[libvirt] [BUG] Hyper-V Enlightenments are broken in 5.5.0+

[Vitaly Kuznetsov]

Jiri Denemark <jdenemar at redhat.com> writes:

> On Thu, Jul 25, 2019 at 11:09:28 +0200, Vitaly Kuznetsov wrote:
>> Jiri Denemark <jdenemar at redhat.com> writes:
>> 
>> > On Wed, Jul 24, 2019 at 18:48:38 +0200, Vitaly Kuznetsov wrote:
>> >> Hi,
>> >> 
>> >> when some Hyper-V enlightenments are added to the domain configuration,
>> >> e.g.
>> >> 
>> >>   <features>
>> >>     ...
>> >>     <hyperv>
>> >>       ..
>> >>       <vpindex state='on'/>
>> >>     </hyperv>
>> >>   ...
>> >> 
>> >> I'm observing the following:
>> >> 
>> >> # virsh create /etc/libvirt/qemu/win2k16.xml 
>> >> error: Failed to create domain from /etc/libvirt/qemu/win2k16.xml
>> >> error: unsupported configuration: host doesn't support hyperv 'vpindex' feature
>> >> 
>> >> the feature is, of course, supported in KVM/QEMU.
>> >> 
>> >> I've bisected the problem to the particular commit:
>> >> 
>> >> commit 63acb7bfd56f117309e4fcaf438639d4d7bc7dcb
>> >> Author: Jiri Denemark <jdenemar at redhat.com>
>> >> Date:   Mon Jun 17 23:38:46 2019 +0200
>> >> 
>> >>     qemu_process: Prefer generic qemuMonitorGetGuestCPU
>> >> 
>> >> Any ideas?
>> >
>> > Is this with QEMU 4.0 (or older) or a current git, i.e., almost 4.1?
>> 
>> QEMU-4.0 is definitely affected.
>
> Hmm, QEMU 4.0 does not support unavailable-features CPU property, which
> means the mentioned commit is a no-op. And I can't reproduce your issue
> in this case.
>
> However, QEMU 4.1.0-rc1 supports unavailable-features and I can
> reproduce the bug. Looks like something is wrong with the new way of
> checking for enabled CPU features.

Sorry, was a bug in my testing. This was QEMU-4.1 from git indeed.

-- 
Vitaly