Re: [PATCH 0/2] KVM: SVM: Final C-bit fixes?

From: Paolo Bonzini
Date: Thu Jul 08 2021 - 12:30:53 EST


On 25/06/21 04:03, Sean Christopherson wrote:
Patch 01 reverts the C-bit truncation patch as the reserved #PF was
confirmed to be due to a magic HyperTransport region (how many magic
addresses are there!?!). Hopefully the original patch simply be dropped,
but just in case...

Patch 02 reverts the C-bit clearing in the #NPF handler. If that somehow
turns out to be incorrect, i.e. there are flows where the CPU doesn't
mask off the C-bit, then it can be conditional on a SEV guest.

I'll be offline for the next two weeks, fingers crossed I've undone all
the damage. :-)

Thanks!

Sean Christopherson (2):
Revert "KVM: x86: Truncate reported guest MAXPHYADDR to C-bit if SEV
is supported"
KVM: SVM: Revert clearing of C-bit on GPA in #NPF handler

arch/x86/kvm/cpuid.c | 11 -----------
arch/x86/kvm/svm/svm.c | 39 +++++++++------------------------------
arch/x86/kvm/x86.c | 3 ---
arch/x86/kvm/x86.h | 1 -
4 files changed, 9 insertions(+), 45 deletions(-)


Queued, thanks.

Paolo