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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 5FAA6C00523 for ; Wed, 8 Jan 2020 09:59:11 +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 25F6A20705 for ; Wed, 8 Jan 2020 09:59:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="d7bDlf64" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25F6A20705 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]:41230 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ip87K-0000Xf-9r for qemu-devel@archiver.kernel.org; Wed, 08 Jan 2020 04:59:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57348) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ip86c-00006J-Ru for qemu-devel@nongnu.org; Wed, 08 Jan 2020 04:58:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ip86b-0007Cv-EP for qemu-devel@nongnu.org; Wed, 08 Jan 2020 04:58:26 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:46294 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ip86b-0007Bt-Ah for qemu-devel@nongnu.org; Wed, 08 Jan 2020 04:58:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578477504; 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=9sycsqZJGVnQw+EqUeY+kh0XYMo8ue/f6Kld1hcvxz8=; b=d7bDlf641fthW2KYfWr2bq1BONQGNJNoc9gJ3j6jAMT2VZEhUzvXlkfHwvB1Y3CjGxKBzw lc51ch227gYJeOf6iT+/oxuYUL0XXbLr+LSg5coWHRZmiJCQS4i5vDZbUN4HjJuWdaM8G7 8p1nQ+9lejzQWrq6ALvJ0Vq3qed7CnY= 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-207-Hy-c3osQPSqa5RsUENJZtg-1; Wed, 08 Jan 2020 04:58:23 -0500 X-MC-Unique: Hy-c3osQPSqa5RsUENJZtg-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 15834800D54; Wed, 8 Jan 2020 09:58:22 +0000 (UTC) Received: from [10.43.2.30] (unknown [10.43.2.30]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6D59E5C241; Wed, 8 Jan 2020 09:58:17 +0000 (UTC) Subject: Re: discuss about pvpanic To: Paolo Bonzini , zhenwei pi References: <2feff896-21fe-2bbe-6f68-9edfb476a110@bytedance.com> From: Michal Privoznik Message-ID: Date: Wed, 8 Jan 2020 10:58:16 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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: "libvir-list@redhat.com" , Greg KH , qemu-devel@nongnu.org, linux-kernel@vger.kernel.org, "yelu@bytedance.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 1/8/20 10:36 AM, Paolo Bonzini wrote: > On 08/01/20 09:25, zhenwei pi wrote: >> Hey, Paolo >> >> Currently, pvpapic only supports bit 0(PVPANIC_PANICKED). >> We usually expect that guest writes ioport (typical 0x505) in panic_notifier_list callback >> during handling panic, then we can handle pvpapic event PVPANIC_PANICKED in QEMU. >> >> On the other hand, guest wants to handle the crash by kdump-tools, and reboots without any >> panic_notifier_list callback. So QEMU only knows that guest has rebooted (because guest >> write 0xcf9 ioport for RCR request), but QEMU can't identify why guest resets. >> >> In production environment, we hit about 100+ guest reboot event everyday, sadly we >> can't separate the abnormal reboot from normal operation. >> >> We want to add a new bit for pvpanic event(maybe PVPANIC_CRASHLOADED) to represent the guest has crashed, >> and the panic is handled by the guest kernel. (here is the previous patch https://lkml.org/lkml/2019/12/14/265) >> >> What do you think about this solution? Or do you have any other suggestions? > > Hi Zhenwei, > > the kernel-side patch certainly makes sense. I assume that you want the > event to propagate up from QEMU to Libvirt and so on? The QEMU patch > would need to declare a new event (qapi/misc.json) and send it in > handle_event (hw/misc/pvpanic.c). For Libvirt I'm not familiar, so I'm > adding the respective list. Adding an event is fairly easy, if everything you want libvirt to do is report the event to upper layers. I volunteer to do it. Question is, how qemu is going to report this, whether some attributes to GUEST_PANICKED event or some new event. But more important is to merge the change into kernel. Michal