KVM: x86: Move kvm_set_apic_base() implementation to lapic.c (from x86.c)

Move kvm_set_apic_base() to lapic.c so that the bulk of KVM's local APIC
code resides in lapic.c, regardless of whether or not KVM is emulating the
local APIC in-kernel.  This will also allow making various helpers visible
only to lapic.c.

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20241009181742.1128779-6-seanjc@google.com
Link: https://lore.kernel.org/r/20241101183555.1794700-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

arch/x86/kvm/lapic.c

@@ -2628,6 +2628,27 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 	}
 }
 
+int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
+{
+	enum lapic_mode old_mode = kvm_get_apic_mode(vcpu);
+	enum lapic_mode new_mode = kvm_apic_mode(msr_info->data);
+	u64 reserved_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu) | 0x2ff |
+		(guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE);
+
+	if ((msr_info->data & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID)
+		return 1;
+	if (!msr_info->host_initiated) {
+		if (old_mode == LAPIC_MODE_X2APIC && new_mode == LAPIC_MODE_XAPIC)
+			return 1;
+		if (old_mode == LAPIC_MODE_DISABLED && new_mode == LAPIC_MODE_X2APIC)
+			return 1;
+	}
+
+	kvm_lapic_set_base(vcpu, msr_info->data);
+	kvm_recalculate_apic_map(vcpu->kvm);
+	return 0;
+}
+
 void kvm_apic_update_apicv(struct kvm_vcpu *vcpu)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;

arch/x86/kvm/x86.c

@@ -668,27 +668,6 @@ static void drop_user_return_notifiers(void)
 		kvm_on_user_return(&msrs->urn);
 }
 
-int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
-{
-	enum lapic_mode old_mode = kvm_get_apic_mode(vcpu);
-	enum lapic_mode new_mode = kvm_apic_mode(msr_info->data);
-	u64 reserved_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu) | 0x2ff |
-		(guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE);
-
-	if ((msr_info->data & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID)
-		return 1;
-	if (!msr_info->host_initiated) {
-		if (old_mode == LAPIC_MODE_X2APIC && new_mode == LAPIC_MODE_XAPIC)
-			return 1;
-		if (old_mode == LAPIC_MODE_DISABLED && new_mode == LAPIC_MODE_X2APIC)
-			return 1;
-	}
-
-	kvm_lapic_set_base(vcpu, msr_info->data);
-	kvm_recalculate_apic_map(vcpu->kvm);
-	return 0;
-}
-
 /*
  * Handle a fault on a hardware virtualization (VMX or SVM) instruction.
  *