diff options
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 19 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 7 |
2 files changed, 15 insertions, 11 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 8c257db23d90..ffecf4e9444e 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -1284,16 +1284,21 @@ void set_dr_addr_mask(unsigned long mask, int dr) bool cpu_has_ibpb_brtype_microcode(void) { - u8 fam = boot_cpu_data.x86; - + switch (boot_cpu_data.x86) { /* Zen1/2 IBPB flushes branch type predictions too. */ - if (fam == 0x17) + case 0x17: return boot_cpu_has(X86_FEATURE_AMD_IBPB); - /* Poke the MSR bit on Zen3/4 to check its presence. */ - else if (fam == 0x19) - return !wrmsrl_safe(MSR_IA32_PRED_CMD, PRED_CMD_SBPB); - else + case 0x19: + /* Poke the MSR bit on Zen3/4 to check its presence. */ + if (!wrmsrl_safe(MSR_IA32_PRED_CMD, PRED_CMD_SBPB)) { + setup_force_cpu_cap(X86_FEATURE_SBPB); + return true; + } else { + return false; + } + default: return false; + } } static void zenbleed_check_cpu(void *unused) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 99bca21a3e62..d31639e3ce28 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2313,14 +2313,13 @@ static void __init srso_select_mitigation(void) * flags for guests. */ setup_force_cpu_cap(X86_FEATURE_IBPB_BRTYPE); - setup_force_cpu_cap(X86_FEATURE_SBPB); /* * Zen1/2 with SMT off aren't vulnerable after the right * IBPB microcode has been applied. */ if ((boot_cpu_data.x86 < 0x19) && - (cpu_smt_control == CPU_SMT_DISABLED)) + (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) setup_force_cpu_cap(X86_FEATURE_SRSO_NO); } @@ -2393,8 +2392,8 @@ static void __init srso_select_mitigation(void) pr_info("%s%s\n", srso_strings[srso_mitigation], (has_microcode ? "" : ", no microcode")); pred_cmd: - if (boot_cpu_has(X86_FEATURE_SRSO_NO) || - srso_cmd == SRSO_CMD_OFF) + if ((boot_cpu_has(X86_FEATURE_SRSO_NO) || srso_cmd == SRSO_CMD_OFF) && + boot_cpu_has(X86_FEATURE_SBPB)) x86_pred_cmd = PRED_CMD_SBPB; } |