Re: [v4.17-rcx] Lost IBPB, IBRS_FW support for spectre_v2 mitigation.

[Thomas Gleixner]

On Tue, 1 May 2018, Thomas Gleixner wrote:
> On Tue, 1 May 2018, Jörg Otte wrote:
> > 2018-04-30 21:53 GMT+02:00 Thomas Gleixner <tglx@xxxxxxxxxxxxx>:
> > > --- a/arch/x86/kernel/cpu/common.c
> > > +++ b/arch/x86/kernel/cpu/common.c
> > > @@ -848,6 +848,11 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
> > >                 c->x86_power = edx;
> > >         }
> > >
> > > +       if (c->extended_cpuid_level >= 0x80000008) {
> > > +               cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
> > > +               c->x86_capability[CPUID_8000_0008_EBX] = ebx;
> > > +       }
> > > +
> > >         if (c->extended_cpuid_level >= 0x8000000a)
> > >                 c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
> > >
> > 
> > No, does not fix it.
> 
> Then I really have no idea how reverting the patch you pointed out would
> fix it.

Can you please carefully recheck:

1) rc3 with d94a155c59c9 reverted.

2) rc3 with the above patch applied.

If #1 works then #2 must work as well.

Thanks,

	tglx