diff options
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 138 |
1 files changed, 137 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 7b8382c11788..ed4417500700 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -59,6 +59,7 @@ #include <asm/cpu_device_id.h> #include <asm/uv/uv.h> #include <asm/sigframe.h> +#include <asm/traps.h> #include "cpu.h" @@ -88,6 +89,83 @@ EXPORT_SYMBOL_GPL(get_llc_id); /* L2 cache ID of each logical CPU */ DEFINE_PER_CPU_READ_MOSTLY(u16, cpu_l2c_id) = BAD_APICID; +static struct ppin_info { + int feature; + int msr_ppin_ctl; + int msr_ppin; +} ppin_info[] = { + [X86_VENDOR_INTEL] = { + .feature = X86_FEATURE_INTEL_PPIN, + .msr_ppin_ctl = MSR_PPIN_CTL, + .msr_ppin = MSR_PPIN + }, + [X86_VENDOR_AMD] = { + .feature = X86_FEATURE_AMD_PPIN, + .msr_ppin_ctl = MSR_AMD_PPIN_CTL, + .msr_ppin = MSR_AMD_PPIN + }, +}; + +static const struct x86_cpu_id ppin_cpuids[] = { + X86_MATCH_FEATURE(X86_FEATURE_AMD_PPIN, &ppin_info[X86_VENDOR_AMD]), + X86_MATCH_FEATURE(X86_FEATURE_INTEL_PPIN, &ppin_info[X86_VENDOR_INTEL]), + + /* Legacy models without CPUID enumeration */ + X86_MATCH_INTEL_FAM6_MODEL(IVYBRIDGE_X, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_D, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL, &ppin_info[X86_VENDOR_INTEL]), + X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM, &ppin_info[X86_VENDOR_INTEL]), + + {} +}; + +static void ppin_init(struct cpuinfo_x86 *c) +{ + const struct x86_cpu_id *id; + unsigned long long val; + struct ppin_info *info; + + id = x86_match_cpu(ppin_cpuids); + if (!id) + return; + + /* + * Testing the presence of the MSR is not enough. Need to check + * that the PPIN_CTL allows reading of the PPIN. + */ + info = (struct ppin_info *)id->driver_data; + + if (rdmsrl_safe(info->msr_ppin_ctl, &val)) + goto clear_ppin; + + if ((val & 3UL) == 1UL) { + /* PPIN locked in disabled mode */ + goto clear_ppin; + } + + /* If PPIN is disabled, try to enable */ + if (!(val & 2UL)) { + wrmsrl_safe(info->msr_ppin_ctl, val | 2UL); + rdmsrl_safe(info->msr_ppin_ctl, &val); + } + + /* Is the enable bit set? */ + if (val & 2UL) { + c->ppin = __rdmsr(info->msr_ppin); + set_cpu_cap(c, info->feature); + return; + } + +clear_ppin: + clear_cpu_cap(c, info->feature); +} + /* correctly size the local cpu masks */ void __init setup_cpu_local_masks(void) { @@ -361,7 +439,8 @@ out: /* These bits should not change their value after CPU init is finished. */ static const unsigned long cr4_pinned_mask = - X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | X86_CR4_FSGSBASE; + X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | + X86_CR4_FSGSBASE | X86_CR4_CET; static DEFINE_STATIC_KEY_FALSE_RO(cr_pinning); static unsigned long cr4_pinned_bits __ro_after_init; @@ -515,6 +594,58 @@ static __init int setup_disable_pku(char *arg) __setup("nopku", setup_disable_pku); #endif /* CONFIG_X86_64 */ +#ifdef CONFIG_X86_KERNEL_IBT + +__noendbr u64 ibt_save(void) +{ + u64 msr = 0; + + if (cpu_feature_enabled(X86_FEATURE_IBT)) { + rdmsrl(MSR_IA32_S_CET, msr); + wrmsrl(MSR_IA32_S_CET, msr & ~CET_ENDBR_EN); + } + + return msr; +} + +__noendbr void ibt_restore(u64 save) +{ + u64 msr; + + if (cpu_feature_enabled(X86_FEATURE_IBT)) { + rdmsrl(MSR_IA32_S_CET, msr); + msr &= ~CET_ENDBR_EN; + msr |= (save & CET_ENDBR_EN); + wrmsrl(MSR_IA32_S_CET, msr); + } +} + +#endif + +static __always_inline void setup_cet(struct cpuinfo_x86 *c) +{ + u64 msr = CET_ENDBR_EN; + + if (!HAS_KERNEL_IBT || + !cpu_feature_enabled(X86_FEATURE_IBT)) + return; + + wrmsrl(MSR_IA32_S_CET, msr); + cr4_set_bits(X86_CR4_CET); + + if (!ibt_selftest()) { + pr_err("IBT selftest: Failed!\n"); + setup_clear_cpu_cap(X86_FEATURE_IBT); + return; + } +} + +__noendbr void cet_disable(void) +{ + if (cpu_feature_enabled(X86_FEATURE_IBT)) + wrmsrl(MSR_IA32_S_CET, 0); +} + /* * Some CPU features depend on higher CPUID levels, which may not always * be available due to CPUID level capping or broken virtualization @@ -1632,6 +1763,7 @@ static void identify_cpu(struct cpuinfo_x86 *c) x86_init_rdrand(c); setup_pku(c); + setup_cet(c); /* * Clear/Set all flags overridden by options, need do it @@ -1655,6 +1787,8 @@ static void identify_cpu(struct cpuinfo_x86 *c) c->x86_capability[i] |= boot_cpu_data.x86_capability[i]; } + ppin_init(c); + /* Init Machine Check Exception if available. */ mcheck_cpu_init(c); @@ -1698,6 +1832,8 @@ void enable_sep_cpu(void) void __init identify_boot_cpu(void) { identify_cpu(&boot_cpu_data); + if (HAS_KERNEL_IBT && cpu_feature_enabled(X86_FEATURE_IBT)) + pr_info("CET detected: Indirect Branch Tracking enabled\n"); #ifdef CONFIG_X86_32 sysenter_setup(); enable_sep_cpu(); |