linux-kernel - [PATCH v2 04/10] KVM: x86: Refactor kvm_x86_ops.get_msr_feature() to avoid kvm_msr

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Message-ID: <20240802181935.292540-5-seanjc@google.com>
Date: Fri,  2 Aug 2024 11:19:29 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Tom Lendacky <thomas.lendacky@....com>, Weijiang Yang <weijiang.yang@...el.com>
Subject: [PATCH v2 04/10] KVM: x86: Refactor kvm_x86_ops.get_msr_feature() to
 avoid kvm_msr_entry

Refactor get_msr_feature() to take the index and data pointer as distinct
parameters in anticipation of eliminating "struct kvm_msr_entry" usage
further up the primary callchain.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/include/asm/kvm_host.h |  2 +-
 arch/x86/kvm/svm/svm.c          | 16 +++++++---------
 arch/x86/kvm/vmx/vmx.c          |  6 +++---
 arch/x86/kvm/vmx/x86_ops.h      |  2 +-
 arch/x86/kvm/x86.c              |  2 +-
 5 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 950a03e0181e..ac7a1387a9a0 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1805,7 +1805,7 @@ struct kvm_x86_ops {
 	int (*vm_move_enc_context_from)(struct kvm *kvm, unsigned int source_fd);
 	void (*guest_memory_reclaimed)(struct kvm *kvm);
 
-	int (*get_msr_feature)(struct kvm_msr_entry *entry);
+	int (*get_msr_feature)(u32 msr, u64 *data);
 
 	int (*check_emulate_instruction)(struct kvm_vcpu *vcpu, int emul_type,
 					 void *insn, int insn_len);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 909ba79067f8..c22e2b235882 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2825,14 +2825,14 @@ static int efer_trap(struct kvm_vcpu *vcpu)
 	return kvm_complete_insn_gp(vcpu, ret);
 }
 
-static int svm_get_msr_feature(struct kvm_msr_entry *msr)
+static int svm_get_msr_feature(u32 msr, u64 *data)
 {
-	msr->data = 0;
+	*data = 0;
 
-	switch (msr->index) {
+	switch (msr) {
 	case MSR_AMD64_DE_CFG:
 		if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC))
-			msr->data |= MSR_AMD64_DE_CFG_LFENCE_SERIALIZE;
+			*data |= MSR_AMD64_DE_CFG_LFENCE_SERIALIZE;
 		break;
 	default:
 		return KVM_MSR_RET_UNSUPPORTED;
@@ -3179,14 +3179,12 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		kvm_pr_unimpl_wrmsr(vcpu, ecx, data);
 		break;
 	case MSR_AMD64_DE_CFG: {
-		struct kvm_msr_entry msr_entry;
+		u64 supported_de_cfg;
 
-		msr_entry.index = msr->index;
-		if (svm_get_msr_feature(&msr_entry))
+		if (svm_get_msr_feature(ecx, &supported_de_cfg))
 			return 1;
 
-		/* Check the supported bits */
-		if (data & ~msr_entry.data)
+		if (data & ~supported_de_cfg)
 			return 1;
 
 		/*
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e5b253e4d421..3d24eb4aeca2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1998,13 +1998,13 @@ static inline bool is_vmx_feature_control_msr_valid(struct vcpu_vmx *vmx,
 	return !(msr->data & ~valid_bits);
 }
 
-int vmx_get_msr_feature(struct kvm_msr_entry *msr)
+int vmx_get_msr_feature(u32 msr, u64 *data)
 {
-	switch (msr->index) {
+	switch (msr) {
 	case KVM_FIRST_EMULATED_VMX_MSR ... KVM_LAST_EMULATED_VMX_MSR:
 		if (!nested)
 			return 1;
-		return vmx_get_vmx_msr(&vmcs_config.nested, msr->index, &msr->data);
+		return vmx_get_vmx_msr(&vmcs_config.nested, msr, data);
 	default:
 		return KVM_MSR_RET_UNSUPPORTED;
 	}
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index ce3221cd1d01..9a0304eb847b 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -56,7 +56,7 @@ bool vmx_has_emulated_msr(struct kvm *kvm, u32 index);
 void vmx_msr_filter_changed(struct kvm_vcpu *vcpu);
 void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu);
 void vmx_update_exception_bitmap(struct kvm_vcpu *vcpu);
-int vmx_get_msr_feature(struct kvm_msr_entry *msr);
+int vmx_get_msr_feature(u32 msr, u64 *data);
 int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
 u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg);
 void vmx_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a55f73ce7b2e..e64aba978380 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1675,7 +1675,7 @@ static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
 		rdmsrl_safe(msr->index, &msr->data);
 		break;
 	default:
-		return kvm_x86_call(get_msr_feature)(msr);
+		return kvm_x86_call(get_msr_feature)(msr->index, &msr->data);
 	}
 	return 0;
 }
-- 
2.46.0.rc2.264.g509ed76dc8-goog