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 66870CD54A9 for ; Tue, 19 Sep 2023 09:45:21 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qiXHi-0004yq-1R; Tue, 19 Sep 2023 05:44:46 -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 1qiXHZ-0004uM-Cy for qemu-devel@nongnu.org; Tue, 19 Sep 2023 05:44:41 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiXHX-0007Pl-N3 for qemu-devel@nongnu.org; Tue, 19 Sep 2023 05:44:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695116674; 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=koZEi9vkyXslV4OU7C8l8laYlKffzDU3srbGrkTsXOY=; b=XcHGcAHrsob/HlqNSbVpQfc+QkOvtvfRPraJ00xrFncAcz2Nf1q0aVsPeogf1pKgmGMCK1 4QG17YVOaIHwwOQXBbJtOEyCac8k7fGhhi1fqqlE12Pe5t77p1WweFXwHyyyYuYmEu0V+w Uaj6je5WqmDzakVZLLvrN8vLKKGrRW8= 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-682-sWKiNggFMM-MMdybyiKI_g-1; Tue, 19 Sep 2023 05:44:23 -0400 X-MC-Unique: sWKiNggFMM-MMdybyiKI_g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (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 7DBB0801779; Tue, 19 Sep 2023 09:44:23 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.25]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 31741C15BB8; Tue, 19 Sep 2023 09:44:23 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 390D621E6900; Tue, 19 Sep 2023 11:44:22 +0200 (CEST) From: Markus Armbruster To: Vladimir Sementsov-Ogievskiy Cc: qemu-devel@nongnu.org, yc-core@yandex-team.ru, eduardo@habkost.net, berrange@redhat.com, pbonzini@redhat.com, eblake@redhat.com, dave@treblig.org, mst@redhat.com Subject: Re: [PATCH v2] virtio: add VIRTQUEUE_ERROR QAPI event References: <20230912175756.151047-1-vsementsov@yandex-team.ru> Date: Tue, 19 Sep 2023 11:44:22 +0200 In-Reply-To: <20230912175756.151047-1-vsementsov@yandex-team.ru> (Vladimir Sementsov-Ogievskiy's message of "Tue, 12 Sep 2023 20:57:56 +0300") Message-ID: <877comzedl.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@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_H3=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 Vladimir Sementsov-Ogievskiy writes: > For now we only log the vhost device error, when virtqueue is actually > stopped. Let's add a QAPI event, which makes possible: > > - collect statistics of such errors > - make immediate actions: take core dumps or do some other debugging > - inform the user through a management API or UI, so that (s)he can > react somehow, e.g. reset the device driver in the guest or even > build up some automation to do so > > Note that basically every inconsistency discovered during virtqueue > processing results in a silent virtqueue stop. The guest then just > sees the requests getting stuck somewhere in the device for no visible > reason. This event provides a means to inform the management layer of > this situation in a timely fashion. > > The event could be reused for some other virtqueue problems (not only > for vhost devices) in future. For this it gets a generic name and > structure. > > We keep original VHOST_OPS_DEBUG(), to keep original debug output as is > here, it's not the only call to VHOST_OPS_DEBUG in the file. > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- [...] > diff --git a/qapi/qdev.json b/qapi/qdev.json > index 6bc5a733b8..199e21cae7 100644 > --- a/qapi/qdev.json > +++ b/qapi/qdev.json > @@ -161,3 +161,28 @@ > ## > { 'event': 'DEVICE_UNPLUG_GUEST_ERROR', > 'data': { '*device': 'str', 'path': 'str' } } > + > +## > +# @VirtqueueError: > +# Missing member documentation: # @vhost-vring-err: Lorem ipsum dolor sit amet, consectetur adipiscing # elit, sed do eiusmod tempor incididunt ut labore et dolore magna # aliqua. > +# Since: 8.2 > +## > +{ 'enum': 'VirtqueueError', > + 'data': [ 'vhost-vring-err' ] } Let's not abbreviate "error" to "err" here. > + > +## > +# @VIRTQUEUE_ERROR: > +# > +# Emitted when a device virtqueue fails in runtime. > +# > +# @device: the device's ID if it has one > +# @path: the device's QOM path > +# @virtqueue: virtqueue index > +# @error: error identifier > +# @description: human readable description > +# > +# Since: 8.2 > +## > +{ 'event': 'VIRTQUEUE_ERROR', > + 'data': { '*device': 'str', 'path': 'str', 'virtqueue': 'int', > + 'error': 'VirtqueueError', 'description': 'str'} }