[dpdk-dev] [PATCH] vhost: fix wait for valid descriptor

[Tomasz Kulasek <tomaszx.kulasek@intel.com>]

For each virt queue's kickfd and callfd, there are 2 invalid
status: VIRTIO_UNINITIALIZED_EVENTFD and VIRTIO_INVALID_EVENTFD.
Don't set the virt queue to ready status until got the valid
descriptor.

This is safe for polling mode drivers in Guest OS, the backend
vhost process will not post notification to interrupt vector for
PMD mode in guest, but the interrupt vector still valid.

Fixes: e049ca6d10e0 ("vhost-user: prepare multiple queue setup")
Cc: yuanhan.liu@linux.intel.com
Cc: stable@dpdk.org

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>
---
 lib/librte_vhost/vhost_user.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 65ee33919..4508f697b 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -766,7 +766,9 @@ vq_is_ready(struct vhost_virtqueue *vq)
 {
 	return vq && vq->desc && vq->avail && vq->used &&
 	       vq->kickfd != VIRTIO_UNINITIALIZED_EVENTFD &&
-	       vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD;
+	       vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD &&
+	       vq->kickfd != VIRTIO_INVALID_EVENTFD &&
+	       vq->callfd != VIRTIO_INVALID_EVENTFD;
 }
 
 static int
-- 
2.14.1