virtio: Set "start_on_kick" on virtio_set_features()

The guest feature is not set correctly on virtio_reset() and
virtio_init(). So we should not use it to set "start_on_kick" at that
point. This patch set "start_on_kick" on virtio_set_features() instead.

Fixes: badaf79cfdbd3 ("virtio: Introduce started flag to VirtioDevice")
Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20190626023130.31315-4-xieyongji@baidu.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 20 insertions, 8 deletions

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index f7504d1395..5fd25d98a9 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1212,7 +1212,7 @@ void virtio_reset(void *opaque)
         k->reset(vdev);
     }
 
-    vdev->start_on_kick = !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1);
+    vdev->start_on_kick = false;
     vdev->started = false;
     vdev->broken = false;
     vdev->guest_features = 0;
@@ -2063,14 +2063,21 @@ int virtio_set_features(VirtIODevice *vdev, uint64_t val)
         return -EINVAL;
     }
     ret = virtio_set_features_nocheck(vdev, val);
-    if (!ret && virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
-        /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches.  */
-        int i;
-        for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
-            if (vdev->vq[i].vring.num != 0) {
-                virtio_init_region_cache(vdev, i);
+    if (!ret) {
+        if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
+            /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches.  */
+            int i;
+            for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
+                if (vdev->vq[i].vring.num != 0) {
+                    virtio_init_region_cache(vdev, i);
+                }
             }
         }
+
+        if (!virtio_device_started(vdev, vdev->status) &&
+            !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
+            vdev->start_on_kick = true;
+        }
     }
     return ret;
 }
@@ -2222,6 +2229,11 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
         }
     }
 
+    if (!virtio_device_started(vdev, vdev->status) &&
+        !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
+        vdev->start_on_kick = true;
+    }
+
     rcu_read_lock();
     for (i = 0; i < num; i++) {
         if (vdev->vq[i].vring.desc) {
@@ -2324,7 +2336,7 @@ void virtio_init(VirtIODevice *vdev, const char *name,
             g_malloc0(sizeof(*vdev->vector_queues) * nvectors);
     }
 
-    vdev->start_on_kick = !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1);
+    vdev->start_on_kick = false;
     vdev->started = false;
     vdev->device_id = device_id;
     vdev->status = 0;