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 lists1p.gnu.org (lists1p.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 E368FC43458 for ; Mon, 13 Jul 2026 09:07:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wjCcg-0002kR-AA; Mon, 13 Jul 2026 05:06:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wjCce-0002kI-Rr for qemu-devel@nongnu.org; Mon, 13 Jul 2026 05:06:44 -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 1wjCcc-0006Wo-BB for qemu-devel@nongnu.org; Mon, 13 Jul 2026 05:06:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783933601; h=from:from:reply-to: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=QGPS4EOkCLBS8LksSHSGcv0enfokJXDvggZ7jdh0YI0=; b=foNGMd/KmpHf+D6LzUzgAxmdVczOjqaRaCY5GPzEWiuSpc9Ki4ptSPLi1s9fr6i+vOGQJY maeE1lLku8swYeOTy4f45x+eriHXtdH4EnKQUtlkmKAnqTooUzoqRIyK+SZGj4o3xz0ICt t+PfE90HYNjivNsj1AktAM6u6/xayKs= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-329-CiIxDI-3PmGmOWeJbcysOg-1; Mon, 13 Jul 2026 05:06:37 -0400 X-MC-Unique: CiIxDI-3PmGmOWeJbcysOg-1 X-Mimecast-MFC-AGG-ID: CiIxDI-3PmGmOWeJbcysOg_1783933596 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8D7BA1800A37; Mon, 13 Jul 2026 09:06:35 +0000 (UTC) Received: from redhat.com (unknown [10.44.50.22]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D353730001A1; Mon, 13 Jul 2026 09:06:31 +0000 (UTC) Date: Mon, 13 Jul 2026 10:06:28 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Cc: Peter Maydell , QEMU Developers , Paolo Bonzini , Pedro Barbuda , Mohamed Mediouni , Nicholas Piggin , Harsh Prateek Bora , Cornelia Huck , Eric Farman , Matthew Rosato Subject: Re: what is qemu_system_guest_panicked() for? Message-ID: References: <87cxwrtgfd.fsf@pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87cxwrtgfd.fsf@pond.sub.org> User-Agent: Mutt/2.3.2 (2026-04-26) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: permerror client-ip=170.10.129.124; envelope-from=berrange@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=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_PASS=-0.001, T_SPF_PERMERROR=0.01 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: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Jul 13, 2026 at 10:57:58AM +0200, Markus Armbruster wrote: > Daniel P. Berrangé writes: > > > On Fri, Jul 10, 2026 at 05:02:53PM +0100, Peter Maydell wrote: > > [...] > > >> So I guess my question is, is it OK to mash these two categories of > >> "we can't keep running the VM" together, or should we define a new > >> one for the "unrecoverable guest error" case, or do we already have > >> some better thing to do that I missed? > > > > IMHO we should NOT be abusing "panicked" for cases which are > > not guest OS panics. > > Point. > > > Adding new QMP events is cheap and we should do so. > > Changing the event sent on a certain situation is technically a > compatibility break. Would it matter here? What wins "compat break" or "bug fix" ? A strict POV prevents almost any bug fixes, if you want to remain bug-for-bug compatible with old QEMU. With my "management app" hat on, I want QEMU to stop sending panic events for things that are not panics, as that is triggering incorrect actions / admin activities. ie on a panic, I'm going to take a guest memory dump and try to analyse what is broken in the guest kernel. The QAPI spec says: ## # @GUEST_PANICKED: # # Emitted when guest OS panic is detected and ## # @RunState: # # An enumeration of VM run states. # .. # @guest-panicked: guest has been panicked as a result of guest OS # panic I don't think "machine check exception" or "unknown VM exit" can be said to match either of those docs, and thus fixing compliance should trump bug-for-bug compatibility IMHO. With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|