diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 85 |
1 files changed, 46 insertions, 39 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 4edb6f0f628c..860b60273df3 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -394,35 +394,6 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c) per_cpu(cpu_llc_id, cpu) = c->cpu_die_id = c->phys_proc_id; } -static void amd_detect_ppin(struct cpuinfo_x86 *c) -{ - unsigned long long val; - - if (!cpu_has(c, X86_FEATURE_AMD_PPIN)) - return; - - /* When PPIN is defined in CPUID, still need to check PPIN_CTL MSR */ - if (rdmsrl_safe(MSR_AMD_PPIN_CTL, &val)) - goto clear_ppin; - - /* PPIN is locked in disabled mode, clear feature bit */ - if ((val & 3UL) == 1UL) - goto clear_ppin; - - /* If PPIN is disabled, try to enable it */ - if (!(val & 2UL)) { - wrmsrl_safe(MSR_AMD_PPIN_CTL, val | 2UL); - rdmsrl_safe(MSR_AMD_PPIN_CTL, &val); - } - - /* If PPIN_EN bit is 1, return from here; otherwise fall through */ - if (val & 2UL) - return; - -clear_ppin: - clear_cpu_cap(c, X86_FEATURE_AMD_PPIN); -} - u32 amd_get_nodes_per_socket(void) { return nodes_per_socket; @@ -532,7 +503,7 @@ static void bsp_init_amd(struct cpuinfo_x86 *c) va_align.flags = ALIGN_VA_32 | ALIGN_VA_64; /* A random value per boot for bit slice [12:upper_bit) */ - va_align.bits = get_random_int() & va_align.mask; + va_align.bits = get_random_u32() & va_align.mask; } if (cpu_has(c, X86_FEATURE_MWAITX)) @@ -585,6 +556,8 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c) * the SME physical address space reduction value. * If BIOS has not enabled SME then don't advertise the * SME feature (set in scattered.c). + * If the kernel has not enabled SME via any means then + * don't advertise the SME feature. * For SEV: If BIOS has not enabled SEV then don't advertise the * SEV and SEV_ES feature (set in scattered.c). * @@ -607,6 +580,9 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c) if (IS_ENABLED(CONFIG_X86_32)) goto clear_all; + if (!sme_me_mask) + setup_clear_cpu_cap(X86_FEATURE_SME); + rdmsrl(MSR_K7_HWCR, msr); if (!(msr & MSR_K7_HWCR_SMMLOCK)) goto clear_sev; @@ -832,7 +808,7 @@ static void clear_rdrand_cpuid_bit(struct cpuinfo_x86 *c) return; /* - * The nordrand option can clear X86_FEATURE_RDRAND, so check for + * The self-test can clear X86_FEATURE_RDRAND, so check for * RDRAND support using the CPUID function directly. */ if (!(cpuid_ecx(1) & BIT(30)) || rdrand_force) @@ -886,6 +862,28 @@ static void init_amd_bd(struct cpuinfo_x86 *c) clear_rdrand_cpuid_bit(c); } +void init_spectral_chicken(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_CPU_UNRET_ENTRY + u64 value; + + /* + * On Zen2 we offer this chicken (bit) on the altar of Speculation. + * + * This suppresses speculation from the middle of a basic block, i.e. it + * suppresses non-branch predictions. + * + * We use STIBP as a heuristic to filter out Zen2 from the rest of F17H + */ + if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && cpu_has(c, X86_FEATURE_AMD_STIBP)) { + if (!rdmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, &value)) { + value |= MSR_ZEN2_SPECTRAL_CHICKEN_BIT; + wrmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, value); + } + } +#endif +} + static void init_amd_zn(struct cpuinfo_x86 *c) { set_cpu_cap(c, X86_FEATURE_ZEN); @@ -894,12 +892,21 @@ static void init_amd_zn(struct cpuinfo_x86 *c) node_reclaim_distance = 32; #endif - /* - * Fix erratum 1076: CPB feature bit not being set in CPUID. - * Always set it, except when running under a hypervisor. - */ - if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && !cpu_has(c, X86_FEATURE_CPB)) - set_cpu_cap(c, X86_FEATURE_CPB); + /* Fix up CPUID bits, but only if not virtualised. */ + if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) { + + /* Erratum 1076: CPB feature bit not being set in CPUID. */ + if (!cpu_has(c, X86_FEATURE_CPB)) + set_cpu_cap(c, X86_FEATURE_CPB); + + /* + * Zen3 (Fam19 model < 0x10) parts are not susceptible to + * Branch Type Confusion, but predate the allocation of the + * BTC_NO bit. + */ + if (c->x86 == 0x19 && !cpu_has(c, X86_FEATURE_BTC_NO)) + set_cpu_cap(c, X86_FEATURE_BTC_NO); + } } static void init_amd(struct cpuinfo_x86 *c) @@ -931,7 +938,8 @@ static void init_amd(struct cpuinfo_x86 *c) case 0x12: init_amd_ln(c); break; case 0x15: init_amd_bd(c); break; case 0x16: init_amd_jg(c); break; - case 0x17: fallthrough; + case 0x17: init_spectral_chicken(c); + fallthrough; case 0x19: init_amd_zn(c); break; } @@ -947,7 +955,6 @@ static void init_amd(struct cpuinfo_x86 *c) amd_detect_cmp(c); amd_get_topology(c); srat_detect_node(c); - amd_detect_ppin(c); init_amd_cacheinfo(c); |