Re: [PATCH v3 3/5] x86: allow Kconfig control over psABI level

[Jason Andryuk <jandryuk@xxxxxxxxx>]

On Wed, Jul 26, 2023 at 6:34 AM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>
> Newer hardware offers more efficient and/or flexible and/or capable
> instructions, some of which we can make good use of in the hypervisor
> as well. Allow a basic way (no alternatives patching) of enabling their
> use. Of course this means that hypervisors thus built won't work
> anymore on older, less capable hardware.
>
> Since older compilers (apparently gcc10 / clang11 and older) won't
> recognize -march=x86-64-v2 etc, also addd fallback logic passing
> -mpopcnt and alike explicitly.
>
> Note that in efi_arch_cpu() the filling of 7c0 and 7d0 are forward-
> looking; we only require 7b0, but we need to use cpuid_count() anyway.
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Jason Andryuk <jandryuk@xxxxxxxxx>

Thanks,
Jason