3 files changed, 28 insertions, 0 deletions
diff --git a/hw/core/machine.c b/hw/core/machine.c
index c7ceb11501..3442f31f94 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -35,6 +35,7 @@
 
 GlobalProperty hw_compat_9_0[] = {
     {"arm-cpu", "backcompat-cntfrq", "true" },
+    {"vfio-pci", "skip-vsc-check", "false" },
 };
 const size_t hw_compat_9_0_len = G_N_ELEMENTS(hw_compat_9_0);
 
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index fc6e54e871..4789d43c0f 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2134,6 +2134,28 @@ static void vfio_check_af_flr(VFIOPCIDevice *vdev, uint8_t pos)
     }
 }
 
+static int vfio_add_vendor_specific_cap(VFIOPCIDevice *vdev, int pos,
+                                        uint8_t size, Error **errp)
+{
+    PCIDevice *pdev = &vdev->pdev;
+
+    pos = pci_add_capability(pdev, PCI_CAP_ID_VNDR, pos, size, errp);
+    if (pos < 0) {
+        return pos;
+    }
+
+    /*
+     * Exempt config space check for Vendor Specific Information during
+     * restore/load.
+     * Config space check is still enforced for 3 byte VSC header.
+     */
+    if (vdev->skip_vsc_check && size > 3) {
+        memset(pdev->cmask + pos + 3, 0, size - 3);
+    }
+
+    return pos;
+}
+
 static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
 {
     ERRP_GUARD();
@@ -2202,6 +2224,9 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
         vfio_check_af_flr(vdev, pos);
         ret = pci_add_capability(pdev, cap_id, pos, size, errp);
         break;
+    case PCI_CAP_ID_VNDR:
+        ret = vfio_add_vendor_specific_cap(vdev, pos, size, errp);
+        break;
     default:
         ret = pci_add_capability(pdev, cap_id, pos, size, errp);
         break;
@@ -3391,6 +3416,7 @@ static Property vfio_pci_dev_properties[] = {
     DEFINE_PROP_LINK("iommufd", VFIOPCIDevice, vbasedev.iommufd,
                      TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
 #endif
+    DEFINE_PROP_BOOL("skip-vsc-check", VFIOPCIDevice, skip_vsc_check, true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 6e64a2654e..92cd62d115 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -177,6 +177,7 @@ struct VFIOPCIDevice {
     OnOffAuto ramfb_migrate;
     bool defer_kvm_irq_routing;
     bool clear_parent_atomics_on_exit;
+    bool skip_vsc_check;
     VFIODisplay *dpy;
     Notifier irqchip_change_notifier;
 };