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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/vfio/group.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/vfio/group.c')
-rw-r--r--drivers/vfio/group.c959
1 files changed, 959 insertions, 0 deletions
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
new file mode 100644
index 0000000000..610a429c61
--- /dev/null
+++ b/drivers/vfio/group.c
@@ -0,0 +1,959 @@
+// 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)) {
+ if (IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
+ group->type == VFIO_NO_IOMMU)
+ ret = iommufd_vfio_compat_set_no_iommu(iommufd);
+ else
+ ret = iommufd_vfio_compat_ioas_create(iommufd);
+
+ if (ret) {
+ iommufd_ctx_put(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 void vfio_device_group_get_kvm_safe(struct vfio_device *device)
+{
+ spin_lock(&device->group->kvm_ref_lock);
+ vfio_device_get_kvm_safe(device, device->group->kvm);
+ spin_unlock(&device->group->kvm_ref_lock);
+}
+
+static int vfio_df_group_open(struct vfio_device_file *df)
+{
+ struct vfio_device *device = df->device;
+ int ret;
+
+ mutex_lock(&device->group->group_lock);
+ if (!vfio_group_has_iommu(device->group)) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ mutex_lock(&device->dev_set->lock);
+
+ /*
+ * Before the first device open, get the KVM pointer currently
+ * associated with the group (if there is one) and obtain a reference
+ * now that will be held until the open_count reaches 0 again. Save
+ * the pointer in the device for use by drivers.
+ */
+ if (device->open_count == 0)
+ vfio_device_group_get_kvm_safe(device);
+
+ df->iommufd = device->group->iommufd;
+ if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) {
+ /*
+ * Require no compat ioas to be assigned to proceed. The basic
+ * statement is that the user cannot have done something that
+ * implies they expected translation to exist
+ */
+ if (!capable(CAP_SYS_RAWIO) ||
+ vfio_iommufd_device_has_compat_ioas(device, df->iommufd))
+ ret = -EPERM;
+ else
+ ret = 0;
+ goto out_put_kvm;
+ }
+
+ ret = vfio_df_open(df);
+ if (ret)
+ goto out_put_kvm;
+
+ if (df->iommufd && device->open_count == 1) {
+ ret = vfio_iommufd_compat_attach_ioas(device, df->iommufd);
+ if (ret)
+ goto out_close_device;
+ }
+
+ /*
+ * Paired with smp_load_acquire() in vfio_device_fops::ioctl/
+ * read/write/mmap and vfio_file_has_device_access()
+ */
+ smp_store_release(&df->access_granted, true);
+
+ mutex_unlock(&device->dev_set->lock);
+ mutex_unlock(&device->group->group_lock);
+ return 0;
+
+out_close_device:
+ vfio_df_close(df);
+out_put_kvm:
+ df->iommufd = NULL;
+ if (device->open_count == 0)
+ vfio_device_put_kvm(device);
+ mutex_unlock(&device->dev_set->lock);
+out_unlock:
+ mutex_unlock(&device->group->group_lock);
+ return ret;
+}
+
+void vfio_df_group_close(struct vfio_device_file *df)
+{
+ struct vfio_device *device = df->device;
+
+ mutex_lock(&device->group->group_lock);
+ mutex_lock(&device->dev_set->lock);
+
+ vfio_df_close(df);
+ df->iommufd = NULL;
+
+ if (device->open_count == 0)
+ vfio_device_put_kvm(device);
+
+ mutex_unlock(&device->dev_set->lock);
+ mutex_unlock(&device->group->group_lock);
+}
+
+static struct file *vfio_device_open_file(struct vfio_device *device)
+{
+ struct vfio_device_file *df;
+ struct file *filep;
+ int ret;
+
+ df = vfio_allocate_device_file(device);
+ if (IS_ERR(df)) {
+ ret = PTR_ERR(df);
+ goto err_out;
+ }
+
+ df->group = device->group;
+
+ ret = vfio_df_group_open(df);
+ if (ret)
+ goto err_free;
+
+ /*
+ * 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,
+ df, 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_df_group_close(df);
+err_free:
+ kfree(df);
+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;
+ }
+}
+
+int vfio_device_block_group(struct vfio_device *device)
+{
+ struct vfio_group *group = device->group;
+ int ret = 0;
+
+ mutex_lock(&group->group_lock);
+ if (group->opened_file) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+
+ group->cdev_device_open_cnt++;
+
+out_unlock:
+ mutex_unlock(&group->group_lock);
+ return ret;
+}
+
+void vfio_device_unblock_group(struct vfio_device *device)
+{
+ struct vfio_group *group = device->group;
+
+ mutex_lock(&group->group_lock);
+ group->cdev_device_open_cnt--;
+ mutex_unlock(&group->group_lock);
+}
+
+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;
+ }
+
+ if (group->cdev_device_open_cnt) {
+ ret = -EBUSY;
+ 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);
+ WARN_ON(group->cdev_device_open_cnt);
+ 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);
+ spin_lock_init(&group->kvm_ref_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);
+
+ 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;
+}
+
+struct vfio_group *vfio_group_from_file(struct file *file)
+{
+ struct vfio_group *group = file->private_data;
+
+ if (file->f_op != &vfio_group_fops)
+ return NULL;
+ return group;
+}
+
+/**
+ * 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 = vfio_group_from_file(file);
+ struct iommu_group *iommu_group = NULL;
+
+ if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
+ return NULL;
+
+ if (!group)
+ 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 a vfio group file
+ * @file: VFIO group file
+ */
+bool vfio_file_is_group(struct file *file)
+{
+ return vfio_group_from_file(file);
+}
+EXPORT_SYMBOL_GPL(vfio_file_is_group);
+
+bool vfio_group_enforced_coherent(struct vfio_group *group)
+{
+ struct vfio_device *device;
+ bool ret = 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;
+}
+
+void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
+{
+ spin_lock(&group->kvm_ref_lock);
+ group->kvm = kvm;
+ spin_unlock(&group->kvm_ref_lock);
+}
+
+/**
+ * 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 = vfio_group_from_file(file);
+
+ if (!group)
+ return false;
+
+ return group == device->group;
+}
+EXPORT_SYMBOL_GPL(vfio_file_has_dev);
+
+static char *vfio_devnode(const 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("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();
+}