[PATCH v21.11.6 2/2] vhost: fix missing lock protection in power monitor API

[Maxime Coquelin <maxime.coquelin@redhat.com>]

The power monitor get API is missing both access lock
protection and access status check.

Fixes: 34fd4373ce76 ("vhost: add power monitor API")
Cc: stable@dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: David Marchand <david.marchand@redhat.com>
(cherry picked from commit b4c4e5675c85a9b471c252305811d15f6a6d2aa6)
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 19c7b92c32..a544839de3 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -2014,6 +2014,7 @@ rte_vhost_get_monitor_addr(int vid, uint16_t queue_id,
 {
 	struct virtio_net *dev = get_device(vid);
 	struct vhost_virtqueue *vq;
+	int ret = 0;
 
 	if (dev == NULL)
 		return -1;
@@ -2024,6 +2025,13 @@ rte_vhost_get_monitor_addr(int vid, uint16_t queue_id,
 	if (vq == NULL)
 		return -1;
 
+	rte_spinlock_lock(&vq->access_lock);
+
+	if (unlikely(!vq->access_ok)) {
+		ret = -1;
+		goto out_unlock;
+	}
+
 	if (vq_is_packed(dev)) {
 		struct vring_packed_desc *desc;
 		desc = vq->desc_packed;
@@ -2043,7 +2051,10 @@ rte_vhost_get_monitor_addr(int vid, uint16_t queue_id,
 		pmc->match = 0;
 	}
 
-	return 0;
+out_unlock:
+	rte_spinlock_unlock(&vq->access_lock);
+
+	return ret;
 }
 
 
-- 
2.42.0