RE: [PATCH 1/1] x86/mce/amd: Add PPIN support for AMD MCE

From: Luck, Tony
Date: Wed Mar 11 2020 - 12:05:10 EST


+ if ((val & 3UL) == 2UL)
+ set_cpu_cap(c, X86_FEATURE_PPIN);

You may have copied a bug of mine from upstream. We recently found
a system where the BIOS enabled PPIN and set the lock bit.

If that is possible on AMD, then you should just check for enabled at this
point. "if (val & 2UL)"

See this commit in TIP tree:

59b5809655bd ("x86/mce: Fix logic and comments around MSR_PPIN_CTL")

Otherwise looks fine:

Acked-by: Tony Luck <tony.luck@xxxxxxxxx>

-Tony