struct ap_matrix_mdev *matrix_mdev)
+{
+	bool do_hotplug = false;
+	int filter_domains = 0;
+	int filter_adapters = 0;
+	DECLARE_BITMAP(apm, AP_DEVICES);
+	DECLARE_BITMAP(aqm, AP_DOMAINS);
+
+	mutex_lock(&matrix_mdev->kvm->lock);
+	mutex_lock(&matrix_dev->mdevs_lock);
+
+	filter_adapters = bitmap_and(apm, matrix_mdev->matrix.apm,
+				     matrix_mdev->apm_add, AP_DEVICES);
+	filter_domains = bitmap_and(aqm, matrix_mdev->matrix.aqm,
+				    matrix_mdev->aqm_add, AP_DOMAINS);
+
+	if (filter_adapters && filter_domains)
+		do_hotplug |= vfio_ap_mdev_filter_matrix(apm, aqm, matrix_mdev);
+	else if (filter_adapters)
+		do_hotplug |=
+			vfio_ap_mdev_filter_matrix(apm,
+						   matrix_mdev->shadow_apcb.aqm,
+						   matrix_mdev);
+	else
+		do_hotplug |=
+			vfio_ap_mdev_filter_matrix(matrix_mdev->shadow_apcb.apm,
+						   aqm, matrix_mdev);
+
+	if (bitmap_intersects(matrix_mdev->matrix.adm, matrix_mdev->adm_add,
+			      AP_DOMAINS))
+		do_hotplug |= vfio_ap_mdev_filter_cdoms(matrix_mdev);
+
+	if (do_hotplug)
+		vfio_ap_mdev_update_guest_apcb(matrix_mdev);
+
+	mutex_unlock(&matrix_dev->mdevs_lock);
+	mutex_unlock(&matrix_mdev->kvm->lock);
+}
+
+void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
+			      struct ap_config_info *old_config_info)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+
+	mutex_lock(&matrix_dev->guests_lock);
+
+	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+		if (bitmap_empty(matrix_mdev->apm_add, AP_DEVICES) &&
+		    bitmap_empty(matrix_mdev->aqm_add, AP_DOMAINS) &&
+		    bitmap_empty(matrix_mdev->adm_add, AP_DOMAINS))
+			continue;
+
+		vfio_ap_mdev_hot_plug_cfg(matrix_mdev);
+		bitmap_clear(matrix_mdev->apm_add, 0, AP_DEVICES);
+		bitmap_clear(matrix_mdev->aqm_add, 0, AP_DOMAINS);
+		bitmap_clear(matrix_mdev->adm_add, 0, AP_DOMAINS);
+	}
+
+	mutex_unlock(&matrix_dev->guests_lock);
 }

drivers/s390/crypto/vfio_ap_private.h

···
 #include <linux/mutex.h>
 #include <linux/kvm_host.h>
 #include <linux/vfio.h>
+#include <linux/hashtable.h>
 
 #include "ap_bus.h"
 
···
  * @available_instances: number of mediated matrix devices that can be created
  * @info:	the struct containing the output from the PQAP(QCI) instruction
  * @mdev_list:	the list of mediated matrix devices created
- * @lock:	mutex for locking the AP matrix device. This lock will be
+ * @mdevs_lock: mutex for locking the AP matrix device. This lock will be
  *		taken every time we fiddle with state managed by the vfio_ap
  *		driver, be it using @mdev_list or writing the state of a
  *		single ap_matrix_mdev device. It's quite coarse but we don't
  *		expect much contention.
  * @vfio_ap_drv: the vfio_ap device driver
+ * @guests_lock: mutex for controlling access to a guest that is using AP
+ *		 devices passed through by the vfio_ap device driver. This lock
+ *		 will be taken when the AP devices are plugged into or unplugged
+ *		 from a guest, and when an ap_matrix_mdev device is added to or
+ *		 removed from @mdev_list or the list is iterated.
  */
 struct ap_matrix_dev {
 	struct device device;
 	atomic_t available_instances;
 	struct ap_config_info info;
 	struct list_head mdev_list;
-	struct mutex lock;
+	struct mutex mdevs_lock; /* serializes access to each ap_matrix_mdev */
 	struct ap_driver  *vfio_ap_drv;
+	struct mutex guests_lock; /* serializes access to each KVM guest */
 };
 
 extern struct ap_matrix_dev *matrix_dev;
···
 };
 
 /**
+ * struct ap_queue_table - a table of queue objects.
+ *
+ * @queues: a hashtable of queues (struct vfio_ap_queue).
+ */
+struct ap_queue_table {
+	DECLARE_HASHTABLE(queues, 8);
+};
+
+/**
  * struct ap_matrix_mdev - Contains the data associated with a matrix mediated
  *			   device.
  * @vdev:	the vfio device
  * @node:	allows the ap_matrix_mdev struct to be added to a list
  * @matrix:	the adapters, usage domains and control domains assigned to the
  *		mediated matrix device.
+ * @shadow_apcb:    the shadow copy of the APCB field of the KVM guest's CRYCB
  * @kvm:	the struct holding guest's state
  * @pqap_hook:	the function pointer to the interception handler for the
  *		PQAP(AQIC) instruction.
  * @mdev:	the mediated device
+ * @qtable:	table of queues (struct vfio_ap_queue) assigned to the mdev
+ * @apm_add:	bitmap of APIDs added to the host's AP configuration
+ * @aqm_add:	bitmap of APQIs added to the host's AP configuration
+ * @adm_add:	bitmap of control domain numbers added to the host's AP
+ *		configuration
  */
 struct ap_matrix_mdev {
 	struct vfio_device vdev;
 	struct list_head node;
 	struct ap_matrix matrix;
+	struct ap_matrix shadow_apcb;
 	struct kvm *kvm;
 	crypto_hook pqap_hook;
 	struct mdev_device *mdev;
+	struct ap_queue_table qtable;
+	DECLARE_BITMAP(apm_add, AP_DEVICES);
+	DECLARE_BITMAP(aqm_add, AP_DOMAINS);
+	DECLARE_BITMAP(adm_add, AP_DOMAINS);
 };
 
 /**
···
  * @saved_iova: the notification indicator byte (nib) address
  * @apqn: the APQN of the AP queue device
  * @saved_isc: the guest ISC registered with the GIB interface
+ * @mdev_qnode: allows the vfio_ap_queue struct to be added to a hashtable
+ * @reset_rc: the status response code from the last reset of the queue
  */
 struct vfio_ap_queue {
 	struct ap_matrix_mdev *matrix_mdev;
···
 	int	apqn;
 #define VFIO_AP_ISC_INVALID 0xff
 	unsigned char saved_isc;
+	struct hlist_node mdev_qnode;
+	unsigned int reset_rc;
 };
 
 int vfio_ap_mdev_register(void);
 void vfio_ap_mdev_unregister(void);
-int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
-			     unsigned int retry);
+
+int vfio_ap_mdev_probe_queue(struct ap_device *queue);
+void vfio_ap_mdev_remove_queue(struct ap_device *queue);
+
+int vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm);
+
+void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
+			    struct ap_config_info *old_config_info);
+void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
+			      struct ap_config_info *old_config_info);
 
 #endif /* _VFIO_AP_PRIVATE_H_ */

include/uapi/linux/elf.h

···
 #define NT_S390_GS_CB	0x30b		/* s390 guarded storage registers */
 #define NT_S390_GS_BC	0x30c		/* s390 guarded storage broadcast control block */
 #define NT_S390_RI_CB	0x30d		/* s390 runtime instrumentation */
+#define NT_S390_PV_CPU_DATA	0x30e	/* s390 protvirt cpu dump data */
 #define NT_ARM_VFP	0x400		/* ARM VFP/NEON registers */
 #define NT_ARM_TLS	0x401		/* ARM TLS register */
 #define NT_ARM_HW_BREAK	0x402		/* ARM hardware breakpoint registers */

tools/testing/crypto/chacha20-s390/test-cipher.c

···
 	memset(plain, 'a', data_size);
 	get_random_bytes(plain, (data_size > 256 ? 256 : data_size));
 
-	cipher_generic = vmalloc(data_size);
+	cipher_generic = vzalloc(data_size);
 	if (!cipher_generic) {
 		pr_info("could not allocate cipher_generic buffer\n");
 		ret = -2;
 		goto out;
 	}
-	memset(cipher_generic, 0, data_size);
 
-	cipher_s390 = vmalloc(data_size);
+	cipher_s390 = vzalloc(data_size);
 	if (!cipher_s390) {
 		pr_info("could not allocate cipher_s390 buffer\n");
 		ret = -2;
 		goto out;
 	}
-	memset(cipher_s390, 0, data_size);
 
-	revert = vmalloc(data_size);
+	revert = vzalloc(data_size);
 	if (!revert) {
 		pr_info("could not allocate revert buffer\n");
 		ret = -2;
 		goto out;
 	}
-	memset(revert, 0, data_size);
 
 	if (debug)
 		print_hex_dump(KERN_INFO, "src: ", DUMP_PREFIX_OFFSET,