10:12 a.m.
The code that saves domain memory by migration to file can be reused
while doing external snapshots of a machine. This patch extracts the
common code and places it in a separate function.
---
src/qemu/qemu_driver.c | 225 ++++++++++++++++++++++++++++---------------------
1 file changed, 127 insertions(+), 98 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index df02783..025633f 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2605,7 +2605,7 @@ bswap_header(struct qemud_save_header *hdr) {
/* return -errno on failure, or 0 on success */
static int
-qemuDomainSaveHeader(int fd, const char *path, char *xml,
+qemuDomainSaveHeader(int fd, const char *path, const char *xml,
struct qemud_save_header *header)
{
int ret = 0;
@@ -2752,98 +2752,38 @@ cleanup:
return fd;
}
-/* This internal function expects the driver lock to already be held on
- * entry and the vm must be active + locked. Vm will be unlocked and
- * potentially free'd after this returns (eg transient VMs are freed
- * shutdown). So 'vm' must not be referenced by the caller after
- * this returns (whether returning success or failure).
- */
+/* Helper function to execute a migration to file with a correct save header
+ * the caller needs to make sure that the processors are stopped and do all other
+ * actions besides saving memory */
static int
-qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
- virDomainObjPtr vm, const char *path,
- int compressed, const char *xmlin, unsigned int flags)
+qemuDomainSaveMemory(struct qemud_driver *driver,
+ virDomainObjPtr vm,
+ const char *path,
+ const char *xml,
+ int compressed,
+ bool was_running,
+ unsigned int flags,
+ enum qemuDomainAsyncJob asyncJob)
{
- char *xml = NULL;
struct qemud_save_header header;
bool bypassSecurityDriver = false;
- int ret = -1;
- int rc;
- virDomainEventPtr event = NULL;
- qemuDomainObjPrivatePtr priv;
bool needUnlink = false;
- size_t len;
- unsigned long long offset;
- unsigned long long pad;
+ int ret = -1;
int fd = -1;
int directFlag = 0;
virFileWrapperFdPtr wrapperFd = NULL;
unsigned int wrapperFlags = VIR_FILE_WRAPPER_NON_BLOCKING;
-
- if (qemuProcessAutoDestroyActive(driver, vm)) {
- virReportError(VIR_ERR_OPERATION_INVALID,
- "%s", _("domain is marked for auto
destroy"));
- goto cleanup;
- }
+ unsigned long long pad;
+ unsigned long long offset;
+ size_t len;
memset(&header, 0, sizeof(header));
memcpy(header.magic, QEMUD_SAVE_PARTIAL, sizeof(header.magic));
header.version = QEMUD_SAVE_VERSION;
+ header.was_running = was_running ? 1 : 0;
header.compressed = compressed;
- priv = vm->privateData;
-
- if (qemuDomainObjBeginAsyncJobWithDriver(driver, vm,
- QEMU_ASYNC_JOB_SAVE) < 0)
- goto cleanup;
-
- memset(&priv->job.info, 0, sizeof(priv->job.info));
- priv->job.info.type = VIR_DOMAIN_JOB_UNBOUNDED;
-
- /* Pause */
- if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING) {
- header.was_running = 1;
- if (qemuProcessStopCPUs(driver, vm, VIR_DOMAIN_PAUSED_SAVE,
- QEMU_ASYNC_JOB_SAVE) < 0)
- goto endjob;
-
- if (!virDomainObjIsActive(vm)) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("guest unexpectedly quit"));
- goto endjob;
- }
- }
- /* libvirt.c already guaranteed these two flags are exclusive. */
- if (flags & VIR_DOMAIN_SAVE_RUNNING)
- header.was_running = 1;
- else if (flags & VIR_DOMAIN_SAVE_PAUSED)
- header.was_running = 0;
-
- /* Get XML for the domain. Restore needs only the inactive xml,
- * including secure. We should get the same result whether xmlin
- * is NULL or whether it was the live xml of the domain moments
- * before. */
- if (xmlin) {
- virDomainDefPtr def = NULL;
-
- if (!(def = virDomainDefParseString(driver->caps, xmlin,
- QEMU_EXPECTED_VIRT_TYPES,
- VIR_DOMAIN_XML_INACTIVE))) {
- goto endjob;
- }
- if (!virDomainDefCheckABIStability(vm->def, def)) {
- virDomainDefFree(def);
- goto endjob;
- }
- xml = qemuDomainDefFormatLive(driver, def, true, true);
- } else {
- xml = qemuDomainDefFormatLive(driver, vm->def, true, true);
- }
- if (!xml) {
- virReportError(VIR_ERR_OPERATION_FAILED,
- "%s", _("failed to get domain xml"));
- goto endjob;
- }
len = strlen(xml) + 1;
offset = sizeof(header) + len;
@@ -2860,7 +2800,7 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
((offset + pad) % QEMU_MONITOR_MIGRATE_TO_FILE_BS));
if (VIR_EXPAND_N(xml, len, pad) < 0) {
virReportOOMError();
- goto endjob;
+ goto cleanup;
}
offset += pad;
header.xml_len = len;
@@ -2878,22 +2818,21 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
fd = qemuOpenFile(driver, path, O_WRONLY | O_TRUNC | O_CREAT | directFlag,
&needUnlink, &bypassSecurityDriver);
if (fd < 0)
- goto endjob;
+ goto cleanup;
+
if (!(wrapperFd = virFileWrapperFdNew(&fd, path, wrapperFlags)))
- goto endjob;
+ goto cleanup;
/* Write header to file, followed by XML */
- if (qemuDomainSaveHeader(fd, path, xml, &header) < 0) {
- VIR_FORCE_CLOSE(fd);
- goto endjob;
- }
+ if (qemuDomainSaveHeader(fd, path, xml, &header) < 0)
+ goto cleanup;
/* Perform the migration */
if (qemuMigrationToFile(driver, vm, fd, offset, path,
qemuCompressProgramName(compressed),
bypassSecurityDriver,
- QEMU_ASYNC_JOB_SAVE) < 0)
- goto endjob;
+ asyncJob) < 0)
+ goto cleanup;
/* Touch up file header to mark image complete. */
@@ -2903,26 +2842,120 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
* that's acceptable. */
if (VIR_CLOSE(fd) < 0) {
virReportSystemError(errno, _("unable to close %s"), path);
- goto endjob;
+ goto cleanup;
}
+
if (virFileWrapperFdClose(wrapperFd) < 0)
- goto endjob;
- fd = qemuOpenFile(driver, path, O_WRONLY, NULL, NULL);
- if (fd < 0)
- goto endjob;
+ goto cleanup;
+
+ if ((fd = qemuOpenFile(driver, path, O_WRONLY, NULL, NULL)) < 0)
+ goto cleanup;
memcpy(header.magic, QEMUD_SAVE_MAGIC, sizeof(header.magic));
+
if (safewrite(fd, &header, sizeof(header)) != sizeof(header)) {
virReportSystemError(errno, _("unable to write %s"), path);
- goto endjob;
+ goto cleanup;
}
+
if (VIR_CLOSE(fd) < 0) {
virReportSystemError(errno, _("unable to close %s"), path);
- goto endjob;
+ goto cleanup;
}
ret = 0;
+cleanup:
+ VIR_FORCE_CLOSE(fd);
+ virFileWrapperFdFree(wrapperFd);
+
+ if (ret != 0 && needUnlink)
+ unlink(path);
+
+ return ret;
+}
+
+/* This internal function expects the driver lock to already be held on
+ * entry and the vm must be active + locked. Vm will be unlocked and
+ * potentially free'd after this returns (eg transient VMs are freed
+ * shutdown). So 'vm' must not be referenced by the caller after
+ * this returns (whether returning success or failure).
+ */
+static int
+qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
+ virDomainObjPtr vm, const char *path,
+ int compressed, const char *xmlin, unsigned int flags)
+{
+ char *xml = NULL;
+ bool was_running = false;
+ int ret = -1;
+ int rc;
+ virDomainEventPtr event = NULL;
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+
+ if (qemuProcessAutoDestroyActive(driver, vm)) {
+ virReportError(VIR_ERR_OPERATION_INVALID,
+ "%s", _("domain is marked for auto
destroy"));
+ goto cleanup;
+ }
+
+ if (qemuDomainObjBeginAsyncJobWithDriver(driver, vm,
+ QEMU_ASYNC_JOB_SAVE) < 0)
+
+ memset(&priv->job.info, 0, sizeof(priv->job.info));
+ priv->job.info.type = VIR_DOMAIN_JOB_UNBOUNDED;
+
+ /* Pause */
+ if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING) {
+ was_running = true;
+ if (qemuProcessStopCPUs(driver, vm, VIR_DOMAIN_PAUSED_SAVE,
+ QEMU_ASYNC_JOB_SAVE) < 0)
+ goto endjob;
+
+ if (!virDomainObjIsActive(vm)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("guest unexpectedly quit"));
+ goto endjob;
+ }
+ }
+
+ /* libvirt.c already guaranteed these two flags are exclusive. */
+ if (flags & VIR_DOMAIN_SAVE_RUNNING)
+ was_running = true;
+ else if (flags & VIR_DOMAIN_SAVE_PAUSED)
+ was_running = false;
+
+ /* Get XML for the domain. Restore needs only the inactive xml,
+ * including secure. We should get the same result whether xmlin
+ * is NULL or whether it was the live xml of the domain moments
+ * before. */
+ if (xmlin) {
+ virDomainDefPtr def = NULL;
+
+ if (!(def = virDomainDefParseString(driver->caps, xmlin,
+ QEMU_EXPECTED_VIRT_TYPES,
+ VIR_DOMAIN_XML_INACTIVE))) {
+ goto endjob;
+ }
+ if (!virDomainDefCheckABIStability(vm->def, def)) {
+ virDomainDefFree(def);
+ goto endjob;
+ }
+ xml = qemuDomainDefFormatLive(driver, def, true, true);
+ } else {
+ xml = qemuDomainDefFormatLive(driver, vm->def, true, true);
+ }
+ if (!xml) {
+ virReportError(VIR_ERR_OPERATION_FAILED,
+ "%s", _("failed to get domain xml"));
+ goto endjob;
+ }
+
+ ret = qemuDomainSaveMemory(driver, vm, path, xml, compressed,
+ was_running, flags, QEMU_ASYNC_JOB_SAVE);
+ if (ret < 0)
+ goto endjob;
+
/* Shut it down */
qemuProcessStop(driver, vm, VIR_DOMAIN_SHUTOFF_SAVED, 0);
virDomainAuditStop(vm, "saved");
@@ -2938,7 +2971,7 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr
dom,
endjob:
if (vm) {
if (ret != 0) {
- if (header.was_running && virDomainObjIsActive(vm)) {
+ if (was_running && virDomainObjIsActive(vm)) {
rc = qemuProcessStartCPUs(driver, vm, dom->conn,
VIR_DOMAIN_RUNNING_SAVE_CANCELED,
QEMU_ASYNC_JOB_SAVE);
@@ -2951,11 +2984,7 @@ endjob:
}
cleanup:
- VIR_FORCE_CLOSE(fd);
- virFileWrapperFdFree(wrapperFd);
VIR_FREE(xml);
- if (ret != 0 && needUnlink)
- unlink(path);
if (event)
qemuDomainEventQueue(driver, event);
if (vm)
--
1.7.12.4