From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752287AbcKIHiq (ORCPT ); Wed, 9 Nov 2016 02:38:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48990 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750967AbcKIHil (ORCPT ); Wed, 9 Nov 2016 02:38:41 -0500 From: Jason Wang To: mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jason Wang Subject: [PATCH 2/3] vhost: better detection of available buffers Date: Wed, 9 Nov 2016 15:38:32 +0800 Message-Id: <1478677113-13126-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1478677113-13126-1-git-send-email-jasowang@redhat.com> References: <1478677113-13126-1-git-send-email-jasowang@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Wed, 09 Nov 2016 07:38:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We should use vq->last_avail_idx instead of vq->avail_idx in the checking of vhost_vq_avail_empty() since latter is the cached avail index from guest but we want to know if there's pending available buffers in the virtqueue. Signed-off-by: Jason Wang --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c6f2d89..fdf4cdf 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2230,7 +2230,7 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) if (r) return false; - return vhost16_to_cpu(vq, avail_idx) == vq->avail_idx; + return vhost16_to_cpu(vq, avail_idx) == vq->last_avail_idx; } EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); -- 2.7.4