Hi,

On Wed, Mar 17, 2021 at 05:05:39PM +0000, Daniel P. Berrangé wrote:
> Possibly you need some of the hyperv enlightenments enabled too. Though
> I can't recall the precise command line offhand, as I just rely on
> virt-install virt-manager to do the right thing for Windows guests.

HuperV support/emulation is only available under KVM and thus only under
Linux, so that is not going to help :-/

My question is more on what causes this? Say a 10% to 20% cpu usage loss due
to IPI's and interrupts not working as smooth as could be is not nice but
workable, a 200% constant cpu usage that makes it unresponsive and bog slow is
unworkable.

Is some interrupt never cleared correctly and constantly triggered? Is the
pauze/wait for interrupt not implemented correctly? Regardless of which
accelerator, basic TCG doesn't work either. And why don't the BSDs and Linux
as guests suffer from this?

How to trace this? Is there something I could trace that details this
behaviour?

With regards,
Reinoud