7 p.m.
There are two classes of management apps that track events - one
that only cares about on/off (and only needs to track EVENT_STARTED
and EVENT_STOPPED), and one that cares about paused/running (also
tracks EVENT_SUSPENDED/EVENT_RESUMED). To keep both classes happy,
any transition that can go from inactive to paused must emit two
back-to-back events - one for started and one for suspended (since
later resuming of the domain will only send RESUMED, but the first
class isn't tracking that).
This also fixes a bug where virDomainCreateWithFlags with the
VIR_DOMAIN_START_PAUSED flag failed to start paused when restoring
from a managed save image.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_EVENT_SUSPENDED_RESTORED)
(VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT)
(VIR_DOMAIN_EVENT_RESUMED_FROM_SNAPSHOT): New sub-events.
* src/qemu/qemu_driver.c (qemuDomainRevertToSnapshot): Use them.
(qemuDomainSaveImageStartVM): Likewise, and add parameter.
(qemudDomainCreate, qemuDomainObjStart): Send suspended event when
starting paused.
(qemuDomainObjRestore): Add parameter.
(qemuDomainObjStart, qemuDomainRestoreFlags): Update callers.
* examples/domain-events/events-c/event-test.c
(eventDetailToString): Map new detail strings.
---
I think this addresses Dan's findings about events related to state
transitions. It turned a 13-line v3 into a 109-line patch. I'll
repost my entire snapshot series as v4 once I finish rebasing on
top of this (since I know it introduces some merge conflicts with
later patches in the series).
examples/domain-events/events-c/event-test.c | 37 +++++++++++++--
include/libvirt/libvirt.h.in | 6 ++-
src/qemu/qemu_driver.c | 66 +++++++++++++++++++++-----
3 files changed, 90 insertions(+), 19 deletions(-)
diff --git a/examples/domain-events/events-c/event-test.c
b/examples/domain-events/events-c/event-test.c
index 4766a0d..6a3ed26 100644
--- a/examples/domain-events/events-c/event-test.c
+++ b/examples/domain-events/events-c/event-test.c
@@ -87,19 +87,45 @@ static const char *eventDetailToString(int event, int detail) {
case VIR_DOMAIN_EVENT_STARTED_RESTORED:
ret = "Restored";
break;
+ case VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT:
+ ret = "Snapshot";
+ break;
}
break;
case VIR_DOMAIN_EVENT_SUSPENDED:
- if (detail == VIR_DOMAIN_EVENT_SUSPENDED_PAUSED)
+ switch (detail) {
+ case VIR_DOMAIN_EVENT_SUSPENDED_PAUSED:
ret = "Paused";
- else if (detail == VIR_DOMAIN_EVENT_SUSPENDED_MIGRATED)
+ break;
+ case VIR_DOMAIN_EVENT_SUSPENDED_MIGRATED:
ret = "Migrated";
+ break;
+ case VIR_DOMAIN_EVENT_SUSPENDED_IOERROR:
+ ret = "I/O Error";
+ break;
+ case VIR_DOMAIN_EVENT_SUSPENDED_WATCHDOG:
+ ret = "Watchdog";
+ break;
+ case VIR_DOMAIN_EVENT_SUSPENDED_RESTORED:
+ ret = "Restored";
+ break;
+ case VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT:
+ ret = "Snapshot";
+ break;
+ }
break;
case VIR_DOMAIN_EVENT_RESUMED:
- if (detail == VIR_DOMAIN_EVENT_RESUMED_UNPAUSED)
+ switch (detail) {
+ case VIR_DOMAIN_EVENT_RESUMED_UNPAUSED:
ret = "Unpaused";
- else if (detail == VIR_DOMAIN_EVENT_RESUMED_MIGRATED)
+ break;
+ case VIR_DOMAIN_EVENT_RESUMED_MIGRATED:
ret = "Migrated";
+ break;
+ case VIR_DOMAIN_EVENT_RESUMED_FROM_SNAPSHOT:
+ ret = "Snapshot";
+ break;
+ }
break;
case VIR_DOMAIN_EVENT_STOPPED:
switch (detail) {
@@ -121,6 +147,9 @@ static const char *eventDetailToString(int event, int detail) {
case VIR_DOMAIN_EVENT_STOPPED_FAILED:
ret = "Failed";
break;
+ case VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT:
+ ret = "Snapshot";
+ break;
}
break;
}
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 53a2f7d..edd197c 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -116,8 +116,7 @@ typedef enum {
VIR_DOMAIN_PAUSED_DUMP = 4, /* paused for offline core dump */
VIR_DOMAIN_PAUSED_IOERROR = 5, /* paused due to a disk I/O error */
VIR_DOMAIN_PAUSED_WATCHDOG = 6, /* paused due to a watchdog event */
- VIR_DOMAIN_PAUSED_FROM_SNAPSHOT = 7, /* restored from a snapshot which was
- * taken while domain was paused */
+ VIR_DOMAIN_PAUSED_FROM_SNAPSHOT = 7, /* paused after restoring from snapshot */
} virDomainPausedReason;
typedef enum {
@@ -2024,6 +2023,8 @@ typedef enum {
VIR_DOMAIN_EVENT_SUSPENDED_MIGRATED = 1, /* Suspended for offline migration */
VIR_DOMAIN_EVENT_SUSPENDED_IOERROR = 2, /* Suspended due to a disk I/O error */
VIR_DOMAIN_EVENT_SUSPENDED_WATCHDOG = 3, /* Suspended due to a watchdog firing */
+ VIR_DOMAIN_EVENT_SUSPENDED_RESTORED = 4, /* Restored from paused state file */
+ VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT = 5, /* Restored from paused snapshot */
} virDomainEventSuspendedDetailType;
/**
@@ -2034,6 +2035,7 @@ typedef enum {
typedef enum {
VIR_DOMAIN_EVENT_RESUMED_UNPAUSED = 0, /* Normal resume due to admin unpause */
VIR_DOMAIN_EVENT_RESUMED_MIGRATED = 1, /* Resumed for completion of migration */
+ VIR_DOMAIN_EVENT_RESUMED_FROM_SNAPSHOT = 2, /* Resumed from snapshot */
} virDomainEventResumedDetailType;
/**
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 737eec8..6becd31 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -1268,6 +1268,7 @@ static virDomainPtr qemudDomainCreate(virConnectPtr conn, const char
*xml,
virDomainObjPtr vm = NULL;
virDomainPtr dom = NULL;
virDomainEventPtr event = NULL;
+ virDomainEventPtr event2 = NULL;
virCheckFlags(VIR_DOMAIN_START_PAUSED |
VIR_DOMAIN_START_AUTODESTROY, NULL);
@@ -1315,6 +1316,16 @@ static virDomainPtr qemudDomainCreate(virConnectPtr conn, const
char *xml,
event = virDomainEventNewFromObj(vm,
VIR_DOMAIN_EVENT_STARTED,
VIR_DOMAIN_EVENT_STARTED_BOOTED);
+ if (event && (flags & VIR_DOMAIN_START_PAUSED)) {
+ /* There are two classes of event-watching clients - those
+ * that only care about on/off (and must see a started event
+ * no matter what, but don't care about suspend events), and
+ * those that also care about running/paused. To satisfy both
+ * client types, we have to send two events. */
+ event2 = virDomainEventNewFromObj(vm,
+ VIR_DOMAIN_EVENT_SUSPENDED,
+ VIR_DOMAIN_EVENT_SUSPENDED_PAUSED);
+ }
virDomainAuditStart(vm, "booted", true);
dom = virGetDomain(conn, vm->def->name, vm->def->uuid);
@@ -1328,8 +1339,11 @@ cleanup:
virDomainDefFree(def);
if (vm)
virDomainObjUnlock(vm);
- if (event)
+ if (event) {
qemuDomainEventQueue(driver, event);
+ if (event2)
+ qemuDomainEventQueue(driver, event2);
+ }
qemuDriverUnlock(driver);
return dom;
}
@@ -3890,7 +3904,8 @@ qemuDomainSaveImageStartVM(virConnectPtr conn,
virDomainObjPtr vm,
int *fd,
const struct qemud_save_header *header,
- const char *path)
+ const char *path,
+ bool start_paused)
{
int ret = -1;
virDomainEventPtr event;
@@ -3961,8 +3976,8 @@ qemuDomainSaveImageStartVM(virConnectPtr conn,
qemuDomainEventQueue(driver, event);
- /* If it was running before, resume it now. */
- if (header->was_running) {
+ /* If it was running before, resume it now unless caller requested pause. */
+ if (header->was_running && !start_paused) {
if (qemuProcessStartCPUs(driver, vm, conn,
VIR_DOMAIN_RUNNING_RESTORED,
QEMU_ASYNC_JOB_NONE) < 0) {
@@ -3975,6 +3990,14 @@ qemuDomainSaveImageStartVM(virConnectPtr conn,
VIR_WARN("Failed to save status on vm %s", vm->def->name);
goto out;
}
+ } else {
+ int detail = (start_paused ? VIR_DOMAIN_EVENT_SUSPENDED_PAUSED :
+ VIR_DOMAIN_EVENT_SUSPENDED_RESTORED);
+ event = virDomainEventNewFromObj(vm,
+ VIR_DOMAIN_EVENT_SUSPENDED,
+ detail);
+ if (event)
+ qemuDomainEventQueue(driver, event);
}
ret = 0;
@@ -4026,7 +4049,8 @@ qemuDomainRestoreFlags(virConnectPtr conn,
if (qemuDomainObjBeginJobWithDriver(driver, vm, QEMU_JOB_MODIFY) < 0)
goto cleanup;
- ret = qemuDomainSaveImageStartVM(conn, driver, vm, &fd, &header, path);
+ ret = qemuDomainSaveImageStartVM(conn, driver, vm, &fd, &header, path,
+ false);
if (virFileDirectFdClose(directFd) < 0)
VIR_WARN("Failed to close %s", path);
@@ -4151,6 +4175,7 @@ qemuDomainObjRestore(virConnectPtr conn,
struct qemud_driver *driver,
virDomainObjPtr vm,
const char *path,
+ bool start_paused,
bool bypass_cache)
{
virDomainDefPtr def = NULL;
@@ -4181,7 +4206,8 @@ qemuDomainObjRestore(virConnectPtr conn,
virDomainObjAssignDef(vm, def, true);
def = NULL;
- ret = qemuDomainSaveImageStartVM(conn, driver, vm, &fd, &header, path);
+ ret = qemuDomainSaveImageStartVM(conn, driver, vm, &fd, &header, path,
+ start_paused);
if (virFileDirectFdClose(directFd) < 0)
VIR_WARN("Failed to close %s", path);
@@ -4459,7 +4485,7 @@ qemuDomainObjStart(virConnectPtr conn,
if (virFileExists(managed_save)) {
ret = qemuDomainObjRestore(conn, driver, vm, managed_save,
- bypass_cache);
+ start_paused, bypass_cache);
if ((ret == 0) && (unlink(managed_save) < 0))
VIR_WARN("Failed to remove the managed state %s", managed_save);
@@ -4475,8 +4501,16 @@ qemuDomainObjStart(virConnectPtr conn,
virDomainEventNewFromObj(vm,
VIR_DOMAIN_EVENT_STARTED,
VIR_DOMAIN_EVENT_STARTED_BOOTED);
- if (event)
+ if (event) {
qemuDomainEventQueue(driver, event);
+ if (start_paused) {
+ event = virDomainEventNewFromObj(vm,
+ VIR_DOMAIN_EVENT_SUSPENDED,
+ VIR_DOMAIN_EVENT_SUSPENDED_PAUSED);
+ if (event)
+ qemuDomainEventQueue(driver, event);
+ }
+ }
}
cleanup:
@@ -8744,6 +8778,7 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr
snapshot,
virDomainSnapshotObjPtr snap = NULL;
char uuidstr[VIR_UUID_STRING_BUFLEN];
virDomainEventPtr event = NULL;
+ virDomainEventPtr event2 = NULL;
qemuDomainObjPrivatePtr priv;
int rc;
@@ -8800,6 +8835,9 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr
snapshot,
goto endjob;
}
+ event = virDomainEventNewFromObj(vm,
+ VIR_DOMAIN_EVENT_STARTED,
+ VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT);
if (snap->def->state == VIR_DOMAIN_PAUSED) {
/* qemu unconditionally starts the domain running again after
* loadvm, so let's pause it to keep consistency
@@ -8810,14 +8848,13 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr
snapshot,
QEMU_ASYNC_JOB_NONE);
if (rc < 0)
goto endjob;
+ event2 = virDomainEventNewFromObj(vm,
+ VIR_DOMAIN_EVENT_SUSPENDED,
+ VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT);
} else {
virDomainObjSetState(vm, VIR_DOMAIN_RUNNING,
VIR_DOMAIN_RUNNING_FROM_SNAPSHOT);
}
-
- event = virDomainEventNewFromObj(vm,
- VIR_DOMAIN_EVENT_STARTED,
- VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT);
} else {
/* qemu is a little funny with running guests and the restoration
* of snapshots. If the snapshot was taken online,
@@ -8860,8 +8897,11 @@ cleanup:
} else if (snap) {
snap->def->current = false;
}
- if (event)
+ if (event) {
qemuDomainEventQueue(driver, event);
+ if (event2)
+ qemuDomainEventQueue(driver, event2);
+ }
if (vm)
virDomainObjUnlock(vm);
qemuDriverUnlock(driver);
--
1.7.4.4