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 AE2C2C7EE30 for ; Tue, 1 Jul 2025 08:25:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uWWIl-000351-LK; Tue, 01 Jul 2025 04:25:15 -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 1uWWIj-00032o-Lg for qemu-devel@nongnu.org; Tue, 01 Jul 2025 04:25:13 -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 1uWWIf-0006KJ-Q0 for qemu-devel@nongnu.org; Tue, 01 Jul 2025 04:25:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1751358306; 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=3zTgEh4BvEEzL46s1pc7IJS5mPWU8IieF8laSoNDYXw=; b=GJICd3aI89W4MtdDyLP3dnrE7Yuxfi6CXCzaKD+bersO2cCfpSEW/s7zyw0Yh64iBypLNx /gjuk2ZxlGu6YhpxU3vUfpjB3uoqMXy3jd0ZCKMYZ9AoqHgUV0y7hB8BqVIC6BCCRlApT6 CsdUHUohuuRaAueweuFT5a11Rgw8Y+U= 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-466-FbtqZBpSOUWHSGNzZRZslA-1; Tue, 01 Jul 2025 04:25:05 -0400 X-MC-Unique: FbtqZBpSOUWHSGNzZRZslA-1 X-Mimecast-MFC-AGG-ID: FbtqZBpSOUWHSGNzZRZslA_1751358305 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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 C4CBA1800268; Tue, 1 Jul 2025 08:25:04 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.10]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 313A419560AB; Tue, 1 Jul 2025 08:25:04 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 81D8621E6A27; Tue, 01 Jul 2025 10:25:01 +0200 (CEST) From: Markus Armbruster To: Fabiano Rosas Cc: qemu-devel@nongnu.org, berrange@redhat.com, Peter Xu , Eric Blake Subject: Re: [PATCH v2 16/24] migration: Add capabilities into MigrationParameters In-Reply-To: <20250630195913.28033-17-farosas@suse.de> (Fabiano Rosas's message of "Mon, 30 Jun 2025 16:59:05 -0300") References: <20250630195913.28033-1-farosas@suse.de> <20250630195913.28033-17-farosas@suse.de> Date: Tue, 01 Jul 2025 10:25:01 +0200 Message-ID: <87jz4sz5b6.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 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: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.237, RCVD_IN_VALIDITY_RPBL_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 Fabiano Rosas writes: > Add capabilities to MigrationParameters. This structure will hold all > migration options. Capabilities will go away in the next patch. > > Also add capabilities to MigrationParameter as the enum needs to be > kept in sync with MigrationParameters. This affects the parsing of > migration HMP commands so make the necessary additions there too. > > From this point on, both QMP and HMP versions of > migrate-set-parameters and query-migrate-parameters gain the ability > to work with capabilities. > > With MigrationParameters now having members for each capability, the > migration capabilities commands (query-migrate-capabilities, > migrate-set-capabilities) will soon be deprecated. Add a set of > helpers to convert between the old MigrationCapability representation > and the new representation as members of MigrationParameters. > > Signed-off-by: Fabiano Rosas [...] > diff --git a/qapi/migration.json b/qapi/migration.json > index 40e00fb86e..3d3f5624c5 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -763,7 +763,14 @@ > 'vcpu-dirty-limit', > 'mode', > 'zero-page-detection', > - 'direct-io'] } > + 'direct-io', 'xbzrle', 'rdma-pin-all', 'auto-converge', > + 'zero-blocks', 'events', 'postcopy-ram', 'x-colo', > + 'release-ram', 'return-path', 'pause-before-switchover', > + 'multifd', 'dirty-bitmaps', 'postcopy-blocktime', > + 'late-block-activate', 'x-ignore-shared', > + 'validate-uuid', 'background-snapshot', > + 'zero-copy-send', 'postcopy-preempt', > + 'switchover-ack', 'dirty-limit', 'mapped-ram' ] } This is MigrateParameter. Different order than in MigrationParameters. Intentional? > > ## > # @migrate-set-parameters: > @@ -934,10 +941,108 @@ > # only has effect if the @mapped-ram capability is enabled. > # (Since 9.1) > # > +# @xbzrle: Migration supports xbzrle (Xor Based Zero Run Length > +# Encoding). This feature allows us to minimize migration traffic > +# for certain work loads, by sending compressed difference of the > +# pages > +# > +# @rdma-pin-all: Controls whether or not the entire VM memory > +# footprint is mlock()'d on demand or all at once. Refer to > +# docs/rdma.txt for usage. Disabled by default. (since 2.0) > +# > +# @zero-blocks: During storage migration encode blocks of zeroes > +# efficiently. This essentially saves 1MB of zeroes per block on > +# the wire. Enabling requires source and target VM to support > +# this feature. To enable it is sufficient to enable the > +# capability on the source VM. The feature is disabled by > +# default. (since 1.6) > +# > +# @events: generate events for each migration state change (since 2.4) > +# > +# @auto-converge: If enabled, QEMU will automatically throttle down > +# the guest to speed up convergence of RAM migration. (since 1.6) > +# > +# @postcopy-ram: Start executing on the migration target before all of > +# RAM has been migrated, pulling the remaining pages along as > +# needed. The capacity must have the same setting on both source > +# and target or migration will not even start. NOTE: If the Make this # and target or migration will not even start. **Note:** if the Crossed with commit 188b31ad425c (qapi: Use proper markup instead of CAPS for emphasis in doc comments). > +# migration fails during postcopy the VM will fail. (since 2.6) > +# > +# @x-colo: If enabled, migration will never end, and the state of the > +# VM on the primary side will be migrated continuously to the VM > +# on secondary side, this process is called COarse-Grain LOck > +# Stepping (COLO) for Non-stop Service. (since 2.8) > +# > +# @release-ram: if enabled, qemu will free the migrated ram pages on And this # @release-ram: if enabled, QEMU will free the migrated ram pages on Crossed with commit 6263225492ba (qapi: Correct spelling of QEMU in doc comments). > +# the source during postcopy-ram migration. (since 2.9) > +# > +# @return-path: If enabled, migration will use the return path even > +# for precopy. (since 2.10) > +# > +# @pause-before-switchover: Pause outgoing migration before > +# serialising device state and before disabling block IO (since > +# 2.11) # serialising device state and before disabling block IO # (since 2.11) Crossed with commit c1a6aa1d443e (qapi: Avoid breaking lines within (since X.Y)) > +# > +# @multifd: Use more than one fd for migration (since 4.0) > +# > +# @dirty-bitmaps: If enabled, QEMU will migrate named dirty bitmaps. > +# (since 2.12) > +# > +# @postcopy-blocktime: Calculate downtime for postcopy live migration > +# (since 3.0) > +# > +# @late-block-activate: If enabled, the destination will not activate > +# block devices (and thus take locks) immediately at the end of > +# migration. (since 3.0) > +# > +# @x-ignore-shared: If enabled, QEMU will not migrate shared memory > +# that is accessible on the destination machine. (since 4.0) > +# > +# @validate-uuid: Send the UUID of the source to allow the destination > +# to ensure it is the same. (since 4.2) > +# > +# @background-snapshot: If enabled, the migration stream will be a > +# snapshot of the VM exactly at the point when the migration > +# procedure starts. The VM RAM is saved with running VM. > +# (since 6.0) > +# > +# @zero-copy-send: Controls behavior on sending memory pages on > +# migration. When true, enables a zero-copy mechanism for sending > +# memory pages, if host supports it. Requires that QEMU be > +# permitted to use locked memory for guest RAM pages. (since 7.1) > +# > +# @postcopy-preempt: If enabled, the migration process will allow > +# postcopy requests to preempt precopy stream, so postcopy > +# requests will be handled faster. This is a performance feature > +# and should not affect the correctness of postcopy migration. > +# (since 7.1) > +# > +# @switchover-ack: If enabled, migration will not stop the source VM > +# and complete the migration until an ACK is received from the > +# destination that it's OK to do so. Exactly when this ACK is > +# sent depends on the migrated devices that use this feature. For > +# example, a device can use it to make sure some of its data is > +# sent and loaded in the destination before doing switchover. > +# This can reduce downtime if devices that support this capability > +# are present. 'return-path' capability must be enabled to use > +# it. (since 8.1) > +# > +# @dirty-limit: If enabled, migration will throttle vCPUs as needed to > +# keep their dirty page rate within @vcpu-dirty-limit. This can > +# improve responsiveness of large guests during live migration, > +# and can result in more stable read performance. Requires KVM > +# with accelerator property "dirty-ring-size" set. (Since 8.1) > +# > +# @mapped-ram: Migrate using fixed offsets in the migration file for > +# each RAM page. Requires a migration URI that supports seeking, > +# such as a file. (since 9.0) > +# > # Features: > # > -# @unstable: Members @x-checkpoint-delay and > -# @x-vcpu-dirty-limit-period are experimental. > +# @unstable: Members @x-checkpoint-delay, @x-vcpu-dirty-limit-period, > +# @x-colo and @x-ignore-shared are experimental. > +# @deprecated: Member @zero-blocks is deprecated as being part of > +# block migration which was already removed. > # > # Since: 2.4 > ## > @@ -972,7 +1077,29 @@ > '*vcpu-dirty-limit': 'uint64', > '*mode': 'MigMode', > '*zero-page-detection': 'ZeroPageDetection', > - '*direct-io': 'bool' } } > + '*direct-io': 'bool', > + '*xbzrle': 'bool', > + '*rdma-pin-all': 'bool', > + '*auto-converge': 'bool', > + '*zero-blocks': { 'type': 'bool', 'features': [ 'deprecated' ] }, > + '*events': 'bool', > + '*postcopy-ram': 'bool', > + '*x-colo': { 'type': 'bool', 'features': [ 'unstable' ] }, > + '*release-ram': 'bool', > + '*return-path': 'bool', > + '*pause-before-switchover': 'bool', > + '*multifd': 'bool', > + '*dirty-bitmaps': 'bool', > + '*postcopy-blocktime': 'bool', > + '*late-block-activate': 'bool', > + '*x-ignore-shared': { 'type': 'bool', 'features': [ 'unstable' ] }, > + '*validate-uuid': 'bool', > + '*background-snapshot': 'bool', > + '*zero-copy-send': 'bool', > + '*postcopy-preempt': 'bool', > + '*switchover-ack': 'bool', > + '*dirty-limit': 'bool', > + '*mapped-ram': 'bool' } } > > ## > # @query-migrate-parameters: