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author | Steve Sistare <steven.sistare@oracle.com> | 2024-01-03 12:05:36 -0800 |
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committer | Peter Xu <peterx@redhat.com> | 2024-01-04 09:52:42 +0800 |
commit | 58b105703e86c1721d1a4cb9f6aaaca49c82145e (patch) | |
tree | bec29b151173d3da31d731a9d6a6dfe6cad6c97f /migration | |
parent | b4e9ddccd1a64239c07d7229afd7e00eed5afcd8 (diff) | |
download | qemu-58b105703e86c1721d1a4cb9f6aaaca49c82145e.zip qemu-58b105703e86c1721d1a4cb9f6aaaca49c82145e.tar.gz qemu-58b105703e86c1721d1a4cb9f6aaaca49c82145e.tar.bz2 |
migration: preserve suspended for snapshot
Restoring a snapshot can break a suspended guest. Snapshots suffer from
the same suspended-state issues that affect live migration, plus they must
handle an additional problematic scenario, which is that a running vm must
remain running if it loads a suspended snapshot.
To save, the existing vm_stop call now completely stops the suspended
state. Finish with vm_resume to leave the vm in the state it had prior
to the save, correctly restoring the suspended state.
To load, if the snapshot is not suspended, then vm_stop + vm_resume
correctly handles all states, and leaves the vm in the state it had prior
to the load. However, if the snapshot is suspended, restoration is
trickier. First, call vm_resume to restore the state to suspended so the
current state matches the saved state. Then, if the pre-load state is
running, call wakeup to resume running.
Prior to these changes, the vm_stop to RUN_STATE_SAVE_VM and
RUN_STATE_RESTORE_VM did not change runstate if the current state was
suspended, but now it does, so allow these transitions.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/1704312341-66640-8-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Diffstat (limited to 'migration')
-rw-r--r-- | migration/migration-hmp-cmds.c | 8 | ||||
-rw-r--r-- | migration/savevm.c | 23 |
2 files changed, 18 insertions, 13 deletions
diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index 99710c8..740a219 100644 --- a/migration/migration-hmp-cmds.c +++ b/migration/migration-hmp-cmds.c @@ -399,15 +399,17 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) void hmp_loadvm(Monitor *mon, const QDict *qdict) { - int saved_vm_running = runstate_is_running(); + RunState saved_state = runstate_get(); + const char *name = qdict_get_str(qdict, "name"); Error *err = NULL; vm_stop(RUN_STATE_RESTORE_VM); - if (load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) { - vm_start(); + if (load_snapshot(name, NULL, false, NULL, &err)) { + load_snapshot_resume(saved_state); } + hmp_handle_error(mon, err); } diff --git a/migration/savevm.c b/migration/savevm.c index 1b9ab7b..74f915f 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -3046,7 +3046,7 @@ bool save_snapshot(const char *name, bool overwrite, const char *vmstate, QEMUSnapshotInfo sn1, *sn = &sn1; int ret = -1, ret2; QEMUFile *f; - int saved_vm_running; + RunState saved_state = runstate_get(); uint64_t vm_state_size; g_autoptr(GDateTime) now = g_date_time_new_now_local(); @@ -3092,8 +3092,6 @@ bool save_snapshot(const char *name, bool overwrite, const char *vmstate, return false; } - saved_vm_running = runstate_is_running(); - global_state_store(); vm_stop(RUN_STATE_SAVE_VM); @@ -3147,9 +3145,7 @@ bool save_snapshot(const char *name, bool overwrite, const char *vmstate, the_end: bdrv_drain_all_end(); - if (saved_vm_running) { - vm_start(); - } + vm_resume(saved_state); return ret == 0; } @@ -3317,6 +3313,14 @@ err_drain: return false; } +void load_snapshot_resume(RunState state) +{ + vm_resume(state); + if (state == RUN_STATE_RUNNING && runstate_get() == RUN_STATE_SUSPENDED) { + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, &error_abort); + } +} + bool delete_snapshot(const char *name, bool has_devices, strList *devices, Error **errp) { @@ -3381,16 +3385,15 @@ static void snapshot_load_job_bh(void *opaque) { Job *job = opaque; SnapshotJob *s = container_of(job, SnapshotJob, common); - int orig_vm_running; + RunState orig_state = runstate_get(); job_progress_set_remaining(&s->common, 1); - orig_vm_running = runstate_is_running(); vm_stop(RUN_STATE_RESTORE_VM); s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp); - if (s->ret && orig_vm_running) { - vm_start(); + if (s->ret) { + load_snapshot_resume(orig_state); } job_progress_update(&s->common, 1); |