[PATCH v7 19/26] KVM: x86: Use KVM-governed feature framework to track "SHSTK/IBT enabled"

From: Yang Weijiang
Date: Fri Nov 24 2023 - 03:00:34 EST


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@xxxxxxxxxx/

Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
---
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 423a73395c10..db7e21c5ecc2 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -16,6 +16,8 @@ KVM_GOVERNED_X86_FEATURE(PAUSEFILTER)
KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)
KVM_GOVERNED_X86_FEATURE(VGIF)
KVM_GOVERNED_X86_FEATURE(VNMI)
+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 d3d0d74fef70..f6ad5ba5d518 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7762,6 +7762,8 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_XSAVES);

kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VMX);
+ 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);

--
2.27.0