On Tue, Mar 16, 2010 at 05:24:38PM +0000, Daniel P. Berrange wrote:
> With the QMP mode monitor, it is possible to get a notification
> when the guest is paused indirectly (eg as result of a disk IO
> error). This patch enables such reporting and when receiving an
> error updates libvirt's view of the guest to indicate that it is
> now paused. It also emits an event
>
> VIR_DOMAIN_EVENT_SUSPENDED
>
> with a detail of:
>
> VIR_DOMAIN_EVENT_SUSPENDED_IOERROR
>
> NB this patch does not make the error behaviour configurable. It
> just copes with the pause transition, if QEMU is setup to do that
> by default (current upstream now works this way for disks).
>
> * include/libvirt/libvirt.h.in: Add VIR_DOMAIN_EVENT_SUSPENDED_IOERROR
> * src/qemu/qemu_driver.c: Update VM state to paused when IO error
> occurrs
> * src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
> src/qemu/qemu_monitor_json.c: Wire up handlers for disk IO errors
> ---
> include/libvirt/libvirt.h.in | 1 +
> src/qemu/qemu_driver.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> src/qemu/qemu_monitor.c | 18 ++++++++++++++++++
> src/qemu/qemu_monitor.h | 16 ++++++++++++++++
> src/qemu/qemu_monitor_json.c | 34 ++++++++++++++++++++++++++++++++++
> 5 files changed, 111 insertions(+), 0 deletions(-)
>
> diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
> index 260505e..b7a6922 100644
> --- a/include/libvirt/libvirt.h.in
> +++ b/include/libvirt/libvirt.h.in
> @@ -1361,6 +1361,7 @@ typedef enum {
> typedef enum {
> VIR_DOMAIN_EVENT_SUSPENDED_PAUSED = 0, /* Normal suspend due to admin pause */
> VIR_DOMAIN_EVENT_SUSPENDED_MIGRATED = 1, /* Suspended for offline migration */
> + VIR_DOMAIN_EVENT_SUSPENDED_IOERROR = 2, /* Suspended due to a disk I/O error */
> } virDomainEventSuspendedDetailType;
>
> /**
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 8766ca2..ae19097 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -824,9 +824,51 @@ cleanup:
> return ret;
> }
>
> +
> +static int
> +qemuHandleDiskIOError(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
> + virDomainObjPtr vm,
> + int action,
> + const char *diskalias ATTRIBUTE_UNUSED)
> +{
> + struct qemud_driver *driver = qemu_driver;
> + virDomainEventPtr event = NULL;
> +
> + VIR_DEBUG("Received IO error on %p '%s': action=%d disk=%s", vm, vm->def->name, action, diskalias);
> +
> + if (action != QEMU_MONITOR_DISK_IO_ERROR_STOP)
> + return 0;
> +
> + virDomainObjLock(vm);
> +
> + if (action == QEMU_MONITOR_DISK_IO_ERROR_STOP &&
> + vm->state == VIR_DOMAIN_RUNNING) {
> + VIR_DEBUG("Transitioned guest %s to paused state", vm->def->name);
> +
> + vm->state = VIR_DOMAIN_PAUSED;
> + event = virDomainEventNewFromObj(vm,
> + VIR_DOMAIN_EVENT_SUSPENDED,
> + VIR_DOMAIN_EVENT_SUSPENDED_IOERROR);
> +
> + if (virDomainSaveStatus(driver->caps, driver->stateDir, vm) < 0)
> + VIR_WARN("Unable to save status on vm %s after IO error", vm->def->name);
> + }
> +
> + virDomainObjUnlock(vm);
> +
> + if (event) {
> + qemuDriverLock(driver);
> + qemuDomainEventQueue(driver, event);
> + qemuDriverUnlock(driver);
> + }
> + return 0;
> +}
> +
> +
> static qemuMonitorCallbacks monitorCallbacks = {
> .eofNotify = qemuHandleMonitorEOF,
> .diskSecretLookup = findVolumeQcowPassphrase,
> + .diskIOError = qemuHandleDiskIOError,
> };
>
> static int
> diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
> index b88532c..7205001 100644
> --- a/src/qemu/qemu_monitor.c
> +++ b/src/qemu/qemu_monitor.c
> @@ -791,6 +791,24 @@ int qemuMonitorEmitStop(qemuMonitorPtr mon)
> }
>
>
> +int qemuMonitorEmitDiskIOError(qemuMonitorPtr mon,
> + int action,
> + const char *deviceAlias)
> +{
> + int ret = -1;
> + VIR_DEBUG("mon=%p action=%d deviceAlias=%s", mon, action, deviceAlias);
> +
> + qemuMonitorRef(mon);
> + qemuMonitorUnlock(mon);
> + if (mon->cb && mon->cb->diskIOError)
> + ret = mon->cb->diskIOError(mon, mon->vm, action, deviceAlias);
> + qemuMonitorLock(mon);
> + qemuMonitorUnref(mon);
> +
> + return ret;
> +}
> +
> +
> int qemuMonitorSetCapabilities(qemuMonitorPtr mon)
> {
> int ret;
> diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
> index 0ac3957..75a2853 100644
> --- a/src/qemu/qemu_monitor.h
> +++ b/src/qemu/qemu_monitor.h
> @@ -60,6 +60,14 @@ struct _qemuMonitorMessage {
> void *passwordOpaque;
> };
>
> +typedef enum {
> + QEMU_MONITOR_DISK_IO_ERROR_STOP,
> + QEMU_MONITOR_DISK_IO_ERROR_REPORT,
> + QEMU_MONITOR_DISK_IO_ERROR_IGNORE,
> +
> + QEMU_MONITOR_DISK_IO_ERROR_LAST
> +} qemuMonitorDiskIOErrorAction;
> +
> typedef struct _qemuMonitorCallbacks qemuMonitorCallbacks;
> typedef qemuMonitorCallbacks *qemuMonitorCallbacksPtr;
> struct _qemuMonitorCallbacks {
> @@ -86,6 +94,11 @@ struct _qemuMonitorCallbacks {
> virDomainObjPtr vm);
> int (*domainStop)(qemuMonitorPtr mon,
> virDomainObjPtr vm);
> +
> + int (*diskIOError)(qemuMonitorPtr mon,
> + virDomainObjPtr vm,
> + int actOBion,
> + const char *diskAlias);
> };
>
>
> @@ -122,6 +135,9 @@ int qemuMonitorEmitShutdown(qemuMonitorPtr mon);
> int qemuMonitorEmitReset(qemuMonitorPtr mon);
> int qemuMonitorEmitPowerdown(qemuMonitorPtr mon);
> int qemuMonitorEmitStop(qemuMonitorPtr mon);
> +int qemuMonitorEmitDiskIOError(qemuMonitorPtr mon,
> + int action,
> + const char *deviceAlias);
>
> int qemuMonitorStartCPUs(qemuMonitorPtr mon,
> virConnectPtr conn);
> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
> index 7b45594..8b3cda1 100644
> --- a/src/qemu/qemu_monitor_json.c
> +++ b/src/qemu/qemu_monitor_json.c
> @@ -49,6 +49,7 @@ static void qemuMonitorJSONHandleShutdown(qemuMonitorPtr mon, virJSONValuePtr da
> static void qemuMonitorJSONHandleReset(qemuMonitorPtr mon, virJSONValuePtr data);
> static void qemuMonitorJSONHandlePowerdown(qemuMonitorPtr mon, virJSONValuePtr data);
> static void qemuMonitorJSONHandleStop(qemuMonitorPtr mon, virJSONValuePtr data);
> +static void qemuMonitorJSONHandleDiskIOError(qemuMonitorPtr mon, virJSONValuePtr data);
>
> struct {
> const char *type;
> @@ -58,6 +59,7 @@ struct {
> { "RESET", qemuMonitorJSONHandleReset, },
> { "POWERDOWN", qemuMonitorJSONHandlePowerdown, },
> { "STOP", qemuMonitorJSONHandleStop, },
> + { "BLOCK_IO_ERROR", qemuMonitorJSONHandleDiskIOError, },
> };
>
>
> @@ -496,6 +498,38 @@ static void qemuMonitorJSONHandleStop(qemuMonitorPtr mon, virJSONValuePtr data A
> }
>
>
> +VIR_ENUM_DECL(qemuMonitorDiskIOErrorAction)
> +VIR_ENUM_IMPL(qemuMonitorDiskIOErrorAction, QEMU_MONITOR_DISK_IO_ERROR_LAST,
> + "stop", "report", "ignore");
> +
> +
> +static void qemuMonitorJSONHandleDiskIOError(qemuMonitorPtr mon, virJSONValuePtr data)
> +{
> + const char *device;
> + const char *action;
> + int actionID;
> +
> + /* Throughout here we try our best to carry on upon errors,
> + since its imporatant to get as much info as possible out
> + to the application */
> +
> + if ((action = virJSONValueObjectGetString(data, "action")) == NULL) {
> + VIR_WARN0("Missing action in disk io error event");
> + action = "ignore";
> + }
> +
> + if ((device = virJSONValueObjectGetString(data, "device")) == NULL) {
> + VIR_WARN0("missing device in disk io error event");
> + }
> +
> + if ((actionID = qemuMonitorDiskIOErrorActionTypeFromString(action)) < 0) {
> + VIR_WARN("unknown disk io error action '%s'", action);
> + actionID = QEMU_MONITOR_DISK_IO_ERROR_IGNORE;
> + }
> +
> + qemuMonitorEmitDiskIOError(mon, actionID, device);
> +}
> +
> int
> qemuMonitorJSONSetCapabilities(qemuMonitorPtr mon)
> {
ACK,
important, please push :-)
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel@xxxxxxxxxxxx | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list