On Wed, Jan 24, 2018 at 04:57:05PM +0000, David Woodhouse wrote: > We don't refuse to load the affected microcodes; just refuse to use SPEC_CTRL > if they're detected. > > AMD has a feature bit for "PRED_CMD only", which Intel didn't do. When > disabling > SPEC_CTRL we can actually turn on that AMD bit to allow IBPB to still be used. > > We handle the other AMD bits here too, because hypervisors *may* have been > exposing those bits even on Intel chips, for fine-grained control of what's > available. > > Signed-off-by: David Woodhouse <[email protected]> > --- > arch/x86/kernel/cpu/intel.c | 76 > +++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 76 insertions(+) > > diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c > index b720dac..f5c7f61 100644 > --- a/arch/x86/kernel/cpu/intel.c > +++ b/arch/x86/kernel/cpu/intel.c > @@ -102,6 +102,64 @@ static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c) > ELF_HWCAP2 |= HWCAP2_RING3MWAIT; > } > > +/* > + * Early microcode releases for the Spectre v2 mitigation were broken. > + * Information taken from; > + * • > https://newsroom.intel.com/wp-content/uploads/sites/11/2018/01/microcode-update-guidance.pdf > + * • https://kb.vmware.com/s/article/52345 > + * • Microcode revisions observed in the wild > + * • releasenote from 20180108 microcode release > + */ > +struct sku_microcode { > + u8 model; > + u8 stepping; > + u32 microcode; > +}; > +static const struct sku_microcode spectre_bad_microcodes[] = { > + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0B, 0x80 }, > + /* Corrected typo in Intel doc */ > + { INTEL_FAM6_KABYLAKE_DESKTOP, 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 }, > + { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, > + /* Dropped repeat of KBL Desktop 906E9, 0x80 */ > + { INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e }, > + /* Dropped repeat of SKX 50654, 0x200003c */
Nit, but why comment that you dropped a repeat? No one cares, do they? You already said above where this info came from. Anyway, not a big deal at all: Reviewed-by: Greg Kroah-Hartman <[email protected]>
