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authorAndi Kleen <ak@linux.intel.com>2019-01-18 16:50:23 -0800
committerBen Hutchings <ben@decadent.org.uk>2019-05-22 23:15:21 +0100
commit5b4088f4ee70a3f6ea8001e17a17bc10ce4ebeb1 (patch)
treecd4121a384f4d0d695dfd2d9913c3ac4e8bea946 /arch
parent8a73fd7fa643248d978595054a82bb7cb00942d5 (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> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
-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 77484080e7c6..95cd58cdee99 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -320,7 +320,7 @@ 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();