This is a note to let you know that I've just added the patch titled
x86/cpu: Allow reducing x86_phys_bits during early_identify_cpu()
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-cpu-allow-reducing-x86_phys_bits-during-early_identify_cpu.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9a458198eba98b7207669a166e64d04b04cb651b Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Date: Thu, 1 Feb 2024 00:09:01 +0100
Subject: x86/cpu: Allow reducing x86_phys_bits during early_identify_cpu()
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
commit 9a458198eba98b7207669a166e64d04b04cb651b upstream.
In commit fbf6449f84bf ("x86/sev-es: Set x86_virt_bits to the correct
value straight away, instead of a two-phase approach"), the initialization
of c->x86_phys_bits was moved after this_cpu->c_early_init(c). This is
incorrect because early_init_amd() expected to be able to reduce the
value according to the contents of CPUID leaf 0x8000001f.
Fortunately, the bug was negated by init_amd()'s call to early_init_amd(),
which does reduce x86_phys_bits in the end. However, this is very
late in the boot process and, most notably, the wrong value is used for
x86_phys_bits when setting up MTRRs.
To fix this, call get_cpu_address_sizes() as soon as X86_FEATURE_CPUID is
set/cleared, and c->extended_cpuid_level is retrieved.
Fixes: fbf6449f84bf ("x86/sev-es: Set x86_virt_bits to the correct value straight away, instead of a two-phase approach")
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc:stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/all/20240131230902.1867092-2-pbonzini%40redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/common.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1596,6 +1596,7 @@ static void __init early_identify_cpu(st
get_cpu_vendor(c);
get_cpu_cap(c);
setup_force_cpu_cap(X86_FEATURE_CPUID);
+ get_cpu_address_sizes(c);
cpu_parse_early_param();
if (this_cpu->c_early_init)
@@ -1608,10 +1609,9 @@ static void __init early_identify_cpu(st
this_cpu->c_bsp_init(c);
} else {
setup_clear_cpu_cap(X86_FEATURE_CPUID);
+ get_cpu_address_sizes(c);
}
- get_cpu_address_sizes(c);
-
setup_force_cpu_cap(X86_FEATURE_ALWAYS);
cpu_set_bug_bits(c);
Patches currently in stable-queue which might be from pbonzini@xxxxxxxxxx are
queue-6.7/x86-cpu-intel-detect-tme-keyid-bits-before-setting-mtrr-mask-registers.patch
queue-6.7/x86-cpu-allow-reducing-x86_phys_bits-during-early_identify_cpu.patch
