x86/mtrr: Revert 90b926e68f50 ("x86/pat: Fix pat_x_mtrr_type() for MTRR disabled...
authorJuergen Gross <jgross@suse.com>
Thu, 9 Feb 2023 07:22:17 +0000 (08:22 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 9 Jun 2023 08:34:22 +0000 (10:34 +0200)
commit03974abbf2a1dc99d00cadbeb1664c7711e3909a
tree0de2f4c10ba20bbb609a9c94a6ac1e2a630b3a24
parent8db2ea7b80d6539c2c3d4e2ca96ca1bc56b982d9
x86/mtrr: Revert 90b926e68f50 ("x86/pat: Fix pat_x_mtrr_type() for MTRR disabled case")

commit f9f57da2c2d119dbf109e3f6e1ceab7659294046 upstream.

Commit

  90b926e68f50 ("x86/pat: Fix pat_x_mtrr_type() for MTRR disabled case")

broke the use case of running Xen dom0 kernels on machines with an
external disk enclosure attached via USB, see Link tag.

What this commit was originally fixing - SEV-SNP guests on Hyper-V - is
a more specialized situation which has other issues at the moment anyway
so reverting this now and addressing the issue properly later is the
prudent thing to do.

So revert it in time for the 6.2 proper release.

  [ bp: Rewrite commit message. ]

Reported-by: Christian Kujau <lists@nerdbynature.de>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/4fe9541e-4d4c-2b2a-f8c8-2d34a7284930@nerdbynature.de
Cc: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/mm/pat/memtype.c