From: "Maciej S. Szmigiero" <maciej.szmigi...@oracle.com> 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 <faro...@suse.de> Reviewed-by: Zhang Chen <zhangc...@gmail.com> # for the COLO part Signed-off-by: Maciej S. Szmigiero <maciej.szmigi...@oracle.com> Link: https://lore.kernel.org/qemu-devel/311be6da85fc7e49a7598684d80aa631778dcbce.1741124640.git.maciej.szmigi...@oracle.com Signed-off-by: Cédric Le Goater <c...@redhat.com> --- include/migration/client-options.h | 4 +++ include/migration/register.h | 12 +++++++++ migration/migration.h | 2 ++ migration/savevm.h | 1 + hw/core/machine.c | 1 + migration/colo.c | 3 +++ migration/migration-hmp-cmds.c | 2 ++ migration/migration.c | 2 ++ migration/options.c | 9 +++++++ migration/savevm.c | 39 ++++++++++++++++++++++++++++++ migration/trace-events | 1 + scripts/analyze-migration.py | 11 +++++++++ 12 files changed, 87 insertions(+) diff --git a/include/migration/client-options.h b/include/migration/client-options.h index 59f4b55cf4f744f222c161ab0b5b9828b53198be..289c9d776221ce3cf35d86f91ce3313fd79427d3 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 0b02927383208d1457f21da7ad4900ba53e93638..ff0faf5f68c8e9ac0fd1144ad91b3fab731d8a2f 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/migration.h b/migration/migration.h index 4639e2a7e42f6b25c1fe45ff1a9c13695306480a..7b4278e2a32b2044fad4cf7f7a5defd4435333ea 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; /* Needed by postcopy-pause state */ QemuSemaphore postcopy_pause_sem; diff --git a/migration/savevm.h b/migration/savevm.h index 7957460062cad0de7129e5f03b9f8d51ba5dc1f9..58f871a7ed9ce8498a16f76ab66b08ef665aee73 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/hw/core/machine.c b/hw/core/machine.c index b68b8b94a3c43865ec89d9a957289e42d1b26da1..d1ddc3a3db595bd746e8f39b006a8bf9cd9a52d6 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -44,6 +44,7 @@ GlobalProperty hw_compat_9_2[] = { { "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 = G_N_ELEMENTS(hw_compat_9_2); diff --git a/migration/colo.c b/migration/colo.c index 9a8e5fbe9b94e9fa56b3c59d3ae4271c1368d7f8..c976b3ff344d7ddf8f850c5a601b3fe42a503610 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 3347e34c489136106e29baf077bb93fb2f95ef1d..49c26daed359fbc04474be212cf7b5c8748043d5 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 c597aa707e5718bfd15ba6f175b4efbd870ee96f..9e9db26667f1adbeaae428be9b97750755c1c144 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2891,6 +2891,8 @@ static bool migration_switchover_start(MigrationState *s, Error **errp) precopy_notify_complete(); + qemu_savevm_maybe_send_switchover_start(s->to_dst_file); + return true; } diff --git a/migration/options.c b/migration/options.c index bb259d192a932d7af1ada20254a020cf3b2178a2..b0ac2ea4083ffbdf20788e0f508ab9f02a955f99 100644 --- a/migration/options.c +++ b/migration/options.c @@ -93,6 +93,8 @@ const 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, @@ -209,6 +211,13 @@ 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 4046faf0091e8ec48c47d4265f325236596a8cc5..faebf47ef51f2c5e6c49df831e1efe585c1a38a9 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; @@ -1687,6 +1702,7 @@ 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); ret = qemu_file_get_error(f); } @@ -2383,6 +2399,26 @@ 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 @@ -2481,6 +2517,9 @@ 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/trace-events b/migration/trace-events index 58c0f07f5b2dc3c7550239eab0c410561a21d645..c506e11a2e1d37a4aa22035248bcce47ac5956b1 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 8e1fbf4c9d9f13151535f95bfbee4f32ce8d7500..67631ac43e9f4807b16d3ae62b4eff2d0e340943 100755 --- a/scripts/analyze-migration.py +++ b/scripts/analyze-migration.py @@ -620,7 +620,9 @@ 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 = { @@ -685,6 +687,15 @@ def read(self, desc_only = False, dump_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: -- 2.48.1
