[RFC PATCH 0/4] x86/alternative: Add ALTERNATIVE_3

[Borislav Petkov <bp@alien8.de>]

From: Borislav Petkov <bp@suse.de>

Hi,

here's a patchset which adds an ALTERNATIVE_3() macro so that we can
finally do RDTSCP in rdtsc_ordered() but also not break all the possible
qemu CPU models out there like some old pentium which doesn't have even
MFENCE. Which is the reason for the three-insn alternative macro, btw.

The stuff works here on all machines I've tested it on but since we're
too close to the merge window, I'll hold on to it for another round and
let it soak slowly into 2019. Thus the RFC tag. In the meantime, it'll
collect your comments and ideas.

:-)

Thanks!

Borislav Petkov (4):
  x86/alternatives: Add macro comments
  x86/alternatives: Print containing function
  x86/alternatives: Add an ALTERNATIVE_3() macro
  x86/TSC: Use RDTSCP

 arch/x86/include/asm/alternative.h | 39 ++++++++++++++++++++++++------
 arch/x86/include/asm/msr.h         | 16 ++++++++++--
 arch/x86/kernel/alternative.c      |  4 +--
 3 files changed, 48 insertions(+), 11 deletions(-)

-- 
2.19.1