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x86/CPU/AMD: Fix disabling XSAVES on AMD family 0x17 due to erratum

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The stable kernel version backport of the patch disabling XSAVES on AMD
Zen family 0x17 applied this change to the wrong function (init_amd_k6()),
one which isn't called for Zen CPUs.

Move the erratum to the init_amd_zn() function instead.

Add an explicit family 0x17 check to the erratum so nothing will break if
someone naively makes this kernel version call init_amd_zn() also for
family 0x19 in the future (as the current upstream code does).

Fixes: f028a7db9824 ("x86/CPU/AMD: Disable XSAVES on AMD family 0x17")
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 771df0145297a1a9f1e7f799da43f8b0f8850e7c)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
This commit is contained in:
Maciej S. Szmigiero 2024-01-25 19:06:54 +01:00 committed by Vegard Nossum
parent 3b71309c66
commit f3497ef960
1 changed files with 11 additions and 9 deletions
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20
arch/x86/kernel/cpu/amd.c
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@ -198,15 +198,6 @@ static void init_amd_k6(struct cpuinfo_x86 *c)
return;
}
#endif
/*
* Work around Erratum 1386. The XSAVES instruction malfunctions in
* certain circumstances on Zen1/2 uarch, and not all parts have had
* updated microcode at the time of writing (March 2023).
*
* Affected parts all have no supervisor XSAVE states, meaning that
* the XSAVEC instruction (which works fine) is equivalent.
*/
clear_cpu_cap(c, X86_FEATURE_XSAVES);
}
static void init_amd_k7(struct cpuinfo_x86 *c)
@ -880,6 +871,17 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
if (c->x86 == 0x19 && !cpu_has(c, X86_FEATURE_BTC_NO))
set_cpu_cap(c, X86_FEATURE_BTC_NO);
}
/*
* Work around Erratum 1386. The XSAVES instruction malfunctions in
* certain circumstances on Zen1/2 uarch, and not all parts have had
* updated microcode at the time of writing (March 2023).
*
* Affected parts all have no supervisor XSAVE states, meaning that
* the XSAVEC instruction (which works fine) is equivalent.
*/
if (c->x86 == 0x17)
clear_cpu_cap(c, X86_FEATURE_XSAVES);
}
static void init_amd(struct cpuinfo_x86 *c)