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pve-qemu-qoup/debian/patches/pve/0018-PVE-add-savevm-async-for-background-state-snapshots.patch
Fiona Ebner db5d2a4b77 squash related patches 
where there is no good reason to keep them separate. It's a pain
during rebase if there are multiple patches changing the same code
over and over again. This was especially bad for the backup-related
patches. If the history of patches really is needed, it can be
extracted via git. Additionally, compilation with partial application
of patches was broken since a long time, because one of the master key
changes became part of an earlier patch during a past rebase.

If only the same files were changed by a subsequent patch and the
changes felt to belong together (obvious for later bug fixes, but also
done for features e.g. adding master key support for PBS), the patches
were squashed together.

The PBS namespace support patch was split into the individual parts
it changes, i.e. PBS block driver, pbs-restore binary and QMP backup
infrastructure, and squashed into the respective patches.

No code change is intended, git diff in the submodule should not show
any difference between applying all patches before this commit and
applying all patches after this commit.

The query-proxmox-support QMP function has been left as part of the
"PVE-Backup: Proxmox backup patches for QEMU" patch, because it's
currently only used there. If it ever is used elsewhere too, it can
be split out from there.

The recent alloc-track and BQL-related savevm-async changes have been
left separate for now, because it's not 100% clear they are the best
approach yet. This depends on what upstream decides about the BQL
stuff and whether and what kind of issues with the changes pop up.

The qemu-img dd snapshot patch has been re-ordered to after the other
qemu-img dd patches.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-22 15:09:14 +02:00

931 lines
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Dietmar Maurer <dietmar@proxmox.com>
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 <t.lamprecht@proxmox.com>
Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
[SR: improve aborting
register yank before migration_incoming_state_destroy]
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
[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 <f.ebner@proxmox.com>
---
hmp-commands-info.hx | 13 +
hmp-commands.hx | 33 +++
include/migration/snapshot.h | 2 +
include/monitor/hmp.h | 5 +
migration/meson.build | 1 +
migration/savevm-async.c | 548 +++++++++++++++++++++++++++++++++++
monitor/hmp-cmds.c | 58 ++++
qapi/migration.json | 34 +++
qapi/misc.json | 32 ++
qemu-options.hx | 12 +
softmmu/vl.c | 10 +
11 files changed, 748 insertions(+)
create mode 100644 migration/savevm-async.c
diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index 47d63d26db..a166bff3d5 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -540,6 +540,19 @@ 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 bb85ee1d26..b66d7fc4ab 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1846,3 +1846,36 @@ 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 = "snapshot-drive",
+ .args_type = "device:s,name:s",
+ .params = "device name",
+ .help = "Create internal snapshot.",
+ .cmd = hmp_snapshot_drive,
+ },
+
+ {
+ .name = "delete-drive-snapshot",
+ .args_type = "device:s,name:s",
+ .params = "device name",
+ .help = "Delete internal snapshot.",
+ .cmd = hmp_delete_drive_snapshot,
+ },
+
+ {
+ .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 fdb69b7f9c..c012bad741 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 +95,10 @@ 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_snapshot_drive(Monitor *mon, const QDict *qdict);
+void hmp_delete_drive_snapshot(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 8a142fc7a9..a7824b5266 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -25,6 +25,7 @@ softmmu_ss.add(files(
'multifd-zlib.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..c5db9e9c1e
--- /dev/null
+++ b/migration/savevm-async.c
@@ -0,0 +1,548 @@
+#include "qemu/osdep.h"
+#include "migration/channel-savevm-async.h"
+#include "migration/migration.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 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);
+ ret = global_state_store();
+ if (ret) {
+ save_snapshot_error("global_state_store error %d", ret);
+ break;
+ }
+
+ 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_use_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(&ram_counters, 0, sizeof(ram_counters));
+ 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");
+}
+
+// FIXME: Deprecated
+void qmp_snapshot_drive(const char *device, const char *name, Error **errp)
+{
+ // Compatibility to older qemu-server.
+ qmp_blockdev_snapshot_internal_sync(device, name, errp);
+}
+
+// FIXME: Deprecated
+void qmp_delete_drive_snapshot(const char *device, const char *name,
+ Error **errp)
+{
+ // Compatibility to older qemu-server.
+ (void)qmp_blockdev_snapshot_delete_internal_sync(device, NULL, name, errp);
+}
+
+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..435f9334f9 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 +444,60 @@ 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 hmp_snapshot_drive(Monitor *mon, const QDict *qdict)
+{
+ Error *errp = NULL;
+ const char *name = qdict_get_str(qdict, "name");
+ const char *device = qdict_get_str(qdict, "device");
+
+ qmp_snapshot_drive(device, name, &errp);
+ hmp_handle_error(mon, errp);
+}
+
+void hmp_delete_drive_snapshot(Monitor *mon, const QDict *qdict)
+{
+ Error *errp = NULL;
+ const char *name = qdict_get_str(qdict, "name");
+ const char *device = qdict_get_str(qdict, "device");
+
+ qmp_delete_drive_snapshot(device, name, &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 c84fa10e86..1702b92553 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -261,6 +261,40 @@
'*compression': 'CompressionStats',
'*socket-address': ['SocketAddress'] } }
+##
+# @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 6ddd16ea28..098c9bbe93 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -469,6 +469,38 @@
##
{ 'command': 'query-fdsets', 'returns': ['FdsetInfo'] }
+##
+# @savevm-start:
+#
+# Prepare for snapshot and halt VM. Save VM state to statefile.
+#
+##
+{ 'command': 'savevm-start', 'data': { '*statefile': 'str' } }
+
+##
+# @snapshot-drive:
+#
+# Create an internal drive snapshot.
+#
+##
+{ 'command': 'snapshot-drive', 'data': { 'device': 'str', 'name': 'str' } }
+
+##
+# @delete-drive-snapshot:
+#
+# Delete a drive snapshot.
+#
+##
+{ 'command': 'delete-drive-snapshot', 'data': { 'device': 'str', 'name': '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 59bdf67a2c..fc6cb23dd9 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4378,6 +4378,18 @@ 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 ea20b23e4c..0eabc71b68 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;
@@ -2612,6 +2613,12 @@ 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();
@@ -3159,6 +3166,9 @@ 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;
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