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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 19:17:10 +0200
commit87f96d5e7525f480d6ad63e866b820c29cec1aaa (patch)
treeeae20e9dde86a19203af32376ae9d6fd45cb07ba /arch/x86
parent78157c977674a9087e7672c422156c16e7578ccc (diff)
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>
Diffstat (limited to 'arch/x86')
-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 c07958b59f50..39501e7afdb4 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -410,7 +410,8 @@ 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();