[Libvir] VIR_DOMAIN_NOSTATE

[Daniel Veillard]

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On Thu, Jan 24, 2008 at 12:32:32PM -0800, Russ Blaine wrote:
> On Solaris-based xen 3.1.2 I am seeing virDomainGetInfo() often returning 
> VIR_DOMAIN_NOSTATE in dominfo.state for domUs that are powered on and 
> running. What exactly does VIR_DOMAIN_NOSTATE mean? Why does it exist? I 

  that we could not extract the state status from the hypervisor.

> suspect it is a catch-all in the API for hosts that don't entirely have 
> their act together, that do not always return a valid guest state. Is that 
> the case?

  Well, info->state is set to VIR_DOMAIN_NOSTATE only if in the SEXPR returned
by xend when asking about the domain, the (domain ... (state X) ...)
is either missing or empty, assuming the call ended up using a Xend RPC.
If the call used an hypercall, then the call should go though
xenHypervisorGetDomInfo and the switch on the domain state extracted
seems to be failing setting info->state to VIR_DOMAIN_NOSTATE (actually it
sets it to VIR_DOMAIN_NONE which is the wrong enum value, but 0 so equivalent
in practice, I will fix this in CVS).

> Is anyone else seeing this on Xen?

  What version of libvirt are you using ? Its behaviour might be different
from the upstream version I looked at, but in both case it really should
imply that we failed to extract the state informations from the hypervisor.

Daniel

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