Re: [PATCH] KVM: x86: Virtualize AMD CPUID faulting

[Jim Mattson]

On Tue, Feb 10, 2026 at 1:09 PM Jamie Liu <jamieliu@xxxxxxxxxx> wrote:
>
> CPUID faulting via MSR_MISC_FEATURES_ENABLES_CPUID_FAULT is only used on
> Intel CPUs. The mechanism virtualized by this change is used on AMD
> CPUs. See arch/x86/kernel/cpu/amd.c:bsp_init_amd(),
> arch/x86/kernel/process.c:set_cpuid_faulting().
>
> Signed-off-by: Jamie Liu <jamieliu@xxxxxxxxxx>

You missed the cpuid faulting check in em_cpuid():

ctxt->ops->get_msr(ctxt, MSR_MISC_FEATURES_ENABLES, &msr);
if (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT &&
    ctxt->ops->cpl(ctxt)) {
return emulate_gp(ctxt, 0);
}