vhost-user-blk: start vhost when guest kicks

Some old guests (before commit 7a11370e5: "virtio_blk: enable VQs early")
kick virtqueue before setting VIRTIO_CONFIG_S_DRIVER_OK. This violates
the virtio spec. But virtio 1.0 transitional devices support this behaviour.
So we should start vhost when guest kicks in this case.

Signed-off-by: Yongji Xie <xieyongji@baidu.com>
Signed-off-by: Chai Wen <chaiwen@baidu.com>
Signed-off-by: Ni Xun <nixun@baidu.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Yongji Xie 2018-06-06 21:24:48 +08:00 committed by Michael S. Tsirkin
parent c28b535d08
commit 110b9463d5

View file

@ -217,7 +217,32 @@ static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
int i;
if (!(virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) &&
!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1))) {
return;
}
if (s->dev.started) {
return;
}
/* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
* vhost here instead of waiting for .set_status().
*/
vhost_user_blk_start(vdev);
/* Kick right away to begin processing requests already in vring */
for (i = 0; i < s->dev.nvqs; i++) {
VirtQueue *kick_vq = virtio_get_queue(vdev, i);
if (!virtio_queue_get_desc_addr(vdev, i)) {
continue;
}
event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
}
}
static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)