Re: [PATCH v1 3/3] hvf: Support AVX512 guests on capable hardware

[Roman Bolshakov]

On Mon, Mar 30, 2020 at 05:16:06PM -0700, Cameron Esfahani wrote:
> macOS lazily enables AVX512.  Explicitly enable it if the processor
> supports it.
> 
> cpu_x86_cpuid() tries to handle OSXSAVE but refers to env->cr[4] for the
> guest copy of CR4.  HVF doesn't support caching CPUID values like KVM,
> so we need to track it ourselves.
> 

Hi Cameron,

Side question, how did you test it? I tried the latest ubuntu and
archlinux iso with -cpu host and noticed that kernel complains about TSC
misbehaviour early during boot.

Also, I didn't look thoroughly into it but do you happen to know if
there could be a case that we're getting AVX512 support without AVX2
support? Wouldn't that be an issue?

Thanks,
Roman