Original code assumed that the memory state file is only migration
stream but it has additional metadata stored by libvirt. To correctly
load the memory state file we need to reuse code that is used when
restoring domain from saved image.
This duplicates some necessary parts of qemuSaveImageStartVM() because
the external snapshot memory state is done by qemuSaveImageCreate().
Signed-off-by: Pavel Hrdina <phrdina@xxxxxxxxxx>
---
src/qemu/qemu_snapshot.c | 115 +++++++++++++++++++++++++++++++++------
1 file changed, 97 insertions(+), 18 deletions(-)
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index ff85d56572..538da6570a 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -2004,6 +2004,22 @@ qemuSnapshotRevertWriteMetadata(virDomainObj *vm,
}
+typedef struct _qemuSnapshotRevertMemoryData {
+ int fd;
+ char *path;
+ virQEMUSaveData *data;
+} qemuSnapshotRevertMemoryData;
+
+
+static void
+qemuSnapshotClearRevertMemoryData(qemuSnapshotRevertMemoryData *memdata)
+{
+ VIR_FORCE_CLOSE(memdata->fd);
+ virQEMUSaveDataFree(memdata->data);
+}
+G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(qemuSnapshotRevertMemoryData, qemuSnapshotClearRevertMemoryData);
+
+
/**
* qemuSnapshotRevertExternalPrepare:
* @vm: domain object
@@ -2011,15 +2027,13 @@ qemuSnapshotRevertWriteMetadata(virDomainObj *vm,
* @snap: snapshot object we are reverting to
* @config: live domain definition
* @inactiveConfig: offline domain definition
- * memsnapFD: pointer to store memory state file FD or NULL
- * memsnapPath: pointer to store memory state file path or NULL
+ * @memdata: struct with data to load memory state
*
* Prepare new temporary snapshot definition @tmpsnapdef that will
* be used while creating new overlay files after reverting to snapshot
* @snap. In case we are reverting to snapshot with memory state it will
- * open it and pass FD via @memsnapFD and path to the file via
- * @memsnapPath, caller is responsible for freeing both @memsnapFD and
- * memsnapPath.
+ * open it and store necessary data in @memdata. Caller is responsible
+ * to clear the data by using qemuSnapshotClearRevertMemoryData().
*
* Returns 0 in success, -1 on error.
*/
@@ -2029,8 +2043,7 @@ qemuSnapshotRevertExternalPrepare(virDomainObj *vm,
virDomainMomentObj *snap,
virDomainDef *config,
virDomainDef *inactiveConfig,
- int *memsnapFD,
- char **memsnapPath)
+ qemuSnapshotRevertMemoryData *memdata)
{
size_t i;
bool active = virDomainObjIsActive(vm);
@@ -2065,12 +2078,20 @@ qemuSnapshotRevertExternalPrepare(virDomainObj *vm,
return -1;
}
- if (memsnapFD && memsnapPath && snapdef->memorysnapshotfile) {
+ if (memdata && snapdef->memorysnapshotfile) {
virQEMUDriver *driver = ((qemuDomainObjPrivate *) vm->privateData)->driver;
- g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
+ g_autoptr(virDomainDef) savedef = NULL;
- *memsnapPath = snapdef->memorysnapshotfile;
- *memsnapFD = qemuDomainOpenFile(cfg, NULL, *memsnapPath, O_RDONLY, NULL);
+ memdata->path = snapdef->memorysnapshotfile;
+ memdata->fd = qemuSaveImageOpen(driver, NULL, memdata->path,
+ &savedef, &memdata->data,
+ false, NULL, false, false);
+
+ if (memdata->fd < 0)
+ return -1;
+
+ if (!virDomainDefCheckABIStability(savedef, domdef, driver->xmlopt))
+ return -1;
}
return 0;
@@ -2254,13 +2275,16 @@ qemuSnapshotRevertActive(virDomainObj *vm,
virObjectEvent *event = NULL;
virObjectEvent *event2 = NULL;
virDomainMomentObj *loadSnap = NULL;
- VIR_AUTOCLOSE memsnapFD = -1;
- char *memsnapPath = NULL;
int detail;
bool defined = false;
qemuDomainSaveCookie *cookie = (qemuDomainSaveCookie *) snapdef->cookie;
int rc;
g_autoptr(virDomainSnapshotDef) tmpsnapdef = NULL;
+ g_auto(qemuSnapshotRevertMemoryData) memdata = { -1, NULL, NULL };
+ g_autoptr(virCommand) cmd = NULL;
+ g_autofree char *errbuf = NULL;
+ VIR_AUTOCLOSE intermediatefd = -1;
+ int memrc = 0;
start_flags |= VIR_QEMU_PROCESS_START_PAUSED;
@@ -2284,7 +2308,7 @@ qemuSnapshotRevertActive(virDomainObj *vm,
if (qemuSnapshotRevertExternalPrepare(vm, tmpsnapdef, snap,
*config, *inactiveConfig,
- &memsnapFD, &memsnapPath) < 0) {
+ &memdata) < 0) {
return -1;
}
} else {
@@ -2298,6 +2322,30 @@ qemuSnapshotRevertActive(virDomainObj *vm,
virDomainObjAssignDef(vm, config, true, NULL);
+ if (virDomainSnapshotIsExternal(snap) && memdata.data) {
+ virQEMUSaveHeader *header = &memdata.data->header;
+
+ if (header && (header->version == 2) &&
+ (header->compressed != QEMU_SAVE_FORMAT_RAW)) {
+ if (!(cmd = qemuSaveImageGetCompressionCommand(header->compressed)))
+ return -1;
+
+ intermediatefd = memdata.fd;
+ memdata.fd = -1;
+
+ virCommandSetInputFD(cmd, intermediatefd);
+ virCommandSetOutputFD(cmd, &memdata.fd);
+ virCommandSetErrorBuffer(cmd, &errbuf);
+ virCommandDoAsyncIO(cmd);
+
+ if (virCommandRunAsync(cmd, NULL) < 0) {
+ memdata.fd = intermediatefd;
+ intermediatefd = -1;
+ return -1;
+ }
+ }
+ }
+
/* No cookie means libvirt which saved the domain was too old to
* mess up the CPU definitions.
*/
@@ -2307,17 +2355,48 @@ qemuSnapshotRevertActive(virDomainObj *vm,
rc = qemuProcessStart(snapshot->domain->conn, driver, vm,
cookie ? cookie->cpu : NULL,
- VIR_ASYNC_JOB_SNAPSHOT, NULL, memsnapFD,
- memsnapPath, loadSnap,
+ VIR_ASYNC_JOB_SNAPSHOT, "stdio",
+ memdata.fd, memdata.path, loadSnap,
VIR_NETDEV_VPORT_PROFILE_OP_CREATE,
start_flags);
+
+ if (virDomainSnapshotIsExternal(snap) && memdata.data) {
+ if (intermediatefd != -1) {
+ virErrorPtr orig_err = NULL;
+
+ if (rc < 0) {
+ /* if there was an error setting up qemu, the intermediate
+ * process will wait forever to write to stdout, so we
+ * must manually kill it and ignore any error related to
+ * the process
+ */
+ virErrorPreserveLast(&orig_err);
+ VIR_FORCE_CLOSE(intermediatefd);
+ VIR_FORCE_CLOSE(memdata.fd);
+ }
+
+ memrc = virCommandWait(cmd, NULL);
+ VIR_DEBUG("Decompression binary stderr: %s", NULLSTR(errbuf));
+ virErrorRestore(&orig_err);
+ }
+ if (VIR_CLOSE(memdata.fd) < 0) {
+ virReportSystemError(errno, _("cannot close file: %1$s"), memdata.path);
+ memrc = -1;
+ }
+
+ /* qemuProcessStart doesn't unset the qemu error reporting infrastructure
+ * in case of migration (which is used in this case) so we need to reset it
+ * so that the handle to virtlogd is not held open unnecessarily */
+ qemuMonitorSetDomainLog(qemuDomainGetMonitor(vm), NULL, NULL, NULL);
+ }
+
virDomainAuditStart(vm, "from-snapshot", rc >= 0);
detail = VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT;
event = virDomainEventLifecycleNewFromObj(vm,
VIR_DOMAIN_EVENT_STARTED,
detail);
virObjectEventStateQueue(driver->domainEventState, event);
- if (rc < 0)
+ if (rc < 0 || memrc < 0)
return -1;
@@ -2428,7 +2507,7 @@ qemuSnapshotRevertInactive(virDomainObj *vm,
if (qemuSnapshotRevertExternalPrepare(vm, tmpsnapdef, snap,
NULL, *inactiveConfig,
- NULL, NULL) < 0) {
+ NULL) < 0) {
return -1;
}
--
2.41.0
