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Tsirkin" , linux-kernel@vger.kernel.org Cc: Christian Brauner , Stefano Garzarella , Luigi Leonardi , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=c3=a9rez?= , Stefan Hajnoczi , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Marco Pinna , virtualization@lists.linux.dev, kvm@vger.kernel.org, netdev@vger.kernel.org References: <3fbfb6e871f625f89eb578c7228e127437b1975a.1727876449.git.mst@redhat.com> From: "Gupta, Pankaj" In-Reply-To: <3fbfb6e871f625f89eb578c7228e127437b1975a.1727876449.git.mst@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: FR2P281CA0044.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:92::18) To IA1PR12MB8189.namprd12.prod.outlook.com (2603:10b6:208:3f0::13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA1PR12MB8189:EE_|SJ2PR12MB9085:EE_ X-MS-Office365-Filtering-Correlation-Id: dcca446a-e32a-4d25-e765-08dce3929f43 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|366016|1800799024; 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In that case, we have a bug: virtio_add_sgs > is called with GFP_KERNEL, and might sleep. > > Pass the gfp flags as an argument, and use GFP_ATOMIC on > the fast path. > > Link: https://lore.kernel.org/all/hfcr2aget2zojmqpr4uhlzvnep4vgskblx5b6xf2ddosbsrke7@nt34bxgp7j2x > Fixes: efcd71af38be ("vsock/virtio: avoid queuing packets when intermediate queue is empty") > Reported-by: Christian Brauner > Cc: Stefano Garzarella > Cc: Luigi Leonardi > Signed-off-by: Michael S. Tsirkin Reviewed-by: Pankaj Gupta > --- > > Lightly tested. Christian, could you pls confirm this fixes the problem > for you? Stefano, it's a holiday here - could you pls help test! > Thanks! > > > net/vmw_vsock/virtio_transport.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c > index f992f9a216f0..0cd965f24609 100644 > --- a/net/vmw_vsock/virtio_transport.c > +++ b/net/vmw_vsock/virtio_transport.c > @@ -96,7 +96,7 @@ static u32 virtio_transport_get_local_cid(void) > > /* Caller need to hold vsock->tx_lock on vq */ > static int virtio_transport_send_skb(struct sk_buff *skb, struct virtqueue *vq, > - struct virtio_vsock *vsock) > + struct virtio_vsock *vsock, gfp_t gfp) > { > int ret, in_sg = 0, out_sg = 0; > struct scatterlist **sgs; > @@ -140,7 +140,7 @@ static int virtio_transport_send_skb(struct sk_buff *skb, struct virtqueue *vq, > } > } > > - ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL); > + ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, gfp); > /* Usually this means that there is no more space available in > * the vq > */ > @@ -178,7 +178,7 @@ virtio_transport_send_pkt_work(struct work_struct *work) > > reply = virtio_vsock_skb_reply(skb); > > - ret = virtio_transport_send_skb(skb, vq, vsock); > + ret = virtio_transport_send_skb(skb, vq, vsock, GFP_KERNEL); > if (ret < 0) { > virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb); > break; > @@ -221,7 +221,7 @@ static int virtio_transport_send_skb_fast_path(struct virtio_vsock *vsock, struc > if (unlikely(ret == 0)) > return -EBUSY; > > - ret = virtio_transport_send_skb(skb, vq, vsock); > + ret = virtio_transport_send_skb(skb, vq, vsock, GFP_ATOMIC); > if (ret == 0) > virtqueue_kick(vq); >