[Solved] CentOS 7.7 and VMM

[MartinR]

I use the Virtual Machine Manager to kick off several VMs when required. I've just done the 7.7 upgrade and now VMM fails for all VMs with the message:

Error starting domain: unsupported configuration: Domain requires KVM, but it is not available. Check that virtualisation is enabled in the host BIOS, and host configuration is setup to load the kvm modules.

Is this a known problem with C7.7 or do I need to go digging in my config?

[avij]

Did you reboot after updating? uname -a ?

[MartinR]

Upgraded last night and did an immediate reboot. Shut down overnight and booted this morning.

Linux XXXX.XXXX 3.10.0-1062.1.1.el7.x86_64 #1 SMP Fri Sep 13 22:55:44 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

[MartinR]

If I tail /var/log/messages I see the following:

Sep 18 12:30:42 XXXX libvirtd: 2019-09-18 11:30:42.370+0000: 2374: error : virQEMUCapsCacheLookupDefault:4924 : invalid argument: KVM is not supported by '/usr/libexec/qemu-kvm' on this host
Sep 18 12:31:00 XXXX libvirtd: 2019-09-18 11:31:00.222+0000: 2375: error : qemuProcessStartValidate:5263 : unsupported configuration: Domain requires KVM, but it is not available. Check that virtualisation is enabled in the host BIOS, and host configuration is setup to load the kvm modules.

The first message occurs as VMM starts up, the second on an attempt to boot a VM. I suspect therefore that the first message may be the root cause. Opinions?

BTW, all the logs in /var/log/libvirt/qemu are empty, both before the upgrade and after it.

[MartinR]

Bump please.

[TrevorH]

What processor do you have? And did you check that your BIOS still has virt extensions enabled?

[MartinR]

From lshw

CPU:
product: Intel(R) Core(TM) i3-4150 CPU @ 3.50GHz
capabilities: virtual mode extensions,

BIOS
Intel virtualization extension: disabled

Changed to enabled and all seems to work. Thanks.

During the reboot after I upgraded the OS the BIOS did drop me into the menu (possible battery issues?), but I changed nothing and booted. I cannot see any way that C7.6 -> 7.7 should have touched the BIOS, so this may just be bad timing. Anyhow it's fixed now, so I can run up a C8 VM next Tuesday. Once again, thanks Trevor.

[TrevorH]

It's fairly usual for the default in BIOSes to be Virt disabled and a battery failure will revert you to defaults. I'm suspecting that you'll be on a shopping trip on ebay sooner rather than later...

[MartinR]

I've just had a quick look at it seems to be an easily replaceable one, not one of those soldered horrors. With luck I'll have the right one in one of those bubble packs you see in Poundland.

[TrevorH]

Indeed, you do see those but my experience with them is that they're not that great and run out pretty quickly. My son has a woolly hat with an LED light on the front of it that uses CR2032's and the cheap ones last about 10 minutes in that.