[libvirt] Cannot find suitable emulator for x86_64

[Daniel P. Berrangé]

On Wed, Jun 13, 2018 at 06:13:04PM +0300, Mathieu Tarral wrote:
> 2018-06-13 18:07 GMT+03:00 Daniel P. Berrangé <berrange at redhat.com>:
> > On Wed, Jun 13, 2018 at 05:59:37PM +0300, Mathieu Tarral wrote:
> >> >> >
> >> >> > What version of QEMU do you have installed ?  Libvirt has recently
> >> >> > become more aggressive at requiring modern QEMU versions, so its
> >> >> > possible if your old libvirt was running against old QEMU, that
> >> >> > might not be supported with new libvirt.
> >> >>
> >> >> I'm using QEMU 2.8 here.
> >> >> That might explain why libvirt cannot find a version that is modern enough.
> >> >
> >> > 2.8 is plenty new enough, so that's not the issue.
> >>
> >> Alright, so let's focus on libvirt 4.4.0.
> >>
> >> When I start the daemon, i can see some warnings related to QEMU:
> >>
> >> warning : virQEMUCapsInit:942 : Failed to get host CPU cache info
> >> warning : virQEMUCapsInit:949 : Failed to get host power management capabilities
> >>
> >> Could this be the reason, or the beginning of an explanation ?
> >> How can I dig and find what is the root cause ?
> >
> > Best bet is to edit libvirtd.conf and set
> >
> >   log_filters="1:qemu_capabilities"
> >   log_outputs="1:file:/var/log/libvirtd.log"
> >
> > and then rm -rf /var/cache/libvirt/qemu and restart libvirtd. The log
> > file should tell you it is detecting qemu-system-x86_64 and probing it.
> > If anything fails it should be covered in the logs.
> 
> Thanks, i have more information now:
> 
> debug : virQEMUCapsCacheLookup:4561 : Returning caps (nil) for
> /usr/bin/qemu-system-x86_64
> debug : virQEMUCapsCacheLookup:4561 : Returning caps (nil) for /usr/bin/kvm
> 
> Does this help you ?

No that just says there's no previous capabiltiies stored in the cache,
which is expected since I just told you to delete the cache :-)

Please attach the full debug log, after running 'virsh capabilities'

Regards,
Daniel
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