On Tue, Jan 23, 2018 at 08:58:36PM +0000, David Woodhouse wrote: > +static const struct sku_microcode spectre_bad_microcodes[] = { > + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0B, 0x80 }, > + { INTEL_FAM6_KABYLAKE_MOBILE, 0x0A, 0x80 }, > + { INTEL_FAM6_KABYLAKE_MOBILE, 0x0A, 0x80 }, > + { INTEL_FAM6_KABYLAKE_MOBILE, 0x09, 0x80 }, > + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x80 }, > + { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003C }, > + { INTEL_FAM6_SKYLAKE_MOBILE, 0x03, 0x000000C2 }, > + { INTEL_FAM6_SKYLAKE_DESKTOP, 0x03, 0x000000C2 }, > + { INTEL_FAM6_BROADWELL_CORE, 0x04, 0x28 }, > + { INTEL_FAM6_BROADWELL_GT3E, 0x01, 0x0000001B }, > + { INTEL_FAM6_HASWELL_ULT, 0x01, 0x21 }, > + { INTEL_FAM6_HASWELL_GT3E, 0x01, 0x18 }, > + { INTEL_FAM6_HASWELL_CORE, 0x03, 0x23 }, > + { INTEL_FAM6_IVYBRIDGE_X, 0x04, 0x42a }, > + { INTEL_FAM6_HASWELL_X, 0x02, 0x3b }, > + { INTEL_FAM6_HASWELL_X, 0x04, 0x10 }, > + { INTEL_FAM6_HASWELL_CORE, 0x03, 0x23 }, > + { INTEL_FAM6_BROADWELL_XEON_D, 0x02, 0x14 }, > + { INTEL_FAM6_BROADWELL_XEON_D, 0x03, 0x7000011 }, > + { INTEL_FAM6_BROADWELL_GT3E, 0x01, 0x0000001B }, > + /* For 406F1 Intel says "0x25, 0x23" while VMware says 0x0B000025 > + * and a real CPU has a firmware in the 0x0B0000xx range. So: */ > + { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, > + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x80 }, > + { INTEL_FAM6_SKYLAKE_X, 0x03, 0x100013e }, > + { INTEL_FAM6_SKYLAKE_X, 0x04, 0x200003c }, > +}; Typically tglx likes to use x86_match_cpu() for these things; see also commit: bd9240a18edfb ("x86/apic: Add TSC_DEADLINE quirk due to errata"). > + > +static int bad_spectre_microcode(struct cpuinfo_x86 *c) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) { > + if (c->x86_model == spectre_bad_microcodes[i].model && > + c->x86_mask == spectre_bad_microcodes[i].stepping) > + return (c->microcode <= spectre_bad_microcodes[i].microcode); > + } > + return 0; > +} The above is Intel only, you should check vendor too I think. > static void early_init_intel(struct cpuinfo_x86 *c) > { > u64 misc_enable; > @@ -122,6 +173,18 @@ static void early_init_intel(struct cpuinfo_x86 *c) > if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) > c->microcode = intel_get_microcode_revision(); > > + if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) || > + cpu_has(c, X86_FEATURE_AMD_SPEC_CTRL) || > + cpu_has(c, X86_FEATURE_AMD_PRED_CMD) || > + cpu_has(c, X86_FEATURE_AMD_STIBP)) && bad_spectre_microcode(c)) { > + pr_warn("Intel Spectre v2 broken microcode detected; disabling SPEC_CTRL\n"); > + clear_cpu_cap(c, X86_FEATURE_SPEC_CTRL); > + clear_cpu_cap(c, X86_FEATURE_STIBP); > + clear_cpu_cap(c, X86_FEATURE_AMD_SPEC_CTRL); > + clear_cpu_cap(c, X86_FEATURE_AMD_PRED_CMD); > + clear_cpu_cap(c, X86_FEATURE_AMD_STIBP); > + } And since its Intel only, what are those AMD features doing there?