Re: [libvirt] [PATCH v3 4/8] test: Implement snapshot create/delete/revert APIs

Again stolen from qemu_driver.c, but dropping all the unneeded bits. This aims to copy all the current qemu validation checks since that's the most commonly used real driver, but some of the checks are completely artificial in the test driver. This only supports creation of internal snapshots for initial simplicity. --- v3: Use STRNEQ_NULLABLE for domain_conf.c change src/conf/domain_conf.c | 2 +- src/test/test_driver.c | 504 ++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 504 insertions(+), 2 deletions(-)

+static int +testDomainRevertToSnapshot(virDomainSnapshotPtr snapshot, + unsigned int flags) +{ + testConnPtr privconn = snapshot->domain->conn->privateData; + virDomainObjPtr vm = NULL; + virDomainSnapshotObjPtr snap = NULL; + virDomainEventPtr event = NULL; + virDomainEventPtr event2 = NULL; + virDomainDefPtr config = NULL; + int ret = -1; + + virCheckFlags(VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING | + VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED | + VIR_DOMAIN_SNAPSHOT_REVERT_FORCE, -1); + + /* We have the following transitions, which create the following events: + * 1. inactive -> inactive: none + * 2. inactive -> running: EVENT_STARTED + * 3. inactive -> paused: EVENT_STARTED, EVENT_PAUSED + * 4. running -> inactive: EVENT_STOPPED + * 5. running -> running: none + * 6. running -> paused: EVENT_PAUSED + * 7. paused -> inactive: EVENT_STOPPED + * 8. paused -> running: EVENT_RESUMED + * 9. paused -> paused: none + * Also, several transitions occur even if we fail partway through, + * and use of FORCE can cause multiple transitions. + */ + + if (!(vm = testDomObjFromSnapshot(snapshot))) + return -1; + + if (!(snap = testSnapObjFromSnapshot(vm, snapshot))) + goto cleanup; + + testDriverLock(privconn); + + if (!vm->persistent && + snap->def->state != VIR_DOMAIN_RUNNING && + snap->def->state != VIR_DOMAIN_PAUSED && + (flags & (VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING | + VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED)) == 0) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("transient domain needs to request run or pause " + "to revert to inactive snapshot")); + goto cleanup; + } + + if (!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_FORCE)) { + if (!snap->def->dom) { + virReportError(VIR_ERR_SNAPSHOT_REVERT_RISKY, + _("snapshot '%s' lacks domain '%s' rollback info"), + snap->def->name, vm->def->name); + goto cleanup; + } + if (virDomainObjIsActive(vm) && + !(snap->def->state == VIR_DOMAIN_RUNNING + || snap->def->state == VIR_DOMAIN_PAUSED) && + (flags & (VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING | + VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED))) { + virReportError(VIR_ERR_SNAPSHOT_REVERT_RISKY, "%s", + _("must respawn guest to start inactive snapshot")); + goto cleanup; + } + } + + + if (vm->current_snapshot) { + vm->current_snapshot->def->current = false; + vm->current_snapshot = NULL; + } + + snap->def->current = true; + config = virDomainDefCopy(snap->def->dom, + privconn->caps, privconn->xmlopt, true); + if (!config) + goto cleanup; +

+ if (snap->def->state == VIR_DOMAIN_RUNNING || + snap->def->state == VIR_DOMAIN_PAUSED) { + /* Transitions 2, 3, 5, 6, 8, 9 */ + bool was_running = false; + bool was_stopped = false; + + if (virDomainObjIsActive(vm)) { + /* Transitions 5, 6, 8, 9 */ + /* Check for ABI compatibility. */ + if (!virDomainDefCheckABIStability(vm->def, config)) { + virErrorPtr err = virGetLastError(); + + if (!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_FORCE)) { + /* Re-spawn error using correct category. */ + if (err->code == VIR_ERR_CONFIG_UNSUPPORTED) + virReportError(VIR_ERR_SNAPSHOT_REVERT_RISKY, "%s", + err->str2); + goto cleanup; + } + + virResetError(err); + testDomainShutdownState(snapshot->domain, vm, + VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT); + event = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_STOPPED, + VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT); + if (event) + testDomainEventQueue(privconn, event); + goto load; + } + + if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING) { + /* Transitions 5, 6 */ + was_running = true; + virDomainObjSetState(vm, VIR_DOMAIN_PAUSED, + VIR_DOMAIN_PAUSED_FROM_SNAPSHOT); + /* Create an event now in case the restore fails, so + * that user will be alerted that they are now paused. + * If restore later succeeds, we might replace this. */ + event = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_SUSPENDED, + VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT); + } + virDomainObjAssignDef(vm, config, false, NULL); + + } else { + /* Transitions 2, 3 */ + load: + was_stopped = true; + virDomainObjAssignDef(vm, config, false, NULL); + if (testDomainStartState(privconn, vm, + VIR_DOMAIN_RUNNING_FROM_SNAPSHOT) < 0) + goto cleanup; + event = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_STARTED, + VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT); + } + + /* Touch up domain state. */ + if (!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING) && + (snap->def->state == VIR_DOMAIN_PAUSED || + (flags & VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED))) { + /* Transitions 3, 6, 9 */ + virDomainObjSetState(vm, VIR_DOMAIN_PAUSED, + VIR_DOMAIN_PAUSED_FROM_SNAPSHOT); + if (was_stopped) { + /* Transition 3, use event as-is and add event2 */ + event2 = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_SUSPENDED, + VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT); + } /* else transition 6 and 9 use event as-is */ + } else { + /* Transitions 2, 5, 8 */ + virDomainEventFree(event); + event = NULL; + + if (was_stopped) { + /* Transition 2 */ + event = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_STARTED, + VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT); + } else if (was_running) { + /* Transition 8 */ + event = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_RESUMED, + VIR_DOMAIN_EVENT_RESUMED); + } + }

+ } else { + /* Transitions 1, 4, 7 */ + virDomainObjAssignDef(vm, config, false, NULL); +

+ if (virDomainObjIsActive(vm)) { + /* Transitions 4, 7 */ + testDomainShutdownState(snapshot->domain, vm, + VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT); + event = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_STOPPED, + VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT);

+ } +

+ if (flags & (VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING | + VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED)) { + /* Flush first event, now do transition 2 or 3 */ + bool paused = (flags & VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED) != 0; +

+ if (event)

+ testDomainEventQueue(privconn, event); + event = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_STARTED, + VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT);

+ if (paused) {

+ event2 = virDomainEventNewFromObj(vm, + VIR_DOMAIN_EVENT_SUSPENDED, + VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT); + } + } + } + + vm->current_snapshot = snap; + ret = 0; +cleanup: + if (event) { + testDomainEventQueue(privconn, event); + if (event2) + testDomainEventQueue(privconn, event2); + }

+ virObjectUnlock(vm); + testDriverUnlock(privconn); + + return ret; +} + +