From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Dietmar Maurer Date: Mon, 6 Apr 2020 12:16:46 +0200 Subject: [PATCH] PVE: add savevm-async for background state snapshots Put qemu_savevm_state_{header,setup} into the main loop and the rest of the iteration into a coroutine. The former need to lock the iothread (and we can't unlock it in the coroutine), and the latter can't deal with being in a separate thread, so a coroutine it must be. Truncate output file at 1024 boundary. Do not block the VM and save the state on aborting a snapshot, as the snapshot will be invalid anyway. Also, when aborting, wait for the target file to be closed, otherwise a client might run into race-conditions when trying to remove the file still opened by QEMU. Signed-off-by: Thomas Lamprecht Signed-off-by: Dietmar Maurer Signed-off-by: Wolfgang Bumiller [SR: improve aborting register yank before migration_incoming_state_destroy] Signed-off-by: Stefan Reiter [FE: further improve aborting adapt to removal of QEMUFileOps improve condition for entering final stage adapt to QAPI and other changes for 8.0] Signed-off-by: Fiona Ebner --- hmp-commands-info.hx | 13 + hmp-commands.hx | 17 ++ include/migration/snapshot.h | 2 + include/monitor/hmp.h | 3 + migration/meson.build | 1 + migration/savevm-async.c | 531 +++++++++++++++++++++++++++++++++++ monitor/hmp-cmds.c | 38 +++ qapi/migration.json | 34 +++ qapi/misc.json | 16 ++ qemu-options.hx | 12 + softmmu/vl.c | 10 + 11 files changed, 677 insertions(+) create mode 100644 migration/savevm-async.c diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx index f5b37eb74a..10fdd822e0 100644 --- a/hmp-commands-info.hx +++ b/hmp-commands-info.hx @@ -525,6 +525,19 @@ SRST Show current migration parameters. ERST + { + .name = "savevm", + .args_type = "", + .params = "", + .help = "show savevm status", + .cmd = hmp_info_savevm, + }, + +SRST + ``info savevm`` + Show savevm status. +ERST + { .name = "balloon", .args_type = "", diff --git a/hmp-commands.hx b/hmp-commands.hx index 2cbd0f77a0..e352f86872 100644 --- a/hmp-commands.hx +++ b/hmp-commands.hx @@ -1865,3 +1865,20 @@ SRST List event channels in the guest ERST #endif + + { + .name = "savevm-start", + .args_type = "statefile:s?", + .params = "[statefile]", + .help = "Prepare for snapshot and halt VM. Save VM state to statefile.", + .cmd = hmp_savevm_start, + }, + + { + .name = "savevm-end", + .args_type = "", + .params = "", + .help = "Resume VM after snaphot.", + .cmd = hmp_savevm_end, + .coroutine = true, + }, diff --git a/include/migration/snapshot.h b/include/migration/snapshot.h index e72083b117..c846d37806 100644 --- a/include/migration/snapshot.h +++ b/include/migration/snapshot.h @@ -61,4 +61,6 @@ bool delete_snapshot(const char *name, bool has_devices, strList *devices, Error **errp); +int load_snapshot_from_blockdev(const char *filename, Error **errp); + #endif diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h index 13f9a2dedb..7a7def7530 100644 --- a/include/monitor/hmp.h +++ b/include/monitor/hmp.h @@ -28,6 +28,7 @@ void hmp_info_status(Monitor *mon, const QDict *qdict); void hmp_info_uuid(Monitor *mon, const QDict *qdict); void hmp_info_chardev(Monitor *mon, const QDict *qdict); void hmp_info_mice(Monitor *mon, const QDict *qdict); +void hmp_info_savevm(Monitor *mon, const QDict *qdict); void hmp_info_migrate(Monitor *mon, const QDict *qdict); void hmp_info_migrate_capabilities(Monitor *mon, const QDict *qdict); void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict); @@ -94,6 +95,8 @@ void hmp_closefd(Monitor *mon, const QDict *qdict); void hmp_mouse_move(Monitor *mon, const QDict *qdict); void hmp_mouse_button(Monitor *mon, const QDict *qdict); void hmp_mouse_set(Monitor *mon, const QDict *qdict); +void hmp_savevm_start(Monitor *mon, const QDict *qdict); +void hmp_savevm_end(Monitor *mon, const QDict *qdict); void hmp_sendkey(Monitor *mon, const QDict *qdict); void coroutine_fn hmp_screendump(Monitor *mon, const QDict *qdict); void hmp_chardev_add(Monitor *mon, const QDict *qdict); diff --git a/migration/meson.build b/migration/meson.build index 37ddcb5d60..07f6057acc 100644 --- a/migration/meson.build +++ b/migration/meson.build @@ -26,6 +26,7 @@ system_ss.add(files( 'options.c', 'postcopy-ram.c', 'savevm.c', + 'savevm-async.c', 'socket.c', 'tls.c', 'threadinfo.c', diff --git a/migration/savevm-async.c b/migration/savevm-async.c new file mode 100644 index 0000000000..e9fc18fb10 --- /dev/null +++ b/migration/savevm-async.c @@ -0,0 +1,531 @@ +#include "qemu/osdep.h" +#include "migration/channel-savevm-async.h" +#include "migration/migration.h" +#include "migration/migration-stats.h" +#include "migration/options.h" +#include "migration/savevm.h" +#include "migration/snapshot.h" +#include "migration/global_state.h" +#include "migration/ram.h" +#include "migration/qemu-file.h" +#include "sysemu/sysemu.h" +#include "sysemu/runstate.h" +#include "block/block.h" +#include "sysemu/block-backend.h" +#include "qapi/error.h" +#include "qapi/qmp/qerror.h" +#include "qapi/qmp/qdict.h" +#include "qapi/qapi-commands-migration.h" +#include "qapi/qapi-commands-misc.h" +#include "qapi/qapi-commands-block.h" +#include "qemu/cutils.h" +#include "qemu/timer.h" +#include "qemu/main-loop.h" +#include "qemu/rcu.h" +#include "qemu/yank.h" + +/* #define DEBUG_SAVEVM_STATE */ + +#ifdef DEBUG_SAVEVM_STATE +#define DPRINTF(fmt, ...) \ + do { printf("savevm-async: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +enum { + SAVE_STATE_DONE, + SAVE_STATE_ERROR, + SAVE_STATE_ACTIVE, + SAVE_STATE_COMPLETED, + SAVE_STATE_CANCELLED +}; + + +static struct SnapshotState { + BlockBackend *target; + size_t bs_pos; + int state; + Error *error; + Error *blocker; + int saved_vm_running; + QEMUFile *file; + int64_t total_time; + QEMUBH *finalize_bh; + Coroutine *co; + QemuCoSleep target_close_wait; +} snap_state; + +static bool savevm_aborted(void) +{ + return snap_state.state == SAVE_STATE_CANCELLED || + snap_state.state == SAVE_STATE_ERROR; +} + +SaveVMInfo *qmp_query_savevm(Error **errp) +{ + SaveVMInfo *info = g_malloc0(sizeof(*info)); + struct SnapshotState *s = &snap_state; + + if (s->state != SAVE_STATE_DONE) { + info->has_bytes = true; + info->bytes = s->bs_pos; + switch (s->state) { + case SAVE_STATE_ERROR: + info->status = g_strdup("failed"); + info->has_total_time = true; + info->total_time = s->total_time; + if (s->error) { + info->error = g_strdup(error_get_pretty(s->error)); + } + break; + case SAVE_STATE_ACTIVE: + info->status = g_strdup("active"); + info->has_total_time = true; + info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + - s->total_time; + break; + case SAVE_STATE_COMPLETED: + info->status = g_strdup("completed"); + info->has_total_time = true; + info->total_time = s->total_time; + break; + } + } + + return info; +} + +static int save_snapshot_cleanup(void) +{ + int ret = 0; + + DPRINTF("save_snapshot_cleanup\n"); + + snap_state.total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - + snap_state.total_time; + + if (snap_state.file) { + ret = qemu_fclose(snap_state.file); + snap_state.file = NULL; + } + + if (snap_state.target) { + if (!savevm_aborted()) { + /* try to truncate, but ignore errors (will fail on block devices). + * note1: bdrv_read() need whole blocks, so we need to round up + * note2: PVE requires 1024 (BDRV_SECTOR_SIZE*2) alignment + */ + size_t size = QEMU_ALIGN_UP(snap_state.bs_pos, BDRV_SECTOR_SIZE*2); + blk_truncate(snap_state.target, size, false, PREALLOC_MODE_OFF, 0, NULL); + } + blk_op_unblock_all(snap_state.target, snap_state.blocker); + error_free(snap_state.blocker); + snap_state.blocker = NULL; + blk_unref(snap_state.target); + snap_state.target = NULL; + + qemu_co_sleep_wake(&snap_state.target_close_wait); + } + + return ret; +} + +static void G_GNUC_PRINTF(1, 2) save_snapshot_error(const char *fmt, ...) +{ + va_list ap; + char *msg; + + va_start(ap, fmt); + msg = g_strdup_vprintf(fmt, ap); + va_end(ap); + + DPRINTF("save_snapshot_error: %s\n", msg); + + if (!snap_state.error) { + error_set(&snap_state.error, ERROR_CLASS_GENERIC_ERROR, "%s", msg); + } + + g_free (msg); + + snap_state.state = SAVE_STATE_ERROR; +} + +static void process_savevm_finalize(void *opaque) +{ + int ret; + AioContext *iohandler_ctx = iohandler_get_aio_context(); + MigrationState *ms = migrate_get_current(); + + bool aborted = savevm_aborted(); + +#ifdef DEBUG_SAVEVM_STATE + int64_t start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); +#endif + + qemu_bh_delete(snap_state.finalize_bh); + snap_state.finalize_bh = NULL; + snap_state.co = NULL; + + /* We need to own the target bdrv's context for the following functions, + * so move it back. It can stay in the main context and live out its live + * there, since we're done with it after this method ends anyway. + */ + aio_context_acquire(iohandler_ctx); + blk_set_aio_context(snap_state.target, qemu_get_aio_context(), NULL); + aio_context_release(iohandler_ctx); + + ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); + if (ret < 0) { + save_snapshot_error("vm_stop_force_state error %d", ret); + } + + if (!aborted) { + /* skip state saving if we aborted, snapshot will be invalid anyway */ + (void)qemu_savevm_state_complete_precopy(snap_state.file, false, false); + ret = qemu_file_get_error(snap_state.file); + if (ret < 0) { + save_snapshot_error("qemu_savevm_state_complete_precopy error %d", ret); + } + } + + DPRINTF("state saving complete\n"); + DPRINTF("timing: process_savevm_finalize (state saving) took %ld ms\n", + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - start_time); + + /* clear migration state */ + migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, + ret || aborted ? MIGRATION_STATUS_FAILED : MIGRATION_STATUS_COMPLETED); + ms->to_dst_file = NULL; + + qemu_savevm_state_cleanup(); + + ret = save_snapshot_cleanup(); + if (ret < 0) { + save_snapshot_error("save_snapshot_cleanup error %d", ret); + } else if (snap_state.state == SAVE_STATE_ACTIVE) { + snap_state.state = SAVE_STATE_COMPLETED; + } else if (aborted) { + /* + * If there was an error, there's no need to set a new one here. + * If the snapshot was canceled, leave setting the state to + * qmp_savevm_end(), which is waked by save_snapshot_cleanup(). + */ + } else { + save_snapshot_error("process_savevm_cleanup: invalid state: %d", + snap_state.state); + } + if (snap_state.saved_vm_running) { + vm_start(); + snap_state.saved_vm_running = false; + } + + DPRINTF("timing: process_savevm_finalize (full) took %ld ms\n", + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - start_time); +} + +static void coroutine_fn process_savevm_co(void *opaque) +{ + int ret; + int64_t maxlen; + BdrvNextIterator it; + BlockDriverState *bs = NULL; + +#ifdef DEBUG_SAVEVM_STATE + int64_t start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); +#endif + + ret = qemu_file_get_error(snap_state.file); + if (ret < 0) { + save_snapshot_error("qemu_savevm_state_setup failed"); + return; + } + + while (snap_state.state == SAVE_STATE_ACTIVE) { + uint64_t pending_size, pend_precopy, pend_postcopy; + uint64_t threshold = 400 * 1000; + + /* + * pending_{estimate,exact} are expected to be called without iothread + * lock. Similar to what is done in migration.c, call the exact variant + * only once pend_precopy in the estimate is below the threshold. + */ + qemu_mutex_unlock_iothread(); + qemu_savevm_state_pending_estimate(&pend_precopy, &pend_postcopy); + if (pend_precopy <= threshold) { + qemu_savevm_state_pending_exact(&pend_precopy, &pend_postcopy); + } + qemu_mutex_lock_iothread(); + pending_size = pend_precopy + pend_postcopy; + + /* + * A guest reaching this cutoff is dirtying lots of RAM. It should be + * large enough so that the guest can't dirty this much between the + * check and the guest actually being stopped, but it should be small + * enough to avoid long downtimes for non-hibernation snapshots. + */ + maxlen = blk_getlength(snap_state.target) - 100*1024*1024; + + /* Note that there is no progress for pend_postcopy when iterating */ + if (pend_precopy > threshold && snap_state.bs_pos + pending_size < maxlen) { + ret = qemu_savevm_state_iterate(snap_state.file, false); + if (ret < 0) { + save_snapshot_error("qemu_savevm_state_iterate error %d", ret); + break; + } + DPRINTF("savevm iterate pending size %lu ret %d\n", pending_size, ret); + } else { + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL); + global_state_store(); + + DPRINTF("savevm iterate complete\n"); + break; + } + } + + DPRINTF("timing: process_savevm_co took %ld ms\n", + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - start_time); + +#ifdef DEBUG_SAVEVM_STATE + int64_t start_time_flush = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); +#endif + /* If a drive runs in an IOThread we can flush it async, and only + * need to sync-flush whatever IO happens between now and + * vm_stop_force_state. bdrv_next can only be called from main AioContext, + * so move there now and after every flush. + */ + aio_co_reschedule_self(qemu_get_aio_context()); + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { + /* target has BDRV_O_NO_FLUSH, no sense calling bdrv_flush on it */ + if (bs == blk_bs(snap_state.target)) { + continue; + } + + AioContext *bs_ctx = bdrv_get_aio_context(bs); + if (bs_ctx != qemu_get_aio_context()) { + DPRINTF("savevm: async flushing drive %s\n", bs->filename); + aio_co_reschedule_self(bs_ctx); + bdrv_graph_co_rdlock(); + bdrv_flush(bs); + bdrv_graph_co_rdunlock(); + aio_co_reschedule_self(qemu_get_aio_context()); + } + } + + DPRINTF("timing: async flushing took %ld ms\n", + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - start_time_flush); + + qemu_bh_schedule(snap_state.finalize_bh); +} + +void qmp_savevm_start(const char *statefile, Error **errp) +{ + Error *local_err = NULL; + MigrationState *ms = migrate_get_current(); + AioContext *iohandler_ctx = iohandler_get_aio_context(); + + int bdrv_oflags = BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH; + + if (snap_state.state != SAVE_STATE_DONE) { + error_set(errp, ERROR_CLASS_GENERIC_ERROR, + "VM snapshot already started\n"); + return; + } + + if (migration_is_running(ms->state)) { + error_set(errp, ERROR_CLASS_GENERIC_ERROR, QERR_MIGRATION_ACTIVE); + return; + } + + if (migrate_block()) { + error_set(errp, ERROR_CLASS_GENERIC_ERROR, + "Block migration and snapshots are incompatible"); + return; + } + + /* initialize snapshot info */ + snap_state.saved_vm_running = runstate_is_running(); + snap_state.bs_pos = 0; + snap_state.total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + snap_state.blocker = NULL; + snap_state.target_close_wait = (QemuCoSleep){ .to_wake = NULL }; + + if (snap_state.error) { + error_free(snap_state.error); + snap_state.error = NULL; + } + + if (!statefile) { + vm_stop(RUN_STATE_SAVE_VM); + snap_state.state = SAVE_STATE_COMPLETED; + return; + } + + if (qemu_savevm_state_blocked(errp)) { + return; + } + + /* Open the image */ + QDict *options = NULL; + options = qdict_new(); + qdict_put_str(options, "driver", "raw"); + snap_state.target = blk_new_open(statefile, NULL, options, bdrv_oflags, &local_err); + if (!snap_state.target) { + error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile); + goto restart; + } + + QIOChannel *ioc = QIO_CHANNEL(qio_channel_savevm_async_new(snap_state.target, + &snap_state.bs_pos)); + snap_state.file = qemu_file_new_output(ioc); + + if (!snap_state.file) { + error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile); + goto restart; + } + + /* + * qemu_savevm_* paths use migration code and expect a migration state. + * State is cleared in process_savevm_co, but has to be initialized + * here (blocking main thread, from QMP) to avoid race conditions. + */ + migrate_init(ms); + memset(&mig_stats, 0, sizeof(mig_stats)); + memset(&compression_counters, 0, sizeof(compression_counters)); + ms->to_dst_file = snap_state.file; + + error_setg(&snap_state.blocker, "block device is in use by savevm"); + blk_op_block_all(snap_state.target, snap_state.blocker); + + snap_state.state = SAVE_STATE_ACTIVE; + snap_state.finalize_bh = qemu_bh_new(process_savevm_finalize, &snap_state); + snap_state.co = qemu_coroutine_create(&process_savevm_co, NULL); + qemu_mutex_unlock_iothread(); + qemu_savevm_state_header(snap_state.file); + qemu_savevm_state_setup(snap_state.file); + qemu_mutex_lock_iothread(); + + /* Async processing from here on out happens in iohandler context, so let + * the target bdrv have its home there. + */ + blk_set_aio_context(snap_state.target, iohandler_ctx, &local_err); + + aio_co_schedule(iohandler_ctx, snap_state.co); + + return; + +restart: + + save_snapshot_error("setup failed"); + + if (snap_state.saved_vm_running) { + vm_start(); + snap_state.saved_vm_running = false; + } +} + +void coroutine_fn qmp_savevm_end(Error **errp) +{ + int64_t timeout; + + if (snap_state.state == SAVE_STATE_DONE) { + error_set(errp, ERROR_CLASS_GENERIC_ERROR, + "VM snapshot not started\n"); + return; + } + + if (snap_state.state == SAVE_STATE_ACTIVE) { + snap_state.state = SAVE_STATE_CANCELLED; + goto wait_for_close; + } + + if (snap_state.saved_vm_running) { + vm_start(); + snap_state.saved_vm_running = false; + } + + snap_state.state = SAVE_STATE_DONE; + +wait_for_close: + if (!snap_state.target) { + DPRINTF("savevm-end: no target file open\n"); + return; + } + + /* wait until cleanup is done before returning, this ensures that after this + * call exits the statefile will be closed and can be removed immediately */ + DPRINTF("savevm-end: waiting for cleanup\n"); + timeout = 30L * 1000 * 1000 * 1000; + qemu_co_sleep_ns_wakeable(&snap_state.target_close_wait, + QEMU_CLOCK_REALTIME, timeout); + if (snap_state.target) { + save_snapshot_error("timeout waiting for target file close in " + "qmp_savevm_end"); + /* we cannot assume the snapshot finished in this case, so leave the + * state alone - caller has to figure something out */ + return; + } + + // File closed and no other error, so ensure next snapshot can be started. + if (snap_state.state != SAVE_STATE_ERROR) { + snap_state.state = SAVE_STATE_DONE; + } + + DPRINTF("savevm-end: cleanup done\n"); +} + +int load_snapshot_from_blockdev(const char *filename, Error **errp) +{ + BlockBackend *be; + Error *local_err = NULL; + Error *blocker = NULL; + + QEMUFile *f; + size_t bs_pos = 0; + int ret = -EINVAL; + + be = blk_new_open(filename, NULL, NULL, 0, &local_err); + + if (!be) { + error_setg(errp, "Could not open VM state file"); + goto the_end; + } + + error_setg(&blocker, "block device is in use by load state"); + blk_op_block_all(be, blocker); + + /* restore the VM state */ + f = qemu_file_new_input(QIO_CHANNEL(qio_channel_savevm_async_new(be, &bs_pos))); + if (!f) { + error_setg(errp, "Could not open VM state file"); + goto the_end; + } + + qemu_system_reset(SHUTDOWN_CAUSE_NONE); + ret = qemu_loadvm_state(f); + + /* dirty bitmap migration has a special case we need to trigger manually */ + dirty_bitmap_mig_before_vm_start(); + + qemu_fclose(f); + + /* state_destroy assumes a real migration which would have added a yank */ + yank_register_instance(MIGRATION_YANK_INSTANCE, &error_abort); + + migration_incoming_state_destroy(); + if (ret < 0) { + error_setg_errno(errp, -ret, "Error while loading VM state"); + goto the_end; + } + + ret = 0; + + the_end: + if (be) { + blk_op_unblock_all(be, blocker); + error_free(blocker); + blk_unref(be); + } + return ret; +} diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index 6c559b48c8..91be698308 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -22,6 +22,7 @@ #include "monitor/monitor-internal.h" #include "qapi/error.h" #include "qapi/qapi-commands-control.h" +#include "qapi/qapi-commands-migration.h" #include "qapi/qapi-commands-misc.h" #include "qapi/qmp/qdict.h" #include "qapi/qmp/qerror.h" @@ -443,3 +444,40 @@ void hmp_info_mtree(Monitor *mon, const QDict *qdict) mtree_info(flatview, dispatch_tree, owner, disabled); } + +void hmp_savevm_start(Monitor *mon, const QDict *qdict) +{ + Error *errp = NULL; + const char *statefile = qdict_get_try_str(qdict, "statefile"); + + qmp_savevm_start(statefile, &errp); + hmp_handle_error(mon, errp); +} + +void coroutine_fn hmp_savevm_end(Monitor *mon, const QDict *qdict) +{ + Error *errp = NULL; + + qmp_savevm_end(&errp); + hmp_handle_error(mon, errp); +} + +void hmp_info_savevm(Monitor *mon, const QDict *qdict) +{ + SaveVMInfo *info; + info = qmp_query_savevm(NULL); + + if (info->status) { + monitor_printf(mon, "savevm status: %s\n", info->status); + monitor_printf(mon, "total time: %" PRIu64 " milliseconds\n", + info->total_time); + } else { + monitor_printf(mon, "savevm status: not running\n"); + } + if (info->has_bytes) { + monitor_printf(mon, "Bytes saved: %"PRIu64"\n", info->bytes); + } + if (info->error) { + monitor_printf(mon, "Error: %s\n", info->error); + } +} diff --git a/qapi/migration.json b/qapi/migration.json index 8843e74b59..aca0ca1ac1 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -291,6 +291,40 @@ '*dirty-limit-throttle-time-per-round': 'uint64', '*dirty-limit-ring-full-time': 'uint64'} } +## +# @SaveVMInfo: +# +# Information about current migration process. +# +# @status: string describing the current savevm status. +# This can be 'active', 'completed', 'failed'. +# If this field is not returned, no savevm process +# has been initiated +# +# @error: string containing error message is status is failed. +# +# @total-time: total amount of milliseconds since savevm started. +# If savevm has ended, it returns the total save time +# +# @bytes: total amount of data transfered +# +# Since: 1.3 +## +{ 'struct': 'SaveVMInfo', + 'data': {'*status': 'str', '*error': 'str', + '*total-time': 'int', '*bytes': 'int'} } + +## +# @query-savevm: +# +# Returns information about current savevm process. +# +# Returns: @SaveVMInfo +# +# Since: 1.3 +## +{ 'command': 'query-savevm', 'returns': 'SaveVMInfo' } + ## # @query-migrate: # diff --git a/qapi/misc.json b/qapi/misc.json index cda2effa81..94a58bb0bf 100644 --- a/qapi/misc.json +++ b/qapi/misc.json @@ -456,6 +456,22 @@ ## { 'command': 'query-fdsets', 'returns': ['FdsetInfo'] } +## +# @savevm-start: +# +# Prepare for snapshot and halt VM. Save VM state to statefile. +# +## +{ 'command': 'savevm-start', 'data': { '*statefile': 'str' } } + +## +# @savevm-end: +# +# Resume VM after a snapshot. +# +## +{ 'command': 'savevm-end', 'coroutine': true } + ## # @CommandLineParameterType: # diff --git a/qemu-options.hx b/qemu-options.hx index 8073f5edf5..dc1ececc9c 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4483,6 +4483,18 @@ SRST Start right away with a saved state (``loadvm`` in monitor) ERST +DEF("loadstate", HAS_ARG, QEMU_OPTION_loadstate, \ + "-loadstate file\n" \ + " start right away with a saved state\n", + QEMU_ARCH_ALL) +SRST +``-loadstate file`` + Start right away with a saved state. This option does not rollback + disk state like @code{loadvm}, so user must make sure that disk + have correct state. @var{file} can be any valid device URL. See the section + for "Device URL Syntax" for more information. +ERST + #ifndef _WIN32 DEF("daemonize", 0, QEMU_OPTION_daemonize, \ "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) diff --git a/softmmu/vl.c b/softmmu/vl.c index ba6ad8a8df..ddeace306e 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -164,6 +164,7 @@ static const char *accelerators; static bool have_custom_ram_size; static const char *ram_memdev_id; static QDict *machine_opts_dict; +static const char *loadstate; static QTAILQ_HEAD(, ObjectOption) object_opts = QTAILQ_HEAD_INITIALIZER(object_opts); static QTAILQ_HEAD(, DeviceOption) device_opts = QTAILQ_HEAD_INITIALIZER(device_opts); static int display_remote; @@ -2647,6 +2648,12 @@ void qmp_x_exit_preconfig(Error **errp) if (loadvm) { load_snapshot(loadvm, NULL, false, NULL, &error_fatal); + } else if (loadstate) { + Error *local_err = NULL; + if (load_snapshot_from_blockdev(loadstate, &local_err) < 0) { + error_report_err(local_err); + autostart = 0; + } } if (replay_mode != REPLAY_MODE_NONE) { replay_vmstate_init(); @@ -3196,6 +3203,9 @@ void qemu_init(int argc, char **argv) case QEMU_OPTION_loadvm: loadvm = optarg; break; + case QEMU_OPTION_loadstate: + loadstate = optarg; + break; case QEMU_OPTION_full_screen: dpy.has_full_screen = true; dpy.full_screen = true;