[libvirt] [PATCH 3/4] Wire up QEMU agent to reboot/shutdown APIs

[Eric Blake]

On 10/05/2011 11:31 AM, Daniel P. Berrange wrote:
> From: "Daniel P. Berrange"<berrange at redhat.com>
>
> This makes use of the QEMU guest agent to implement the
> virDomainShutdownFlags and virDomainReboot APIs. With
> no flags specified, it will prefer to use the agent, but
> fallback to ACPI. Explicit choice can be made by using
> a suitable flag
>
> * src/qemu/qemu_driver.c: Wire up use of agent

For backport purposes, should we split this into two patches?  1. wire 
up the agent with no user control, 2. wire up virDomainShutdownFlags for 
additional control over the agent.  Then patch 1 can be pulled across 
backports to platforms that cannot rebase due to API reasons, but want 
to try out the agent (I'm thinking specifically of F16).

> @@ -1552,42 +1584,67 @@ static int qemuDomainReboot(virDomainPtr dom, unsigned int flags) {
>           goto cleanup;
>       }
>
> -#if HAVE_YAJL
>       priv = vm->privateData;
>
> -    if (qemuCapsGet(priv->qemuCaps, QEMU_CAPS_MONITOR_JSON)) {
> -        if (!qemuCapsGet(priv->qemuCaps, QEMU_CAPS_NO_SHUTDOWN)) {
> +    if ((flags&  VIR_DOMAIN_SHUTDOWN_GUEST_AGENT) ||

Hmm, since the use of the agent requires JSON, and since JSON requires 
compilation with HAVE_YAJL, are we introducing problems here for 
compilation on a system without yajl?


> +    if (useAgent) {
> +        qemuDomainObjEnterAgent(driver, vm);
> +        ret = qemuAgentShutdown(priv->agent, QEMU_AGENT_SHUTDOWN_REBOOT);
> +        qemuDomainObjExitAgent(driver, vm);
> +    } else {
>           qemuDomainObjEnterMonitor(driver, vm);
>           ret = qemuMonitorSystemPowerdown(priv->mon);
>           qemuDomainObjExitMonitor(driver, vm);
>
>           if (ret == 0)
>               qemuDomainSetFakeReboot(driver, vm, true);
> -
> -    endjob:
> -        if (qemuDomainObjEndJob(driver, vm) == 0)
> -            vm = NULL;
> -    } else {
> -#endif

In particular, the qemuMonitorSystemPowerdown call used to be protected 
by HAVE_YAJL and now it is not.

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org