From patchwork Sun Nov 17 19:20:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej S. Szmigiero" X-Patchwork-Id: 13877932 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 8239CD10F28 for ; Sun, 17 Nov 2024 19:24:39 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tCkq6-0002gL-SY; Sun, 17 Nov 2024 14:21:42 -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 1tCkq5-0002gD-9F for qemu-devel@nongnu.org; Sun, 17 Nov 2024 14:21:41 -0500 Received: from vps-ovh.mhejs.net ([145.239.82.108]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tCkq2-0005sT-1K for qemu-devel@nongnu.org; Sun, 17 Nov 2024 14:21:41 -0500 Received: from MUA by vps-ovh.mhejs.net with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.98) (envelope-from ) id 1tCkpy-00000002GTX-1tPD; Sun, 17 Nov 2024 20:21:34 +0100 From: "Maciej S. Szmigiero" To: Peter Xu , Fabiano Rosas Cc: Alex Williamson , =?utf-8?q?C=C3=A9dric_Le_G?= =?utf-8?q?oater?= , Eric Blake , Markus Armbruster , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , Avihai Horon , Joao Martins , qemu-devel@nongnu.org Subject: [PATCH v3 05/24] migration: Add MIG_CMD_SWITCHOVER_START and its load handler Date: Sun, 17 Nov 2024 20:20:00 +0100 Message-ID: <624309a8e37f7779336bd5c0573d24f155b2ed41.1731773021.git.maciej.szmigiero@oracle.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: none client-ip=145.239.82.108; envelope-from=mhej@vps-ovh.mhejs.net; helo=vps-ovh.mhejs.net X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=no 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 From: "Maciej S. Szmigiero" This QEMU_VM_COMMAND sub-command and its switchover_start SaveVMHandler is used to mark the switchover point in main migration stream. It can be used to inform the destination that all pre-switchover main migration stream data has been sent/received so it can start to process post-switchover data that it might have received via other migration channels like the multifd ones. Add also the relevant MigrationState bit stream compatibility property and its hw_compat entry. Signed-off-by: Maciej S. Szmigiero --- hw/core/machine.c | 1 + include/migration/client-options.h | 4 +++ include/migration/register.h | 12 +++++++++ migration/colo.c | 3 +++ migration/migration-hmp-cmds.c | 2 ++ migration/migration.c | 3 +++ migration/migration.h | 2 ++ migration/options.c | 9 +++++++ migration/savevm.c | 39 ++++++++++++++++++++++++++++++ migration/savevm.h | 1 + migration/trace-events | 1 + scripts/analyze-migration.py | 11 +++++++++ 12 files changed, 88 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index a35c4a8faecb..ed8d39fd769f 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -38,6 +38,7 @@ GlobalProperty hw_compat_9_1[] = { { TYPE_PCI_DEVICE, "x-pcie-ext-tag", "false" }, + { "migration", "send-switchover-start", "off"}, }; const size_t hw_compat_9_1_len = G_N_ELEMENTS(hw_compat_9_1); diff --git a/include/migration/client-options.h b/include/migration/client-options.h index 59f4b55cf4f7..289c9d776221 100644 --- a/include/migration/client-options.h +++ b/include/migration/client-options.h @@ -10,6 +10,10 @@ #ifndef QEMU_MIGRATION_CLIENT_OPTIONS_H #define QEMU_MIGRATION_CLIENT_OPTIONS_H + +/* properties */ +bool migrate_send_switchover_start(void); + /* capabilities */ bool migrate_background_snapshot(void); diff --git a/include/migration/register.h b/include/migration/register.h index 0b0292738320..ff0faf5f68c8 100644 --- a/include/migration/register.h +++ b/include/migration/register.h @@ -279,6 +279,18 @@ typedef struct SaveVMHandlers { * otherwise */ bool (*switchover_ack_needed)(void *opaque); + + /** + * @switchover_start + * + * Notifies that the switchover has started. Called only on + * the destination. + * + * @opaque: data pointer passed to register_savevm_live() + * + * Returns zero to indicate success and negative for error + */ + int (*switchover_start)(void *opaque); } SaveVMHandlers; /** diff --git a/migration/colo.c b/migration/colo.c index 9590f281d0f1..a75c2c41b464 100644 --- a/migration/colo.c +++ b/migration/colo.c @@ -452,6 +452,9 @@ static int colo_do_checkpoint_transaction(MigrationState *s, bql_unlock(); goto out; } + + qemu_savevm_maybe_send_switchover_start(s->to_dst_file); + /* Note: device state is saved into buffer */ ret = qemu_save_device_state(fb); diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index 20d1a6e21948..59d0c48a3e0d 100644 --- a/migration/migration-hmp-cmds.c +++ b/migration/migration-hmp-cmds.c @@ -46,6 +46,8 @@ static void migration_global_dump(Monitor *mon) ms->send_configuration ? "on" : "off"); monitor_printf(mon, "send-section-footer: %s\n", ms->send_section_footer ? "on" : "off"); + monitor_printf(mon, "send-switchover-start: %s\n", + ms->send_switchover_start ? "on" : "off"); monitor_printf(mon, "clear-bitmap-shift: %u\n", ms->clear_bitmap_shift); } diff --git a/migration/migration.c b/migration/migration.c index 8c5bd0a75c85..2e9d6d5087d7 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2543,6 +2543,8 @@ static int postcopy_start(MigrationState *ms, Error **errp) } restart_block = true; + qemu_savevm_maybe_send_switchover_start(ms->to_dst_file); + /* * Cause any non-postcopiable, but iterative devices to * send out their final data. @@ -2742,6 +2744,7 @@ static int migration_completion_precopy(MigrationState *s, */ s->block_inactive = !migrate_colo(); migration_rate_set(RATE_LIMIT_DISABLED); + qemu_savevm_maybe_send_switchover_start(s->to_dst_file); ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false, s->block_inactive); out_unlock: diff --git a/migration/migration.h b/migration/migration.h index 0956e9274b2c..2a18349cfec2 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -403,6 +403,8 @@ struct MigrationState { bool send_configuration; /* Whether we send section footer during migration */ bool send_section_footer; + /* Whether we send switchover start notification during migration */ + bool send_switchover_start; /* Needed by postcopy-pause state */ QemuSemaphore postcopy_pause_sem; diff --git a/migration/options.c b/migration/options.c index ad8d6989a807..f916c8ed4e09 100644 --- a/migration/options.c +++ b/migration/options.c @@ -92,6 +92,8 @@ Property migration_properties[] = { send_configuration, true), DEFINE_PROP_BOOL("send-section-footer", MigrationState, send_section_footer, true), + DEFINE_PROP_BOOL("send-switchover-start", MigrationState, + send_switchover_start, true), DEFINE_PROP_BOOL("multifd-flush-after-each-section", MigrationState, multifd_flush_after_each_section, false), DEFINE_PROP_UINT8("x-clear-bitmap-shift", MigrationState, @@ -206,6 +208,13 @@ bool migrate_auto_converge(void) return s->capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; } +bool migrate_send_switchover_start(void) +{ + MigrationState *s = migrate_get_current(); + + return s->send_switchover_start; +} + bool migrate_background_snapshot(void) { MigrationState *s = migrate_get_current(); diff --git a/migration/savevm.c b/migration/savevm.c index f4e4876f7202..a254c38edcca 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -90,6 +90,7 @@ enum qemu_vm_cmd { MIG_CMD_ENABLE_COLO, /* Enable COLO */ MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */ MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */ + MIG_CMD_SWITCHOVER_START, /* Switchover start notification */ MIG_CMD_MAX }; @@ -109,6 +110,7 @@ static struct mig_cmd_args { [MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" }, [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" }, [MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" }, + [MIG_CMD_SWITCHOVER_START] = { .len = 0, .name = "SWITCHOVER_START" }, [MIG_CMD_MAX] = { .len = -1, .name = "MAX" }, }; @@ -1201,6 +1203,19 @@ void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name) qemu_savevm_command_send(f, MIG_CMD_RECV_BITMAP, len + 1, (uint8_t *)buf); } +static void qemu_savevm_send_switchover_start(QEMUFile *f) +{ + trace_savevm_send_switchover_start(); + qemu_savevm_command_send(f, MIG_CMD_SWITCHOVER_START, 0, NULL); +} + +void qemu_savevm_maybe_send_switchover_start(QEMUFile *f) +{ + if (migrate_send_switchover_start()) { + qemu_savevm_send_switchover_start(f); + } +} + bool qemu_savevm_state_blocked(Error **errp) { SaveStateEntry *se; @@ -1713,6 +1728,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) ret = qemu_file_get_error(f); if (ret == 0) { + qemu_savevm_maybe_send_switchover_start(f); qemu_savevm_state_complete_precopy(f, false, false); ret = qemu_file_get_error(f); } @@ -2413,6 +2429,26 @@ static int loadvm_process_enable_colo(MigrationIncomingState *mis) return ret; } +static int loadvm_postcopy_handle_switchover_start(void) +{ + SaveStateEntry *se; + + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + int ret; + + if (!se->ops || !se->ops->switchover_start) { + continue; + } + + ret = se->ops->switchover_start(se->opaque); + if (ret < 0) { + return ret; + } + } + + return 0; +} + /* * Process an incoming 'QEMU_VM_COMMAND' * 0 just a normal return @@ -2511,6 +2547,9 @@ static int loadvm_process_command(QEMUFile *f) case MIG_CMD_ENABLE_COLO: return loadvm_process_enable_colo(mis); + + case MIG_CMD_SWITCHOVER_START: + return loadvm_postcopy_handle_switchover_start(); } return 0; diff --git a/migration/savevm.h b/migration/savevm.h index 9ec96a995c93..4d402723bc3c 100644 --- a/migration/savevm.h +++ b/migration/savevm.h @@ -53,6 +53,7 @@ void qemu_savevm_send_postcopy_listen(QEMUFile *f); void qemu_savevm_send_postcopy_run(QEMUFile *f); void qemu_savevm_send_postcopy_resume(QEMUFile *f); void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name); +void qemu_savevm_maybe_send_switchover_start(QEMUFile *f); void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name, uint16_t len, diff --git a/migration/trace-events b/migration/trace-events index bb0e0cc6dcfe..551f5af0740f 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -39,6 +39,7 @@ savevm_send_postcopy_run(void) "" savevm_send_postcopy_resume(void) "" savevm_send_colo_enable(void) "" savevm_send_recv_bitmap(char *name) "%s" +savevm_send_switchover_start(void) "" savevm_state_setup(void) "" savevm_state_resume_prepare(void) "" savevm_state_header(void) "" diff --git a/scripts/analyze-migration.py b/scripts/analyze-migration.py index 8a254a5b6a2e..a4d4042584c0 100755 --- a/scripts/analyze-migration.py +++ b/scripts/analyze-migration.py @@ -564,7 +564,9 @@ class MigrationDump(object): QEMU_VM_SUBSECTION = 0x05 QEMU_VM_VMDESCRIPTION = 0x06 QEMU_VM_CONFIGURATION = 0x07 + QEMU_VM_COMMAND = 0x08 QEMU_VM_SECTION_FOOTER= 0x7e + QEMU_MIG_CMD_SWITCHOVER_START = 0x0b def __init__(self, filename): self.section_classes = { @@ -626,6 +628,15 @@ def read(self, desc_only = False, dump_memory = False, write_memory = False): elif section_type == self.QEMU_VM_SECTION_PART or section_type == self.QEMU_VM_SECTION_END: section_id = file.read32() self.sections[section_id].read() + elif section_type == self.QEMU_VM_COMMAND: + command_type = file.read16() + command_data_len = file.read16() + if command_type != self.QEMU_MIG_CMD_SWITCHOVER_START: + raise Exception("Unknown QEMU_VM_COMMAND: %x" % + (command_type)) + if command_data_len != 0: + raise Exception("Invalid SWITCHOVER_START length: %x" % + (command_data_len)) elif section_type == self.QEMU_VM_SECTION_FOOTER: read_section_id = file.read32() if read_section_id != section_id: