From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2265BC433DB for ; Thu, 18 Feb 2021 07:26:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1BF664E6F for ; Thu, 18 Feb 2021 07:25:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230334AbhBRHVq (ORCPT ); Thu, 18 Feb 2021 02:21:46 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:51032 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231272AbhBRGtl (ORCPT ); Thu, 18 Feb 2021 01:49:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613630882; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0xSBP2JIYUC8xWmwZs/YoFdX+EUOlZ0kViYULbocJus=; b=KwQnpwzZiRbrXd7x6Se6f/dhnFjrr5ypojdIUleEQYIvrF1WwO3ySJ7GhkgblykSfSgOqw ebrIvc/Efgy/yshMW540SklfoyurGZDzMCSGLSNuFEY7CtoJXbBH4r5xq0r3MnJ2J7Yr13 Ll8ytZlWyVGVVw1NmNzM88QW18vUE+4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-64-NL4_CLGsNk2Km3TLHXsk0Q-1; Thu, 18 Feb 2021 01:36:52 -0500 X-MC-Unique: NL4_CLGsNk2Km3TLHXsk0Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DCF14107ACE4; Thu, 18 Feb 2021 06:36:50 +0000 (UTC) Received: from [10.72.13.28] (ovpn-13-28.pek2.redhat.com [10.72.13.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id 662645B6AB; Thu, 18 Feb 2021 06:36:45 +0000 (UTC) Subject: Re: [PATCH v2 2/3] vdpa/mlx5: fix feature negotiation across device reset To: Si-Wei Liu , mst@redhat.com, elic@nvidia.com Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org References: <1612993680-29454-1-git-send-email-si-wei.liu@oracle.com> <1612993680-29454-3-git-send-email-si-wei.liu@oracle.com> From: Jason Wang Message-ID: <386fffb2-be75-9ce0-0a4d-1d47f91e7d16@redhat.com> Date: Thu, 18 Feb 2021 14:36:43 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <1612993680-29454-3-git-send-email-si-wei.liu@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/2/11 上午5:47, Si-Wei Liu wrote: > The mlx_features denotes the capability for which > set of virtio features is supported by device. In > principle, this field needs not be cleared during > virtio device reset, as this capability is static > and does not change across reset. > > In fact, the current code may have the assumption > that mlx_features can be reloaded from firmware > via the .get_features ops after device is reset > (via the .set_status ops), which is unfortunately > not true. The userspace VMM might save a copy > of backend capable features and won't call into > kernel again to get it on reset. This causes all > virtio features getting disabled on newly created > virtqs after device reset, while guest would hold > mismatched view of available features. For e.g., > the guest may still assume tx checksum offload > is available after reset and feature negotiation, > causing frames with bogus (incomplete) checksum > transmitted on the wire. > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices") > Signed-off-by: Si-Wei Liu Acked-by: Jason Wang > --- > drivers/vdpa/mlx5/net/mlx5_vnet.c | 25 +++++++++++++++---------- > 1 file changed, 15 insertions(+), 10 deletions(-) > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c > index b8416c4..7c1f789 100644 > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > @@ -1486,16 +1486,8 @@ static u64 mlx_to_vritio_features(u16 dev_features) > static u64 mlx5_vdpa_get_features(struct vdpa_device *vdev) > { > struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev); > - struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev); > - u16 dev_features; > > - dev_features = MLX5_CAP_DEV_VDPA_EMULATION(mvdev->mdev, device_features_bits_mask); > - ndev->mvdev.mlx_features = mlx_to_vritio_features(dev_features); > - if (MLX5_CAP_DEV_VDPA_EMULATION(mvdev->mdev, virtio_version_1_0)) > - ndev->mvdev.mlx_features |= BIT_ULL(VIRTIO_F_VERSION_1); > - ndev->mvdev.mlx_features |= BIT_ULL(VIRTIO_F_ACCESS_PLATFORM); > - print_features(mvdev, ndev->mvdev.mlx_features, false); > - return ndev->mvdev.mlx_features; > + return mvdev->mlx_features; > } > > static int verify_min_features(struct mlx5_vdpa_dev *mvdev, u64 features) > @@ -1788,7 +1780,6 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) > clear_virtqueues(ndev); > mlx5_vdpa_destroy_mr(&ndev->mvdev); > ndev->mvdev.status = 0; > - ndev->mvdev.mlx_features = 0; > ++mvdev->generation; > return; > } > @@ -1907,6 +1898,19 @@ static int mlx5_get_vq_irq(struct vdpa_device *vdv, u16 idx) > .free = mlx5_vdpa_free, > }; > > +static void query_virtio_features(struct mlx5_vdpa_net *ndev) > +{ > + struct mlx5_vdpa_dev *mvdev = &ndev->mvdev; > + u16 dev_features; > + > + dev_features = MLX5_CAP_DEV_VDPA_EMULATION(mvdev->mdev, device_features_bits_mask); > + mvdev->mlx_features = mlx_to_vritio_features(dev_features); > + if (MLX5_CAP_DEV_VDPA_EMULATION(mvdev->mdev, virtio_version_1_0)) > + mvdev->mlx_features |= BIT_ULL(VIRTIO_F_VERSION_1); > + mvdev->mlx_features |= BIT_ULL(VIRTIO_F_ACCESS_PLATFORM); > + print_features(mvdev, mvdev->mlx_features, false); > +} > + > static int query_mtu(struct mlx5_core_dev *mdev, u16 *mtu) > { > u16 hw_mtu; > @@ -2005,6 +2009,7 @@ static int mlx5v_probe(struct auxiliary_device *adev, > init_mvqs(ndev); > mutex_init(&ndev->reslock); > config = &ndev->config; > + query_virtio_features(ndev); > err = query_mtu(mdev, &ndev->mtu); > if (err) > goto err_mtu;