Re: [PATCH v6 00/16] x86/mtrr: fix handling with PAT but without MTRR

From: Juergen Gross
Date: Wed May 31 2023 - 03:29:08 EST


On 30.05.23 17:28, Borislav Petkov wrote:
On Mon, May 22, 2023 at 04:17:50PM +0200, Juergen Gross wrote:
The attached diff is for patch 13.

Merged and pushed out into same branch.

Next issue. Diffing /proc/mtrr shows:

--- proc-mtrr.6.3 2023-05-30 17:00:13.215999483 +0200
+++ proc-mtrr.after 2023-05-30 16:01:38.281997816 +0200
@@ -1,8 +1,8 @@
reg00: base=0x000000000 ( 0MB), size= 2048MB, count=1: write-back
-reg01: base=0x080000000 ( 2048MB), size= 512MB, count=1: write-back
+reg01: base=0x080000000 ( 2048MB), size= 1024MB, count=1: write-back
reg02: base=0x0a0000000 ( 2560MB), size= 256MB, count=1: write-back
reg03: base=0x0ae000000 ( 2784MB), size= 32MB, count=1: uncachable
-reg04: base=0x100000000 ( 4096MB), size= 4096MB, count=1: write-back
+reg04: base=0x100000000 ( 4096MB), size= 256MB, count=1: write-back
reg05: base=0x200000000 ( 8192MB), size= 8192MB, count=1: write-back
reg06: base=0x400000000 (16384MB), size= 1024MB, count=1: write-back
reg07: base=0x440000000 (17408MB), size= 256MB, count=1: write-back


Weird.

Can you please boot the system with the MTRR patches and specify "mtrr=debug"
on the command line? I'd be interested in the raw register values being read
and the resulting memory type map.


Juergen

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