[libvirt PATCH] qemu: fix detection of vCPU pids when multiple dies are present

[Daniel P. Berrangé]

On Mon, Mar 16, 2020 at 09:53:13AM +0100, Peter Krempa wrote:
> On Fri, Mar 13, 2020 at 16:46:16 +0000, Daniel Berrange wrote:
> > The logic for querying hotpluggable CPUs needs to sort the list
> > of CPUs returned by QEMU. Unfortunately our sorting method failed
> > to use the die_id field, so CPUs were not correctly sorted.
> > 
> > This is seen when configuring a guest with partially populated
> > CPUs
> > 
> >   <vcpu placement='static' current='1'>16</vcpu>
> >   <cpu...>
> >     <topology sockets='4' dies='2' cores='1' threads='2'/>
> >   </cpu>
> > 
> > Then trying to start it would fail:
> > 
> >   # virsh -c qemu:///system start demo
> >   error: Failed to start domain demo
> >   error: internal error: qemu didn't report thread id for vcpu '0'
> > 
> > Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> > ---
> >  src/qemu/qemu_domain.c       | 10 ++++++++--
> >  src/qemu/qemu_monitor.c      |  2 ++
> >  src/qemu/qemu_monitor.h      |  2 ++
> >  src/qemu/qemu_monitor_json.c |  4 ++++
> >  4 files changed, 16 insertions(+), 2 deletions(-)
> 
> Please add a test entry to 'testQemuMonitorCPUInfo' test case for this
> purpose. You'll need to extend testQemuMonitorCPUInfoFormat.

That test suite doesn't illustrate the brokenness AFAICT. I added
the data files and it still passes, even without the fix.


Regards,
Daniel
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