[libvirt] [PATCH] Support reboots with the QEMU driver
Wen Congyang
wency at cn.fujitsu.com
Fri Jun 17 02:52:03 UTC 2011
At 06/16/2011 01:06 AM, Daniel P. Berrange Write:
> For controlled shutdown we issue a 'system_powerdown' command
> to the QEMU monitor. This triggers an ACPI event which (most)
> guest OS wire up to a controlled shutdown. There is no equiv
> ACPI event to trigger a controlled reboot. This patch attempts
> to fake a reboot.
>
> - In qemuDomainObjPrivatePtr we have a bool fakeReboot
> flag.
> - The virDomainReboot method sets this flag and then
> triggers a normal 'system_powerdown'.
> - The QEMU process is started with '-no-shutdown'
> so that the guest CPUs pause when it powers off the
> guest
> - When we receive the 'POWEROFF' event from QEMU JSON
> monitor if fakeReboot is not set we invoke the
> qemuProcessKill command and shutdown continues
> normally
> - If fakeReboot was set, we spawn a background thread
> which issues 'system_reset' to perform a warm reboot
> of the guest hardware. Then it issues 'cont' to
> start the CPUs again
>
> * src/qemu/qemu_command.c: Add -no-shutdown flag if
> we have JSON support
> * src/qemu/qemu_domain.h: Add 'fakeReboot' flag to
> qemuDomainObjPrivate struct
> * src/qemu/qemu_driver.c: Fake reboot using the
> system_powerdown command if JSON support is available
> * src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
> src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
> src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
> binding for system_reset command
> * src/qemu/qemu_process.c: Reset the guest & start CPUs if
> fakeReboot is set
> ---
> src/qemu/qemu_command.c | 7 +++
> src/qemu/qemu_domain.h | 2 +
> src/qemu/qemu_driver.c | 65 ++++++++++++++++++++++++++++-
> src/qemu/qemu_monitor.c | 19 ++++++++
> src/qemu/qemu_monitor.h | 1 +
> src/qemu/qemu_monitor_json.c | 19 ++++++++
> src/qemu/qemu_monitor_json.h | 1 +
> src/qemu/qemu_monitor_text.c | 13 ++++++
> src/qemu/qemu_monitor_text.h | 1 +
> src/qemu/qemu_process.c | 95 +++++++++++++++++++++++++++++++++++++++++-
> 10 files changed, 220 insertions(+), 3 deletions(-)
>
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index 6346243..9ae1409 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -3207,6 +3207,13 @@ qemuBuildCommandLine(virConnectPtr conn,
> def->onReboot != VIR_DOMAIN_LIFECYCLE_RESTART)
> virCommandAddArg(cmd, "-no-reboot");
>
> + /* If JSON monitor is enabled, we can receive an event
> + * when QEMU stops. If we use no-shutdown, then we can
> + * watch for this event and do a soft/warm reboot.
> + */
> + if (monitor_json)
> + virCommandAddArg(cmd, "-no-shutdown");
> +
> if (!(def->features & (1 << VIR_DOMAIN_FEATURE_ACPI)))
> virCommandAddArg(cmd, "-no-acpi");
>
> diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
> index bacf5b5..b8469b6 100644
> --- a/src/qemu/qemu_domain.h
> +++ b/src/qemu/qemu_domain.h
> @@ -89,6 +89,8 @@ struct _qemuDomainObjPrivate {
>
> virBitmapPtr qemuCaps;
> char *lockState;
> +
> + bool fakeReboot;
> };
>
> struct qemuDomainWatchdogEvent
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 853c84c..4c827cf 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -1429,7 +1429,7 @@ cleanup:
> }
>
>
> -static int qemudDomainShutdown(virDomainPtr dom) {
> +static int qemuDomainShutdown(virDomainPtr dom) {
> struct qemud_driver *driver = dom->conn->privateData;
> virDomainObjPtr vm;
> int ret = -1;
> @@ -1461,6 +1461,8 @@ static int qemudDomainShutdown(virDomainPtr dom) {
> ret = qemuMonitorSystemPowerdown(priv->mon);
> qemuDomainObjExitMonitor(vm);
>
> + priv->fakeReboot = false;
> +
> endjob:
> if (qemuDomainObjEndJob(vm) == 0)
> vm = NULL;
> @@ -1472,11 +1474,66 @@ cleanup:
> }
>
>
> +static int qemuDomainReboot(virDomainPtr dom, unsigned int flags ATTRIBUTE_UNUSED) {
> + struct qemud_driver *driver = dom->conn->privateData;
> + virDomainObjPtr vm;
> + int ret = -1;
> + qemuDomainObjPrivatePtr priv;
> +
> + qemuDriverLock(driver);
> + vm = virDomainFindByUUID(&driver->domains, dom->uuid);
> + qemuDriverUnlock(driver);
> +
> + if (!vm) {
> + char uuidstr[VIR_UUID_STRING_BUFLEN];
> + virUUIDFormat(dom->uuid, uuidstr);
> + qemuReportError(VIR_ERR_NO_DOMAIN,
> + _("no domain with matching uuid '%s'"), uuidstr);
> + goto cleanup;
> + }
> + priv = vm->privateData;
> +
> +#if HAVE_YAJL
> + if (qemuCapsGet(priv->qemuCaps, QEMU_CAPS_MONITOR_JSON)) {
> + if (qemuDomainObjBeginJob(vm) < 0)
> + goto cleanup;
> +
> + if (!virDomainObjIsActive(vm)) {
> + qemuReportError(VIR_ERR_OPERATION_INVALID,
> + "%s", _("domain is not running"));
> + goto endjob;
> + }
> +
> + qemuDomainObjEnterMonitor(vm);
> + ret = qemuMonitorSystemPowerdown(priv->mon);
> + qemuDomainObjExitMonitor(vm);
> +
> + priv->fakeReboot = true;
> +
> + endjob:
> + if (qemuDomainObjEndJob(vm) == 0)
> + vm = NULL;
> + } else {
> +#endif
> + qemuReportError(VIR_ERR_NO_SUPPORT, "%s",
> + _("Reboot is not supported without the JSON monitor"));
> +#if HAVE_YAJL
> + }
> +#endif
> +
> +cleanup:
> + if (vm)
> + virDomainObjUnlock(vm);
> + return ret;
> +}
> +
> +
> static int qemudDomainDestroy(virDomainPtr dom) {
> struct qemud_driver *driver = dom->conn->privateData;
> virDomainObjPtr vm;
> int ret = -1;
> virDomainEventPtr event = NULL;
> + qemuDomainObjPrivatePtr priv;
>
> qemuDriverLock(driver);
> vm = virDomainFindByUUID(&driver->domains, dom->uuid);
> @@ -1488,6 +1545,9 @@ static int qemudDomainDestroy(virDomainPtr dom) {
> goto cleanup;
> }
>
> + priv = vm->privateData;
> + priv->fakeReboot = false;
> +
> /* Although qemuProcessStop does this already, there may
> * be an outstanding job active. We want to make sure we
> * can kill the process even if a job is active. Killing
> @@ -8146,7 +8206,8 @@ static virDriver qemuDriver = {
> .domainLookupByName = qemudDomainLookupByName, /* 0.2.0 */
> .domainSuspend = qemudDomainSuspend, /* 0.2.0 */
> .domainResume = qemudDomainResume, /* 0.2.0 */
> - .domainShutdown = qemudDomainShutdown, /* 0.2.0 */
> + .domainShutdown = qemuDomainShutdown, /* 0.2.0 */
> + .domainReboot = qemuDomainReboot, /* 0.9.3 */
> .domainDestroy = qemudDomainDestroy, /* 0.2.0 */
> .domainGetOSType = qemudDomainGetOSType, /* 0.2.2 */
> .domainGetMaxMemory = qemudDomainGetMaxMemory, /* 0.4.2 */
> diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
> index 1428921..1dafc4b 100644
> --- a/src/qemu/qemu_monitor.c
> +++ b/src/qemu/qemu_monitor.c
> @@ -1096,6 +1096,25 @@ int qemuMonitorSystemPowerdown(qemuMonitorPtr mon)
> }
>
>
> +int qemuMonitorSystemReset(qemuMonitorPtr mon)
> +{
> + int ret;
> + VIR_DEBUG("mon=%p", mon);
> +
> + if (!mon) {
> + qemuReportError(VIR_ERR_INVALID_ARG, "%s",
> + _("monitor must not be NULL"));
> + return -1;
> + }
> +
> + if (mon->json)
> + ret = qemuMonitorJSONSystemReset(mon);
> + else
> + ret = qemuMonitorTextSystemReset(mon);
> + return ret;
> +}
> +
> +
> int qemuMonitorGetCPUInfo(qemuMonitorPtr mon,
> int **pids)
> {
> diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
> index 3bb0269..ae74a3c 100644
> --- a/src/qemu/qemu_monitor.h
> +++ b/src/qemu/qemu_monitor.h
> @@ -194,6 +194,7 @@ int qemuMonitorStartCPUs(qemuMonitorPtr mon,
> int qemuMonitorStopCPUs(qemuMonitorPtr mon);
> int qemuMonitorGetStatus(qemuMonitorPtr mon, bool *running);
>
> +int qemuMonitorSystemReset(qemuMonitorPtr mon);
> int qemuMonitorSystemPowerdown(qemuMonitorPtr mon);
>
> int qemuMonitorGetCPUInfo(qemuMonitorPtr mon,
> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
> index 56ec65b..6cc6ea7 100644
> --- a/src/qemu/qemu_monitor_json.c
> +++ b/src/qemu/qemu_monitor_json.c
> @@ -947,6 +947,25 @@ int qemuMonitorJSONSystemPowerdown(qemuMonitorPtr mon)
> }
>
>
> +int qemuMonitorJSONSystemReset(qemuMonitorPtr mon)
> +{
> + int ret;
> + virJSONValuePtr cmd = qemuMonitorJSONMakeCommand("system_reset", NULL);
> + virJSONValuePtr reply = NULL;
> + if (!cmd)
> + return -1;
> +
> + ret = qemuMonitorJSONCommand(mon, cmd, &reply);
> +
> + if (ret == 0)
> + ret = qemuMonitorJSONCheckError(cmd, reply);
> +
> + virJSONValueFree(cmd);
> + virJSONValueFree(reply);
> + return ret;
> +}
> +
> +
> /*
> * [ { "CPU": 0, "current": true, "halted": false, "pc": 3227107138 },
> * { "CPU": 1, "current": false, "halted": true, "pc": 7108165 } ]
> diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
> index 393d8fc..a72bf7c 100644
> --- a/src/qemu/qemu_monitor_json.h
> +++ b/src/qemu/qemu_monitor_json.h
> @@ -49,6 +49,7 @@ int qemuMonitorJSONStopCPUs(qemuMonitorPtr mon);
> int qemuMonitorJSONGetStatus(qemuMonitorPtr mon, bool *running);
>
> int qemuMonitorJSONSystemPowerdown(qemuMonitorPtr mon);
> +int qemuMonitorJSONSystemReset(qemuMonitorPtr mon);
>
> int qemuMonitorJSONGetCPUInfo(qemuMonitorPtr mon,
> int **pids);
> diff --git a/src/qemu/qemu_monitor_text.c b/src/qemu/qemu_monitor_text.c
> index a16ea91..67333aa 100644
> --- a/src/qemu/qemu_monitor_text.c
> +++ b/src/qemu/qemu_monitor_text.c
> @@ -417,6 +417,19 @@ int qemuMonitorTextSystemPowerdown(qemuMonitorPtr mon) {
> }
>
>
> +int qemuMonitorTextSystemReset(qemuMonitorPtr mon) {
> + char *info;
> +
> + if (qemuMonitorHMPCommand(mon, "system_reset", &info) < 0) {
> + qemuReportError(VIR_ERR_OPERATION_FAILED,
> + "%s", _("system reset operation failed"));
> + return -1;
> + }
> + VIR_FREE(info);
> + return 0;
> +}
> +
> +
> int qemuMonitorTextGetCPUInfo(qemuMonitorPtr mon,
> int **pids)
> {
> diff --git a/src/qemu/qemu_monitor_text.h b/src/qemu/qemu_monitor_text.h
> index 4fa5064..7536557 100644
> --- a/src/qemu/qemu_monitor_text.h
> +++ b/src/qemu/qemu_monitor_text.h
> @@ -46,6 +46,7 @@ int qemuMonitorTextStopCPUs(qemuMonitorPtr mon);
> int qemuMonitorTextGetStatus(qemuMonitorPtr mon, bool *running);
>
> int qemuMonitorTextSystemPowerdown(qemuMonitorPtr mon);
> +int qemuMonitorTextSystemReset(qemuMonitorPtr mon);
>
> int qemuMonitorTextGetCPUInfo(qemuMonitorPtr mon,
> int **pids);
> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> index 6838417..694d8a9 100644
> --- a/src/qemu/qemu_process.c
> +++ b/src/qemu/qemu_process.c
> @@ -348,12 +348,99 @@ qemuProcessHandleReset(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
> }
>
>
> +/*
> + * Since we have the '-no-shutdown' flag set, the
> + * QEMU process will currently have guest OS shutdown
> + * and the CPUS stopped. To fake the reboot, we thus
> + * want todo a reset of the virtual hardware, followed
> + * by restart of the CPUs. This should result in the
> + * guest OS booting up again
> + */
> +static void
> +qemuProcessFakeReboot(void *opaque)
> +{
> + struct qemud_driver *driver = qemu_driver;
> + virDomainObjPtr vm = opaque;
> + qemuDomainObjPrivatePtr priv = vm->privateData;
> + virDomainEventPtr event = NULL;
> + int ret = -1;
> + VIR_DEBUG("vm=%p", vm);
> + qemuDriverLock(driver);
> + virDomainObjLock(vm);
> + if (qemuDomainObjBeginJob(vm) < 0)
> + goto cleanup;
> +
> + if (!virDomainObjIsActive(vm)) {
> + qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> + _("guest unexpectedly quit"));
> + goto endjob;
> + }
> +
> + qemuDomainObjEnterMonitorWithDriver(driver, vm);
> + if (qemuMonitorSystemReset(priv->mon) < 0) {
> + qemuDomainObjExitMonitorWithDriver(driver, vm);
> + goto endjob;
> + }
> + qemuDomainObjExitMonitorWithDriver(driver, vm);
> +
> + if (!virDomainObjIsActive(vm)) {
> + qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> + _("guest unexpectedly quit"));
> + goto endjob;
> + }
> +
> + if (qemuProcessStartCPUs(driver, vm, NULL,
> + VIR_DOMAIN_RUNNING_BOOTED) < 0) {
> + if (virGetLastError() == NULL)
> + qemuReportError(VIR_ERR_INTERNAL_ERROR,
> + "%s", _("resume operation failed"));
> + goto endjob;
> + }
> + event = virDomainEventNewFromObj(vm,
> + VIR_DOMAIN_EVENT_RESUMED,
> + VIR_DOMAIN_EVENT_RESUMED_UNPAUSED);
> +
> + ret = 0;
> +
> +endjob:
> + if (qemuDomainObjEndJob(vm) == 0)
> + vm = NULL;
> +
> +cleanup:
> + if (vm) {
> + if (ret == -1)
> + qemuProcessKill(vm);
> + if (virDomainObjUnref(vm) > 0)
> + virDomainObjUnlock(vm);
> + }
> + if (event)
> + qemuDomainEventQueue(driver, event);
> + qemuDriverUnlock(driver);
> +}
> +
> +
> static int
> qemuProcessHandleShutdown(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
> virDomainObjPtr vm)
> {
> + qemuDomainObjPrivatePtr priv = vm->privateData;
I think we should get vm->privateData after we lock vm.
> + VIR_DEBUG("vm=%p", vm);
> +
> virDomainObjLock(vm);
> - ((qemuDomainObjPrivatePtr) vm->privateData)->gotShutdown = true;
> + priv->gotShutdown = true;
> + if (priv->fakeReboot) {
> + virDomainObjRef(vm);
> + virThread th;
> + if (virThreadCreate(&th,
> + false,
> + qemuProcessFakeReboot,
> + vm) < 0) {
> + VIR_ERROR("Failed to create reboot thread, killing domain");
> + qemuProcessKill(vm);
We should hold an extra reference the vm here. If the vm is not persistent
and we destroy the vm before the thread runs, libvirtd may crash(I think, not test
it).
> + }
> + } else {
> + qemuProcessKill(vm);
> + }
> virDomainObjUnlock(vm);
>
> return 0;
> @@ -1920,6 +2007,11 @@ qemuProcessPrepareMonitorChr(struct qemud_driver *driver,
> }
>
>
> +/*
> + * Precondition: Both driver and vm must be locked,
> + * and a job must be active. This method will call
> + * {Enter,Exit}MonitorWithDriver
> + */
> int
> qemuProcessStartCPUs(struct qemud_driver *driver, virDomainObjPtr vm,
> virConnectPtr conn, virDomainRunningReason reason)
> @@ -2182,6 +2274,7 @@ int qemuProcessStart(virConnectPtr conn,
> goto cleanup;
>
> vm->def->id = driver->nextvmid++;
> + priv->fakeReboot = false;
>
> /* Run an early hook to set-up missing devices */
> if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
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