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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 3544FE784BA for ; Mon, 2 Oct 2023 19:49:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qnOuP-0002Rs-3H; Mon, 02 Oct 2023 15:48:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qnOuL-0002RS-Rv for qemu-devel@nongnu.org; Mon, 02 Oct 2023 15:48:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qnOuG-0002JT-0m for qemu-devel@nongnu.org; Mon, 02 Oct 2023 15:48:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696276117; 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=WFzmZQqLQUt35caRZP/5pvBiboZC4+c8WT4I98C/NyI=; b=Q8xGQ8jAKzcvTXjy3O3ywdSq+BSGRYdeYKMLwxyyN/q7sav6mh4q/vdXebYBrTCKi4HZ7S F/8gW5pCr2vpLx8wUKtQ/Go+GvDTxi7QBWyABoVav0hH91WbVB0JcydCHlEyBFdEhWY4IR CXyEQbPoNTf8pG6hq/1niraT2cXnnZw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-323-_ophFPhpPCmatQ9IuLcbFQ-1; Mon, 02 Oct 2023 15:48:24 -0400 X-MC-Unique: _ophFPhpPCmatQ9IuLcbFQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CBC7F8039C8; Mon, 2 Oct 2023 19:48:23 +0000 (UTC) Received: from [10.39.192.119] (unknown [10.39.192.119]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A646110EE6CE; Mon, 2 Oct 2023 19:48:21 +0000 (UTC) Message-ID: Date: Mon, 2 Oct 2023 21:48:20 +0200 MIME-Version: 1.0 Subject: Re: [PATCH v2 1/7] vhost-user: strip superfluous whitespace Content-Language: en-US To: Albert Esteve Cc: qemu-devel@nongnu.org, "Michael S. Tsirkin" , Eugenio Perez Martin , German Maglione , Liu Jiang , Sergio Lopez Pascual , Stefano Garzarella , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= References: <20230830134055.106812-1-lersek@redhat.com> <20230830134055.106812-2-lersek@redhat.com> From: Laszlo Ersek In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.129.124; envelope-from=lersek@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 9/6/23 09:12, Albert Esteve wrote: > > > On Thu, Aug 31, 2023 at 9:14 AM Laszlo Ersek > wrote: > > On 8/30/23 15:40, Laszlo Ersek wrote: > > Cc: "Michael S. Tsirkin" > > (supporter:vhost) > > Cc: Eugenio Perez Martin > > > Cc: German Maglione > > > Cc: Liu Jiang > > > Cc: Sergio Lopez Pascual > > > Cc: Stefano Garzarella > > > Signed-off-by: Laszlo Ersek > > > Reviewed-by: Stefano Garzarella > > > --- > > > > Notes: > >     v2: > >      > >     - pick up Stefano's R-b > > > >  hw/virtio/vhost-user.c | 2 +- > >  1 file changed, 1 insertion(+), 1 deletion(-) > > This has been > > Reviewed-by: Philippe Mathieu-Daudé > > > under the (identical) v1 posting: > > http://mid.mail-archive.com/cd0604a1-6826-ac6c-6c47-dcb6def64b28@linaro.org > > Thanks, Phil! (and sorry that I posted v2 too quickly -- I forgot that > sometimes reviewers split a review over multiple days.) > > Laszlo > > > > > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > > index 8dcf049d422b..b4b677c1ce66 100644 > > --- a/hw/virtio/vhost-user.c > > +++ b/hw/virtio/vhost-user.c > > @@ -398,7 +398,7 @@ static int vhost_user_write(struct vhost_dev > *dev, VhostUserMsg *msg, > >       * operations such as configuring device memory mappings or > issuing device > >       * resets, which affect the whole device instead of > individual VQs, > >       * vhost-user messages should only be sent once. > > -     * > > +     * > >       * Devices with multiple vhost_devs are given an associated > dev->vq_index > >       * so per_device requests are only sent if vq_index is 0. > >       */ > > > > > Thanks for the series! > I had a timeout problem with a virtio device I am developing, and I was > not sure yet what was going on. > Your description of the problem seemed to fit mine, in my case the > driver sent a command through the data plane > right after the feature negotiation that reached the backend too soon. > Adding delays alleviated the issue, so it > already hinted me to a race condition. > > I tested using this patch series and according to my experiments, it > really lowers the chances to get the deadlock. > Sadly, I do still get the issue sometimes, though (not frequently)... > However, I think probably the solution comes not > from the Qemu side, but from the rust-vmm vhost-user-backend crate. I am > looking for that solution on my side. > > But that does not invalidate this patch, which I think is a necessary > improvement, and in my tests it really > helps a lot with the described issue. Therefore: > > Tested-by: Albert Esteve > Thanks again -- I'm picking this up for the whole series. Laszlo > > BR, > Albert