[PATCH 10/12] vdpa: define SVQ transitioning state for mode switching

[Si-Wei Liu <si-wei.liu@oracle.com>]

Will be used in following patches.

DISABLING(-1) means SVQ is being switched off to passthrough
mode.

ENABLING(1) means passthrough VQs are being switched to SVQ.

DONE(0) means SVQ switching is completed.

Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
---
 include/hw/virtio/vhost-vdpa.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index ad754eb..449bf5c 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -30,6 +30,12 @@ typedef struct VhostVDPAHostNotifier {
     void *addr;
 } VhostVDPAHostNotifier;
 
+typedef enum SVQTransitionState {
+    SVQ_TSTATE_DISABLING = -1,
+    SVQ_TSTATE_DONE,
+    SVQ_TSTATE_ENABLING
+} SVQTransitionState;
+
 /* Info shared by all vhost_vdpa device models */
 typedef struct vhost_vdpa_shared {
     int device_fd;
@@ -67,6 +73,9 @@ typedef struct vhost_vdpa_shared {
 
     /* Vdpa must send shadow addresses as IOTLB key for data queues, not GPA */
     bool shadow_data;
+
+    /* SVQ switching is in progress, or already completed? */
+    SVQTransitionState svq_switching;
 } VhostVDPAShared;
 
 typedef struct vhost_vdpa {
-- 
1.8.3.1