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charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.5 (bf161cf53efb) (2018-04-13) X-Originating-IP: [172.20.187.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To HQMAIL107.nvidia.com (172.20.187.13) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: eccd31f8-51db-4d32-fc90-08d9afe41997 X-MS-TrafficTypeDiagnostic: DM6PR12MB4500: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.112.34;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:schybrid03.nvidia.com;CAT:NONE;SFS:(4636009)(46966006)(36840700001)(356005)(1076003)(8936002)(83380400001)(7696005)(70586007)(8676002)(5660300002)(70206006)(336012)(316002)(33656002)(54906003)(4326008)(9686003)(6916009)(7636003)(508600001)(53546011)(86362001)(36860700001)(426003)(26005)(2906002)(55016003)(16526019)(186003)(47076005)(82310400004);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Nov 2021 07:20:46.5291 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: eccd31f8-51db-4d32-fc90-08d9afe41997 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.112.34];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT031.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4500 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 25, 2021 at 03:15:33PM +0800, Jason Wang wrote: > On Thu, Nov 25, 2021 at 3:09 PM Eli Cohen wrote: > > > > On Thu, Nov 25, 2021 at 02:05:47PM +0800, Jason Wang wrote: > > > When VIRTIO_NET_F_MTU feature is not negotiated, we assume a very > > > large max_mtu. In this case, using small packet mode is not correct > > > since it may breaks the networking when MTU is grater than > > > ETH_DATA_LEN. > > > > > > To have a quick fix, simply enable the big packet mode when > > > VIRTIO_NET_F_MTU is not negotiated. We can do optimization on top. > > > > > > Reported-by: Eli Cohen > > > Cc: Eli Cohen > > > Signed-off-by: Jason Wang > > > --- > > > drivers/net/virtio_net.c | 7 ++++--- > > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > index 7c43bfc1ce44..83ae3ef5eb11 100644 > > > --- a/drivers/net/virtio_net.c > > > +++ b/drivers/net/virtio_net.c > > > @@ -3200,11 +3200,12 @@ static int virtnet_probe(struct virtio_device *vdev) > > > dev->mtu = mtu; > > > dev->max_mtu = mtu; > > > > > > - /* TODO: size buffers correctly in this case. */ > > > - if (dev->mtu > ETH_DATA_LEN) > > > - vi->big_packets = true; > > > } > > > > > > + /* TODO: size buffers correctly in this case. */ > > > + if (dev->max_mtu > ETH_DATA_LEN) > > > + vi->big_packets = true; > > > + > > > > If VIRTIO_NET_F_MTU is provided, then dev->max_mtu is going to equal > > ETH_DATA_LEN (will be set in ether_setup()) so I don't think it will set > > big_packets to true. > > I may miss something, the dev->max_mtu is just assigned to the mtu > value read from the config space in the code block above (inside the > feature check of VIRTIO_NET_F_MTU). Sorry, I meant "If VIRTIO_NET_F_MTU is ***NOT*** provided". In that case dev->max_mtu eauals ETH_DATA_LEN so you won't set vi->big_packets to true. > > Thanks > > > > > > > > if (vi->any_header_sg) > > > dev->needed_headroom = vi->hdr_len; > > > > > > -- > > > 2.25.1 > > > > > >