From nobody Thu Apr 3 10:56:03 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1741125954984746.6430149103758; Tue, 4 Mar 2025 14:05:54 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tpaO9-0008Ji-PH; Tue, 04 Mar 2025 17:05:23 -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 1tpaO7-0008Gr-EZ for qemu-devel@nongnu.org; Tue, 04 Mar 2025 17:05:19 -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 1tpaO4-0000hU-Vu for qemu-devel@nongnu.org; Tue, 04 Mar 2025 17:05:19 -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 1tpaO0-00000000LX6-3ykg; Tue, 04 Mar 2025 23:05:12 +0100 From: "Maciej S. Szmigiero" To: Peter Xu , Fabiano Rosas Cc: Alex Williamson , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Eric Blake , Markus Armbruster , =?UTF-8?q?Daniel=20P=20=2E=20Berrang=C3=A9?= , Avihai Horon , Joao Martins , qemu-devel@nongnu.org Subject: [PATCH v6 05/36] migration: Add MIG_CMD_SWITCHOVER_START and its load handler Date: Tue, 4 Mar 2025 23:03:32 +0100 Message-ID: <311be6da85fc7e49a7598684d80aa631778dcbce.1741124640.git.maciej.szmigiero@oracle.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=145.239.82.108; envelope-from=mhej@vps-ovh.mhejs.net; helo=vps-ovh.mhejs.net 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, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1741125958328019000 Content-Type: text/plain; charset="utf-8" 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. Reviewed-by: Fabiano Rosas Reviewed-by: Zhang Chen # for the COLO part 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 | 2 ++ 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, 87 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index b68b8b94a3c4..d1ddc3a3db59 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -44,6 +44,7 @@ GlobalProperty hw_compat_9_2[] =3D { { "virtio-balloon-pci-non-transitional", "vectors", "0" }, { "virtio-mem-pci", "vectors", "0" }, { "migration", "multifd-clean-tls-termination", "false" }, + { "migration", "send-switchover-start", "off"}, }; const size_t hw_compat_9_2_len =3D G_N_ELEMENTS(hw_compat_9_2); =20 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 =20 + +/* properties */ +bool migrate_send_switchover_start(void); + /* capabilities */ =20 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; =20 /** diff --git a/migration/colo.c b/migration/colo.c index 9a8e5fbe9b94..c976b3ff344d 100644 --- a/migration/colo.c +++ b/migration/colo.c @@ -452,6 +452,9 @@ static int colo_do_checkpoint_transaction(MigrationStat= e *s, bql_unlock(); goto out; } + + qemu_savevm_maybe_send_switchover_start(s->to_dst_file); + /* Note: device state is saved into buffer */ ret =3D qemu_save_device_state(fb); =20 diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index 3347e34c4891..49c26daed359 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 c597aa707e57..9e9db26667f1 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2891,6 +2891,8 @@ static bool migration_switchover_start(MigrationState= *s, Error **errp) =20 precopy_notify_complete(); =20 + qemu_savevm_maybe_send_switchover_start(s->to_dst_file); + return true; } =20 diff --git a/migration/migration.h b/migration/migration.h index 4639e2a7e42f..7b4278e2a32b 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -400,6 +400,8 @@ 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; =20 /* Needed by postcopy-pause state */ QemuSemaphore postcopy_pause_sem; diff --git a/migration/options.c b/migration/options.c index bb259d192a93..b0ac2ea4083f 100644 --- a/migration/options.c +++ b/migration/options.c @@ -93,6 +93,8 @@ const Property migration_properties[] =3D { 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, @@ -209,6 +211,13 @@ bool migrate_auto_converge(void) return s->capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; } =20 +bool migrate_send_switchover_start(void) +{ + MigrationState *s =3D migrate_get_current(); + + return s->send_switchover_start; +} + bool migrate_background_snapshot(void) { MigrationState *s =3D migrate_get_current(); diff --git a/migration/savevm.c b/migration/savevm.c index 4046faf0091e..faebf47ef51f 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 }; =20 @@ -109,6 +110,7 @@ static struct mig_cmd_args { [MIG_CMD_POSTCOPY_RESUME] =3D { .len =3D 0, .name =3D "POSTCOPY_RESU= ME" }, [MIG_CMD_PACKAGED] =3D { .len =3D 4, .name =3D "PACKAGED" }, [MIG_CMD_RECV_BITMAP] =3D { .len =3D -1, .name =3D "RECV_BITMAP" = }, + [MIG_CMD_SWITCHOVER_START] =3D { .len =3D 0, .name =3D "SWITCHOVER_ST= ART" }, [MIG_CMD_MAX] =3D { .len =3D -1, .name =3D "MAX" }, }; =20 @@ -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 *)b= uf); } =20 +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; @@ -1687,6 +1702,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **err= p) =20 ret =3D qemu_file_get_error(f); if (ret =3D=3D 0) { + qemu_savevm_maybe_send_switchover_start(f); qemu_savevm_state_complete_precopy(f, false); ret =3D qemu_file_get_error(f); } @@ -2383,6 +2399,26 @@ static int loadvm_process_enable_colo(MigrationIncom= ingState *mis) return ret; } =20 +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 =3D se->ops->switchover_start(se->opaque); + if (ret < 0) { + return ret; + } + } + + return 0; +} + /* * Process an incoming 'QEMU_VM_COMMAND' * 0 just a normal return @@ -2481,6 +2517,9 @@ static int loadvm_process_command(QEMUFile *f) =20 case MIG_CMD_ENABLE_COLO: return loadvm_process_enable_colo(mis); + + case MIG_CMD_SWITCHOVER_START: + return loadvm_postcopy_handle_switchover_start(); } =20 return 0; diff --git a/migration/savevm.h b/migration/savevm.h index 7957460062ca..58f871a7ed9c 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); =20 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 58c0f07f5b2d..c506e11a2e1d 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 8e1fbf4c9d9f..67631ac43e9f 100755 --- a/scripts/analyze-migration.py +++ b/scripts/analyze-migration.py @@ -620,7 +620,9 @@ class MigrationDump(object): QEMU_VM_SUBSECTION =3D 0x05 QEMU_VM_VMDESCRIPTION =3D 0x06 QEMU_VM_CONFIGURATION =3D 0x07 + QEMU_VM_COMMAND =3D 0x08 QEMU_VM_SECTION_FOOTER=3D 0x7e + QEMU_MIG_CMD_SWITCHOVER_START =3D 0x0b =20 def __init__(self, filename): self.section_classes =3D { @@ -685,6 +687,15 @@ def read(self, desc_only =3D False, dump_memory =3D Fa= lse, elif section_type =3D=3D self.QEMU_VM_SECTION_PART or section_= type =3D=3D self.QEMU_VM_SECTION_END: section_id =3D file.read32() self.sections[section_id].read() + elif section_type =3D=3D self.QEMU_VM_COMMAND: + command_type =3D file.read16() + command_data_len =3D file.read16() + if command_type !=3D self.QEMU_MIG_CMD_SWITCHOVER_START: + raise Exception("Unknown QEMU_VM_COMMAND: %x" % + (command_type)) + if command_data_len !=3D 0: + raise Exception("Invalid SWITCHOVER_START length: %x" % + (command_data_len)) elif section_type =3D=3D self.QEMU_VM_SECTION_FOOTER: read_section_id =3D file.read32() if read_section_id !=3D section_id: