[PATCH 0/3] x86/microcode: Add a microcode loader callback

From: Borislav Petkov
Date: Fri Feb 16 2018 - 06:26:56 EST


From: Borislav Petkov <bp@xxxxxxx>

Add a callback which the microcode loader calls after microcode has been
upgraded late to let the user know that any CPUID changes potentially
won't take effect.

One possible example for this is that late loading happens after
alternatives have run and thus patching which relies on those new CPUID
features won't happen.

@Ashok: I haven't added your tags yet because I did a small change to
run the callback only when no error has been encountered during loading.
Please run them on your setup to confirm everything's still fine.

Thanks.

Borislav Petkov (3):
x86/microcode: Propagate return value from updating functions
x86/CPU: Add a microcode loader callback
x86/CPU: Check CPU feature bits after microcode upgrade

arch/x86/include/asm/microcode.h | 9 ++++++--
arch/x86/include/asm/processor.h | 1 +
arch/x86/kernel/cpu/common.c | 30 +++++++++++++++++++++++++++
arch/x86/kernel/cpu/microcode/amd.c | 10 ++++-----
arch/x86/kernel/cpu/microcode/core.c | 39 ++++++++++++++++++++---------------
arch/x86/kernel/cpu/microcode/intel.c | 10 ++++-----
6 files changed, 70 insertions(+), 29 deletions(-)

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2.13.0