[PATCH] vhost: fix vring addr update with vDPA

[David Marchand <david.marchand@redhat.com>]

For vDPA devices, vq are not locked once the device has been configured
at runtime.

On the other hand, we need to hold the vq lock to evaluate vq->access_ok,
invalidate vring addresses and translate them.

Move vring address update earlier and, when vDPA is configured, skip parts
which expect lock to be taken.

Bugzilla ID: 1394
Fixes: 741dc052eaf9 ("vhost: annotate virtqueue access checks")

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/vhost/vhost_user.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 3aba32c95a..7fe1687f08 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -986,17 +986,20 @@ vhost_user_set_vring_addr(struct virtio_net **pdev,
 	/* addr->index refers to the queue index. The txq 1, rxq is 0. */
 	vq = dev->virtqueue[ctx->msg.payload.addr.index];
 
-	/* vhost_user_lock_all_queue_pairs locked all qps */
-	VHOST_USER_ASSERT_LOCK(dev, vq, VHOST_USER_SET_VRING_ADDR);
-
-	access_ok = vq->access_ok;
-
 	/*
 	 * Rings addresses should not be interpreted as long as the ring is not
 	 * started and enabled
 	 */
 	memcpy(&vq->ring_addrs, addr, sizeof(*addr));
 
+	if (dev->flags & VIRTIO_DEV_VDPA_CONFIGURED)
+		goto out;
+
+	/* vhost_user_lock_all_queue_pairs locked all qps */
+	VHOST_USER_ASSERT_LOCK(dev, vq, VHOST_USER_SET_VRING_ADDR);
+
+	access_ok = vq->access_ok;
+
 	vring_invalidate(dev, vq);
 
 	if ((vq->enabled && (dev->features &
@@ -1006,6 +1009,7 @@ vhost_user_set_vring_addr(struct virtio_net **pdev,
 		*pdev = dev;
 	}
 
+out:
 	return RTE_VHOST_MSG_RESULT_OK;
 }
 
-- 
2.43.0