[virt-tools-list] 2 questions

[Hetz Ben Hamo]

Hi,

On Fri, Feb 1, 2019 at 5:04 PM Daniel P. Berrangé <berrange at redhat.com>
wrote:

> On Fri, Feb 01, 2019 at 04:56:23PM +0200, Hetz Ben Hamo wrote:
> > Hi,
> >
> > I hope I'm asking in the right place.
> >
> > First question: I'm using AMD Ryzen 2700 CPU, and the VM's were running
> > super slow. Checking on the net, most of the docs shows that I should
> look
> > at lscpu output which indeed shows that my CPU has SVM. However, it took
> me
> > a bit more time to figure out that the kvm_amd module was not loaded
> > because SVM was disabled in the BIOS, so my question is: Could the VMM
> team
> > add a simple check before starting a VM if kvm-intel or kvm_amd modules
> are
> > loaded and if not - show a warning message to enable VT-X/SVM on the
> > BIOS/UEFI please?
>
> FWIW,  virt-host-validate command line tool should report on this problem,
> but of course you have to know it exists first, so wouldn't have helped
> your situation.
>

Yes, that's the utility that helped me to diagnose the issue. My idea was
thinking about an end-user who doesn't have much experience with Linux,
just to notify him with a warning window to go set it in the BIOS. Just an
idea ;)


>
> > Second question: After enabling the SVM in the BIOS and restarting the
> VMM,
> > the previously configured VM was still running super-slow. I recreated
> the
> > VM and only the new VM was running fast, so I assume that a parameter not
> > to use the SVM is written in the VM configuration? if so, where can I
> > change it in the VM configuration GUI? (I thought it was related to the
> > copy/mode of the CPU, which doesn't change things)
>
> Whether to use TCG (emulation) or KVM (hardware acceleration) is in the
> guest XML configuration.
>

Is it possible to change "TGC" in the virt-manager to "TCG (emulation)"?
that could help.


>
> I don't think its changable in the GUI.
>
> If you use the command line tool 'virsh edit $GUESTNAME' as root you will
> see
>
>   <domain type='qemu'>
>   ....
>
> Just change that to 'kvm' instead.
>

Oh, thanks!




>
>
> Regards,
> Daniel
> --
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