[PATCH v9 19/27] KVM: x86: Use KVM-governed feature framework to track "SHSTK/IBT enabled"

Yang Weijiang
2024-01-24T02:42:45Z

Use the governed feature framework to track whether X86_FEATURE_SHSTK
and X86_FEATURE_IBT features can be used by userspace and guest, i.e.,
the features can be used iff both KVM and guest CPUID can support them.

TODO: remove this patch once Sean's refactor to "KVM-governed" framework
is upstreamed. See the work here [*].

[*]: https://lore.kernel.org/all/20231110235528.1561679-1-seanjc@google.com/

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/governed_features.h | 2 ++
arch/x86/kvm/vmx/vmx.c | 2 ++
2 files changed, 4 insertions(+)

diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index ad463b1ed4e4..daf0c0a3e29c 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -17,6 +17,8 @@ KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)
KVM_GOVERNED_X86_FEATURE(VGIF)
KVM_GOVERNED_X86_FEATURE(VNMI)
KVM_GOVERNED_X86_FEATURE(LAM)
+KVM_GOVERNED_X86_FEATURE(SHSTK)
+KVM_GOVERNED_X86_FEATURE(IBT)

#undef KVM_GOVERNED_X86_FEATURE
#undef KVM_GOVERNED_FEATURE
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b2f6bcf3bf9b..29a0fd3e83c5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7764,6 +7764,8 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)

kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VMX);
kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_LAM);
+ kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_SHSTK);
+ kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_IBT);

vmx_setup_uret_msrs(vmx);

--
2.39.3