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=-18.8 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,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 CF8ACC43462 for ; Tue, 13 Apr 2021 05:48:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF04961221 for ; Tue, 13 Apr 2021 05:48:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344615AbhDMFsY (ORCPT ); Tue, 13 Apr 2021 01:48:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:52109 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344626AbhDMFsR (ORCPT ); Tue, 13 Apr 2021 01:48:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618292877; 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: in-reply-to:in-reply-to:references:references; bh=6jg8BCGbpMnOAIkNzLWva23V8vKuJlUTOTl6SMonbbA=; b=fCcIv0LYgGUpI8R06kINj2Jh34BmCIIfIuoetroiTYty4A2JGQtDL4igiaQWCwOQEFArjc bCobrZCu35REpTam5WI06+FGj6zHGb2FaJ2X/fhzEwJma83X87OOoLYSRImFMsHym8QE8W ZMcfzjjLtaQ9xTVWJ5VZvR7eGINma8M= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-597-i1lePNbiPquKNemhZgov1Q-1; Tue, 13 Apr 2021 01:47:56 -0400 X-MC-Unique: i1lePNbiPquKNemhZgov1Q-1 Received: by mail-wr1-f71.google.com with SMTP id j4so304526wru.20 for ; Mon, 12 Apr 2021 22:47:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=6jg8BCGbpMnOAIkNzLWva23V8vKuJlUTOTl6SMonbbA=; b=K0ff6xouLq0tqrgoHSPtu0CQIfZe97tVb390oz1nRbylfvQESBw7ODMqlN9wzL+rFL HdoJQkHrpddYlOyS2OuUPD7zli1mcRcgLraM01oYGpU3Q0aeyEyNoZNR+aRU5LRAMAoN GLcPmUqsgGT5AY74K9lmYkVgKKyZXsV7kukpIe/v18xV4R6lZpH3ObEKjrCONJNkRtgX tGjmdewWvjcQEZ50fhQytH/mxkkm26mcuJzVAUX4H/5sVxY7sjzleqJc8ATI/6oBQVvS W3HolmMCzIqEv34S0QPPMScaHSjgE439aCvSorksT9sNBeEbnmKazIybNWRxLxmTYxy+ MeLA== X-Gm-Message-State: AOAM533wHOCF9b0corJcVAdP6QF3pjqfzU9l78T0eaSG70c/IOgEoadQ 2PMHMW5Qpnea6JoUKS3xP0D4VGtLf4TuFW00CkTCLLHw5yMEVc3HHSLlKj/1ZVTdiRu0ZL1jg6u hVm4Cu9g4p8wUiaiB9pgT9fNFr8J9VyaCz/gtICDysrRIMVRP7/oc81G+w/sqBJJpwJVL5A== X-Received: by 2002:a5d:4e08:: with SMTP id p8mr35572390wrt.4.1618292874845; Mon, 12 Apr 2021 22:47:54 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwlOFgyL/tLR6N8M+xp6zE98QryIgkrAWDLF0SSu1myLxGcVLWj/Riydxj6MeQAxcymfF/BrA== X-Received: by 2002:a5d:4e08:: with SMTP id p8mr35572375wrt.4.1618292874631; Mon, 12 Apr 2021 22:47:54 -0700 (PDT) Received: from redhat.com ([2a10:8006:2281:0:1994:c627:9eac:1825]) by smtp.gmail.com with ESMTPSA id i4sm1264707wmq.12.2021.04.12.22.47.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Apr 2021 22:47:54 -0700 (PDT) Date: Tue, 13 Apr 2021 01:47:52 -0400 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Jakub Kicinski , Jason Wang , Wei Wang , David Miller , netdev@vger.kernel.org, Willem de Bruijn , virtualization@lists.linux-foundation.org Subject: [PATCH RFC v2 3/4] virtio_net: move tx vq operation under tx queue lock Message-ID: <20210413054733.36363-4-mst@redhat.com> References: <20210413054733.36363-1-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210413054733.36363-1-mst@redhat.com> X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's unsafe to operate a vq from multiple threads. Unfortunately this is exactly what we do when invoking clean tx poll from rx napi. As a fix move everything that deals with the vq to under tx lock. Signed-off-by: Michael S. Tsirkin --- drivers/net/virtio_net.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 16d5abed582c..460ccdbb840e 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1505,6 +1505,8 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) struct virtnet_info *vi = sq->vq->vdev->priv; unsigned int index = vq2txq(sq->vq); struct netdev_queue *txq; + int opaque; + bool done; if (unlikely(is_xdp_raw_buffer_queue(vi, index))) { /* We don't need to enable cb for XDP */ @@ -1514,10 +1516,28 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) txq = netdev_get_tx_queue(vi->dev, index); __netif_tx_lock(txq, raw_smp_processor_id()); + virtqueue_disable_cb(sq->vq); free_old_xmit_skbs(sq, true); + + opaque = virtqueue_enable_cb_prepare(sq->vq); + + done = napi_complete_done(napi, 0); + + if (!done) + virtqueue_disable_cb(sq->vq); + __netif_tx_unlock(txq); - virtqueue_napi_complete(napi, sq->vq, 0); + if (done) { + if (unlikely(virtqueue_poll(sq->vq, opaque))) { + if (napi_schedule_prep(napi)) { + __netif_tx_lock(txq, raw_smp_processor_id()); + virtqueue_disable_cb(sq->vq); + __netif_tx_unlock(txq); + __napi_schedule(napi); + } + } + } if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) netif_tx_wake_queue(txq); -- MST 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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 56B5FC433B4 for ; Tue, 13 Apr 2021 05:48:02 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 11A446109D for ; 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Mon, 12 Apr 2021 22:47:54 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwlOFgyL/tLR6N8M+xp6zE98QryIgkrAWDLF0SSu1myLxGcVLWj/Riydxj6MeQAxcymfF/BrA== X-Received: by 2002:a5d:4e08:: with SMTP id p8mr35572375wrt.4.1618292874631; Mon, 12 Apr 2021 22:47:54 -0700 (PDT) Received: from redhat.com ([2a10:8006:2281:0:1994:c627:9eac:1825]) by smtp.gmail.com with ESMTPSA id i4sm1264707wmq.12.2021.04.12.22.47.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Apr 2021 22:47:54 -0700 (PDT) Date: Tue, 13 Apr 2021 01:47:52 -0400 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Subject: [PATCH RFC v2 3/4] virtio_net: move tx vq operation under tx queue lock Message-ID: <20210413054733.36363-4-mst@redhat.com> References: <20210413054733.36363-1-mst@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210413054733.36363-1-mst@redhat.com> X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mst@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Cc: Willem de Bruijn , netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, Jakub Kicinski , Wei Wang , David Miller X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" It's unsafe to operate a vq from multiple threads. Unfortunately this is exactly what we do when invoking clean tx poll from rx napi. As a fix move everything that deals with the vq to under tx lock. Signed-off-by: Michael S. Tsirkin --- drivers/net/virtio_net.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 16d5abed582c..460ccdbb840e 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1505,6 +1505,8 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) struct virtnet_info *vi = sq->vq->vdev->priv; unsigned int index = vq2txq(sq->vq); struct netdev_queue *txq; + int opaque; + bool done; if (unlikely(is_xdp_raw_buffer_queue(vi, index))) { /* We don't need to enable cb for XDP */ @@ -1514,10 +1516,28 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) txq = netdev_get_tx_queue(vi->dev, index); __netif_tx_lock(txq, raw_smp_processor_id()); + virtqueue_disable_cb(sq->vq); free_old_xmit_skbs(sq, true); + + opaque = virtqueue_enable_cb_prepare(sq->vq); + + done = napi_complete_done(napi, 0); + + if (!done) + virtqueue_disable_cb(sq->vq); + __netif_tx_unlock(txq); - virtqueue_napi_complete(napi, sq->vq, 0); + if (done) { + if (unlikely(virtqueue_poll(sq->vq, opaque))) { + if (napi_schedule_prep(napi)) { + __netif_tx_lock(txq, raw_smp_processor_id()); + virtqueue_disable_cb(sq->vq); + __netif_tx_unlock(txq); + __napi_schedule(napi); + } + } + } if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) netif_tx_wake_queue(txq); -- MST _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization