Re: [PATCH v4 4/8] KVM: x86: nSVM: Redirect IA32_PAT accesses to either hPAT or gPAT

[Yosry Ahmed]

On Thu, Mar 26, 2026 at 2:19 PM Jim Mattson <jmattson@xxxxxxxxxx> wrote:
>
> On Tue, Feb 17, 2026 at 3:27 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> > Side topic, either as a prep patch (to duplicate code) or as a follow-up patch
> > (to move the PAT handling in x86.c to vmx.c), the "common" handling of PAT should
> > be fully forked between VMX and SVM.  As of this patch, it's not just misleading,
> > it's actively dangerous since calling kvm_get_msr_common() for SVM would get the
> > wrong value.
>
> Though I included this change in v5 and v6, TIL that TDX calls
> kvm_[gs]et_msr_common(MSR_IA32_CR_PAT), so the common handling is not
> fully forked.

Do you plan to drop this patch or add PAT handling in
tdx_{get/set}_msr()? If you'll drop it, maybe add a warning if
kvm_[gs]et_msr_common(MSR_IA32_CR_PAT) is called from SVM?