KVM: x86: Rename msr_filter_changed() => recalc_msr_intercepts()

Rename msr_filter_changed() to recalc_msr_intercepts() and drop the
trampoline wrapper now that both SVM and VMX use a filter-agnostic recalc
helper to react to the new userspace filter.

No functional change intended.

Reviewed-by: Xin Li (Intel) <xin@zytor.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20250610225737.156318-21-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

7 files changed, 15 insertions, 20 deletions

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 9e0c37ea267e..6a24f0a01ff6 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -138,7 +138,7 @@ KVM_X86_OP(check_emulate_instruction)
 KVM_X86_OP(apic_init_signal_blocked)
 KVM_X86_OP_OPTIONAL(enable_l2_tlb_flush)
 KVM_X86_OP_OPTIONAL(migrate_timers)
-KVM_X86_OP(msr_filter_changed)
+KVM_X86_OP(recalc_msr_intercepts)
 KVM_X86_OP(complete_emulated_msr)
 KVM_X86_OP(vcpu_deliver_sipi_vector)
 KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons);
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5e0415a8ee3f..8f38c24cce63 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1897,7 +1897,7 @@ struct kvm_x86_ops {
 	int (*enable_l2_tlb_flush)(struct kvm_vcpu *vcpu);
 
 	void (*migrate_timers)(struct kvm_vcpu *vcpu);
-	void (*msr_filter_changed)(struct kvm_vcpu *vcpu);
+	void (*recalc_msr_intercepts)(struct kvm_vcpu *vcpu);
 	int (*complete_emulated_msr)(struct kvm_vcpu *vcpu, int err);
 
 	void (*vcpu_deliver_sipi_vector)(struct kvm_vcpu *vcpu, u8 vector);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 290823e94557..20f566ca1b37 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -890,11 +890,6 @@ static void svm_recalc_msr_intercepts(struct kvm_vcpu *vcpu)
 	 */
 }
 
-static void svm_msr_filter_changed(struct kvm_vcpu *vcpu)
-{
-	svm_recalc_msr_intercepts(vcpu);
-}
-
 void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb)
 {
 	to_vmcb->save.dbgctl		= from_vmcb->save.dbgctl;
@@ -923,7 +918,6 @@ static void svm_disable_lbrv(struct kvm_vcpu *vcpu)
 	struct vcpu_svm *svm = to_svm(vcpu);
 
 	KVM_BUG_ON(sev_es_guest(vcpu->kvm), vcpu->kvm);
-
 	svm->vmcb->control.virt_ext &= ~LBR_CTL_ENABLE_MASK;
 	svm_recalc_lbr_msr_intercepts(vcpu);
 
@@ -5216,7 +5210,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 
 	.apic_init_signal_blocked = svm_apic_init_signal_blocked,
 
-	.msr_filter_changed = svm_msr_filter_changed,
+	.recalc_msr_intercepts = svm_recalc_msr_intercepts,
 	.complete_emulated_msr = svm_complete_emulated_msr,
 
 	.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 4a6d4460f947..047d314fa4e4 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -220,7 +220,7 @@ static int vt_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	return vmx_get_msr(vcpu, msr_info);
 }
 
-static void vt_msr_filter_changed(struct kvm_vcpu *vcpu)
+static void vt_recalc_msr_intercepts(struct kvm_vcpu *vcpu)
 {
 	/*
 	 * TDX doesn't allow VMM to configure interception of MSR accesses.
@@ -231,7 +231,7 @@ static void vt_msr_filter_changed(struct kvm_vcpu *vcpu)
 	if (is_td_vcpu(vcpu))
 		return;
 
-	vmx_msr_filter_changed(vcpu);
+	vmx_recalc_msr_intercepts(vcpu);
 }
 
 static int vt_complete_emulated_msr(struct kvm_vcpu *vcpu, int err)
@@ -1027,7 +1027,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.apic_init_signal_blocked = vt_op(apic_init_signal_blocked),
 	.migrate_timers = vmx_migrate_timers,
 
-	.msr_filter_changed = vt_op(msr_filter_changed),
+	.recalc_msr_intercepts = vt_op(recalc_msr_intercepts),
 	.complete_emulated_msr = vt_op(complete_emulated_msr),
 
 	.vcpu_deliver_sipi_vector = kvm_vcpu_deliver_sipi_vector,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0ca9f5de37ce..e38f4648e612 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4085,7 +4085,7 @@ void pt_update_intercept_for_msr(struct kvm_vcpu *vcpu)
 	}
 }
 
-static void vmx_recalc_msr_intercepts(struct kvm_vcpu *vcpu)
+void vmx_recalc_msr_intercepts(struct kvm_vcpu *vcpu)
 {
 	if (!cpu_has_vmx_msr_bitmap())
 		return;
@@ -4134,11 +4134,6 @@ static void vmx_recalc_msr_intercepts(struct kvm_vcpu *vcpu)
 	 */
 }
 
-void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
-{
-	vmx_recalc_msr_intercepts(vcpu);
-}
-
 static int vmx_deliver_nested_posted_interrupt(struct kvm_vcpu *vcpu,
 						int vector)
 {
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 0b4f5c5558d0..ffd72f036213 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -52,7 +52,7 @@ void vmx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,
 			   int trig_mode, int vector);
 void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu);
 bool vmx_has_emulated_msr(struct kvm *kvm, u32 index);
-void vmx_msr_filter_changed(struct kvm_vcpu *vcpu);
+void vmx_recalc_msr_intercepts(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_feature_msr(u32 msr, u64 *data);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 179c2c550c8d..7227696c75e6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10927,8 +10927,14 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 			kvm_vcpu_update_apicv(vcpu);
 		if (kvm_check_request(KVM_REQ_APF_READY, vcpu))
 			kvm_check_async_pf_completion(vcpu);
+
+		/*
+		 * Recalc MSR intercepts as userspace may want to intercept
+		 * accesses to MSRs that KVM would otherwise pass through to
+		 * the guest.
+		 */
 		if (kvm_check_request(KVM_REQ_MSR_FILTER_CHANGED, vcpu))
-			kvm_x86_call(msr_filter_changed)(vcpu);
+			kvm_x86_call(recalc_msr_intercepts)(vcpu);
 
 		if (kvm_check_request(KVM_REQ_UPDATE_CPU_DIRTY_LOGGING, vcpu))
 			kvm_x86_call(update_cpu_dirty_logging)(vcpu);