Merge patch series "Move group specific code into group.c"

Yi Liu <yi.l.liu@intel.com> says:

==================
With the introduction of iommufd, VFIO is towarding to provide device
centric uAPI after adapting to iommufd. With this trend, existing VFIO
group infrastructure is optional once VFIO converted to device centric.

This series moves the group specific code out of vfio_main.c, prepares
for compiling group infrastructure out after adding vfio device cdev[2]

[2] https://github.com/yiliu1765/iommufd/tree/wip/vfio_device_cdev
==================

Link: https://lore.kernel.org/all/20221201145535.589687-1-yi.l.liu@intel.com/Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/vfio/Makefile

@@ -4,6 +4,7 @@ vfio_virqfd-y := virqfd.o
 obj-$(CONFIG_VFIO) += vfio.o
 
 vfio-y += vfio_main.o \
+	  group.o \
 	  iova_bitmap.o
 vfio-$(CONFIG_IOMMUFD) += iommufd.o
 vfio-$(CONFIG_VFIO_CONTAINER) += container.o

drivers/vfio/container.c

@@ -540,10 +540,12 @@ void vfio_group_unuse_container(struct vfio_group *group)
 	fput(group->opened_file);
 }
 
-int vfio_container_pin_pages(struct vfio_container *container,
-			     struct iommu_group *iommu_group, dma_addr_t iova,
-			     int npage, int prot, struct page **pages)
+int vfio_device_container_pin_pages(struct vfio_device *device,
+				    dma_addr_t iova, int npage,
+				    int prot, struct page **pages)
 {
+	struct vfio_container *container = device->group->container;
+	struct iommu_group *iommu_group = device->group->iommu_group;
 	struct vfio_iommu_driver *driver = container->iommu_driver;
 
 	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
@@ -555,9 +557,11 @@ int vfio_container_pin_pages(struct vfio_container *container,
 				      npage, prot, pages);
 }
 
-void vfio_container_unpin_pages(struct vfio_container *container,
+void vfio_device_container_unpin_pages(struct vfio_device *device,
 				       dma_addr_t iova, int npage)
 {
+	struct vfio_container *container = device->group->container;
+
 	if (WARN_ON(npage <= 0 || npage > VFIO_PIN_PAGES_MAX_ENTRIES))
 		return;
 
@@ -565,9 +569,11 @@ void vfio_container_unpin_pages(struct vfio_container *container,
 						  npage);
 }
 
-int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
-			  void *data, size_t len, bool write)
+int vfio_device_container_dma_rw(struct vfio_device *device,
+				 dma_addr_t iova, void *data,
+				 size_t len, bool write)
 {
+	struct vfio_container *container = device->group->container;
 	struct vfio_iommu_driver *driver = container->iommu_driver;
 
 	if (unlikely(!driver || !driver->ops->dma_rw))

drivers/vfio/group.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VFIO core
+ *
+ * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+ *     Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * Derived from original vfio:
+ * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
+ * Author: Tom Lyon, pugs@cisco.com
+ */
+
+#include <linux/vfio.h>
+#include <linux/iommufd.h>
+#include <linux/anon_inodes.h>
+#include "vfio.h"
+
+static struct vfio {
+	struct class			*class;
+	struct list_head		group_list;
+	struct mutex			group_lock; /* locks group_list */
+	struct ida			group_ida;
+	dev_t				group_devt;
+} vfio;
+
+static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
+						     char *buf)
+{
+	struct vfio_device *it, *device = ERR_PTR(-ENODEV);
+
+	mutex_lock(&group->device_lock);
+	list_for_each_entry(it, &group->device_list, group_next) {
+		int ret;
+
+		if (it->ops->match) {
+			ret = it->ops->match(it, buf);
+			if (ret < 0) {
+				device = ERR_PTR(ret);
+				break;
+			}
+		} else {
+			ret = !strcmp(dev_name(it->dev), buf);
+		}
+
+		if (ret && vfio_device_try_get_registration(it)) {
+			device = it;
+			break;
+		}
+	}
+	mutex_unlock(&group->device_lock);
+
+	return device;
+}
+
+/*
+ * VFIO Group fd, /dev/vfio/$GROUP
+ */
+static bool vfio_group_has_iommu(struct vfio_group *group)
+{
+	lockdep_assert_held(&group->group_lock);
+	/*
+	 * There can only be users if there is a container, and if there is a
+	 * container there must be users.
+	 */
+	WARN_ON(!group->container != !group->container_users);
+
+	return group->container || group->iommufd;
+}
+
+/*
+ * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
+ * if there was no container to unset.  Since the ioctl is called on
+ * the group, we know that still exists, therefore the only valid
+ * transition here is 1->0.
+ */
+static int vfio_group_ioctl_unset_container(struct vfio_group *group)
+{
+	int ret = 0;
+
+	mutex_lock(&group->group_lock);
+	if (!vfio_group_has_iommu(group)) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+	if (group->container) {
+		if (group->container_users != 1) {
+			ret = -EBUSY;
+			goto out_unlock;
+		}
+		vfio_group_detach_container(group);
+	}
+	if (group->iommufd) {
+		iommufd_ctx_put(group->iommufd);
+		group->iommufd = NULL;
+	}
+
+out_unlock:
+	mutex_unlock(&group->group_lock);
+	return ret;
+}
+
+static int vfio_group_ioctl_set_container(struct vfio_group *group,
+					  int __user *arg)
+{
+	struct vfio_container *container;
+	struct iommufd_ctx *iommufd;
+	struct fd f;
+	int ret;
+	int fd;
+
+	if (get_user(fd, arg))
+		return -EFAULT;
+
+	f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
+
+	mutex_lock(&group->group_lock);
+	if (vfio_group_has_iommu(group)) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+	if (!group->iommu_group) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	container = vfio_container_from_file(f.file);
+	if (container) {
+		ret = vfio_container_attach_group(container, group);
+		goto out_unlock;
+	}
+
+	iommufd = iommufd_ctx_from_file(f.file);
+	if (!IS_ERR(iommufd)) {
+		u32 ioas_id;
+
+		ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
+		if (ret) {
+			iommufd_ctx_put(group->iommufd);
+			goto out_unlock;
+		}
+
+		group->iommufd = iommufd;
+		goto out_unlock;
+	}
+
+	/* The FD passed is not recognized. */
+	ret = -EBADFD;
+
+out_unlock:
+	mutex_unlock(&group->group_lock);
+	fdput(f);
+	return ret;
+}
+
+static int vfio_device_group_open(struct vfio_device *device)
+{
+	int ret;
+
+	mutex_lock(&device->group->group_lock);
+	if (!vfio_group_has_iommu(device->group)) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	/*
+	 * Here we pass the KVM pointer with the group under the lock.  If the
+	 * device driver will use it, it must obtain a reference and release it
+	 * during close_device.
+	 */
+	ret = vfio_device_open(device, device->group->iommufd,
+			       device->group->kvm);
+
+out_unlock:
+	mutex_unlock(&device->group->group_lock);
+	return ret;
+}
+
+void vfio_device_group_close(struct vfio_device *device)
+{
+	mutex_lock(&device->group->group_lock);
+	vfio_device_close(device, device->group->iommufd);
+	mutex_unlock(&device->group->group_lock);
+}
+
+static struct file *vfio_device_open_file(struct vfio_device *device)
+{
+	struct file *filep;
+	int ret;
+
+	ret = vfio_device_group_open(device);
+	if (ret)
+		goto err_out;
+
+	/*
+	 * We can't use anon_inode_getfd() because we need to modify
+	 * the f_mode flags directly to allow more than just ioctls
+	 */
+	filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
+				   device, O_RDWR);
+	if (IS_ERR(filep)) {
+		ret = PTR_ERR(filep);
+		goto err_close_device;
+	}
+
+	/*
+	 * TODO: add an anon_inode interface to do this.
+	 * Appears to be missing by lack of need rather than
+	 * explicitly prevented.  Now there's need.
+	 */
+	filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE);
+
+	if (device->group->type == VFIO_NO_IOMMU)
+		dev_warn(device->dev, "vfio-noiommu device opened by user "
+			 "(%s:%d)\n", current->comm, task_pid_nr(current));
+	/*
+	 * On success the ref of device is moved to the file and
+	 * put in vfio_device_fops_release()
+	 */
+	return filep;
+
+err_close_device:
+	vfio_device_group_close(device);
+err_out:
+	return ERR_PTR(ret);
+}
+
+static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
+					  char __user *arg)
+{
+	struct vfio_device *device;
+	struct file *filep;
+	char *buf;
+	int fdno;
+	int ret;
+
+	buf = strndup_user(arg, PAGE_SIZE);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	device = vfio_device_get_from_name(group, buf);
+	kfree(buf);
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	fdno = get_unused_fd_flags(O_CLOEXEC);
+	if (fdno < 0) {
+		ret = fdno;
+		goto err_put_device;
+	}
+
+	filep = vfio_device_open_file(device);
+	if (IS_ERR(filep)) {
+		ret = PTR_ERR(filep);
+		goto err_put_fdno;
+	}
+
+	fd_install(fdno, filep);
+	return fdno;
+
+err_put_fdno:
+	put_unused_fd(fdno);
+err_put_device:
+	vfio_device_put_registration(device);
+	return ret;
+}
+
+static int vfio_group_ioctl_get_status(struct vfio_group *group,
+				       struct vfio_group_status __user *arg)
+{
+	unsigned long minsz = offsetofend(struct vfio_group_status, flags);
+	struct vfio_group_status status;
+
+	if (copy_from_user(&status, arg, minsz))
+		return -EFAULT;
+
+	if (status.argsz < minsz)
+		return -EINVAL;
+
+	status.flags = 0;
+
+	mutex_lock(&group->group_lock);
+	if (!group->iommu_group) {
+		mutex_unlock(&group->group_lock);
+		return -ENODEV;
+	}
+
+	/*
+	 * With the container FD the iommu_group_claim_dma_owner() is done
+	 * during SET_CONTAINER but for IOMMFD this is done during
+	 * VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd
+	 * VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due
+	 * to viability.
+	 */
+	if (vfio_group_has_iommu(group))
+		status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET |
+				VFIO_GROUP_FLAGS_VIABLE;
+	else if (!iommu_group_dma_owner_claimed(group->iommu_group))
+		status.flags |= VFIO_GROUP_FLAGS_VIABLE;
+	mutex_unlock(&group->group_lock);
+
+	if (copy_to_user(arg, &status, minsz))
+		return -EFAULT;
+	return 0;
+}
+
+static long vfio_group_fops_unl_ioctl(struct file *filep,
+				      unsigned int cmd, unsigned long arg)
+{
+	struct vfio_group *group = filep->private_data;
+	void __user *uarg = (void __user *)arg;
+
+	switch (cmd) {
+	case VFIO_GROUP_GET_DEVICE_FD:
+		return vfio_group_ioctl_get_device_fd(group, uarg);
+	case VFIO_GROUP_GET_STATUS:
+		return vfio_group_ioctl_get_status(group, uarg);
+	case VFIO_GROUP_SET_CONTAINER:
+		return vfio_group_ioctl_set_container(group, uarg);
+	case VFIO_GROUP_UNSET_CONTAINER:
+		return vfio_group_ioctl_unset_container(group);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static int vfio_group_fops_open(struct inode *inode, struct file *filep)
+{
+	struct vfio_group *group =
+		container_of(inode->i_cdev, struct vfio_group, cdev);
+	int ret;
+
+	mutex_lock(&group->group_lock);
+
+	/*
+	 * drivers can be zero if this races with vfio_device_remove_group(), it
+	 * will be stable at 0 under the group rwsem
+	 */
+	if (refcount_read(&group->drivers) == 0) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+
+	/*
+	 * Do we need multiple instances of the group open?  Seems not.
+	 */
+	if (group->opened_file) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+	group->opened_file = filep;
+	filep->private_data = group;
+	ret = 0;
+out_unlock:
+	mutex_unlock(&group->group_lock);
+	return ret;
+}
+
+static int vfio_group_fops_release(struct inode *inode, struct file *filep)
+{
+	struct vfio_group *group = filep->private_data;
+
+	filep->private_data = NULL;
+
+	mutex_lock(&group->group_lock);
+	/*
+	 * Device FDs hold a group file reference, therefore the group release
+	 * is only called when there are no open devices.
+	 */
+	WARN_ON(group->notifier.head);
+	if (group->container)
+		vfio_group_detach_container(group);
+	if (group->iommufd) {
+		iommufd_ctx_put(group->iommufd);
+		group->iommufd = NULL;
+	}
+	group->opened_file = NULL;
+	mutex_unlock(&group->group_lock);
+	return 0;
+}
+
+static const struct file_operations vfio_group_fops = {
+	.owner		= THIS_MODULE,
+	.unlocked_ioctl	= vfio_group_fops_unl_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.open		= vfio_group_fops_open,
+	.release	= vfio_group_fops_release,
+};
+
+/*
+ * Group objects - create, release, get, put, search
+ */
+static struct vfio_group *
+vfio_group_find_from_iommu(struct iommu_group *iommu_group)
+{
+	struct vfio_group *group;
+
+	lockdep_assert_held(&vfio.group_lock);
+
+	/*
+	 * group->iommu_group from the vfio.group_list cannot be NULL
+	 * under the vfio.group_lock.
+	 */
+	list_for_each_entry(group, &vfio.group_list, vfio_next) {
+		if (group->iommu_group == iommu_group)
+			return group;
+	}
+	return NULL;
+}
+
+static void vfio_group_release(struct device *dev)
+{
+	struct vfio_group *group = container_of(dev, struct vfio_group, dev);
+
+	mutex_destroy(&group->device_lock);
+	mutex_destroy(&group->group_lock);
+	WARN_ON(group->iommu_group);
+	ida_free(&vfio.group_ida, MINOR(group->dev.devt));
+	kfree(group);
+}
+
+static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
+					   enum vfio_group_type type)
+{
+	struct vfio_group *group;
+	int minor;
+
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	if (!group)
+		return ERR_PTR(-ENOMEM);
+
+	minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL);
+	if (minor < 0) {
+		kfree(group);
+		return ERR_PTR(minor);
+	}
+
+	device_initialize(&group->dev);
+	group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor);
+	group->dev.class = vfio.class;
+	group->dev.release = vfio_group_release;
+	cdev_init(&group->cdev, &vfio_group_fops);
+	group->cdev.owner = THIS_MODULE;
+
+	refcount_set(&group->drivers, 1);
+	mutex_init(&group->group_lock);
+	INIT_LIST_HEAD(&group->device_list);
+	mutex_init(&group->device_lock);
+	group->iommu_group = iommu_group;
+	/* put in vfio_group_release() */
+	iommu_group_ref_get(iommu_group);
+	group->type = type;
+	BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
+
+	return group;
+}
+
+static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
+		enum vfio_group_type type)
+{
+	struct vfio_group *group;
+	struct vfio_group *ret;
+	int err;
+
+	lockdep_assert_held(&vfio.group_lock);
+
+	group = vfio_group_alloc(iommu_group, type);
+	if (IS_ERR(group))
+		return group;
+
+	err = dev_set_name(&group->dev, "%s%d",
+			   group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
+			   iommu_group_id(iommu_group));
+	if (err) {
+		ret = ERR_PTR(err);
+		goto err_put;
+	}
+
+	err = cdev_device_add(&group->cdev, &group->dev);
+	if (err) {
+		ret = ERR_PTR(err);
+		goto err_put;
+	}
+
+	list_add(&group->vfio_next, &vfio.group_list);
+
+	return group;
+
+err_put:
+	put_device(&group->dev);
+	return ret;
+}
+
+static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
+		enum vfio_group_type type)
+{
+	struct iommu_group *iommu_group;
+	struct vfio_group *group;
+	int ret;
+
+	iommu_group = iommu_group_alloc();
+	if (IS_ERR(iommu_group))
+		return ERR_CAST(iommu_group);
+
+	ret = iommu_group_set_name(iommu_group, "vfio-noiommu");
+	if (ret)
+		goto out_put_group;
+	ret = iommu_group_add_device(iommu_group, dev);
+	if (ret)
+		goto out_put_group;
+
+	mutex_lock(&vfio.group_lock);
+	group = vfio_create_group(iommu_group, type);
+	mutex_unlock(&vfio.group_lock);
+	if (IS_ERR(group)) {
+		ret = PTR_ERR(group);
+		goto out_remove_device;
+	}
+	iommu_group_put(iommu_group);
+	return group;
+
+out_remove_device:
+	iommu_group_remove_device(dev);
+out_put_group:
+	iommu_group_put(iommu_group);
+	return ERR_PTR(ret);
+}
+
+static bool vfio_group_has_device(struct vfio_group *group, struct device *dev)
+{
+	struct vfio_device *device;
+
+	mutex_lock(&group->device_lock);
+	list_for_each_entry(device, &group->device_list, group_next) {
+		if (device->dev == dev) {
+			mutex_unlock(&group->device_lock);
+			return true;
+		}
+	}
+	mutex_unlock(&group->device_lock);
+	return false;
+}
+
+static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
+{
+	struct iommu_group *iommu_group;
+	struct vfio_group *group;
+
+	iommu_group = iommu_group_get(dev);
+	if (!iommu_group && vfio_noiommu) {
+		/*
+		 * With noiommu enabled, create an IOMMU group for devices that
+		 * don't already have one, implying no IOMMU hardware/driver
+		 * exists.  Taint the kernel because we're about to give a DMA
+		 * capable device to a user without IOMMU protection.
+		 */
+		group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
+		if (!IS_ERR(group)) {
+			add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+			dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
+		}
+		return group;
+	}
+
+	if (!iommu_group)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
+	 * restore cache coherency. It has to be checked here because it is only
+	 * valid for cases where we are using iommu groups.
+	 */
+	if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) {
+		iommu_group_put(iommu_group);
+		return ERR_PTR(-EINVAL);
+	}
+
+	mutex_lock(&vfio.group_lock);
+	group = vfio_group_find_from_iommu(iommu_group);
+	if (group) {
+		if (WARN_ON(vfio_group_has_device(group, dev)))
+			group = ERR_PTR(-EINVAL);
+		else
+			refcount_inc(&group->drivers);
+	} else {
+		group = vfio_create_group(iommu_group, VFIO_IOMMU);
+	}
+	mutex_unlock(&vfio.group_lock);
+
+	/* The vfio_group holds a reference to the iommu_group */
+	iommu_group_put(iommu_group);
+	return group;
+}
+
+int vfio_device_set_group(struct vfio_device *device,
+			  enum vfio_group_type type)
+{
+	struct vfio_group *group;
+
+	if (type == VFIO_IOMMU)
+		group = vfio_group_find_or_alloc(device->dev);
+	else
+		group = vfio_noiommu_group_alloc(device->dev, type);
+
+	if (IS_ERR(group))
+		return PTR_ERR(group);
+
+	/* Our reference on group is moved to the device */
+	device->group = group;
+	return 0;
+}
+
+void vfio_device_remove_group(struct vfio_device *device)
+{
+	struct vfio_group *group = device->group;
+	struct iommu_group *iommu_group;
+
+	if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
+		iommu_group_remove_device(device->dev);
+
+	/* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */
+	if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock))
+		return;
+	list_del(&group->vfio_next);
+
+	/*
+	 * We could concurrently probe another driver in the group that might
+	 * race vfio_device_remove_group() with vfio_get_group(), so we have to
+	 * ensure that the sysfs is all cleaned up under lock otherwise the
+	 * cdev_device_add() will fail due to the name aready existing.
+	 */
+	cdev_device_del(&group->cdev, &group->dev);
+
+	mutex_lock(&group->group_lock);
+	/*
+	 * These data structures all have paired operations that can only be
+	 * undone when the caller holds a live reference on the device. Since
+	 * all pairs must be undone these WARN_ON's indicate some caller did not
+	 * properly hold the group reference.
+	 */
+	WARN_ON(!list_empty(&group->device_list));
+	WARN_ON(group->notifier.head);
+
+	/*
+	 * Revoke all users of group->iommu_group. At this point we know there
+	 * are no devices active because we are unplugging the last one. Setting
+	 * iommu_group to NULL blocks all new users.
+	 */
+	if (group->container)
+		vfio_group_detach_container(group);
+	iommu_group = group->iommu_group;
+	group->iommu_group = NULL;
+	mutex_unlock(&group->group_lock);
+	mutex_unlock(&vfio.group_lock);
+
+	iommu_group_put(iommu_group);
+	put_device(&group->dev);
+}
+
+void vfio_device_group_register(struct vfio_device *device)
+{
+	mutex_lock(&device->group->device_lock);
+	list_add(&device->group_next, &device->group->device_list);
+	mutex_unlock(&device->group->device_lock);
+}
+
+void vfio_device_group_unregister(struct vfio_device *device)
+{
+	mutex_lock(&device->group->device_lock);
+	list_del(&device->group_next);
+	mutex_unlock(&device->group->device_lock);
+}
+
+int vfio_device_group_use_iommu(struct vfio_device *device)
+{
+	struct vfio_group *group = device->group;
+	int ret = 0;
+
+	lockdep_assert_held(&group->group_lock);
+
+	if (WARN_ON(!group->container))
+		return -EINVAL;
+
+	ret = vfio_group_use_container(group);
+	if (ret)
+		return ret;
+	vfio_device_container_register(device);
+	return 0;
+}
+
+void vfio_device_group_unuse_iommu(struct vfio_device *device)
+{
+	struct vfio_group *group = device->group;
+
+	lockdep_assert_held(&group->group_lock);
+
+	if (WARN_ON(!group->container))
+		return;
+
+	vfio_device_container_unregister(device);
+	vfio_group_unuse_container(group);
+}
+
+bool vfio_device_has_container(struct vfio_device *device)
+{
+	return device->group->container;
+}
+
+/**
+ * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
+ * @file: VFIO group file
+ *
+ * The returned iommu_group is valid as long as a ref is held on the file. This
+ * returns a reference on the group. This function is deprecated, only the SPAPR
+ * path in kvm should call it.
+ */
+struct iommu_group *vfio_file_iommu_group(struct file *file)
+{
+	struct vfio_group *group = file->private_data;
+	struct iommu_group *iommu_group = NULL;
+
+	if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
+		return NULL;
+
+	if (!vfio_file_is_group(file))
+		return NULL;
+
+	mutex_lock(&group->group_lock);
+	if (group->iommu_group) {
+		iommu_group = group->iommu_group;
+		iommu_group_ref_get(iommu_group);
+	}
+	mutex_unlock(&group->group_lock);
+	return iommu_group;
+}
+EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
+
+/**
+ * vfio_file_is_group - True if the file is usable with VFIO aPIS
+ * @file: VFIO group file
+ */
+bool vfio_file_is_group(struct file *file)
+{
+	return file->f_op == &vfio_group_fops;
+}
+EXPORT_SYMBOL_GPL(vfio_file_is_group);
+
+/**
+ * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
+ *        is always CPU cache coherent
+ * @file: VFIO group file
+ *
+ * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
+ * bit in DMA transactions. A return of false indicates that the user has
+ * rights to access additional instructions such as wbinvd on x86.
+ */
+bool vfio_file_enforced_coherent(struct file *file)
+{
+	struct vfio_group *group = file->private_data;
+	struct vfio_device *device;
+	bool ret = true;
+
+	if (!vfio_file_is_group(file))
+		return true;
+
+	/*
+	 * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then
+	 * any domain later attached to it will also not support it. If the cap
+	 * is set then the iommu_domain eventually attached to the device/group
+	 * must use a domain with enforce_cache_coherency().
+	 */
+	mutex_lock(&group->device_lock);
+	list_for_each_entry(device, &group->device_list, group_next) {
+		if (!device_iommu_capable(device->dev,
+					  IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) {
+			ret = false;
+			break;
+		}
+	}
+	mutex_unlock(&group->device_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
+
+/**
+ * vfio_file_set_kvm - Link a kvm with VFIO drivers
+ * @file: VFIO group file
+ * @kvm: KVM to link
+ *
+ * When a VFIO device is first opened the KVM will be available in
+ * device->kvm if one was associated with the group.
+ */
+void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+{
+	struct vfio_group *group = file->private_data;
+
+	if (!vfio_file_is_group(file))
+		return;
+
+	mutex_lock(&group->group_lock);
+	group->kvm = kvm;
+	mutex_unlock(&group->group_lock);
+}
+EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
+
+/**
+ * vfio_file_has_dev - True if the VFIO file is a handle for device
+ * @file: VFIO file to check
+ * @device: Device that must be part of the file
+ *
+ * Returns true if given file has permission to manipulate the given device.
+ */
+bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
+{
+	struct vfio_group *group = file->private_data;
+
+	if (!vfio_file_is_group(file))
+		return false;
+
+	return group == device->group;
+}
+EXPORT_SYMBOL_GPL(vfio_file_has_dev);
+
+static char *vfio_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
+}
+
+int __init vfio_group_init(void)
+{
+	int ret;
+
+	ida_init(&vfio.group_ida);
+	mutex_init(&vfio.group_lock);
+	INIT_LIST_HEAD(&vfio.group_list);
+
+	ret = vfio_container_init();
+	if (ret)
+		return ret;
+
+	/* /dev/vfio/$GROUP */
+	vfio.class = class_create(THIS_MODULE, "vfio");
+	if (IS_ERR(vfio.class)) {
+		ret = PTR_ERR(vfio.class);
+		goto err_group_class;
+	}
+
+	vfio.class->devnode = vfio_devnode;
+
+	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
+	if (ret)
+		goto err_alloc_chrdev;
+	return 0;
+
+err_alloc_chrdev:
+	class_destroy(vfio.class);
+	vfio.class = NULL;
+err_group_class:
+	vfio_container_cleanup();
+	return ret;
+}
+
+void vfio_group_cleanup(void)
+{
+	WARN_ON(!list_empty(&vfio.group_list));
+	ida_destroy(&vfio.group_ida);
+	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
+	class_destroy(vfio.class);
+	vfio.class = NULL;
+	vfio_container_cleanup();
+}

drivers/vfio/vfio.h

@@ -6,6 +6,7 @@
 #ifndef __VFIO_VFIO_H__
 #define __VFIO_VFIO_H__
 
+#include <linux/file.h>
 #include <linux/device.h>
 #include <linux/cdev.h>
 #include <linux/module.h>
@@ -15,6 +16,15 @@ struct iommu_group;
 struct vfio_device;
 struct vfio_container;
 
+void vfio_device_put_registration(struct vfio_device *device);
+bool vfio_device_try_get_registration(struct vfio_device *device);
+int vfio_device_open(struct vfio_device *device,
+		     struct iommufd_ctx *iommufd, struct kvm *kvm);
+void vfio_device_close(struct vfio_device *device,
+		       struct iommufd_ctx *iommufd);
+
+extern const struct file_operations vfio_device_fops;
+
 enum vfio_group_type {
 	/*
 	 * Physical device with IOMMU backing.
@@ -66,6 +76,18 @@ struct vfio_group {
 	struct iommufd_ctx		*iommufd;
 };
 
+int vfio_device_set_group(struct vfio_device *device,
+			  enum vfio_group_type type);
+void vfio_device_remove_group(struct vfio_device *device);
+void vfio_device_group_register(struct vfio_device *device);
+void vfio_device_group_unregister(struct vfio_device *device);
+int vfio_device_group_use_iommu(struct vfio_device *device);
+void vfio_device_group_unuse_iommu(struct vfio_device *device);
+void vfio_device_group_close(struct vfio_device *device);
+bool vfio_device_has_container(struct vfio_device *device);
+int __init vfio_group_init(void);
+void vfio_group_cleanup(void);
+
 #if IS_ENABLED(CONFIG_VFIO_CONTAINER)
 /* events for the backend driver notify callback */
 enum vfio_iommu_notify_type {
@@ -122,13 +144,14 @@ int vfio_container_attach_group(struct vfio_container *container,
 void vfio_group_detach_container(struct vfio_group *group);
 void vfio_device_container_register(struct vfio_device *device);
 void vfio_device_container_unregister(struct vfio_device *device);
-int vfio_container_pin_pages(struct vfio_container *container,
-			     struct iommu_group *iommu_group, dma_addr_t iova,
-			     int npage, int prot, struct page **pages);
-void vfio_container_unpin_pages(struct vfio_container *container,
+int vfio_device_container_pin_pages(struct vfio_device *device,
+				    dma_addr_t iova, int npage,
+				    int prot, struct page **pages);
+void vfio_device_container_unpin_pages(struct vfio_device *device,
 				       dma_addr_t iova, int npage);
-int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
-			  void *data, size_t len, bool write);
+int vfio_device_container_dma_rw(struct vfio_device *device,
+				 dma_addr_t iova, void *data,
+				 size_t len, bool write);
 
 int __init vfio_container_init(void);
 void vfio_container_cleanup(void);
@@ -166,22 +189,21 @@ static inline void vfio_device_container_unregister(struct vfio_device *device)
 {
 }
 
-static inline int vfio_container_pin_pages(struct vfio_container *container,
-					   struct iommu_group *iommu_group,
-					   dma_addr_t iova, int npage, int prot,
-					   struct page **pages)
+static inline int vfio_device_container_pin_pages(struct vfio_device *device,
+						  dma_addr_t iova, int npage,
+						  int prot, struct page **pages)
 {
 	return -EOPNOTSUPP;
 }
 
-static inline void vfio_container_unpin_pages(struct vfio_container *container,
+static inline void vfio_device_container_unpin_pages(struct vfio_device *device,
 						     dma_addr_t iova, int npage)
 {
 }
 
-static inline int vfio_container_dma_rw(struct vfio_container *container,
-					dma_addr_t iova, void *data, size_t len,
-					bool write)
+static inline int vfio_device_container_dma_rw(struct vfio_device *device,
+					       dma_addr_t iova, void *data,
+					       size_t len, bool write)
 {
 	return -EOPNOTSUPP;
 }

drivers/vfio/vfio_main.c

@@ -13,8 +13,6 @@
 #include <linux/cdev.h>
 #include <linux/compat.h>
 #include <linux/device.h>
-#include <linux/file.h>
-#include <linux/anon_inodes.h>
 #include <linux/fs.h>
 #include <linux/idr.h>
 #include <linux/iommu.h>
@@ -43,17 +41,11 @@
 #define DRIVER_DESC	"VFIO - User Level meta-driver"
 
 static struct vfio {
-	struct class			*class;
-	struct list_head		group_list;
-	struct mutex			group_lock; /* locks group_list */
-	struct ida			group_ida;
-	dev_t				group_devt;
 	struct class			*device_class;
 	struct ida			device_ida;
 } vfio;
 
 static DEFINE_XARRAY(vfio_device_set_xa);
-static const struct file_operations vfio_group_fops;
 
 int vfio_assign_device_set(struct vfio_device *device, void *set_id)
 {
@@ -139,208 +131,21 @@ unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
 }
 EXPORT_SYMBOL_GPL(vfio_device_set_open_count);
 
-/*
- * Group objects - create, release, get, put, search
- */
-static struct vfio_group *
-__vfio_group_get_from_iommu(struct iommu_group *iommu_group)
-{
-	struct vfio_group *group;
-
-	/*
-	 * group->iommu_group from the vfio.group_list cannot be NULL
-	 * under the vfio.group_lock.
-	 */
-	list_for_each_entry(group, &vfio.group_list, vfio_next) {
-		if (group->iommu_group == iommu_group) {
-			refcount_inc(&group->drivers);
-			return group;
-		}
-	}
-	return NULL;
-}
-
-static struct vfio_group *
-vfio_group_get_from_iommu(struct iommu_group *iommu_group)
-{
-	struct vfio_group *group;
-
-	mutex_lock(&vfio.group_lock);
-	group = __vfio_group_get_from_iommu(iommu_group);
-	mutex_unlock(&vfio.group_lock);
-	return group;
-}
-
-static void vfio_group_release(struct device *dev)
-{
-	struct vfio_group *group = container_of(dev, struct vfio_group, dev);
-
-	mutex_destroy(&group->device_lock);
-	mutex_destroy(&group->group_lock);
-	WARN_ON(group->iommu_group);
-	ida_free(&vfio.group_ida, MINOR(group->dev.devt));
-	kfree(group);
-}
-
-static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
-					   enum vfio_group_type type)
-{
-	struct vfio_group *group;
-	int minor;
-
-	group = kzalloc(sizeof(*group), GFP_KERNEL);
-	if (!group)
-		return ERR_PTR(-ENOMEM);
-
-	minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL);
-	if (minor < 0) {
-		kfree(group);
-		return ERR_PTR(minor);
-	}
-
-	device_initialize(&group->dev);
-	group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor);
-	group->dev.class = vfio.class;
-	group->dev.release = vfio_group_release;
-	cdev_init(&group->cdev, &vfio_group_fops);
-	group->cdev.owner = THIS_MODULE;
-
-	refcount_set(&group->drivers, 1);
-	mutex_init(&group->group_lock);
-	INIT_LIST_HEAD(&group->device_list);
-	mutex_init(&group->device_lock);
-	group->iommu_group = iommu_group;
-	/* put in vfio_group_release() */
-	iommu_group_ref_get(iommu_group);
-	group->type = type;
-	BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
-
-	return group;
-}
-
-static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
-		enum vfio_group_type type)
-{
-	struct vfio_group *group;
-	struct vfio_group *ret;
-	int err;
-
-	group = vfio_group_alloc(iommu_group, type);
-	if (IS_ERR(group))
-		return group;
-
-	err = dev_set_name(&group->dev, "%s%d",
-			   group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
-			   iommu_group_id(iommu_group));
-	if (err) {
-		ret = ERR_PTR(err);
-		goto err_put;
-	}
-
-	mutex_lock(&vfio.group_lock);
-
-	/* Did we race creating this group? */
-	ret = __vfio_group_get_from_iommu(iommu_group);
-	if (ret)
-		goto err_unlock;
-
-	err = cdev_device_add(&group->cdev, &group->dev);
-	if (err) {
-		ret = ERR_PTR(err);
-		goto err_unlock;
-	}
-
-	list_add(&group->vfio_next, &vfio.group_list);
-
-	mutex_unlock(&vfio.group_lock);
-	return group;
-
-err_unlock:
-	mutex_unlock(&vfio.group_lock);
-err_put:
-	put_device(&group->dev);
-	return ret;
-}
-
-static void vfio_device_remove_group(struct vfio_device *device)
-{
-	struct vfio_group *group = device->group;
-	struct iommu_group *iommu_group;
-
-	if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
-		iommu_group_remove_device(device->dev);
-
-	/* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */
-	if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock))
-		return;
-	list_del(&group->vfio_next);
-
-	/*
-	 * We could concurrently probe another driver in the group that might
-	 * race vfio_device_remove_group() with vfio_get_group(), so we have to
-	 * ensure that the sysfs is all cleaned up under lock otherwise the
-	 * cdev_device_add() will fail due to the name aready existing.
-	 */
-	cdev_device_del(&group->cdev, &group->dev);
-
-	mutex_lock(&group->group_lock);
-	/*
-	 * These data structures all have paired operations that can only be
-	 * undone when the caller holds a live reference on the device. Since
-	 * all pairs must be undone these WARN_ON's indicate some caller did not
-	 * properly hold the group reference.
-	 */
-	WARN_ON(!list_empty(&group->device_list));
-	WARN_ON(group->notifier.head);
-
-	/*
-	 * Revoke all users of group->iommu_group. At this point we know there
-	 * are no devices active because we are unplugging the last one. Setting
-	 * iommu_group to NULL blocks all new users.
-	 */
-	if (group->container)
-		vfio_group_detach_container(group);
-	iommu_group = group->iommu_group;
-	group->iommu_group = NULL;
-	mutex_unlock(&group->group_lock);
-	mutex_unlock(&vfio.group_lock);
-
-	iommu_group_put(iommu_group);
-	put_device(&group->dev);
-}
-
 /*
  * Device objects - create, release, get, put, search
  */
 /* Device reference always implies a group reference */
-static void vfio_device_put_registration(struct vfio_device *device)
+void vfio_device_put_registration(struct vfio_device *device)
 {
 	if (refcount_dec_and_test(&device->refcount))
 		complete(&device->comp);
 }
 
-static bool vfio_device_try_get_registration(struct vfio_device *device)
+bool vfio_device_try_get_registration(struct vfio_device *device)
 {
 	return refcount_inc_not_zero(&device->refcount);
 }
 
-static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
-						 struct device *dev)
-{
-	struct vfio_device *device;
-
-	mutex_lock(&group->device_lock);
-	list_for_each_entry(device, &group->device_list, group_next) {
-		if (device->dev == dev &&
-		    vfio_device_try_get_registration(device)) {
-			mutex_unlock(&group->device_lock);
-			return device;
-		}
-	}
-	mutex_unlock(&group->device_lock);
-	return NULL;
-}
-
 /*
  * VFIO driver API
  */
@@ -449,95 +254,11 @@ void vfio_free_device(struct vfio_device *device)
 }
 EXPORT_SYMBOL_GPL(vfio_free_device);
 
-static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
-		enum vfio_group_type type)
-{
-	struct iommu_group *iommu_group;
-	struct vfio_group *group;
-	int ret;
-
-	iommu_group = iommu_group_alloc();
-	if (IS_ERR(iommu_group))
-		return ERR_CAST(iommu_group);
-
-	ret = iommu_group_set_name(iommu_group, "vfio-noiommu");
-	if (ret)
-		goto out_put_group;
-	ret = iommu_group_add_device(iommu_group, dev);
-	if (ret)
-		goto out_put_group;
-
-	group = vfio_create_group(iommu_group, type);
-	if (IS_ERR(group)) {
-		ret = PTR_ERR(group);
-		goto out_remove_device;
-	}
-	iommu_group_put(iommu_group);
-	return group;
-
-out_remove_device:
-	iommu_group_remove_device(dev);
-out_put_group:
-	iommu_group_put(iommu_group);
-	return ERR_PTR(ret);
-}
-
-static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
-{
-	struct iommu_group *iommu_group;
-	struct vfio_group *group;
-
-	iommu_group = iommu_group_get(dev);
-	if (!iommu_group && vfio_noiommu) {
-		/*
-		 * With noiommu enabled, create an IOMMU group for devices that
-		 * don't already have one, implying no IOMMU hardware/driver
-		 * exists.  Taint the kernel because we're about to give a DMA
-		 * capable device to a user without IOMMU protection.
-		 */
-		group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
-		if (!IS_ERR(group)) {
-			add_taint(TAINT_USER, LOCKDEP_STILL_OK);
-			dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
-		}
-		return group;
-	}
-
-	if (!iommu_group)
-		return ERR_PTR(-EINVAL);
-
-	/*
-	 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
-	 * restore cache coherency. It has to be checked here because it is only
-	 * valid for cases where we are using iommu groups.
-	 */
-	if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) {
-		iommu_group_put(iommu_group);
-		return ERR_PTR(-EINVAL);
-	}
-
-	group = vfio_group_get_from_iommu(iommu_group);
-	if (!group)
-		group = vfio_create_group(iommu_group, VFIO_IOMMU);
-
-	/* The vfio_group holds a reference to the iommu_group */
-	iommu_group_put(iommu_group);
-	return group;
-}
-
 static int __vfio_register_dev(struct vfio_device *device,
-		struct vfio_group *group)
+			       enum vfio_group_type type)
 {
-	struct vfio_device *existing_device;
 	int ret;
 
-	/*
-	 * In all cases group is the output of one of the group allocation
-	 * functions and we have group->drivers incremented for us.
-	 */
-	if (IS_ERR(group))
-		return PTR_ERR(group);
-
 	if (WARN_ON(device->ops->bind_iommufd &&
 		    (!device->ops->unbind_iommufd ||
 		     !device->ops->attach_ioas)))
@@ -550,25 +271,13 @@ static int __vfio_register_dev(struct vfio_device *device,
 	if (!device->dev_set)
 		vfio_assign_device_set(device, device);
 
-	existing_device = vfio_group_get_device(group, device->dev);
-	if (existing_device) {
-		/*
-		 * group->iommu_group is non-NULL because we hold the drivers
-		 * refcount.
-		 */
-		dev_WARN(device->dev, "Device already exists on group %d\n",
-			 iommu_group_id(group->iommu_group));
-		vfio_device_put_registration(existing_device);
-		ret = -EBUSY;
-		goto err_out;
-	}
-
-	/* Our reference on group is moved to the device */
-	device->group = group;
-
 	ret = dev_set_name(&device->device, "vfio%d", device->index);
 	if (ret)
-		goto err_out;
+		return ret;
+
+	ret = vfio_device_set_group(device, type);
+	if (ret)
+		return ret;
 
 	ret = device_add(&device->device);
 	if (ret)
@@ -577,9 +286,7 @@ static int __vfio_register_dev(struct vfio_device *device,
 	/* Refcounting can't start until the driver calls register */
 	refcount_set(&device->refcount, 1);
 
-	mutex_lock(&group->device_lock);
-	list_add(&device->group_next, &group->device_list);
-	mutex_unlock(&group->device_lock);
+	vfio_device_group_register(device);
 
 	return 0;
 err_out:
@@ -589,8 +296,7 @@ static int __vfio_register_dev(struct vfio_device *device,
 
 int vfio_register_group_dev(struct vfio_device *device)
 {
-	return __vfio_register_dev(device,
-		vfio_group_find_or_alloc(device->dev));
+	return __vfio_register_dev(device, VFIO_IOMMU);
 }
 EXPORT_SYMBOL_GPL(vfio_register_group_dev);
 
@@ -600,46 +306,15 @@ EXPORT_SYMBOL_GPL(vfio_register_group_dev);
  */
 int vfio_register_emulated_iommu_dev(struct vfio_device *device)
 {
-	return __vfio_register_dev(device,
-		vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU));
+	return __vfio_register_dev(device, VFIO_EMULATED_IOMMU);
 }
 EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
 
-static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
-						     char *buf)
-{
-	struct vfio_device *it, *device = ERR_PTR(-ENODEV);
-
-	mutex_lock(&group->device_lock);
-	list_for_each_entry(it, &group->device_list, group_next) {
-		int ret;
-
-		if (it->ops->match) {
-			ret = it->ops->match(it, buf);
-			if (ret < 0) {
-				device = ERR_PTR(ret);
-				break;
-			}
-		} else {
-			ret = !strcmp(dev_name(it->dev), buf);
-		}
-
-		if (ret && vfio_device_try_get_registration(it)) {
-			device = it;
-			break;
-		}
-	}
-	mutex_unlock(&group->device_lock);
-
-	return device;
-}
-
 /*
  * Decrement the device reference count and wait for the device to be
  * removed.  Open file descriptors for the device... */
 void vfio_unregister_group_dev(struct vfio_device *device)
 {
-	struct vfio_group *group = device->group;
 	unsigned int i = 0;
 	bool interrupted = false;
 	long rc;
@@ -667,128 +342,24 @@ void vfio_unregister_group_dev(struct vfio_device *device)
 		}
 	}
 
-	mutex_lock(&group->device_lock);
-	list_del(&device->group_next);
-	mutex_unlock(&group->device_lock);
+	vfio_device_group_unregister(device);
 
 	/* Balances device_add in register path */
 	device_del(&device->device);
 
+	/* Balances vfio_device_set_group in register path */
 	vfio_device_remove_group(device);
 }
 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
 
-/*
- * VFIO Group fd, /dev/vfio/$GROUP
- */
-static bool vfio_group_has_iommu(struct vfio_group *group)
-{
-	lockdep_assert_held(&group->group_lock);
-	/*
-	 * There can only be users if there is a container, and if there is a
-	 * container there must be users.
-	 */
-	WARN_ON(!group->container != !group->container_users);
-
-	return group->container || group->iommufd;
-}
-
-/*
- * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
- * if there was no container to unset.  Since the ioctl is called on
- * the group, we know that still exists, therefore the only valid
- * transition here is 1->0.
- */
-static int vfio_group_ioctl_unset_container(struct vfio_group *group)
-{
-	int ret = 0;
-
-	mutex_lock(&group->group_lock);
-	if (!vfio_group_has_iommu(group)) {
-		ret = -EINVAL;
-		goto out_unlock;
-	}
-	if (group->container) {
-		if (group->container_users != 1) {
-			ret = -EBUSY;
-			goto out_unlock;
-		}
-		vfio_group_detach_container(group);
-	}
-	if (group->iommufd) {
-		iommufd_ctx_put(group->iommufd);
-		group->iommufd = NULL;
-	}
-
-out_unlock:
-	mutex_unlock(&group->group_lock);
-	return ret;
-}
-
-static int vfio_group_ioctl_set_container(struct vfio_group *group,
-					  int __user *arg)
-{
-	struct vfio_container *container;
-	struct iommufd_ctx *iommufd;
-	struct fd f;
-	int ret;
-	int fd;
-
-	if (get_user(fd, arg))
-		return -EFAULT;
-
-	f = fdget(fd);
-	if (!f.file)
-		return -EBADF;
-
-	mutex_lock(&group->group_lock);
-	if (vfio_group_has_iommu(group)) {
-		ret = -EINVAL;
-		goto out_unlock;
-	}
-	if (!group->iommu_group) {
-		ret = -ENODEV;
-		goto out_unlock;
-	}
-
-	container = vfio_container_from_file(f.file);
-	if (container) {
-		ret = vfio_container_attach_group(container, group);
-		goto out_unlock;
-	}
-
-	iommufd = iommufd_ctx_from_file(f.file);
-	if (!IS_ERR(iommufd)) {
-		u32 ioas_id;
-
-		ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
-		if (ret) {
-			iommufd_ctx_put(group->iommufd);
-			goto out_unlock;
-		}
-
-		group->iommufd = iommufd;
-		goto out_unlock;
-	}
-
-	/* The FD passed is not recognized. */
-	ret = -EBADFD;
-
-out_unlock:
-	mutex_unlock(&group->group_lock);
-	fdput(f);
-	return ret;
-}
-
-static const struct file_operations vfio_device_fops;
-
 /* true if the vfio_device has open_device() called but not close_device() */
 static bool vfio_assert_device_open(struct vfio_device *device)
 {
 	return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
 }
 
-static int vfio_device_first_open(struct vfio_device *device)
+static int vfio_device_first_open(struct vfio_device *device,
+				  struct iommufd_ctx *iommufd, struct kvm *kvm)
 {
 	int ret;
 
@@ -797,286 +368,75 @@ static int vfio_device_first_open(struct vfio_device *device)
 	if (!try_module_get(device->dev->driver->owner))
 		return -ENODEV;
 
-	/*
-	 * Here we pass the KVM pointer with the group under the lock.  If the
-	 * device driver will use it, it must obtain a reference and release it
-	 * during close_device.
-	 */
-	mutex_lock(&device->group->group_lock);
-	if (!vfio_group_has_iommu(device->group)) {
-		ret = -EINVAL;
-		goto err_module_put;
-	}
-
-	if (device->group->container) {
-		ret = vfio_group_use_container(device->group);
-		if (ret)
-			goto err_module_put;
-	} else if (device->group->iommufd) {
-		ret = vfio_iommufd_bind(device, device->group->iommufd);
+	if (iommufd)
+		ret = vfio_iommufd_bind(device, iommufd);
+	else
+		ret = vfio_device_group_use_iommu(device);
 	if (ret)
 		goto err_module_put;
-	}
 
-	device->kvm = device->group->kvm;
+	device->kvm = kvm;
 	if (device->ops->open_device) {
 		ret = device->ops->open_device(device);
 		if (ret)
-			goto err_container;
+			goto err_unuse_iommu;
 	}
-	if (device->group->container)
-		vfio_device_container_register(device);
-	mutex_unlock(&device->group->group_lock);
 	return 0;
 
-err_container:
+err_unuse_iommu:
 	device->kvm = NULL;
-	if (device->group->container)
-		vfio_group_unuse_container(device->group);
-	else if (device->group->iommufd)
+	if (iommufd)
 		vfio_iommufd_unbind(device);
+	else
+		vfio_device_group_unuse_iommu(device);
 err_module_put:
-	mutex_unlock(&device->group->group_lock);
 	module_put(device->dev->driver->owner);
 	return ret;
 }
 
-static void vfio_device_last_close(struct vfio_device *device)
+static void vfio_device_last_close(struct vfio_device *device,
+				   struct iommufd_ctx *iommufd)
 {
 	lockdep_assert_held(&device->dev_set->lock);
 
-	mutex_lock(&device->group->group_lock);
-	if (device->group->container)
-		vfio_device_container_unregister(device);
 	if (device->ops->close_device)
 		device->ops->close_device(device);
 	device->kvm = NULL;
-	if (device->group->container)
-		vfio_group_unuse_container(device->group);
-	else if (device->group->iommufd)
+	if (iommufd)
 		vfio_iommufd_unbind(device);
-	mutex_unlock(&device->group->group_lock);
+	else
+		vfio_device_group_unuse_iommu(device);
 	module_put(device->dev->driver->owner);
 }
 
-static struct file *vfio_device_open(struct vfio_device *device)
+int vfio_device_open(struct vfio_device *device,
+		     struct iommufd_ctx *iommufd, struct kvm *kvm)
 {
-	struct file *filep;
-	int ret;
+	int ret = 0;
 
 	mutex_lock(&device->dev_set->lock);
 	device->open_count++;
 	if (device->open_count == 1) {
-		ret = vfio_device_first_open(device);
+		ret = vfio_device_first_open(device, iommufd, kvm);
 		if (ret)
-			goto err_unlock;
+			device->open_count--;
 	}
 	mutex_unlock(&device->dev_set->lock);
 
-	/*
-	 * We can't use anon_inode_getfd() because we need to modify
-	 * the f_mode flags directly to allow more than just ioctls
-	 */
-	filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
-				   device, O_RDWR);
-	if (IS_ERR(filep)) {
-		ret = PTR_ERR(filep);
-		goto err_close_device;
-	}
-
-	/*
-	 * TODO: add an anon_inode interface to do this.
-	 * Appears to be missing by lack of need rather than
-	 * explicitly prevented.  Now there's need.
-	 */
-	filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE);
-
-	if (device->group->type == VFIO_NO_IOMMU)
-		dev_warn(device->dev, "vfio-noiommu device opened by user "
-			 "(%s:%d)\n", current->comm, task_pid_nr(current));
-	/*
-	 * On success the ref of device is moved to the file and
-	 * put in vfio_device_fops_release()
-	 */
-	return filep;
+	return ret;
+}
 
-err_close_device:
+void vfio_device_close(struct vfio_device *device,
+		       struct iommufd_ctx *iommufd)
+{
 	mutex_lock(&device->dev_set->lock);
+	vfio_assert_device_open(device);
 	if (device->open_count == 1)
-		vfio_device_last_close(device);
-err_unlock:
+		vfio_device_last_close(device, iommufd);
 	device->open_count--;
 	mutex_unlock(&device->dev_set->lock);
-	return ERR_PTR(ret);
-}
-
-static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
-					  char __user *arg)
-{
-	struct vfio_device *device;
-	struct file *filep;
-	char *buf;
-	int fdno;
-	int ret;
-
-	buf = strndup_user(arg, PAGE_SIZE);
-	if (IS_ERR(buf))
-		return PTR_ERR(buf);
-
-	device = vfio_device_get_from_name(group, buf);
-	kfree(buf);
-	if (IS_ERR(device))
-		return PTR_ERR(device);
-
-	fdno = get_unused_fd_flags(O_CLOEXEC);
-	if (fdno < 0) {
-		ret = fdno;
-		goto err_put_device;
-	}
-
-	filep = vfio_device_open(device);
-	if (IS_ERR(filep)) {
-		ret = PTR_ERR(filep);
-		goto err_put_fdno;
-	}
-
-	fd_install(fdno, filep);
-	return fdno;
-
-err_put_fdno:
-	put_unused_fd(fdno);
-err_put_device:
-	vfio_device_put_registration(device);
-	return ret;
-}
-
-static int vfio_group_ioctl_get_status(struct vfio_group *group,
-				       struct vfio_group_status __user *arg)
-{
-	unsigned long minsz = offsetofend(struct vfio_group_status, flags);
-	struct vfio_group_status status;
-
-	if (copy_from_user(&status, arg, minsz))
-		return -EFAULT;
-
-	if (status.argsz < minsz)
-		return -EINVAL;
-
-	status.flags = 0;
-
-	mutex_lock(&group->group_lock);
-	if (!group->iommu_group) {
-		mutex_unlock(&group->group_lock);
-		return -ENODEV;
-	}
-
-	/*
-	 * With the container FD the iommu_group_claim_dma_owner() is done
-	 * during SET_CONTAINER but for IOMMFD this is done during
-	 * VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd
-	 * VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due
-	 * to viability.
-	 */
-	if (vfio_group_has_iommu(group))
-		status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET |
-				VFIO_GROUP_FLAGS_VIABLE;
-	else if (!iommu_group_dma_owner_claimed(group->iommu_group))
-		status.flags |= VFIO_GROUP_FLAGS_VIABLE;
-	mutex_unlock(&group->group_lock);
-
-	if (copy_to_user(arg, &status, minsz))
-		return -EFAULT;
-	return 0;
-}
-
-static long vfio_group_fops_unl_ioctl(struct file *filep,
-				      unsigned int cmd, unsigned long arg)
-{
-	struct vfio_group *group = filep->private_data;
-	void __user *uarg = (void __user *)arg;
-
-	switch (cmd) {
-	case VFIO_GROUP_GET_DEVICE_FD:
-		return vfio_group_ioctl_get_device_fd(group, uarg);
-	case VFIO_GROUP_GET_STATUS:
-		return vfio_group_ioctl_get_status(group, uarg);
-	case VFIO_GROUP_SET_CONTAINER:
-		return vfio_group_ioctl_set_container(group, uarg);
-	case VFIO_GROUP_UNSET_CONTAINER:
-		return vfio_group_ioctl_unset_container(group);
-	default:
-		return -ENOTTY;
-	}
-}
-
-static int vfio_group_fops_open(struct inode *inode, struct file *filep)
-{
-	struct vfio_group *group =
-		container_of(inode->i_cdev, struct vfio_group, cdev);
-	int ret;
-
-	mutex_lock(&group->group_lock);
-
-	/*
-	 * drivers can be zero if this races with vfio_device_remove_group(), it
-	 * will be stable at 0 under the group rwsem
-	 */
-	if (refcount_read(&group->drivers) == 0) {
-		ret = -ENODEV;
-		goto out_unlock;
-	}
-
-	if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
-		ret = -EPERM;
-		goto out_unlock;
-	}
-
-	/*
-	 * Do we need multiple instances of the group open?  Seems not.
-	 */
-	if (group->opened_file) {
-		ret = -EBUSY;
-		goto out_unlock;
-	}
-	group->opened_file = filep;
-	filep->private_data = group;
-	ret = 0;
-out_unlock:
-	mutex_unlock(&group->group_lock);
-	return ret;
 }
 
-static int vfio_group_fops_release(struct inode *inode, struct file *filep)
-{
-	struct vfio_group *group = filep->private_data;
-
-	filep->private_data = NULL;
-
-	mutex_lock(&group->group_lock);
-	/*
-	 * Device FDs hold a group file reference, therefore the group release
-	 * is only called when there are no open devices.
-	 */
-	WARN_ON(group->notifier.head);
-	if (group->container)
-		vfio_group_detach_container(group);
-	if (group->iommufd) {
-		iommufd_ctx_put(group->iommufd);
-		group->iommufd = NULL;
-	}
-	group->opened_file = NULL;
-	mutex_unlock(&group->group_lock);
-	return 0;
-}
-
-static const struct file_operations vfio_group_fops = {
-	.owner		= THIS_MODULE,
-	.unlocked_ioctl	= vfio_group_fops_unl_ioctl,
-	.compat_ioctl	= compat_ptr_ioctl,
-	.open		= vfio_group_fops_open,
-	.release	= vfio_group_fops_release,
-};
-
 /*
  * Wrapper around pm_runtime_resume_and_get().
  * Return error code on failure or 0 on success.
@@ -1117,12 +477,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
 {
 	struct vfio_device *device = filep->private_data;
 
-	mutex_lock(&device->dev_set->lock);
-	vfio_assert_device_open(device);
-	if (device->open_count == 1)
-		vfio_device_last_close(device);
-	device->open_count--;
-	mutex_unlock(&device->dev_set->lock);
+	vfio_device_group_close(device);
 
 	vfio_device_put_registration(device);
 
@@ -1645,7 +1000,7 @@ static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
 	return device->ops->mmap(device, vma);
 }
 
-static const struct file_operations vfio_device_fops = {
+const struct file_operations vfio_device_fops = {
 	.owner		= THIS_MODULE,
 	.release	= vfio_device_fops_release,
 	.read		= vfio_device_fops_read,
@@ -1655,121 +1010,6 @@ static const struct file_operations vfio_device_fops = {
 	.mmap		= vfio_device_fops_mmap,
 };
 
-/**
- * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
- * @file: VFIO group file
- *
- * The returned iommu_group is valid as long as a ref is held on the file. This
- * returns a reference on the group. This function is deprecated, only the SPAPR
- * path in kvm should call it.
- */
-struct iommu_group *vfio_file_iommu_group(struct file *file)
-{
-	struct vfio_group *group = file->private_data;
-	struct iommu_group *iommu_group = NULL;
-
-	if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
-		return NULL;
-
-	if (!vfio_file_is_group(file))
-		return NULL;
-
-	mutex_lock(&group->group_lock);
-	if (group->iommu_group) {
-		iommu_group = group->iommu_group;
-		iommu_group_ref_get(iommu_group);
-	}
-	mutex_unlock(&group->group_lock);
-	return iommu_group;
-}
-EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
-
-/**
- * vfio_file_is_group - True if the file is usable with VFIO aPIS
- * @file: VFIO group file
- */
-bool vfio_file_is_group(struct file *file)
-{
-	return file->f_op == &vfio_group_fops;
-}
-EXPORT_SYMBOL_GPL(vfio_file_is_group);
-
-/**
- * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
- *        is always CPU cache coherent
- * @file: VFIO group file
- *
- * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
- * bit in DMA transactions. A return of false indicates that the user has
- * rights to access additional instructions such as wbinvd on x86.
- */
-bool vfio_file_enforced_coherent(struct file *file)
-{
-	struct vfio_group *group = file->private_data;
-	struct vfio_device *device;
-	bool ret = true;
-
-	if (!vfio_file_is_group(file))
-		return true;
-
-	/*
-	 * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then
-	 * any domain later attached to it will also not support it. If the cap
-	 * is set then the iommu_domain eventually attached to the device/group
-	 * must use a domain with enforce_cache_coherency().
-	 */
-	mutex_lock(&group->device_lock);
-	list_for_each_entry(device, &group->device_list, group_next) {
-		if (!device_iommu_capable(device->dev,
-					  IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) {
-			ret = false;
-			break;
-		}
-	}
-	mutex_unlock(&group->device_lock);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
-
-/**
- * vfio_file_set_kvm - Link a kvm with VFIO drivers
- * @file: VFIO group file
- * @kvm: KVM to link
- *
- * When a VFIO device is first opened the KVM will be available in
- * device->kvm if one was associated with the group.
- */
-void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
-{
-	struct vfio_group *group = file->private_data;
-
-	if (!vfio_file_is_group(file))
-		return;
-
-	mutex_lock(&group->group_lock);
-	group->kvm = kvm;
-	mutex_unlock(&group->group_lock);
-}
-EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
-
-/**
- * vfio_file_has_dev - True if the VFIO file is a handle for device
- * @file: VFIO file to check
- * @device: Device that must be part of the file
- *
- * Returns true if given file has permission to manipulate the given device.
- */
-bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
-{
-	struct vfio_group *group = file->private_data;
-
-	if (!vfio_file_is_group(file))
-		return false;
-
-	return group == device->group;
-}
-EXPORT_SYMBOL_GPL(vfio_file_has_dev);
-
 /*
  * Sub-module support
  */
@@ -1901,7 +1141,7 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
  * Return error or number of pages pinned.
  *
  * A driver may only call this function if the vfio_device was created
- * by vfio_register_emulated_iommu_dev() due to vfio_container_pin_pages().
+ * by vfio_register_emulated_iommu_dev() due to vfio_device_container_pin_pages().
  */
 int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
 		   int npage, int prot, struct page **pages)
@@ -1909,10 +1149,9 @@ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
 	/* group->container cannot change while a vfio device is open */
 	if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device)))
 		return -EINVAL;
-	if (device->group->container)
-		return vfio_container_pin_pages(device->group->container,
-						device->group->iommu_group,
-						iova, npage, prot, pages);
+	if (vfio_device_has_container(device))
+		return vfio_device_container_pin_pages(device, iova,
+						       npage, prot, pages);
 	if (device->iommufd_access) {
 		int ret;
 
@@ -1948,9 +1187,8 @@ void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage)
 	if (WARN_ON(!vfio_assert_device_open(device)))
 		return;
 
-	if (device->group->container) {
-		vfio_container_unpin_pages(device->group->container, iova,
-					   npage);
+	if (vfio_device_has_container(device)) {
+		vfio_device_container_unpin_pages(device, iova, npage);
 		return;
 	}
 	if (device->iommufd_access) {
@@ -1987,8 +1225,8 @@ int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data,
 	if (!data || len <= 0 || !vfio_assert_device_open(device))
 		return -EINVAL;
 
-	if (device->group->container)
-		return vfio_container_dma_rw(device->group->container, iova,
+	if (vfio_device_has_container(device))
+		return vfio_device_container_dma_rw(device, iova,
 						    data, len, write);
 
 	if (device->iommufd_access) {
@@ -2012,33 +1250,16 @@ EXPORT_SYMBOL(vfio_dma_rw);
 /*
  * Module/class support
  */
-static char *vfio_devnode(struct device *dev, umode_t *mode)
-{
-	return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
-}
-
 static int __init vfio_init(void)
 {
 	int ret;
 
-	ida_init(&vfio.group_ida);
 	ida_init(&vfio.device_ida);
-	mutex_init(&vfio.group_lock);
-	INIT_LIST_HEAD(&vfio.group_list);
 
-	ret = vfio_container_init();
+	ret = vfio_group_init();
 	if (ret)
 		return ret;
 
-	/* /dev/vfio/$GROUP */
-	vfio.class = class_create(THIS_MODULE, "vfio");
-	if (IS_ERR(vfio.class)) {
-		ret = PTR_ERR(vfio.class);
-		goto err_group_class;
-	}
-
-	vfio.class->devnode = vfio_devnode;
-
 	/* /sys/class/vfio-dev/vfioX */
 	vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
 	if (IS_ERR(vfio.device_class)) {
@@ -2046,36 +1267,20 @@ static int __init vfio_init(void)
 		goto err_dev_class;
 	}
 
-	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
-	if (ret)
-		goto err_alloc_chrdev;
-
 	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 	return 0;
 
-err_alloc_chrdev:
-	class_destroy(vfio.device_class);
-	vfio.device_class = NULL;
 err_dev_class:
-	class_destroy(vfio.class);
-	vfio.class = NULL;
-err_group_class:
-	vfio_container_cleanup();
+	vfio_group_cleanup();
 	return ret;
 }
 
 static void __exit vfio_cleanup(void)
 {
-	WARN_ON(!list_empty(&vfio.group_list));
-
 	ida_destroy(&vfio.device_ida);
-	ida_destroy(&vfio.group_ida);
-	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
 	class_destroy(vfio.device_class);
 	vfio.device_class = NULL;
-	class_destroy(vfio.class);
-	vfio_container_cleanup();
-	vfio.class = NULL;
+	vfio_group_cleanup();
 	xa_destroy(&vfio_device_set_xa);
 }