Re: [PATCH 0/2] KVM: SVM: Fix unexpected #UD on INT3 in SEV guests

From: Sean Christopherson
Date: Thu Aug 24 2023 - 12:09:08 EST


On Wed, Aug 23, 2023, Sean Christopherson wrote:
> One idea to make the original bug repro on every run would be to constantly
> toggle nx_huge_pages between "off" and "force" while the guest is booting. Toggling
> nx_huge_pages should force KVM to rebuild the SPTEs and all but guarantee trying
> to deliver the #BP will hit a #NPF.

Mwhahaha. That, plus a delay in the guest and disabling THP, makes this 100%
reproducible. I'll verify the fix actually works before posting v2.