linux-kernel - [PATCH 08/12] KVM: nSVM: Use KVM-governed feature framework to track "vVM{SAVE,LOAD} enabled"

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Message-ID: <20230217231022.816138-9-seanjc@google.com>
Date:   Fri, 17 Feb 2023 15:10:18 -0800
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 08/12] KVM: nSVM: Use KVM-governed feature framework to track
 "vVM{SAVE,LOAD} enabled"

Track "virtual VMSAVE/VMLOAD 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@...gle.com>
---
 arch/x86/kvm/governed_features.h | 1 +
 arch/x86/kvm/svm/nested.c        | 2 +-
 arch/x86/kvm/svm/svm.c           | 5 ++---
 arch/x86/kvm/svm/svm.h           | 1 -
 4 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index 0335576a80a8..b66b9d550f33 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -9,6 +9,7 @@ KVM_GOVERNED_X86_FEATURE(GBPAGES)
 KVM_GOVERNED_X86_FEATURE(XSAVES)
 KVM_GOVERNED_X86_FEATURE(NRIPS)
 KVM_GOVERNED_X86_FEATURE(TSCRATEMSR)
+KVM_GOVERNED_X86_FEATURE(V_VMSAVE_VMLOAD)
 
 #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 30e00c4e07c7..6a96058c0e48 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -107,7 +107,7 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
 
 static bool nested_vmcb_needs_vls_intercept(struct vcpu_svm *svm)
 {
-	if (!svm->v_vmload_vmsave_enabled)
+	if (!guest_can_use(&svm->vcpu, X86_FEATURE_V_VMSAVE_VMLOAD))
 		return true;
 
 	if (!nested_npt_enabled(svm))
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index dd4aead5462c..b3f0271c73b9 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1162,8 +1162,6 @@ static inline void init_vmcb_after_set_cpuid(struct kvm_vcpu *vcpu)
 
 		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_EIP, 0, 0);
 		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_ESP, 0, 0);
-
-		svm->v_vmload_vmsave_enabled = false;
 	} else {
 		/*
 		 * If hardware supports Virtual VMLOAD VMSAVE then enable it
@@ -4153,7 +4151,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 
 	svm->lbrv_enabled = lbrv && guest_cpuid_has(vcpu, X86_FEATURE_LBRV);
 
-	svm->v_vmload_vmsave_enabled = vls && guest_cpuid_has(vcpu, X86_FEATURE_V_VMSAVE_VMLOAD);
+	if (vls && !guest_cpuid_is_intel(vcpu))
+		kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_V_VMSAVE_VMLOAD);
 
 	svm->pause_filter_enabled = kvm_cpu_cap_has(X86_FEATURE_PAUSEFILTER) &&
 			guest_cpuid_has(vcpu, X86_FEATURE_PAUSEFILTER);
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a523cfcdd12e..1e3e7462b1d7 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -258,7 +258,6 @@ struct vcpu_svm {
 	bool soft_int_injected;
 
 	/* optional nested SVM features that are enabled for this guest  */
-	bool v_vmload_vmsave_enabled      : 1;
 	bool lbrv_enabled                 : 1;
 	bool pause_filter_enabled         : 1;
 	bool pause_threshold_enabled      : 1;
-- 
2.39.2.637.g21b0678d19-goog