diff options
| author | Borislav Petkov (AMD) <bp@alien8.de> | 2023-10-07 13:57:02 +0300 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-10-11 12:00:11 +0300 |
| commit | f454b18e07f518bcd0c05af17a2239138bff52de (patch) | |
| tree | 40a451e8c48c061044510f55109a206ed049d5ff /arch/x86 | |
| parent | 025d5ac978cc3b47874cc1c03ab096a78b49f278 (diff) | |
| download | linux-f454b18e07f518bcd0c05af17a2239138bff52de.tar.xz | |
x86/cpu: Fix AMD erratum #1485 on Zen4-based CPUs
Fix erratum #1485 on Zen4 parts where running with STIBP disabled can
cause an #UD exception. The performance impact of the fix is negligible.
Reported-by: René Rebe <rene@exactcode.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: René Rebe <rene@exactcode.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/D99589F4-BC5D-430B-87B2-72C20370CF57@exactcode.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 9 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 8 |
2 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 1d111350197f..b37abb55e948 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -637,12 +637,17 @@ /* AMD Last Branch Record MSRs */ #define MSR_AMD64_LBR_SELECT 0xc000010e -/* Fam 17h MSRs */ -#define MSR_F17H_IRPERF 0xc00000e9 +/* Zen4 */ +#define MSR_ZEN4_BP_CFG 0xc001102e +#define MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT 5 +/* Zen 2 */ #define MSR_ZEN2_SPECTRAL_CHICKEN 0xc00110e3 #define MSR_ZEN2_SPECTRAL_CHICKEN_BIT BIT_ULL(1) +/* Fam 17h MSRs */ +#define MSR_F17H_IRPERF 0xc00000e9 + /* Fam 16h MSRs */ #define MSR_F16H_L2I_PERF_CTL 0xc0010230 #define MSR_F16H_L2I_PERF_CTR 0xc0010231 diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 03ef962a6992..ece2b5b7b0fe 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -80,6 +80,10 @@ static const int amd_div0[] = AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0x00, 0x0, 0x2f, 0xf), AMD_MODEL_RANGE(0x17, 0x50, 0x0, 0x5f, 0xf)); +static const int amd_erratum_1485[] = + AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x19, 0x10, 0x0, 0x1f, 0xf), + AMD_MODEL_RANGE(0x19, 0x60, 0x0, 0xaf, 0xf)); + static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum) { int osvw_id = *erratum++; @@ -1149,6 +1153,10 @@ static void init_amd(struct cpuinfo_x86 *c) pr_notice_once("AMD Zen1 DIV0 bug detected. Disable SMT for full protection.\n"); setup_force_cpu_bug(X86_BUG_DIV0); } + + if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && + cpu_has_amd_erratum(c, amd_erratum_1485)) + msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT); } #ifdef CONFIG_X86_32 |