Re: [V2 PATCH 4/8] KVM: selftests: x86: Precompute the result for is_{intel,amd}_cpu()

On Thu, Sep 15, 2022 at 12:04:44AM +0000, Vishal Annapurve wrote:

Cache the vendor CPU type in a global variable so that multiple calls to is_intel_cpu() do not need to re-execute CPUID.

Add cpu vendor check in kvm_hypercall() so that it executes correct vmcall/vmmcall instruction when running on Intel/AMD hosts. This avoids exit to KVM which anyway tries to patch the instruction according to the cpu type.

Out of curiousity, why do we want to avoid this exit?