[PATCH 0/4] x86/microcode: Drop old interface and default-disable late loading

[Borislav Petkov]

From: Borislav Petkov <bp@xxxxxxx>

Now tested.

AMD:

[  349.234368] microcode: Attempting late microcode loading - it is dangerous and taints the kernel.
[  349.244128] microcode: You should switch to early loading, if possible.
...
[  349.391934] microcode: Reload completed, microcode revision: 0xa001173

Intel:

[   50.726917] microcode: Attempting late microcode loading - it is dangerous and taints the kernel.
[   50.736139] microcode: You should switch to early loading, if possible.
[   50.745504] microcode: updated to revision 0x718, date = 2019-05-21
[   50.752000] x86/CPU: CPU features have changed after loading microcode, but might not take effect.
[   50.761158] x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.
[   50.771362] microcode: Reload completed, microcode revision: 0x718

Changelog:
----------

v0:

Totally untested, just sending out as a RFC first. This is something
Peter and I talked about recently and think it makes sense.

Borislav Petkov (4):
  x86/microcode: Rip out the OLD_INTERFACE
  x86/microcode: Default-disable late loading
  x86/microcode: Taint and warn on late loading
  x86/microcode: Remove unnecessary perf callback

 arch/x86/Kconfig                     |  15 ++--
 arch/x86/kernel/cpu/common.c         |   2 +
 arch/x86/kernel/cpu/microcode/core.c | 115 +++------------------------
 3 files changed, 20 insertions(+), 112 deletions(-)

-- 
2.35.1