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authorAndi Kleen <ak@linux.intel.com>2019-01-18 16:50:23 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-14 19:17:54 +0200
commitde89ff6f167405a059b6e8b70f0a3ec486d1bc55 (patch)
treea5303472e59a499df429bfc70e2a705e3e069533
parentaca9e8d8e2ce7dca4b3fb7047160f2970066371d (diff)
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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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/x86/kvm/cpuid.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index fe9907517fb4..b810102a9cfa 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -412,7 +412,8 @@ 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(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 */
get_cpu();