[PATCH v3 08/15] KVM: nSVM: Use KVM-governed feature framework to track "NRIPS enabled"

From: Sean Christopherson
Date: Tue Aug 15 2023 - 16:38:53 EST


Track "NRIPS exposed to L1" via a governed feature flag instead of using
a dedicated bit/flag in vcpu_svm.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/governed_features.h | 1 +
arch/x86/kvm/svm/nested.c | 6 +++---
arch/x86/kvm/svm/svm.c | 4 +---
arch/x86/kvm/svm/svm.h | 1 -
4 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index 22446614bf49..722b66af412c 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -8,6 +8,7 @@ BUILD_BUG()
KVM_GOVERNED_X86_FEATURE(GBPAGES)
KVM_GOVERNED_X86_FEATURE(XSAVES)
KVM_GOVERNED_X86_FEATURE(VMX)
+KVM_GOVERNED_X86_FEATURE(NRIPS)

#undef KVM_GOVERNED_X86_FEATURE
#undef KVM_GOVERNED_FEATURE
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 3342cc4a5189..9092f3f8dccf 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -716,7 +716,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
* what a nrips=0 CPU would do (L1 is responsible for advancing RIP
* prior to injecting the event).
*/
- if (svm->nrips_enabled)
+ if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
vmcb02->control.next_rip = svm->nested.ctl.next_rip;
else if (boot_cpu_has(X86_FEATURE_NRIPS))
vmcb02->control.next_rip = vmcb12_rip;
@@ -726,7 +726,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
svm->soft_int_injected = true;
svm->soft_int_csbase = vmcb12_csbase;
svm->soft_int_old_rip = vmcb12_rip;
- if (svm->nrips_enabled)
+ if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
svm->soft_int_next_rip = svm->nested.ctl.next_rip;
else
svm->soft_int_next_rip = vmcb12_rip;
@@ -1026,7 +1026,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
if (vmcb12->control.exit_code != SVM_EXIT_ERR)
nested_save_pending_event_to_vmcb12(svm, vmcb12);

- if (svm->nrips_enabled)
+ if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
vmcb12->control.next_rip = vmcb02->control.next_rip;

vmcb12->control.int_ctl = svm->nested.ctl.int_ctl;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index d67f6e23dcd2..c8b97cb3138c 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4288,9 +4288,7 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
guest_cpuid_has(vcpu, X86_FEATURE_XSAVE))
kvm_governed_feature_set(vcpu, X86_FEATURE_XSAVES);

- /* Update nrips enabled cache */
- svm->nrips_enabled = kvm_cpu_cap_has(X86_FEATURE_NRIPS) &&
- guest_cpuid_has(vcpu, X86_FEATURE_NRIPS);
+ kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_NRIPS);

svm->tsc_scaling_enabled = tsc_scaling && guest_cpuid_has(vcpu, X86_FEATURE_TSCRATEMSR);
svm->lbrv_enabled = lbrv && guest_cpuid_has(vcpu, X86_FEATURE_LBRV);
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 5115b35a4d31..e147f2046ffa 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -259,7 +259,6 @@ struct vcpu_svm {
bool soft_int_injected;

/* optional nested SVM features that are enabled for this guest */
- bool nrips_enabled : 1;
bool tsc_scaling_enabled : 1;
bool v_vmload_vmsave_enabled : 1;
bool lbrv_enabled : 1;
--
2.41.0.694.ge786442a9b-goog