Commit 6c4dbbd1 authored by Andi Kleen's avatar Andi Kleen Committed by Thomas Gleixner

x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests

X86_FEATURE_MD_CLEAR is a new CPUID bit which is set when microcode
provides the mechanism to invoke a flush of various exploitable CPU buffers
by invoking the VERW instruction.

Hand it through to guests so they can adjust their mitigations.

This also requires corresponding qemu changes, which are available
separately.

[ tglx: Massaged changelog ]
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: default avatarJon Masters <jcm@redhat.com>
Tested-by: default avatarJon Masters <jcm@redhat.com>
parent e261f209
...@@ -410,7 +410,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, ...@@ -410,7 +410,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
/* cpuid 7.0.edx*/ /* cpuid 7.0.edx*/
const u32 kvm_cpuid_7_0_edx_x86_features = const u32 kvm_cpuid_7_0_edx_x86_features =
F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP); F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
F(MD_CLEAR);
/* all calls to cpuid_count() should be made on the same cpu */ /* all calls to cpuid_count() should be made on the same cpu */
get_cpu(); get_cpu();
......
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