From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Habkost Subject: [PATCH] kvm: x86: Report STIBP on GET_SUPPORTED_CPUID Date: Wed, 5 Dec 2018 17:19:56 -0200 Message-ID: <20181205191956.31480-1-ehabkost@redhat.com> Cc: Jim Mattson , x86@kernel.org, linux-kernel@vger.kernel.org, KarimAllah Ahmed , David Woodhouse To: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , kvm@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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 --- arch/x86/kvm/cpuid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 7bcfa61375c0..cc6dd65828a4 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -381,7 +381,7 @@ 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 = @@ -411,7 +411,7 @@ 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(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | - F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); + F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); -- 2.18.0.rc1.1.g3f1ff2140