[libvirt] [PATCH 0/4] Add support for QEMU guest agent control

[Daniel P. Berrange]

On Thu, Oct 20, 2011 at 09:39:20AM +0900, MATSUDA, Daiki wrote:
> (2011/10/06 2:31), Daniel P. Berrange wrote:
> >The QEMU guest agent "/usr/bin/qemu-ga" has some handy functions
> >for controlling the guest, not least, shutdown/reboot and filesystem
> >freeze/thaw.
> >
> >In Fedora 15/16 the semantics of the ACPI power button have been
> >changed to suspend-to-RAM which breaks our current shutdown
> >implementation.
> >
> >By adding support for the agent we gain a more predictable way
> >to shutdown / reboot guests.
> >
> >NB: the code currently has the same "flaw" as the monitor, in
> >so much as we wait forever for a guest agent reply. We need to
> >add a timeout ability to the agent code
> >
> >--
> >libvir-list mailing list
> >libvir-list at redhat.com
> >https://www.redhat.com/mailman/listinfo/libvir-list
> >
> >
> 
> The QEMU guest agent has other function FS Freeze. But your patches
> does not support it. Do you have a plan ?

I expect Eric will add FS freeze support as part of his ongoing
effort to improve snapshotting.

> In addition, the QEMU guest agent requires specified socket. Virt IO
> Console, too. But unfortunately libvirt does not support to xml tags
> to give socket name options to QEMU for the QEMU guest agent and
> Virt IO Console.

Err, yes we do.

    <channel type='unix'>
      <source mode='bind' path='/var/lib/libvirt/qemu/f16x86_64.agent'/>
      <target type='virtio' name='org.qemu.guest_agent.0'/>
    </channel>


Or for the console

    <console type='unix'>
      <source mode='bind' path='/var/lib/libvirt/qemu/f16x86_64.console'/>
      <target type='virtio'/>
    </channel>

though you really want to use type=pty for consoles, so that 'virsh console'
works correctly.

Daniel
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