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[188.78.141.109]) by smtp.gmail.com with ESMTPSA id t129sm7723980wmf.41.2020.06.10.07.00.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jun 2020 07:00:03 -0700 (PDT) Message-ID: <313ad30e073974d71ac4c2fc3bc75db690ec8c72.camel@redhat.com> Subject: Re: [PATCH RFC v7 02/14] fixup! vhost: option to fetch descriptors through an independent struct From: Eugenio =?ISO-8859-1?Q?P=E9rez?= To: "Michael S. Tsirkin" , linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, Jason Wang Date: Wed, 10 Jun 2020 16:00:01 +0200 In-Reply-To: <20200610113515.1497099-3-mst@redhat.com> References: <20200610113515.1497099-1-mst@redhat.com> <20200610113515.1497099-3-mst@redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-6.el8) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2020-06-10 at 07:35 -0400, Michael S. Tsirkin wrote: > --- > 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 180b7b58c76b..11433d709651 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -2614,7 +2614,7 @@ int vhost_get_vq_desc_batch(struct vhost_virtqueue *vq, > err_fetch: > vq->ndescs = 0; > > - return ret; > + return ret ? ret : vq->num; > } > EXPORT_SYMBOL_GPL(vhost_get_vq_desc_batch); > I'm able to lock the vhost_get_vq_desc running virtio_test with no arguments against this patch. It does not happen if it returns vq->num early, appended below. Let me know if you prefer your conditional at the end of the function and I will investigate the cause. Thanks! diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 28f324fd77df..4d198994e7be 100644 @@ -2350,7 +2345,9 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, int ret = fetch_descs(vq); int i; - if (ret <= 0) + if (ret == 0) + return vq->num; + else if (ret < 0) goto err; /* Now convert to IOV */