KVM: x86: Rename handle_fastpath_set_msr_irqoff() to handle_fastpath_wrmsr()

Rename the WRMSR fastpath API to drop "irqoff", as that information is
redundant (the fastpath always runs with IRQs disabled), and to prepare
for adding a fastpath for the immediate variant of WRMSRNS.

No functional change intended.

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
[sean: split to separate patch, write changelog]
Link: https://lore.kernel.org/r/20250805202224.1475590-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: xinli-intel

arch/x86/kvm/svm/svm.c

@@ -4197,7 +4197,7 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
 	case SVM_EXIT_MSR:
 		if (!control->exit_info_1)
 			break;
-		return handle_fastpath_set_msr_irqoff(vcpu);
+		return handle_fastpath_wrmsr(vcpu);
 	case SVM_EXIT_HLT:
 		return handle_fastpath_hlt(vcpu);
 	case SVM_EXIT_INVD:

arch/x86/kvm/vmx/vmx.c

@@ -7170,7 +7170,7 @@ static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu,
 
 	switch (vmx_get_exit_reason(vcpu).basic) {
 	case EXIT_REASON_MSR_WRITE:
-		return handle_fastpath_set_msr_irqoff(vcpu);
+		return handle_fastpath_wrmsr(vcpu);
 	case EXIT_REASON_PREEMPTION_TIMER:
 		return handle_fastpath_preemption_timer(vcpu, force_immediate_exit);
 	case EXIT_REASON_HLT:

arch/x86/kvm/x86.c

@@ -2143,7 +2143,7 @@ static inline bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu)
 	       kvm_request_pending(vcpu) || xfer_to_guest_mode_work_pending();
 }
 
-fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu)
+fastpath_t handle_fastpath_wrmsr(struct kvm_vcpu *vcpu)
 {
 	u64 data = kvm_read_edx_eax(vcpu);
 	u32 msr = kvm_rcx_read(vcpu);
@@ -2168,7 +2168,7 @@ fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu)
 
 	return EXIT_FASTPATH_REENTER_GUEST;
 }
-EXPORT_SYMBOL_GPL(handle_fastpath_set_msr_irqoff);
+EXPORT_SYMBOL_GPL(handle_fastpath_wrmsr);
 
 /*
  * Adapt set_msr() to msr_io()'s calling convention

arch/x86/kvm/x86.h

@@ -437,7 +437,7 @@ int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type,
 				    void *insn, int insn_len);
 int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 			    int emulation_type, void *insn, int insn_len);
-fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu);
+fastpath_t handle_fastpath_wrmsr(struct kvm_vcpu *vcpu);
 fastpath_t handle_fastpath_hlt(struct kvm_vcpu *vcpu);
 fastpath_t handle_fastpath_invd(struct kvm_vcpu *vcpu);