KVM: x86: extract KVM_GET_CLOCK/KVM_SET_CLOCK to separate functions

No functional change intended.
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

@@ -5817,6 +5817,54 @@ int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state)
 }
 #endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */
 
+static int kvm_vm_ioctl_get_clock(struct kvm *kvm, void __user *argp)
+{
+	struct kvm_clock_data data;
+	u64 now_ns;
+
+	now_ns = get_kvmclock_ns(kvm);
+	user_ns.clock = now_ns;
+	user_ns.flags = kvm->arch.use_master_clock ? KVM_CLOCK_TSC_STABLE : 0;
+	memset(&user_ns.pad, 0, sizeof(user_ns.pad));
+
+	if (copy_to_user(argp, &data, sizeof(data)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int kvm_vm_ioctl_set_clock(struct kvm *kvm, void __user *argp)
+{
+	struct kvm_arch *ka = &kvm->arch;
+	struct kvm_clock_data data;
+	u64 now_ns;
+
+	if (copy_from_user(&data, argp, sizeof(data)))
+		return -EFAULT;
+
+	if (data.flags)
+		return -EINVAL;
+
+	kvm_hv_invalidate_tsc_page(kvm);
+	kvm_start_pvclock_update(kvm);
+	pvclock_update_vm_gtod_copy(kvm);
+
+	/*
+	 * This pairs with kvm_guest_time_update(): when masterclock is
+	 * in use, we use master_kernel_ns + kvmclock_offset to set
+	 * unsigned 'system_time' so if we use get_kvmclock_ns() (which
+	 * is slightly ahead) here we risk going negative on unsigned
+	 * 'system_time' when 'data.clock' is very small.
+	 */
+	if (kvm->arch.use_master_clock)
+		now_ns = ka->master_kernel_ns;
+	else
+		now_ns = get_kvmclock_base_ns();
+	ka->kvmclock_offset = data.clock - now_ns;
+	kvm_end_pvclock_update(kvm);
+	return 0;
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
@@ -6060,55 +6108,12 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		break;
 	}
 #endif
-	case KVM_SET_CLOCK: {
-		struct kvm_arch *ka = &kvm->arch;
-		struct kvm_clock_data user_ns;
-		u64 now_ns;
-
-		r = -EFAULT;
-		if (copy_from_user(&user_ns, argp, sizeof(user_ns)))
-			goto out;
-
-		r = -EINVAL;
-		if (user_ns.flags)
-			goto out;
-
-		r = 0;
-
-		kvm_hv_invalidate_tsc_page(kvm);
-		kvm_start_pvclock_update(kvm);
-		pvclock_update_vm_gtod_copy(kvm);
-
-		/*
-		 * This pairs with kvm_guest_time_update(): when masterclock is
-		 * in use, we use master_kernel_ns + kvmclock_offset to set
-		 * unsigned 'system_time' so if we use get_kvmclock_ns() (which
-		 * is slightly ahead) here we risk going negative on unsigned
-		 * 'system_time' when 'user_ns.clock' is very small.
-		 */
-		if (kvm->arch.use_master_clock)
-			now_ns = ka->master_kernel_ns;
-		else
-			now_ns = get_kvmclock_base_ns();
-		ka->kvmclock_offset = user_ns.clock - now_ns;
-		kvm_end_pvclock_update(kvm);
+	case KVM_SET_CLOCK:
+		r = kvm_vm_ioctl_set_clock(kvm, argp);
 		break;
-	}
-	case KVM_GET_CLOCK: {
-		struct kvm_clock_data user_ns;
-		u64 now_ns;
-
-		now_ns = get_kvmclock_ns(kvm);
-		user_ns.clock = now_ns;
-		user_ns.flags = kvm->arch.use_master_clock ? KVM_CLOCK_TSC_STABLE : 0;
-		memset(&user_ns.pad, 0, sizeof(user_ns.pad));
-
-		r = -EFAULT;
-		if (copy_to_user(argp, &user_ns, sizeof(user_ns)))
-			goto out;
-		r = 0;
+	case KVM_GET_CLOCK:
+		r = kvm_vm_ioctl_get_clock(kvm, argp);
 		break;
-	}
 	case KVM_MEMORY_ENCRYPT_OP: {
 		r = -ENOTTY;
 		if (kvm_x86_ops.mem_enc_op)