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 DBF4DC02192 for ; Mon, 3 Feb 2025 18:55:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tf1az-00057v-7X; Mon, 03 Feb 2025 13:54:57 -0500 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 1tf1aw-00057K-Hk for qemu-devel@nongnu.org; Mon, 03 Feb 2025 13:54:54 -0500 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 1tf1au-0005pH-H3 for qemu-devel@nongnu.org; Mon, 03 Feb 2025 13:54:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738608891; 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=WcE8RO/WqVj98QtmRoz22s/cTT5kEhfgbsspVsxa2NE=; b=W45ebdou2nWgV43fL+vmVnYyowqlOPNTJWqIj5QZ8hEZmxWCnDWVPU5UIqnwzT0wyRTkjh kgpT+mgYhIXQvG1svPSO1hrWewvoEffixK09VIG5o5BqIsuTMr0LBwppgPKcNdRVVnxlVf 2kLHEgb3MfbFAi31OTOHIRbm4gSQe98= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-660-owGdt7T5P1qBX9KpyilC4Q-1; Mon, 03 Feb 2025 13:54:48 -0500 X-MC-Unique: owGdt7T5P1qBX9KpyilC4Q-1 X-Mimecast-MFC-AGG-ID: owGdt7T5P1qBX9KpyilC4Q Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 325F519560B4; Mon, 3 Feb 2025 18:54:46 +0000 (UTC) Received: from localhost (unknown [10.2.16.131]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 589731800360; Mon, 3 Feb 2025 18:54:45 +0000 (UTC) Date: Mon, 3 Feb 2025 13:54:44 -0500 From: Stefan Hajnoczi To: Kevin Wolf Cc: qemu-block@nongnu.org, hreitz@redhat.com, pkrempa@redhat.com, peterx@redhat.com, farosas@suse.de, qemu-devel@nongnu.org Subject: Re: [PATCH v2 08/15] block: Add blockdev-set-active QMP command Message-ID: <20250203185444.GJ268514@fedora> References: <20250130171240.286878-1-kwolf@redhat.com> <20250130171240.286878-9-kwolf@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="WsxZbAqrnnOXe0tJ" Content-Disposition: inline In-Reply-To: <20250130171240.286878-9-kwolf@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@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_H2=0.001, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org --WsxZbAqrnnOXe0tJ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jan 30, 2025 at 06:12:39PM +0100, Kevin Wolf wrote: > The system emulator tries to automatically activate and inactivate block > nodes at the right point during migration. However, there are still > cases where it's necessary that the user can do this manually. >=20 > Images are only activated on the destination VM of a migration when the > VM is actually resumed. If the VM was paused, this doesn't happen > automatically. The user may want to perform some operation on a block > device (e.g. taking a snapshot or starting a block job) without also > resuming the VM yet. This is an example where a manual command is > necessary. >=20 > Another example is VM migration when the image files are opened by an > external qemu-storage-daemon instance on each side. In this case, the > process that needs to hand over the images isn't even part of the > migration and can't know when the migration completes. Management tools > need a way to explicitly inactivate images on the source and activate > them on the destination. >=20 > This adds a new blockdev-set-active QMP command that lets the user > change the status of individual nodes (this is necessary in > qemu-storage-daemon because it could be serving multiple VMs and only > one of them migrates at a time). For convenience, operating on all > devices (like QEMU does automatically during migration) is offered as an > option, too, and can be used in the context of single VM. >=20 > Signed-off-by: Kevin Wolf > --- > qapi/block-core.json | 32 ++++++++++++++++++++++++++++++ > include/block/block-global-state.h | 3 +++ > block.c | 21 ++++++++++++++++++++ > blockdev.c | 32 ++++++++++++++++++++++++++++++ > 4 files changed, 88 insertions(+) Reviewed-by: Stefan Hajnoczi --WsxZbAqrnnOXe0tJ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmehEPQACgkQnKSrs4Gr c8jhvQf/UuTNpiGdjJ3Gv5xI6OairynZPIQX4uJe8vokMYcdkSHoJVOzBqVFjtd+ qGq/QaeJVEkyOQtjVtflh8qUxNbjV/mVsE3vcTfrjaSVuUn2NUgNKP//TLD9JGf/ V9p0bZfHRHfJwdKoYBqg3ATzpnXiYo0MwRq+hGKMuYt+w0tCu2ega+A8PVEtJEvW Y+StpwgmVZ/a9mZxS7OIEC8123WpiVkkjS8ZPgERpq2WcobQpJuOAMNk48VJJNJX zJPMLDEosa3OmajqmzEwxCEFd+uc4L306ZKuxSp4vSX+GxcN0n9875ud/J33uJdM NTDo0nq9zlZnsOhsyLx/ppA231puaw== =Sj5v -----END PGP SIGNATURE----- --WsxZbAqrnnOXe0tJ--