[libvirt] [PATCH v2] qemu: Report shutdown event details

[Eric Blake]

On 05/16/2017 08:49 AM, Martin Kletzander wrote:
> QEMU will likely report the details of it shutting down, particularly
> whether the shutdown was initiated by the guest or host.  We should
> forward that information along, at least for shutdown events.  Reset
> has that as well, however that is not a lifecycle event and would add
> extra constants that might not be used.  It can be added later on.
> 
> Since the only way we can extend information provided to the user is
> adding event details, we might as well emit multiple events (one with
> the reason for the shutdown and keep the one for the shutdown being
> finished for clarity and compatibility).
> 
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1384007
> 
> Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
> ---
> v2:
>  - Adapt to new message format
> 
> Patch in QEMU:        https://lists.gnu.org/archive/html/qemu-devel/2017-05/msg03624.html
> Applied to qapi-next: https://lists.gnu.org/archive/html/qemu-devel/2017-05/msg03742.html

Not in qemu master yet, but should land there prior to the next libvirt
release.


> +++ b/include/libvirt/libvirt-domain.h
> @@ -2983,7 +2983,16 @@ typedef enum {
>   * Details on the cause of a 'shutdown' lifecycle event
>   */
>  typedef enum {
> -    VIR_DOMAIN_EVENT_SHUTDOWN_FINISHED = 0, /* Guest finished shutdown sequence */
> +    /* Guest finished shutdown sequence */
> +    VIR_DOMAIN_EVENT_SHUTDOWN_FINISHED = 0,
> +
> +    /* Guest is shutting down due to request from guest (e.g. hardware-specific
> +     * action) */
> +    VIR_DOMAIN_EVENT_SHUTDOWN_GUEST = 1,
> +
> +    /* Guest is shutting down due to request from host (e.g. killed by a
> +     * signal) */
> +    VIR_DOMAIN_EVENT_SHUTDOWN_HOST = 2,
> 

Looks reasonable.

> +++ b/src/qemu/qemu_monitor_json.c
> @@ -523,9 +523,15 @@ qemuMonitorJSONKeywordStringToJSON(const char *str, const char *firstkeyword)
>  }
> 
> 
> -static void qemuMonitorJSONHandleShutdown(qemuMonitorPtr mon, virJSONValuePtr data ATTRIBUTE_UNUSED)
> +static void qemuMonitorJSONHandleShutdown(qemuMonitorPtr mon, virJSONValuePtr data)
>  {
> -    qemuMonitorEmitShutdown(mon);
> +    bool guest = false;
> +    virTristateBool guest_initiated = VIR_TRISTATE_BOOL_ABSENT;
> +
> +    if (virJSONValueObjectGetBoolean(data, "guest", &guest) == 0)
> +        guest_initiated = guest ? VIR_TRISTATE_BOOL_YES : VIR_TRISTATE_BOOL_NO;
> +
> +    qemuMonitorEmitShutdown(mon, guest_initiated);

Yes, that uses the new qemu interface correctly.

> @@ -678,6 +699,7 @@ qemuProcessHandleShutdown(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
> 
>   unlock:
>      virObjectUnlock(vm);
> +    qemuDomainEventQueue(driver, pre_event);
>      qemuDomainEventQueue(driver, event);
>      virObjectUnref(cfg);

Nice - you send the same event as always so old clients don't break, but
new clients can now look for the new cause.

ACK
although I'd wait until it is actually in qemu.git master before pushing
to libvirt.git

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

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