Messages in this thread |  | | Date | Tue, 30 Jan 2018 11:37:49 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel |
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On Mon, 29 Jan 2018, David Woodhouse wrote:
> Despite the fact that all the other code there seems to be doing it, > just using set_cpu_cap() in early_intel_init() doesn't actually work. > > When the CPU is queried again in identify_boot_cpu(), it all gets > overwritten again. Do it in init_scattered_cpuid_features() instead. > > Turning the bits off for bad microcode can use setup_clear_cpu_cap() > to force them off for all CPUs; I was less keen on forcing the feature > bits *on* that way. > > Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> > Fixes: 2961298e ("x86/cpufeatures: Clean up Spectre v2 related CPUID flags") > --- > I feel I must be missing something. Is the rest of early_init_intel() broken too?
A lot of that stuff is duct taped and works more by chance than by design. Borislav is looking into cleaning that up already.
Thanks,
tglx
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