Re: AMD SME + KASAN = doom

[Qian Cai]

> On Jun 13, 2020, at 11:54 AM, Borislav Petkov <bp@xxxxxxx> wrote:
> 
> $ head arch/x86/mm/Makefile
> # SPDX-License-Identifier: GPL-2.0
> # Kernel does not boot with instrumentation of tlb.c and mem_encrypt*.c
> KCOV_INSTRUMENT_tlb.o                   := n
> KCOV_INSTRUMENT_mem_encrypt.o           := n
> KCOV_INSTRUMENT_mem_encrypt_identity.o  := n
> 
> KASAN_SANITIZE_mem_encrypt.o            := n
> KASAN_SANITIZE_mem_encrypt_identity.o   := n
> 
> so something else needs to be de-KASAN-ed too.

Okay, Iâll try to figure out what else needs to be done.

> 
> For now flip your Subject: AMD SME - KASAN = boot.

Which is a bit of shame because KASAN is proved useful for testing and at the same time SME could flags some issues with drivers like megasas_raid (where the driver will do a  firmware dump during the boot which I plan to debug more a bit later).