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authorAndi Kleen <ak@linux.intel.com>2019-01-19 03:50:23 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-14 20:19:40 +0300
commiteb2aa332cfe39e05585534017ad94b7717dbdf85 (patch)
tree9d072863197b587504b9fe498c7e8d87a3b118eb /arch/x86/kvm
parent1cdffecc34ba5d5af61b456fb0f46abbb3a86816 (diff)
downloadlinux-eb2aa332cfe39e05585534017ad94b7717dbdf85.tar.xz
x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests
commit 6c4dbbd14730c43f4ed808a9c42ca41625925c22 upstream. 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: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> [bwh: Backported to 4.9: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/cpuid.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 82c670b7bda1..fc8236fd2495 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -382,7 +382,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
/* cpuid 7.0.edx*/
const u32 kvm_cpuid_7_0_edx_x86_features =
F(SPEC_CTRL) | F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) |
- F(INTEL_STIBP);
+ F(INTEL_STIBP) | F(MD_CLEAR);
/* all calls to cpuid_count() should be made on the same cpu */
get_cpu();