commit d2fc4402cb152d3e526f736d7d53dbd050ef8794
author Marc-André Lureau <marcandre.lureau@redhat.com> Fri Oct 09 17:17:27 2015 +0200
committer Michael S. Tsirkin <mst@redhat.com> Thu Oct 22 14:34:49 2015 +0300
tree 3c0cc81541a9d589d7d899fa69f1ba2ebbd83c19
parent 9a78a5dd272a190d262b5ba5d4721ab93d48c564

vhost-user: add a migration blocker

If VHOST_USER_PROTOCOL_F_LOG_SHMFD is not announced, block vhost-user
migration. The blocker is removed in vhost_dev_cleanup().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>

hw/virtio/vhost.c

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 65c09bf..a5532560 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -961,6 +961,8 @@
     uint64_t features;
     int i, r;
 
+    hdev->migration_blocker = NULL;
+
     if (vhost_set_backend_type(hdev, backend_type) < 0) {
         close((uintptr_t)opaque);
         return -1;
@@ -1012,12 +1014,18 @@
         .eventfd_del = vhost_eventfd_del,
         .priority = 10
     };
-    hdev->migration_blocker = NULL;
-    if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) {
-        error_setg(&hdev->migration_blocker,
-                   "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature.");
+
+    if (hdev->migration_blocker == NULL) {
+        if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) {
+            error_setg(&hdev->migration_blocker,
+                       "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature.");
+        }
+    }
+
+    if (hdev->migration_blocker != NULL) {
         migrate_add_blocker(hdev->migration_blocker);
     }
+
     hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions));
     hdev->n_mem_sections = 0;
     hdev->mem_sections = NULL;