[libvirt] Cannot find suitable emulator for x86_64

[Mathieu Tarral]

2018-06-13 18:23 GMT+03:00 Daniel P. Berrangé <berrange at redhat.com>:
> 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 :-)

My bad :D

> Please attach the full debug log, after running 'virsh capabilities'
Sure.
I copy pasted everything in a Github Gist, which is easier to read I think.
https://gist.github.com/Wenzel/805558263b7d6d8b3366a684d5673217

Thanks !

-- 
Mathieu Tarral