Re: [for-4.18][PATCH 1/2] xen/x86: Add family guards to the is_zen[12]_uarch() macros

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 13/10/2023 7:36 pm, Roger Pau Monné wrote:

> On Fri, Oct 13, 2023 at 12:23:43PM +0100, Alejandro Vallejo wrote:
> > > > diff --git a/xen/arch/x86/include/asm/amd.h b/xen/arch/x86/include/asm/amd.h
> > > > index d862cb7972..5a40bcc2ba 100644
> > > > --- a/xen/arch/x86/include/asm/amd.h
> > > > +++ b/xen/arch/x86/include/asm/amd.h
> > > > @@ -145,11 +145,12 @@
> > > >   * Hygon (Fam18h) but without simple model number rules.  Instead, use STIBP
> > > >   * as a heuristic that distinguishes the two.
> > > >   *
> > > > - * The caller is required to perform the appropriate vendor/family checks
> > > > - * first.
> > > > + * The caller is required to perform the appropriate vendor check first.
> > > >   */
> > > > -#define is_zen1_uarch() (!boot_cpu_has(X86_FEATURE_AMD_STIBP))
> > > > -#define is_zen2_uarch()   boot_cpu_has(X86_FEATURE_AMD_STIBP)
> > > > +#define is_zen1_uarch() ((boot_cpu_data.x86 == 0x17 || boot_cpu_data.x86 == 0x18) && \
> > > > +                         !boot_cpu_has(X86_FEATURE_AMD_STIBP))
> > > > +#define is_zen2_uarch() (boot_cpu_data.x86 == 0x17 && \
> > > > +                         boot_cpu_has(X86_FEATURE_AMD_STIBP))
> > > >           
> > > What leads you to believe there aren't Hygon Zen2's ?
> > >         
> > The same argument that a Hygon zen2 supports STIBP. Having seen neither HW
> > nor docs all that's left is divination skills :)
> >       
>     
    
    Hygon reported/fixed Zen2 uarch issues in Xen.  Something clearly
    exists.
    
    ~Andrew