[libvirt] [PATCH] qemu driver: sync guest time via qemu-guest-agent when domain is resumed

[Marcelo Tosatti]

On Wed, Feb 12, 2014 at 10:22:11AM +0000, Daniel P. Berrange wrote:
> I agree that this should be a completely separate command, not
> merely a flag to the Resume API.  The reason is that you cannot
> do sensible error reporting if you overload this in one API
> call.  ie consider that resuming the CPUs succeeds, but syncing
> time fails. If you return "success" to the caller you are lieing
> about the result of time sync. If you return "error" to the caller
> you are lieing about the result of resuming the CPUs.
> 
> If there is a separate API to invoke then the caller can clearly
> see which operation succeeded vs failed.

Well then just require a new guest agent command. No need
for a separate command.

Going from "resume" to "resume-and-sync" versus

Going from "resume" to "resume; send-guest-agent-command" 

Is not very different is it? In both cases qemu guest agent channel 
must be operational.

I'll go write a virsh alias and virt-manager patch.

(BTW, error reporting would be in the libvirt logs,
GuestAgentError with all the details why time-sync failed).