linux-kernel - [PATCH 11/12] KVM: nSVM: Use KVM-governed feature framework to track "vGIF enabled"

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Message-ID: <20230217231022.816138-12-seanjc@google.com>
Date:   Fri, 17 Feb 2023 15:10:21 -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 11/12] KVM: nSVM: Use KVM-governed feature framework to track
 "vGIF enabled"

Track "virtual GIF 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        | 3 ++-
 arch/x86/kvm/svm/svm.c           | 3 ++-
 arch/x86/kvm/svm/svm.h           | 7 +++----
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index 93c7d840e546..b49fdabb88c4 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -13,6 +13,7 @@ KVM_GOVERNED_X86_FEATURE(V_VMSAVE_VMLOAD)
 KVM_GOVERNED_X86_FEATURE(LBRV)
 KVM_GOVERNED_X86_FEATURE(PAUSEFILTER)
 KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)
+KVM_GOVERNED_X86_FEATURE(VGIF)
 
 #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 c38f17ba818e..c73c2acaf4c0 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -648,7 +648,8 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
 	 * exit_int_info, exit_int_info_err, next_rip, insn_len, insn_bytes.
 	 */
 
-	if (svm->vgif_enabled && (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK))
+	if (guest_can_use(vcpu, X86_FEATURE_VGIF) &&
+	    (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK))
 		int_ctl_vmcb12_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
 	else
 		int_ctl_vmcb01_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b18bd0b33942..11068e8eb969 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4163,7 +4163,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 	if (kvm_cpu_cap_has(X86_FEATURE_PFTHRESHOLD))
 		kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_PFTHRESHOLD);
 
-	svm->vgif_enabled = vgif && guest_cpuid_has(vcpu, X86_FEATURE_VGIF);
+	if (vgif)
+		kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VGIF);
 
 	svm_recalc_instruction_intercepts(vcpu, svm);
 
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index c05eea319d28..be5419975694 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -22,6 +22,7 @@
 #include <asm/svm.h>
 #include <asm/sev-common.h>
 
+#include "cpuid.h"
 #include "kvm_cache_regs.h"
 
 #define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)
@@ -257,9 +258,6 @@ struct vcpu_svm {
 	unsigned long soft_int_next_rip;
 	bool soft_int_injected;
 
-	/* optional nested SVM features that are enabled for this guest  */
-	bool vgif_enabled                 : 1;
-
 	u32 ldr_reg;
 	u32 dfr_reg;
 	struct page *avic_backing_page;
@@ -484,7 +482,8 @@ static inline bool svm_is_intercept(struct vcpu_svm *svm, int bit)
 
 static inline bool nested_vgif_enabled(struct vcpu_svm *svm)
 {
-	return svm->vgif_enabled && (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK);
+	return guest_can_use(&svm->vcpu, X86_FEATURE_VGIF) &&
+	       (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK);
 }
 
 static inline struct vmcb *get_vgif_vmcb(struct vcpu_svm *svm)
-- 
2.39.2.637.g21b0678d19-goog