virtio-pci: fix 1.0 virtqueue migration

We don't migrate the followings fields for virtio-pci:

uint32_t dfselect;
uint32_t gfselect;
uint32_t guest_features[2];
struct {
    uint16_t num;
    bool enabled;
    uint32_t desc[2];
    uint32_t avail[2];
    uint32_t used[2];
} vqs[VIRTIO_QUEUE_MAX];

This will confuse driver if migrating during initialization. Solves
this issue by:

- introduce transport specific callbacks to load and store extra
  virtqueue states.
- add a new subsection for virtio to migrate transport specific modern
  device state.
- implement pci specific callbacks.
- add a new property for virtio-pci for whether or not to migrate
  extra state.
- compat the migration for 2.4 and elder machine types

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 801c23aef3..58679f78bf 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -75,6 +75,10 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
 #define VIRTIO_PCI_FLAG_DISABLE_LEGACY (1 << VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT)
 #define VIRTIO_PCI_FLAG_DISABLE_MODERN (1 << VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT)
 
+/* migrate extra state */
+#define VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT 4
+#define VIRTIO_PCI_FLAG_MIGRATE_EXTRA (1 << VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT)
+
 typedef struct {
     MSIMessage msg;
     int virq;
@@ -104,6 +108,14 @@ typedef struct VirtIOPCIRegion {
     uint32_t type;
 } VirtIOPCIRegion;
 
+typedef struct VirtIOPCIQueue {
+  uint16_t num;
+  bool enabled;
+  uint32_t desc[2];
+  uint32_t avail[2];
+  uint32_t used[2];
+} VirtIOPCIQueue;
+
 struct VirtIOPCIProxy {
     PCIDevice pci_dev;
     MemoryRegion bar;
@@ -124,13 +136,7 @@ struct VirtIOPCIProxy {
     uint32_t dfselect;
     uint32_t gfselect;
     uint32_t guest_features[2];
-    struct {
-        uint16_t num;
-        bool enabled;
-        uint32_t desc[2];
-        uint32_t avail[2];
-        uint32_t used[2];
-    } vqs[VIRTIO_QUEUE_MAX];
+    VirtIOPCIQueue vqs[VIRTIO_QUEUE_MAX];
 
     bool ioeventfd_disabled;
     bool ioeventfd_started;