vdpa: remove msg type of vhost_vdpa

It is always VHOST_IOTLB_MSG_V2. We can always make it back per
vhost_dev if needed.

This change makes easier for vhost_vdpa_map and unmap not to depend on
vhost_vdpa but only in VhostVDPAShared.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20231221174322.3130442-10-eperezma@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/virtio/vhost-vdpa.c

@@ -93,7 +93,7 @@ int vhost_vdpa_dma_map(struct vhost_vdpa *v, uint32_t asid, hwaddr iova,
     int fd = v->shared->device_fd;
     int ret = 0;
 
-    msg.type = v->msg_type;
+    msg.type = VHOST_IOTLB_MSG_V2;
     msg.asid = asid;
     msg.iotlb.iova = iova;
     msg.iotlb.size = size;
@@ -125,7 +125,7 @@ int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, uint32_t asid, hwaddr iova,
     int fd = v->shared->device_fd;
     int ret = 0;
 
-    msg.type = v->msg_type;
+    msg.type = VHOST_IOTLB_MSG_V2;
     msg.asid = asid;
     msg.iotlb.iova = iova;
     msg.iotlb.size = size;
@@ -147,7 +147,7 @@ static void vhost_vdpa_listener_begin_batch(struct vhost_vdpa *v)
 {
     int fd = v->shared->device_fd;
     struct vhost_msg_v2 msg = {
-        .type = v->msg_type,
+        .type = VHOST_IOTLB_MSG_V2,
         .iotlb.type = VHOST_IOTLB_BATCH_BEGIN,
     };
 
@@ -183,7 +183,7 @@ static void vhost_vdpa_listener_commit(MemoryListener *listener)
         return;
     }
 
-    msg.type = v->msg_type;
+    msg.type = VHOST_IOTLB_MSG_V2;
     msg.iotlb.type = VHOST_IOTLB_BATCH_END;
 
     trace_vhost_vdpa_listener_commit(v->shared, fd, msg.type, msg.iotlb.type);
@@ -597,7 +597,6 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
     v->dev = dev;
     dev->opaque =  opaque ;
     v->listener = vhost_vdpa_memory_listener;
-    v->msg_type = VHOST_IOTLB_MSG_V2;
     vhost_vdpa_init_svq(dev, v);
 
     error_propagate(&dev->migration_blocker, v->migration_blocker);

include/hw/virtio/vhost-vdpa.h

@@ -49,7 +49,6 @@ typedef struct vhost_vdpa_shared {
 
 typedef struct vhost_vdpa {
     int index;
-    uint32_t msg_type;
     uint32_t address_space_id;
     MemoryListener listener;
     uint64_t acked_features;