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=-17.6 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=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 0E3B3C49EA3 for ; Mon, 21 Jun 2021 06:22:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA8C3610EA for ; Mon, 21 Jun 2021 06:22:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229710AbhFUGYj (ORCPT ); Mon, 21 Jun 2021 02:24:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:48502 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229695AbhFUGYe (ORCPT ); Mon, 21 Jun 2021 02:24:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624256489; 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=eCe0XqT7hlnzVykEXgQZZ3co5Ktu3F1QMr/REXMNOgY=; b=KOJpasMzA37O7vVn6DrvUYAfmkQQdCZQBAkWoCq89We4ah/oZ5vsBc55oL4VY8dhXd0p3U 2TINkA9nljNatkEUW7f//k1Ks2mhBLVtV4nv0B5FG/ttueksfpJoZPSFZei4/CbzjLCv5k SjX505+C8HIfA49pRTNgaa8gIToyRHM= Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-161-eJMSdKF_PdOw6GP3ZA4Rvw-1; Mon, 21 Jun 2021 02:21:24 -0400 X-MC-Unique: eJMSdKF_PdOw6GP3ZA4Rvw-1 Received: by mail-pg1-f198.google.com with SMTP id y1-20020a655b410000b02902235977d00cso2120687pgr.21 for ; Sun, 20 Jun 2021 23:21:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=eCe0XqT7hlnzVykEXgQZZ3co5Ktu3F1QMr/REXMNOgY=; b=byzoIgmMdrPXmV/yvNyoImHZblNkam+vBhEFDPFbRgay+9S45Rkxlnh084Dow/ihSe /CiltYWPlDBED4hViIqenaauVphzi1Pts0GhRGPWk84V1TwePzGwgkR0R2KKOb9gcUUW bx4IU3sCuOHHHtC9SitQd/D1RcGXh2GE9AiSHDhE/6Zbj3U5t231m/qerCBjTqFANDip Uu6Gsal17Iq1VqZEZGawHX2zJEYvBzCw0igng2DeJBJQwP/UrSqKqjRNqkqvE1EDibNj 15hB3yg3j3X5PDB88vmbcqHeHHAGJ5ZS5unzacG3AK2dnDYev3V8L8zlbHrHkIPeeU8H FVTA== X-Gm-Message-State: AOAM533mkvvs2nMzDca98tMJjaUnpiRRAKFMSf0I/ih0YPGpS/VaW2C1 ITOBFq5Av5RPU1+UftHXrcWsYj+oi+2IHUJ4YcU0ISbzRYedylym30CKLXk/WgKKRMenxsvByK6 QzPe5i3gR1w7FEGwCZCYtVOqr1Pf+0DvbU/D1Xw6QidvWbP5zUsybdWqKUIeET1w9uB4pt55HdE gf X-Received: by 2002:a17:902:aa8d:b029:11a:9225:3ea with SMTP id d13-20020a170902aa8db029011a922503eamr16511422plr.49.1624256482848; Sun, 20 Jun 2021 23:21:22 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzJeu9sPwDlIU9dv9ukuvBcRNyJ/YNl903d3lts/alsUMOf5sU5/MEufbhvdpGykP1ZvZWlSQ== X-Received: by 2002:a17:902:aa8d:b029:11a:9225:3ea with SMTP id d13-20020a170902aa8db029011a922503eamr16511400plr.49.1624256482597; Sun, 20 Jun 2021 23:21:22 -0700 (PDT) Received: from wangxiaodeMacBook-Air.local ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id j8sm7324717pfu.60.2021.06.20.23.21.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 20 Jun 2021 23:21:22 -0700 (PDT) Subject: Re: [PATCH] virtio_net: Enable MSI-X vector for ctrl queue To: "Michael S. Tsirkin" , Keiichi Watanabe Cc: netdev@vger.kernel.org, chirantan@chromium.org, "David S . Miller" , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20210618072625.957837-1-keiichiw@chromium.org> <20210618083650-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: <0933f13d-b52e-321e-4be1-1b0e3cfb346b@redhat.com> Date: Mon, 21 Jun 2021 14:21:18 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210618083650-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ÔÚ 2021/6/18 ÏÂÎç8:38, Michael S. Tsirkin дµÀ: > On Fri, Jun 18, 2021 at 04:26:25PM +0900, Keiichi Watanabe wrote: >> When we use vhost-user backend on the host, MSI-X vector should be set >> so that the vmm can get an irq FD and send it to the backend device >> process with vhost-user protocol. >> Since whether the vector is set for a queue is determined depending on >> the queue has a callback, this commit sets an empty callback for >> virtio-net's control queue. >> >> Signed-off-by: Keiichi Watanabe > I'm confused by this explanation. If the vmm wants to get > an interrupt it can do so - why change the guest driver? +1, it sounds like a bug in the backend or we probably need more context here. Thanks > >> --- >> drivers/net/virtio_net.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 11f722460513..002e3695d4b3 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -2696,6 +2696,11 @@ static void virtnet_del_vqs(struct virtnet_info *vi) >> virtnet_free_queues(vi); >> } >> >> +static void virtnet_ctrlq_done(struct virtqueue *rvq) >> +{ >> + /* Do nothing */ >> +} >> + >> /* How large should a single buffer be so a queue full of these can fit at >> * least one full packet? >> * Logic below assumes the mergeable buffer header is used. >> @@ -2748,7 +2753,7 @@ static int virtnet_find_vqs(struct virtnet_info *vi) >> >> /* Parameters for control virtqueue, if any */ >> if (vi->has_cvq) { >> - callbacks[total_vqs - 1] = NULL; >> + callbacks[total_vqs - 1] = virtnet_ctrlq_done; >> names[total_vqs - 1] = "control"; >> } >> >> -- >> 2.32.0.288.g62a8d224e6-goog