From 6198041f012eda83d6cfb28912db6061ee2702b4 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost <ehabkost@redhat.com> Date: Wed, 5 Dec 2018 17:19:56 -0200 Subject: [PATCH] kvm: x86: Report STIBP on GET_SUPPORTED_CPUID commit d7b09c827a6cf291f66637a36f46928dd1423184 upstream. Months ago, we have added code to allow direct access to MSR_IA32_SPEC_CTRL to the guest, which makes STIBP available to guests. This was implemented by commits d28b387fb74d ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL") and b2ac58f90540 ("KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL"). However, we never updated GET_SUPPORTED_CPUID to let userspace know that STIBP can be enabled in CPUID. Fix that by updating kvm_cpuid_8000_0008_ebx_x86_features and kvm_cpuid_7_0_edx_x86_features. Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [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> --- arch/x86/kvm/cpuid.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index b6435f3be254..82c670b7bda1 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -356,7 +356,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 0x80000008.ebx */ const u32 kvm_cpuid_8000_0008_ebx_x86_features = F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) | - F(AMD_SSB_NO); + F(AMD_SSB_NO) | F(AMD_STIBP); /* cpuid 0xC0000001.edx */ const u32 kvm_cpuid_C000_0001_edx_x86_features = @@ -381,7 +381,8 @@ 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(SPEC_CTRL) | F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); + F(SPEC_CTRL) | F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | + F(INTEL_STIBP); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); -- 2.30.9