diff options
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8a1f9a889eb4..f2b902200948 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1320,10 +1320,52 @@ static bool __init vulnerable_to_rfds(u64 x86_arch_cap_msr) return cpu_matches(cpu_vuln_blacklist, RFDS); } +static struct x86_cpu_id cpu_latest_microcode[] = { +#include "microcode/intel-ucode-defs.h" + {} +}; + +static bool __init cpu_has_old_microcode(void) +{ + const struct x86_cpu_id *m = x86_match_cpu(cpu_latest_microcode); + + /* Give unknown CPUs a pass: */ + if (!m) { + /* Intel CPUs should be in the list. Warn if not: */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) + pr_info("x86/CPU: Model not found in latest microcode list\n"); + return false; + } + + /* + * Hosts usually lie to guests with a super high microcode + * version. Just ignore what hosts tell guests: + */ + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) + return false; + + /* Consider all debug microcode to be old: */ + if (boot_cpu_data.microcode & BIT(31)) + return true; + + /* Give new microcode a pass: */ + if (boot_cpu_data.microcode >= m->driver_data) + return false; + + /* Uh oh, too old: */ + return true; +} + static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) { u64 x86_arch_cap_msr = x86_read_arch_cap_msr(); + if (cpu_has_old_microcode()) { + pr_warn("x86/CPU: Running old microcode\n"); + setup_force_cpu_bug(X86_BUG_OLD_MICROCODE); + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + } + /* Set ITLB_MULTIHIT bug if cpu is not in the whitelist and not mitigated */ if (!cpu_matches(cpu_vuln_whitelist, NO_ITLB_MULTIHIT) && !(x86_arch_cap_msr & ARCH_CAP_PSCHANGE_MC_NO)) |