This is the basis for using the newly-added microcode features for speculation control on both Intel and AMD CPUs. We just add the CPUID feature bits (with associated cleanup now we were using 5 bits out of the same subleaf as "scattered" bits), add the MSR definitions, and turn off KPTI for Intel CPUs which say they don't need it.
The rest of the bits to actually *use* the features are still being worked out, but this much is fairly straightforward so it's a good start. David Woodhouse (4): x86/cpufeatures: Add Intel feature bits for Speculation Control x86/cpufeatures: Add AMD feature bits for Prediction Command x86/msr: Add definitions for new speculation control MSRs x86/pti: Do not enable PTI on fixed Intel processors arch/x86/include/asm/cpufeature.h | 7 +++++-- arch/x86/include/asm/cpufeatures.h | 13 ++++++++++--- arch/x86/include/asm/disabled-features.h | 3 ++- arch/x86/include/asm/msr-index.h | 11 +++++++++++ arch/x86/include/asm/required-features.h | 3 ++- arch/x86/kernel/cpu/common.c | 10 ++++++++-- arch/x86/kernel/cpu/scattered.c | 3 +-- 7 files changed, 39 insertions(+), 11 deletions(-) -- 2.7.4
