Re: [PATCH 2/2] x86/rdrand: hide RDRAND and RDSEED from CPUID in case of a malfunction

[Mikhail Paulyshka]

On 3/12/25 3:45 PM, Borislav Petkov wrote:
> On Wed, Mar 12, 2025 at 03:31:30PM +0300, Mikhail Paulyshka wrote:
> > @@ -46,6 +47,8 @@ void x86_init_rdrand(struct cpuinfo_x86 *c)
> >   
> >   	if (failure) {
> >   		clear_cpu_cap(c, X86_FEATURE_RDRAND);
> > +		if (c->x86_vendor == X86_VENDOR_AMD || c->x86_vendor == X86_VENDOR_HYGON)
> Hygon is family 0x18. Have you tested it there?

My bad, I thought Hygon is backwards compatible with AMD Zen1/2. Then it 
can be removed in case Hygon's MSRs are different.