Merge tag 'for-linus-6.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

- cleanup: remove an used function

- add support for a XenServer specific virtual PCI device

- fix the handling of a sparse Xen hypervisor symbol table

- avoid warnings when building the kernel with gcc 15

- fix use of devices behind a VMD bridge when running as a Xen PV dom0

* tag 'for-linus-6.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
PCI/MSI: Convert pci_msi_ignore_mask to per MSI domain flag
PCI: vmd: Disable MSI remapping bypass under Xen
xen/pci: Do not register devices with segments >= 0x10000
xen/pciback: Remove unused pcistub_get_pci_dev
xenfs/xensyms: respect hypervisor's "next" indication
xen/mcelog: Add __nonstring annotations for unterminated strings
xen: Add support for XenServer 6.1 platform device

arch/x86/pci/xen.c

···
 };
 
 static struct msi_domain_info xen_pci_msi_domain_info = {
-	.flags			= MSI_FLAG_PCI_MSIX | MSI_FLAG_FREE_MSI_DESCS | MSI_FLAG_DEV_SYSFS,
+	.flags			= MSI_FLAG_PCI_MSIX | MSI_FLAG_FREE_MSI_DESCS |
+				  MSI_FLAG_DEV_SYSFS | MSI_FLAG_NO_MASK,
 	.ops			= &xen_pci_msi_domain_ops,
 };
 
···
 	 * in allocating the native domain and never use it.
 	 */
 	x86_init.irqs.create_pci_msi_domain = xen_create_pci_msi_domain;
-	/*
-	 * With XEN PIRQ/Eventchannels in use PCI/MSI[-X] masking is solely
-	 * controlled by the hypervisor.
-	 */
-	pci_msi_ignore_mask = 1;
 }
 
 #else /* CONFIG_PCI_MSI */

drivers/pci/controller/vmd.c

···
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 
+#include <xen/xen.h>
+
 #include <asm/irqdomain.h>
 
 #define VMD_CFGBAR	0
···
 	unsigned long features = (unsigned long) id->driver_data;
 	struct vmd_dev *vmd;
 	int err;
+
+	if (xen_domain()) {
+		/*
+		 * Xen doesn't have knowledge about devices in the VMD bus
+		 * because the config space of devices behind the VMD bridge is
+		 * not known to Xen, and hence Xen cannot discover or configure
+		 * them in any way.
+		 *
+		 * Bypass of MSI remapping won't work in that case as direct
+		 * write by Linux to the MSI entries won't result in functional
+		 * interrupts, as Xen is the entity that manages the host
+		 * interrupt controller and must configure interrupts.  However
+		 * multiplexing of interrupts by the VMD bridge will work under
+		 * Xen, so force the usage of that mode which must always be
+		 * supported by VMD bridges.
+		 */
+		features &= ~VMD_FEAT_CAN_BYPASS_MSI_REMAP;
+	}
 
 	if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
 		return -ENOMEM;

drivers/pci/msi/msi.c

···
 #include <linux/err.h>
 #include <linux/export.h>
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 
 #include "../pci.h"
 #include "msi.h"
 
 int pci_msi_enable = 1;
-int pci_msi_ignore_mask;
 
 /**
  * pci_msi_supported - check whether MSI may be enabled on a device
···
 static int msi_setup_msi_desc(struct pci_dev *dev, int nvec,
 			      struct irq_affinity_desc *masks)
 {
+	const struct irq_domain *d = dev_get_msi_domain(&dev->dev);
+	const struct msi_domain_info *info = d->host_data;
 	struct msi_desc desc;
 	u16 control;
 
···
 	/* Lies, damned lies, and MSIs */
 	if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING)
 		control |= PCI_MSI_FLAGS_MASKBIT;
-	/* Respect XEN's mask disabling */
-	if (pci_msi_ignore_mask)
+	if (info->flags & MSI_FLAG_NO_MASK)
 		control &= ~PCI_MSI_FLAGS_MASKBIT;
 
 	desc.nvec_used			= nvec;
···
  */
 void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc)
 {
+	const struct irq_domain *d = dev_get_msi_domain(&dev->dev);
+	const struct msi_domain_info *info = d->host_data;
+
 	desc->nvec_used				= 1;
 	desc->pci.msi_attrib.is_msix		= 1;
 	desc->pci.msi_attrib.is_64		= 1;
 	desc->pci.msi_attrib.default_irq	= dev->irq;
 	desc->pci.mask_base			= dev->msix_base;
-	desc->pci.msi_attrib.can_mask		= !pci_msi_ignore_mask &&
+	desc->pci.msi_attrib.can_mask		= !(info->flags & MSI_FLAG_NO_MASK) &&
 						  !desc->pci.msi_attrib.is_virtual;
 
 	if (desc->pci.msi_attrib.can_mask) {
···
 {
 	u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT;
 	int i;
-
-	if (pci_msi_ignore_mask)
-		return;
 
 	for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE)
 		writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
···
 static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
 				int nvec, struct irq_affinity *affd)
 {
+	const struct irq_domain *d = dev_get_msi_domain(&dev->dev);
+	const struct msi_domain_info *info = d->host_data;
 	int ret, tsize;
 	u16 control;
 
···
 	/* Disable INTX */
 	pci_intx_for_msi(dev, 0);
 
-	/*
-	 * Ensure that all table entries are masked to prevent
-	 * stale entries from firing in a crash kernel.
-	 *
-	 * Done late to deal with a broken Marvell NVME device
-	 * which takes the MSI-X mask bits into account even
-	 * when MSI-X is disabled, which prevents MSI delivery.
-	 */
-	msix_mask_all(dev->msix_base, tsize);
+	if (!(info->flags & MSI_FLAG_NO_MASK)) {
+		/*
+		 * Ensure that all table entries are masked to prevent
+		 * stale entries from firing in a crash kernel.
+		 *
+		 * Done late to deal with a broken Marvell NVME device
+		 * which takes the MSI-X mask bits into account even
+		 * when MSI-X is disabled, which prevents MSI delivery.
+		 */
+		msix_mask_all(dev->msix_base, tsize);
+	}
 	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
 
 	pcibios_free_irq(dev);

drivers/xen/pci.c

···
 		pci_mcfg_reserved = true;
 	}
 #endif
+
+	if (pci_domain_nr(pci_dev->bus) >> 16) {
+		/*
+		 * The hypercall interface is limited to 16bit PCI segment
+		 * values, do not attempt to register devices with Xen in
+		 * segments greater or equal than 0x10000.
+		 */
+		dev_info(dev,
+			 "not registering with Xen: invalid PCI segment\n");
+		return 0;
+	}
+
 	if (pci_seg_supported) {
 		DEFINE_RAW_FLEX(struct physdev_pci_device_add, add, optarr, 1);
 
···
 	int r;
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 
+	if (pci_domain_nr(pci_dev->bus) >> 16) {
+		/*
+		 * The hypercall interface is limited to 16bit PCI segment
+		 * values.
+		 */
+		dev_info(dev,
+			 "not unregistering with Xen: invalid PCI segment\n");
+		return 0;
+	}
+
 	if (pci_seg_supported) {
 		struct physdev_pci_device device = {
 			.seg = pci_domain_nr(pci_dev->bus),
···
 		.dev.devfn = dev->devfn,
 		.flags = PCI_DEVICE_RESET_FLR,
 	};
+
+	if (pci_domain_nr(dev->bus) >> 16) {
+		/*
+		 * The hypercall interface is limited to 16bit PCI segment
+		 * values.
+		 */
+		dev_info(&dev->dev,
+			 "unable to notify Xen of device reset: invalid PCI segment\n");
+		return 0;
+	}
 
 	return HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_reset, &device);
 }

drivers/xen/platform-pci.c

···
 
 #define DRV_NAME    "xen-platform-pci"
 
+#define PCI_DEVICE_ID_XEN_PLATFORM_XS61	0x0002
+
 static unsigned long platform_mmio;
 static unsigned long platform_mmio_alloc;
 static unsigned long platform_mmiolen;
···
 
 static const struct pci_device_id platform_pci_tbl[] = {
 	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM_XS61,
 		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
 	{0,}
 };

drivers/xen/xen-pciback/pci_stub.c

···
 	return found_dev;
 }
 
-struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
-				    struct pci_dev *dev)
-{
-	struct pcistub_device *psdev;
-	struct pci_dev *found_dev = NULL;
-	unsigned long flags;
-
-	spin_lock_irqsave(&pcistub_devices_lock, flags);
-
-	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
-		if (psdev->dev == dev) {
-			found_dev = pcistub_device_get_pci_dev(pdev, psdev);
-			break;
-		}
-	}
-
-	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
-	return found_dev;
-}
-
 /*
  * Called when:
  *  - XenBus state has been reconfigure (pci unplug). See xen_pcibk_remove_device

drivers/xen/xen-pciback/pciback.h

···
 struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 					    int domain, int bus,
 					    int slot, int func);
-struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
-				    struct pci_dev *dev);
 void pcistub_put_pci_dev(struct pci_dev *dev);
 
 static inline bool xen_pcibk_pv_support(void)

drivers/xen/xenfs/xensyms.c

···
 			return -ENOMEM;
 
 		set_xen_guest_handle(symdata->name, xs->name);
-		symdata->symnum--; /* Rewind */
+		symdata->symnum = symnum; /* Rewind */
 
 		ret = HYPERVISOR_platform_op(&xs->op);
 		if (ret < 0)
···
 {
 	struct xensyms *xs = m->private;
 
-	xs->op.u.symdata.symnum = ++(*pos);
+	*pos = xs->op.u.symdata.symnum;
 
 	if (xensyms_next_sym(xs))
 		return NULL;

include/linux/msi.h

···
 	};
 };
 
-extern int pci_msi_ignore_mask;
 /* Helper functions */
 struct msi_desc;
 struct pci_dev;
···
 	MSI_FLAG_PCI_MSIX_ALLOC_DYN	= (1 << 20),
 	/* PCI MSIs cannot be steered separately to CPU cores */
 	MSI_FLAG_NO_AFFINITY		= (1 << 21),
+	/* Inhibit usage of entry masking */
+	MSI_FLAG_NO_MASK		= (1 << 22),
 };
 
 /*

include/xen/interface/xen-mca.h

···
 #define XEN_MCE_LOG_LEN 32
 
 struct xen_mce_log {
-	char signature[12]; /* "MACHINECHECK" */
+	char signature[12] __nonstring; /* "MACHINECHECK" */
 	unsigned len;	    /* = XEN_MCE_LOG_LEN */
 	unsigned next;
 	unsigned flags;

kernel/irq/msi.c

···
 	if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
 		return false;
 
-	if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_ignore_mask)
+	if (info->flags & MSI_FLAG_NO_MASK)
 		return false;
 
 	/*