From ed0c3125fb103c48943c1a2f5233b51c1d4d1cdf Mon Sep 17 00:00:00 2001
From: Yao Liu <yotta.liu@ucloud.cn>
Date: Tue, 13 Oct 2020 17:57:54 +0800
Subject: [PATCH] vhost: add missing smp_rmb in vhost_vq_avail_ring_get

Signed-off-by: Yao Liu <yotta.liu@ucloud.cn>
Change-Id: Ie8f42cb41ae923ae0926290019cc79d9f5afc868
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4647
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
---
 lib/vhost/vhost.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 369215148..a17004f4c 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -184,6 +184,8 @@ vhost_vq_avail_ring_get(struct spdk_vhost_virtqueue *virtqueue, uint16_t *reqs,
 	uint16_t last_idx = virtqueue->last_avail_idx, avail_idx = avail->idx;
 	uint16_t count, i;
 
+	spdk_smp_rmb();
+
 	count = avail_idx - last_idx;
 	if (spdk_likely(count == 0)) {
 		return 0;