[PATCH] block/vhost-user-blk: Fix hang on boot for some odd guests

[Andrey Ryabinin]

Some guests hang on boot when using the vhost-user-blk-pci device,
but boot normally when using the virtio-blk device. The problem occurs
because the guest advertises VIRTIO_F_VERSION_1 but kicks the virtqueue
before setting VIRTIO_CONFIG_S_DRIVER_OK, causing vdev->start_on_kick to
be false in vhost_user_blk_handle_output() and preventing the device from
starting.

Fix this by removing the check for vdev->start_on_kick to ensure
that the device starts after the kick. This aligns the behavior of
'vhost-user-blk-pci' device with 'virtio-blk' as it does the similar
thing in its virtio_blk_handle_output() function.

Fixes: 110b9463d5c8 ("vhost-user-blk: start vhost when guest kicks")
Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com>
---
 hw/block/vhost-user-blk.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index aff4d2b8cbd..448ead448f3 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -279,10 +279,6 @@ static void vhost_user_blk_handle_output(VirtIODevice 
*vdev, VirtQueue *vq)
     Error *local_err = NULL;
     int i, ret;
 
-    if (!vdev->start_on_kick) {
-        return;
-    }
-
     if (!s->connected) {
         return;
     }
-- 
2.39.2