Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Borislav Petkov <> | Subject | [PATCH 02/13] x86/CPU/AMD: Carve out the erratum 1386 fix | Date | Mon, 20 Nov 2023 11:41:41 +0100 |
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From: "Borislav Petkov (AMD)" <bp@alien8.de>
Call it on the affected CPU generations.
No functional changes.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> --- arch/x86/kernel/cpu/amd.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index fa6ba63ca7e2..b3f939101368 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -984,6 +984,19 @@ static void init_amd_bd(struct cpuinfo_x86 *c) clear_rdrand_cpuid_bit(c); } +static void fix_erratum_1386(struct cpuinfo_x86 *c) +{ + /* + * 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); +} + void init_spectral_chicken(struct cpuinfo_x86 *c) { #ifdef CONFIG_CPU_UNRET_ENTRY @@ -1004,15 +1017,6 @@ void init_spectral_chicken(struct cpuinfo_x86 *c) } } #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_zn(struct cpuinfo_x86 *c) @@ -1040,10 +1044,12 @@ static void init_amd_zn(struct cpuinfo_x86 *c) static void init_amd_zen(struct cpuinfo_x86 *c) { + fix_erratum_1386(c); } static void init_amd_zen2(struct cpuinfo_x86 *c) { + fix_erratum_1386(c); } static void init_amd_zen3(struct cpuinfo_x86 *c) -- 2.42.0.rc0.25.ga82fb66fed25
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