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 1F62FC36011 for ; Thu, 27 Mar 2025 14:55:21 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1txodI-0006eV-5Q; Thu, 27 Mar 2025 10:55:00 -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 1txodG-0006cm-1M for qemu-devel@nongnu.org; Thu, 27 Mar 2025 10:54:58 -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 1txodE-0000OR-AL for qemu-devel@nongnu.org; Thu, 27 Mar 2025 10:54:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743087294; 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:in-reply-to:in-reply-to: references:references; bh=OPfZCq1yBX3u0TLKpvUCfXtatrQ4gpTdm49B6uBySic=; b=WxjlYRI1RjJ9qJ45woK7FpkyVMNfZlpwnfmq+AM/K4Itroaq/jzg40GmMwql+kgybFiNBo xkLZTx45MoGa+sgBc9hg8vZfYyXJDI/eVDCZfut8YIb5NlvW4BQoTQV6gyI4LBd1BfN9fc CdzHe+dugiOqFqqB14ZHXmNz6UFr59I= 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-582-AEAnI6VFPF2wcZbGtsUo1Q-1; Thu, 27 Mar 2025 10:54:51 -0400 X-MC-Unique: AEAnI6VFPF2wcZbGtsUo1Q-1 X-Mimecast-MFC-AGG-ID: AEAnI6VFPF2wcZbGtsUo1Q_1743087290 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 E91C818001F6; Thu, 27 Mar 2025 14:54:48 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.90]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C7DAB192C7D7; Thu, 27 Mar 2025 14:54:46 +0000 (UTC) Date: Thu, 27 Mar 2025 14:54:43 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Fabiano Rosas Cc: qemu-devel@nongnu.org, Peter Xu , Prasad Pandit , Juraj Marcin , Marco Cavenati Subject: Re: [PATCH 1/4] migration/savevm: Add a compatibility check for capabilities Message-ID: References: <20250327143934.7935-1-farosas@suse.de> <20250327143934.7935-2-farosas@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250327143934.7935-2-farosas@suse.de> User-Agent: Mutt/2.2.13 (2024-03-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; 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_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: , 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 Thu, Mar 27, 2025 at 11:39:31AM -0300, Fabiano Rosas wrote: > It has always been possible to enable arbitrary migration capabilities > and attempt to take a snapshot of the VM with the savevm/loadvm > commands as well as their QMP counterparts > snapshot-save/snapshot-load. > > Most migration capabilities are not meant to be used with snapshots > and there's a risk of crashing QEMU or producing incorrect > behavior. Ideally, every migration capability would either be > implemented for savevm or explicitly rejected. IMHO, this a prime example of why migration config shouldn't be held as global state, and instead passed as parameters to the commands that need them. The snapshot-save/load commands would then only be able to accept what few settings are actually relevant, instead of inheriting any/all global migration state. > Add a compatibility check routine and reject the snapshot command if > an incompatible capability is enabled. For now only act on the the two > that actually cause a crash: multifd and mapped-ram. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2818 Issue is 2881 not 2818 ^^^^^^^ > Signed-off-by: Fabiano Rosas > --- > migration/options.c | 26 ++++++++++++++++++++++++++ > migration/options.h | 1 + > migration/savevm.c | 8 ++++++++ > 3 files changed, 35 insertions(+) With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|