From: David Marchand <david.marchand@redhat.com>
Date: Mon, 11 Apr 2022 11:00:08 +0000 (+0200)
Subject: vhost: fix async access
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=2d47fd3dfb596d266b89d82c2c4b2351c3d6fe20;p=dpdk.git

vhost: fix async access

vq->async accesses must be protected with vq->access_lock.

Fixes: eb666d24085f ("vhost: fix async unregister deadlock")
Fixes: 0c0935c5f794 ("vhost: allow to check in-flight packets for async vhost")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Sunil Pai G <sunil.pai.g@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index df0bb9d043..14863144f3 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -1753,27 +1753,23 @@ rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)
 	if (vq == NULL)
 		return ret;
 
-	ret = 0;
-
-	if (!vq->async)
-		return ret;
-
 	if (!rte_spinlock_trylock(&vq->access_lock)) {
 		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async channel, virtqueue busy.\n",
 				dev->ifname);
-		return -1;
+		return ret;
 	}
 
-	if (vq->async->pkts_inflight_n) {
+	if (!vq->async) {
+		ret = 0;
+	} else if (vq->async->pkts_inflight_n) {
 		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async channel.\n", dev->ifname);
 		VHOST_LOG_CONFIG(ERR, "(%s) inflight packets must be completed before unregistration.\n",
 			dev->ifname);
-		ret = -1;
-		goto out;
+	} else {
+		vhost_free_async_mem(vq);
+		ret = 0;
 	}
 
-	vhost_free_async_mem(vq);
-out:
 	rte_spinlock_unlock(&vq->access_lock);
 
 	return ret;
@@ -1891,9 +1887,6 @@ rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
 	if (vq == NULL)
 		return ret;
 
-	if (!vq->async)
-		return ret;
-
 	if (!rte_spinlock_trylock(&vq->access_lock)) {
 		VHOST_LOG_CONFIG(DEBUG,
 			"(%s) failed to check in-flight packets. virtqueue busy.\n",
@@ -1901,7 +1894,9 @@ rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
 		return ret;
 	}
 
-	ret = vq->async->pkts_inflight_n;
+	if (vq->async)
+		ret = vq->async->pkts_inflight_n;
+
 	rte_spinlock_unlock(&vq->access_lock);
 
 	return ret;