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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 AE081C433E0 for ; Thu, 4 Feb 2021 17:47:46 +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 1A21164DF2 for ; Thu, 4 Feb 2021 17:47:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A21164DF2 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]:32994 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l7ijJ-00035C-5k for qemu-devel@archiver.kernel.org; Thu, 04 Feb 2021 12:47:45 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41964) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l7hih-0004E8-EZ for qemu-devel@nongnu.org; Thu, 04 Feb 2021 11:43:03 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:25963) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l7hif-00064G-2w for qemu-devel@nongnu.org; Thu, 04 Feb 2021 11:43:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612456979; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LKnF4pRrKwqKPZxcNddLx6h5pLWcgzICdlkmoGEpkSY=; b=fg3u3MWIRHu6H54bWAAG/cAmvc/ZLNvCFKLYWFTid5rNfk+dNSDAfo61ftTtbHEdeMMzvF RRrOZB+xkQ4wOJYyDk6JtLM5Bmw/4+v9IDwAGu4pwXArz/tQ2WczdO7GHmmEAE2iBO2S6W GxkotQAo8zJ57Ubqtj13Us5gQxo5YLI= 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-367-Ku1skO6qOCOvgik6BSMPJg-1; Thu, 04 Feb 2021 11:42:54 -0500 X-MC-Unique: Ku1skO6qOCOvgik6BSMPJg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1E380512D; Thu, 4 Feb 2021 16:42:53 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-114-21.ams2.redhat.com [10.36.114.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id A1CAB1A38C; Thu, 4 Feb 2021 16:42:49 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, andrey.gruzdev@virtuozzo.com, berrange@redhat.com, gaojinhao@huawei.com, armbru@redhat.com, mst@redhat.com, philmd@redhat.com, wainersm@redhat.com Subject: [PULL 27/27] migration: introduce snapshot-{save, load, delete} QMP commands Date: Thu, 4 Feb 2021 16:39:59 +0000 Message-Id: <20210204163959.377618-28-dgilbert@redhat.com> In-Reply-To: <20210204163959.377618-1-dgilbert@redhat.com> References: <20210204163959.377618-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.351, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 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" From: Daniel P. Berrangé savevm, loadvm and delvm are some of the few HMP commands that have never been converted to use QMP. The reasons for the lack of conversion are that they blocked execution of the event thread, and the semantics around choice of disks were ill-defined. Despite this downside, however, libvirt and applications using libvirt have used these commands for as long as QMP has existed, via the "human-monitor-command" passthrough command. IOW, while it is clearly desirable to be able to fix the problems, they are not a blocker to all real world usage. Meanwhile there is a need for other features which involve adding new parameters to the commands. This is possible with HMP passthrough, but it provides no reliable way for apps to introspect features, so using QAPI modelling is highly desirable. This patch thus introduces new snapshot-{load,save,delete} commands to QMP that are intended to replace the old HMP counterparts. The new commands are given different names, because they will be using the new QEMU job framework and thus will have diverging behaviour from the HMP originals. It would thus be misleading to keep the same name. While this design uses the generic job framework, the current impl is still blocking. The intention that the blocking problem is fixed later. None the less applications using these new commands should assume that they are asynchronous and thus wait for the job status change event to indicate completion. In addition to using the job framework, the new commands require the caller to be explicit about all the block device nodes used in the snapshot operations, with no built-in default heuristics in use. Note that the existing "query-named-block-nodes" can be used to query what snapshots currently exist for block nodes. Acked-by: Markus Armbruster Signed-off-by: Daniel P. Berrangé Message-Id: <20210204124834.774401-13-berrange@redhat.com> Signed-off-by: Dr. David Alan Gilbert dgilbert: removed tests for now, the output ordering isn't deterministic --- migration/savevm.c | 184 ++++++++++++++++++++++++++++++++++++++++++++ qapi/job.json | 9 ++- qapi/migration.json | 173 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 365 insertions(+), 1 deletion(-) diff --git a/migration/savevm.c b/migration/savevm.c index 0c5d61ae20..52e2d72e4b 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -3112,3 +3112,187 @@ bool vmstate_check_only_migratable(const VMStateDescription *vmsd) return !(vmsd && vmsd->unmigratable); } + +typedef struct SnapshotJob { + Job common; + char *tag; + char *vmstate; + strList *devices; + Coroutine *co; + Error **errp; + bool ret; +} SnapshotJob; + +static void qmp_snapshot_job_free(SnapshotJob *s) +{ + g_free(s->tag); + g_free(s->vmstate); + qapi_free_strList(s->devices); +} + + +static void snapshot_load_job_bh(void *opaque) +{ + Job *job = opaque; + SnapshotJob *s = container_of(job, SnapshotJob, common); + int orig_vm_running; + + job_progress_set_remaining(&s->common, 1); + + orig_vm_running = runstate_is_running(); + vm_stop(RUN_STATE_RESTORE_VM); + + s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp); + if (s->ret && orig_vm_running) { + vm_start(); + } + + job_progress_update(&s->common, 1); + + qmp_snapshot_job_free(s); + aio_co_wake(s->co); +} + +static void snapshot_save_job_bh(void *opaque) +{ + Job *job = opaque; + SnapshotJob *s = container_of(job, SnapshotJob, common); + + job_progress_set_remaining(&s->common, 1); + s->ret = save_snapshot(s->tag, false, s->vmstate, + true, s->devices, s->errp); + job_progress_update(&s->common, 1); + + qmp_snapshot_job_free(s); + aio_co_wake(s->co); +} + +static void snapshot_delete_job_bh(void *opaque) +{ + Job *job = opaque; + SnapshotJob *s = container_of(job, SnapshotJob, common); + + job_progress_set_remaining(&s->common, 1); + s->ret = delete_snapshot(s->tag, true, s->devices, s->errp); + job_progress_update(&s->common, 1); + + qmp_snapshot_job_free(s); + aio_co_wake(s->co); +} + +static int coroutine_fn snapshot_save_job_run(Job *job, Error **errp) +{ + SnapshotJob *s = container_of(job, SnapshotJob, common); + s->errp = errp; + s->co = qemu_coroutine_self(); + aio_bh_schedule_oneshot(qemu_get_aio_context(), + snapshot_save_job_bh, job); + qemu_coroutine_yield(); + return s->ret ? 0 : -1; +} + +static int coroutine_fn snapshot_load_job_run(Job *job, Error **errp) +{ + SnapshotJob *s = container_of(job, SnapshotJob, common); + s->errp = errp; + s->co = qemu_coroutine_self(); + aio_bh_schedule_oneshot(qemu_get_aio_context(), + snapshot_load_job_bh, job); + qemu_coroutine_yield(); + return s->ret ? 0 : -1; +} + +static int coroutine_fn snapshot_delete_job_run(Job *job, Error **errp) +{ + SnapshotJob *s = container_of(job, SnapshotJob, common); + s->errp = errp; + s->co = qemu_coroutine_self(); + aio_bh_schedule_oneshot(qemu_get_aio_context(), + snapshot_delete_job_bh, job); + qemu_coroutine_yield(); + return s->ret ? 0 : -1; +} + + +static const JobDriver snapshot_load_job_driver = { + .instance_size = sizeof(SnapshotJob), + .job_type = JOB_TYPE_SNAPSHOT_LOAD, + .run = snapshot_load_job_run, +}; + +static const JobDriver snapshot_save_job_driver = { + .instance_size = sizeof(SnapshotJob), + .job_type = JOB_TYPE_SNAPSHOT_SAVE, + .run = snapshot_save_job_run, +}; + +static const JobDriver snapshot_delete_job_driver = { + .instance_size = sizeof(SnapshotJob), + .job_type = JOB_TYPE_SNAPSHOT_DELETE, + .run = snapshot_delete_job_run, +}; + + +void qmp_snapshot_save(const char *job_id, + const char *tag, + const char *vmstate, + strList *devices, + Error **errp) +{ + SnapshotJob *s; + + s = job_create(job_id, &snapshot_save_job_driver, NULL, + qemu_get_aio_context(), JOB_MANUAL_DISMISS, + NULL, NULL, errp); + if (!s) { + return; + } + + s->tag = g_strdup(tag); + s->vmstate = g_strdup(vmstate); + s->devices = QAPI_CLONE(strList, devices); + + job_start(&s->common); +} + +void qmp_snapshot_load(const char *job_id, + const char *tag, + const char *vmstate, + strList *devices, + Error **errp) +{ + SnapshotJob *s; + + s = job_create(job_id, &snapshot_load_job_driver, NULL, + qemu_get_aio_context(), JOB_MANUAL_DISMISS, + NULL, NULL, errp); + if (!s) { + return; + } + + s->tag = g_strdup(tag); + s->vmstate = g_strdup(vmstate); + s->devices = QAPI_CLONE(strList, devices); + + job_start(&s->common); +} + +void qmp_snapshot_delete(const char *job_id, + const char *tag, + strList *devices, + Error **errp) +{ + SnapshotJob *s; + + s = job_create(job_id, &snapshot_delete_job_driver, NULL, + qemu_get_aio_context(), JOB_MANUAL_DISMISS, + NULL, NULL, errp); + if (!s) { + return; + } + + s->tag = g_strdup(tag); + s->devices = QAPI_CLONE(strList, devices); + + job_start(&s->common); +} diff --git a/qapi/job.json b/qapi/job.json index 280c2f76f1..1a6ef03451 100644 --- a/qapi/job.json +++ b/qapi/job.json @@ -22,10 +22,17 @@ # # @amend: image options amend job type, see "x-blockdev-amend" (since 5.1) # +# @snapshot-load: snapshot load job type, see "snapshot-load" (since 6.0) +# +# @snapshot-save: snapshot save job type, see "snapshot-save" (since 6.0) +# +# @snapshot-delete: snapshot delete job type, see "snapshot-delete" (since 6.0) +# # Since: 1.7 ## { 'enum': 'JobType', - 'data': ['commit', 'stream', 'mirror', 'backup', 'create', 'amend'] } + 'data': ['commit', 'stream', 'mirror', 'backup', 'create', 'amend', + 'snapshot-load', 'snapshot-save', 'snapshot-delete'] } ## # @JobStatus: diff --git a/qapi/migration.json b/qapi/migration.json index 076d2d5634..ce14d78071 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -1854,3 +1854,176 @@ # Since: 5.2 ## { 'command': 'query-dirty-rate', 'returns': 'DirtyRateInfo' } + +## +# @snapshot-save: +# +# Save a VM snapshot +# +# @job-id: identifier for the newly created job +# @tag: name of the snapshot to create +# @vmstate: block device node name to save vmstate to +# @devices: list of block device node names to save a snapshot to +# +# Applications should not assume that the snapshot save is complete +# when this command returns. The job commands / events must be used +# to determine completion and to fetch details of any errors that arise. +# +# Note that execution of the guest CPUs may be stopped during the +# time it takes to save the snapshot. A future version of QEMU +# may ensure CPUs are executing continuously. +# +# It is strongly recommended that @devices contain all writable +# block device nodes if a consistent snapshot is required. +# +# If @tag already exists, an error will be reported +# +# Returns: nothing +# +# Example: +# +# -> { "execute": "snapshot-save", +# "data": { +# "job-id": "snapsave0", +# "tag": "my-snap", +# "vmstate": "disk0", +# "devices": ["disk0", "disk1"] +# } +# } +# <- { "return": { } } +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "created", "id": "snapsave0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "running", "id": "snapsave0"}} +# <- {"event": "STOP"} +# <- {"event": "RESUME"} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "waiting", "id": "snapsave0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "pending", "id": "snapsave0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "concluded", "id": "snapsave0"}} +# -> {"execute": "query-jobs"} +# <- {"return": [{"current-progress": 1, +# "status": "concluded", +# "total-progress": 1, +# "type": "snapshot-save", +# "id": "snapsave0"}]} +# +# Since: 6.0 +## +{ 'command': 'snapshot-save', + 'data': { 'job-id': 'str', + 'tag': 'str', + 'vmstate': 'str', + 'devices': ['str'] } } + +## +# @snapshot-load: +# +# Load a VM snapshot +# +# @job-id: identifier for the newly created job +# @tag: name of the snapshot to load. +# @vmstate: block device node name to load vmstate from +# @devices: list of block device node names to load a snapshot from +# +# Applications should not assume that the snapshot load is complete +# when this command returns. The job commands / events must be used +# to determine completion and to fetch details of any errors that arise. +# +# Note that execution of the guest CPUs will be stopped during the +# time it takes to load the snapshot. +# +# It is strongly recommended that @devices contain all writable +# block device nodes that can have changed since the original +# @snapshot-save command execution. +# +# Returns: nothing +# +# Example: +# +# -> { "execute": "snapshot-load", +# "data": { +# "job-id": "snapload0", +# "tag": "my-snap", +# "vmstate": "disk0", +# "devices": ["disk0", "disk1"] +# } +# } +# <- { "return": { } } +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "created", "id": "snapload0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "running", "id": "snapload0"}} +# <- {"event": "STOP"} +# <- {"event": "RESUME"} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "waiting", "id": "snapload0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "pending", "id": "snapload0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "concluded", "id": "snapload0"}} +# -> {"execute": "query-jobs"} +# <- {"return": [{"current-progress": 1, +# "status": "concluded", +# "total-progress": 1, +# "type": "snapshot-load", +# "id": "snapload0"}]} +# +# Since: 6.0 +## +{ 'command': 'snapshot-load', + 'data': { 'job-id': 'str', + 'tag': 'str', + 'vmstate': 'str', + 'devices': ['str'] } } + +## +# @snapshot-delete: +# +# Delete a VM snapshot +# +# @job-id: identifier for the newly created job +# @tag: name of the snapshot to delete. +# @devices: list of block device node names to delete a snapshot from +# +# Applications should not assume that the snapshot delete is complete +# when this command returns. The job commands / events must be used +# to determine completion and to fetch details of any errors that arise. +# +# Returns: nothing +# +# Example: +# +# -> { "execute": "snapshot-delete", +# "data": { +# "job-id": "snapdelete0", +# "tag": "my-snap", +# "devices": ["disk0", "disk1"] +# } +# } +# <- { "return": { } } +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "created", "id": "snapdelete0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "running", "id": "snapdelete0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "waiting", "id": "snapdelete0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "pending", "id": "snapdelete0"}} +# <- {"event": "JOB_STATUS_CHANGE", +# "data": {"status": "concluded", "id": "snapdelete0"}} +# -> {"execute": "query-jobs"} +# <- {"return": [{"current-progress": 1, +# "status": "concluded", +# "total-progress": 1, +# "type": "snapshot-delete", +# "id": "snapdelete0"}]} +# +# Since: 6.0 +## +{ 'command': 'snapshot-delete', + 'data': { 'job-id': 'str', + 'tag': 'str', + 'devices': ['str'] } } -- 2.29.2