Re: [PATCH] x86/CPU/AMD: Fix AMD TLBI Erratum #1718

[Rik van Riel]

On Fri, 2026-10-02 at 14:16 -0700, Borislav Petkov wrote:
> From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>
> 
> The processor may fail to invalidate a TLB entry while executing an
> INVLPGB/TLBSYNC instruction pair.
> 
> Detect the erratum and apply a software workaround when a microcode
> fix
> is not present.
> 
> Fixes: 82378c6c2f43 ("x86/mm: Use INVLPGB for kernel TLB flushes")
> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxx>
> 
This same change fell out of my testing with
a reproducer earlier this year, so I know it
works, at least for the test case I have.

I am surprised that it was good enough to be 
a real workaround, but I'll take it ;)

Tested-by: Rik van Riel <riel@xxxxxxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxxx>

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