Re: [Libvir] VIR_DOMAIN_NOSTATE
On Tue, Jan 29, 2008 at 10:01:35AM -0800, Russ Blaine wrote:
Daniel P. Berrange wrote:
>Can you edit the src/xen_internal.c file and in the
>xenHypervisorGetDomInfo()
>method, add a printf() for the 'domain_flags' flags variable. IMHO the
>way we deal with this isn't quite correct. We merely mask out the high
>bits and then switch on the resulting value. This isn't the way the Xen
>hypervisor uses this field though. Xen more or less uses the whole thing
>as as bitmask, allowing near arbitrary combinations of bits to be set.
>So I think what is happening is there's a combo of bits set which cause
>the switch() statement to fail all cases, resulting in NOSTATE.
>
>We'll probably need to replace the switch(domain_flags) with something
>which explicitly tests for the bits we're interested in, rather than
>looking at the value as a whole.
when xenHypervisorGetDomInfo() returns VIR_DOMAIN_NONE, domain_flags is 0
(sampled after the HVM bit has been masked out). So is there some other
state implied by domain_flags being 0? In all cases I have seen, the domain
is actually running -- accumulating CPU time, etc.
What hypervisor version are you running. I'm struggling to see the codepath
in the hypervisor 'getdomaininfo' call which could lead to domain_flags
being zero. AFAICT, as well as the HVM flags, there must always be at
least one other bit set.
int flags = XEN_DOMINF_blocked;
for_each_vcpu ( d, v )
{
....
if ( !test_bit(_VPF_down, &v->pause_flags) )
{
if ( !(v->pause_flags & VPF_blocked) )
flags &= ~XEN_DOMINF_blocked;
if ( v->is_running )
flags |= XEN_DOMINF_running;
info->nr_online_vcpus++;
}
}
Guarenteed either XEN_DOMINF_blocked or XEN_DOMINF_running is
set now.
And this next block, simply sets a few more bits
info->flags = flags |
((d->is_dying == DOMDYING_dead) ? XEN_DOMINF_dying : 0) |
(d->is_shut_down ? XEN_DOMINF_shutdown : 0) |
(d->is_paused_by_controller ? XEN_DOMINF_paused : 0) |
(d->debugger_attached ? XEN_DOMINF_debugged : 0) |
d->shutdown_code << XEN_DOMINF_shutdownshift;
if ( is_hvm_domain(d) )
info->flags |= XEN_DOMINF_hvm_guest;
This is all in getdomaininfo, from xen/common/domctl.c
Regards,
Dan.
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