[Qemu-devel] [PATCH V3 1/4] vfio: introduce a new VFIO subregion for mdev device migration support

[Yulei Zhang <yulei.zhang@intel.com>]

New VFIO sub region VFIO_REGION_SUBTYPE_DEVICE_STATE is added
to fetch and restore the status of mdev device vGPU during the
live migration.

Signed-off-by: Yulei Zhang <yulei.zhang@intel.com>
---
 hw/vfio/pci.c              | 14 +++++++++++++-
 hw/vfio/pci.h              |  1 +
 linux-headers/linux/vfio.h |  9 ++++++---
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 31e1edf..2fe20e4 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -37,6 +37,7 @@
 
 static void vfio_disable_interrupts(VFIOPCIDevice *vdev);
 static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled);
+static VMStateDescription vfio_pci_vmstate;
 
 /*
  * Disabling BAR mmaping can be slow, but toggling it around INTx can
@@ -2813,6 +2814,17 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
         vfio_vga_quirk_setup(vdev);
     }
 
+    struct vfio_region_info *device_state;
+    /* device state region setup */
+    if (!vfio_get_dev_region_info(&vdev->vbasedev,
+                VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL,
+                VFIO_REGION_SUBTYPE_DEVICE_STATE, &device_state)) {
+        memcpy(&vdev->device_state, device_state,
+               sizeof(struct vfio_region_info));
+        g_free(device_state);
+        vfio_pci_vmstate.unmigratable = 0;
+    }
+
     for (i = 0; i < PCI_ROM_SLOT; i++) {
         vfio_bar_quirk_setup(vdev, i);
     }
@@ -2994,7 +3006,7 @@ static Property vfio_pci_dev_properties[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
-static const VMStateDescription vfio_pci_vmstate = {
+static VMStateDescription vfio_pci_vmstate = {
     .name = "vfio-pci",
     .unmigratable = 1,
 };
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index a8366bb..6a1d26e 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -116,6 +116,7 @@ typedef struct VFIOPCIDevice {
     VFIOBAR bars[PCI_NUM_REGIONS - 1]; /* No ROM */
     VFIOVGA *vga; /* 0xa0000, 0x3b0, 0x3c0 */
     void *igd_opregion;
+    struct vfio_region_info device_state;
     PCIHostDeviceAddress host;
     EventNotifier err_notifier;
     EventNotifier req_notifier;
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index 4e7ab4c..c3b8e4a 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -296,9 +296,12 @@ struct vfio_region_info_cap_type {
 #define VFIO_REGION_TYPE_PCI_VENDOR_MASK	(0xffff)
 
 /* 8086 Vendor sub-types */
-#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION	(1)
-#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG	(2)
-#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG	(3)
+#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION		(1)
+#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG		(2)
+#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG		(3)
+
+/* Mdev sub-type for device state save and restore */
+#define VFIO_REGION_SUBTYPE_DEVICE_STATE	(4)
 
 /**
  * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
-- 
2.7.4