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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 9BD79C433DF for ; Thu, 11 Jun 2020 03:06:31 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 5FC73206FA for ; Thu, 11 Jun 2020 03:06:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OTL63c3g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FC73206FA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54596 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jjDXy-0003Zv-Kf for qemu-devel@archiver.kernel.org; Wed, 10 Jun 2020 23:06:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42670) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jjDXL-0003A5-BB for qemu-devel@nongnu.org; Wed, 10 Jun 2020 23:05:51 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:40818 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jjDXJ-0000Tt-LT for qemu-devel@nongnu.org; Wed, 10 Jun 2020 23:05:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591844747; 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=w7AIw2fiyk7/k1benMaqZ9evm5ERCQVsfSsvu9O/d5g=; b=OTL63c3gERYY2+fbt9u2qOq97Vv8/0PNPbs6DK8S5OYJdDfKuRLjVDgidiLF5MJ+WMRa26 wbtWcJeFmrk/lGJYySjZlvgt43PSPA1wihaqRx6ypf+O/hM7GEiQOXYtCvLsxGkPC8jxzA qloVrWq+WwQc8xipJzWRnjQOv7cjYG0= 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-445-qPD9_IcGP_ysy92aAZYx7w-1; Wed, 10 Jun 2020 23:05:45 -0400 X-MC-Unique: qPD9_IcGP_ysy92aAZYx7w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 13C89107ACCD for ; Thu, 11 Jun 2020 03:05:45 +0000 (UTC) Received: from [10.72.12.125] (ovpn-12-125.pek2.redhat.com [10.72.12.125]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6C71F5C1B0; Thu, 11 Jun 2020 03:05:37 +0000 (UTC) Subject: Re: [PATCH V2] virtio-pci: fix queue_enable write To: Stefano Garzarella , "Michael S. Tsirkin" References: <20200610054351.15811-1-jasowang@redhat.com> <20200610085726.jerorykxbycoesyu@steredhat> <20200610054248-mutt-send-email-mst@kernel.org> <20200610095224.2q4ivledb42ubsz4@steredhat> From: Jason Wang Message-ID: <03fafc96-cefc-a086-b82f-cd87730d9d98@redhat.com> Date: Thu, 11 Jun 2020 11:05:35 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200610095224.2q4ivledb42ubsz4@steredhat> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=jasowang@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/10 23:05:47 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org, stefanha@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2020/6/10 下午5:52, Stefano Garzarella wrote: > On Wed, Jun 10, 2020 at 05:42:54AM -0400, Michael S. Tsirkin wrote: >> On Wed, Jun 10, 2020 at 10:57:26AM +0200, Stefano Garzarella wrote: >>> On Wed, Jun 10, 2020 at 01:43:51PM +0800, Jason Wang wrote: >>>> Spec said: The driver uses this to selectively prevent the device from >>>> executing requests from this virtqueue. 1 - enabled; 0 - disabled. >>>> >>>> Though write 0 to queue_enable is forbidden by the spec, we should not >>>> assume that the value is 1. >>>> >>>> Fix this by ignore the write value other than 1. >>>> >>>> Signed-off-by: Jason Wang >>>> --- >>>> Changes from V1: >>>> - fix typo >>>> - warn wrong value through virtio_error >>>> --- >>>> hw/virtio/virtio-pci.c | 12 ++++++++---- >>>> 1 file changed, 8 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c >>>> index d028c17c24..7bc8c1c056 100644 >>>> --- a/hw/virtio/virtio-pci.c >>>> +++ b/hw/virtio/virtio-pci.c >>>> @@ -1273,16 +1273,20 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, >>>> virtio_queue_set_vector(vdev, vdev->queue_sel, val); >>>> break; >>>> case VIRTIO_PCI_COMMON_Q_ENABLE: >>>> - virtio_queue_set_num(vdev, vdev->queue_sel, >>>> - proxy->vqs[vdev->queue_sel].num); >>>> - virtio_queue_set_rings(vdev, vdev->queue_sel, >>>> + if (val == 1) { >>> Does it have to be 1 or can it be any value other than 0? >>> >>> Thanks, >>> Stefano >> spec says 1 > I was confused by "The driver MUST NOT write a 0 to queue_enable.", > interpreting it as "can write anything other than 0". Yes, the spec is unclear about what happens if we write a value other than 0 or 1. Maybe we should clarify that only 1 is allowed. Or writing value other than 1 may cause unexpected result. > > But as Jason also wrote in the commit message, the driver should write > 1 to enable, so > > Reviewed-by: Stefano Garzarella Thanks > > Thanks, > Stefano >