kvm/vfio: Move KVM_DEV_VFIO_GROUP_* ioctls into functions

To make it easier to read and change in following patches.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

virt/kvm/vfio.c

@@ -181,21 +181,14 @@ static void kvm_vfio_update_coherency(struct kvm_device *dev)
 	mutex_unlock(&kv->lock);
 }
 
-static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
+static int kvm_vfio_group_add(struct kvm_device *dev, unsigned int fd)
 {
 	struct kvm_vfio *kv = dev->private;
 	struct vfio_group *vfio_group;
 	struct kvm_vfio_group *kvg;
-	int32_t __user *argp = (int32_t __user *)(unsigned long)arg;
 	struct fd f;
-	int32_t fd;
 	int ret;
 
-	switch (attr) {
-	case KVM_DEV_VFIO_GROUP_ADD:
-		if (get_user(fd, argp))
-			return -EFAULT;
-
 	f = fdget(fd);
 	if (!f.file)
 		return -EBADF;
@@ -210,17 +203,15 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
 
 	list_for_each_entry(kvg, &kv->group_list, node) {
 		if (kvg->vfio_group == vfio_group) {
-				mutex_unlock(&kv->lock);
+			ret = -EEXIST;
-				kvm_vfio_group_put_external_user(vfio_group);
+			goto err_unlock;
-				return -EEXIST;
 		}
 	}
 
 	kvg = kzalloc(sizeof(*kvg), GFP_KERNEL_ACCOUNT);
 	if (!kvg) {
-			mutex_unlock(&kv->lock);
+		ret = -ENOMEM;
-			kvm_vfio_group_put_external_user(vfio_group);
+		goto err_unlock;
-			return -ENOMEM;
 	}
 
 	list_add_tail(&kvg->node, &kv->group_list);
@@ -231,14 +222,21 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
 	mutex_unlock(&kv->lock);
 
 	kvm_vfio_group_set_kvm(vfio_group, dev->kvm);
-
 	kvm_vfio_update_coherency(dev);
 
 	return 0;
+err_unlock:
+	mutex_unlock(&kv->lock);
+	kvm_vfio_group_put_external_user(vfio_group);
+	return ret;
+}
 
-	case KVM_DEV_VFIO_GROUP_DEL:
+static int kvm_vfio_group_del(struct kvm_device *dev, unsigned int fd)
-		if (get_user(fd, argp))
+{
-			return -EFAULT;
+	struct kvm_vfio *kv = dev->private;
+	struct kvm_vfio_group *kvg;
+	struct fd f;
+	int ret;
 
 	f = fdget(fd);
 	if (!f.file)
@@ -256,8 +254,7 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
 		list_del(&kvg->node);
 		kvm_arch_end_assignment(dev->kvm);
 #ifdef CONFIG_SPAPR_TCE_IOMMU
-			kvm_spapr_tce_release_vfio_group(dev->kvm,
+		kvm_spapr_tce_release_vfio_group(dev->kvm, kvg->vfio_group);
-							 kvg->vfio_group);
 #endif
 		kvm_vfio_group_set_kvm(kvg->vfio_group, NULL);
 		kvm_vfio_group_put_external_user(kvg->vfio_group);
@@ -273,18 +270,21 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
 	kvm_vfio_update_coherency(dev);
 
 	return ret;
+}
 
 #ifdef CONFIG_SPAPR_TCE_IOMMU
-	case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: {
+static int kvm_vfio_group_set_spapr_tce(struct kvm_device *dev,
+					void __user *arg)
+{
 	struct kvm_vfio_spapr_tce param;
 	struct kvm_vfio *kv = dev->private;
 	struct vfio_group *vfio_group;
 	struct kvm_vfio_group *kvg;
 	struct fd f;
 	struct iommu_group *grp;
+	int ret;
 
-		if (copy_from_user(&param, (void __user *)arg,
+	if (copy_from_user(&param, arg, sizeof(struct kvm_vfio_spapr_tce)))
-				sizeof(struct kvm_vfio_spapr_tce)))
 		return -EFAULT;
 
 	f = fdget(param.groupfd);
@@ -299,8 +299,8 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
 
 	grp = kvm_vfio_group_get_iommu_group(vfio_group);
 	if (WARN_ON_ONCE(!grp)) {
-			kvm_vfio_group_put_external_user(vfio_group);
+		ret = -EIO;
-			return -EIO;
+		goto err_put_external;
 	}
 
 	ret = -ENOENT;
@@ -311,19 +311,41 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
 		if (kvg->vfio_group != vfio_group)
 			continue;
 
-			ret = kvm_spapr_tce_attach_iommu_group(dev->kvm,
+		ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
-					param.tablefd, grp);
+						       grp);
 		break;
 	}
 
 	mutex_unlock(&kv->lock);
 
 	iommu_group_put(grp);
+err_put_external:
 	kvm_vfio_group_put_external_user(vfio_group);
-
 	return ret;
 }
-#endif /* CONFIG_SPAPR_TCE_IOMMU */
+#endif
+
+static int kvm_vfio_set_group(struct kvm_device *dev, long attr,
+			      void __user *arg)
+{
+	int32_t __user *argp = arg;
+	int32_t fd;
+
+	switch (attr) {
+	case KVM_DEV_VFIO_GROUP_ADD:
+		if (get_user(fd, argp))
+			return -EFAULT;
+		return kvm_vfio_group_add(dev, fd);
+
+	case KVM_DEV_VFIO_GROUP_DEL:
+		if (get_user(fd, argp))
+			return -EFAULT;
+		return kvm_vfio_group_del(dev, fd);
+
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+	case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE:
+		return kvm_vfio_group_set_spapr_tce(dev, arg);
+#endif
 	}
 
 	return -ENXIO;
@@ -334,7 +356,8 @@ static int kvm_vfio_set_attr(struct kvm_device *dev,
 {
 	switch (attr->group) {
 	case KVM_DEV_VFIO_GROUP:
-		return kvm_vfio_set_group(dev, attr->attr, attr->addr);
+		return kvm_vfio_set_group(dev, attr->attr,
+					  u64_to_user_ptr(attr->addr));
 	}
 
 	return -ENXIO;