diff options
Diffstat (limited to 'drivers/vfio/vfio_main.c')
| -rw-r--r-- | drivers/vfio/vfio_main.c | 1891 |
1 files changed, 1891 insertions, 0 deletions
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c new file mode 100644 index 000000000..6e8804fe0 --- /dev/null +++ b/drivers/vfio/vfio_main.c @@ -0,0 +1,1891 @@ +// 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/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> +#include <linux/list.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/pci.h> +#include <linux/rwsem.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/uaccess.h> +#include <linux/vfio.h> +#include <linux/wait.h> +#include <linux/sched/signal.h> +#include <linux/pm_runtime.h> +#include <linux/interval_tree.h> +#include <linux/iova_bitmap.h> +#include "vfio.h" + +#define DRIVER_VERSION "0.3" +#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" +#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) +{ + unsigned long idx = (unsigned long)set_id; + struct vfio_device_set *new_dev_set; + struct vfio_device_set *dev_set; + + if (WARN_ON(!set_id)) + return -EINVAL; + + /* + * Atomically acquire a singleton object in the xarray for this set_id + */ + xa_lock(&vfio_device_set_xa); + dev_set = xa_load(&vfio_device_set_xa, idx); + if (dev_set) + goto found_get_ref; + xa_unlock(&vfio_device_set_xa); + + new_dev_set = kzalloc(sizeof(*new_dev_set), GFP_KERNEL); + if (!new_dev_set) + return -ENOMEM; + mutex_init(&new_dev_set->lock); + INIT_LIST_HEAD(&new_dev_set->device_list); + new_dev_set->set_id = set_id; + + xa_lock(&vfio_device_set_xa); + dev_set = __xa_cmpxchg(&vfio_device_set_xa, idx, NULL, new_dev_set, + GFP_KERNEL); + if (!dev_set) { + dev_set = new_dev_set; + goto found_get_ref; + } + + kfree(new_dev_set); + if (xa_is_err(dev_set)) { + xa_unlock(&vfio_device_set_xa); + return xa_err(dev_set); + } + +found_get_ref: + dev_set->device_count++; + xa_unlock(&vfio_device_set_xa); + mutex_lock(&dev_set->lock); + device->dev_set = dev_set; + list_add_tail(&device->dev_set_list, &dev_set->device_list); + mutex_unlock(&dev_set->lock); + return 0; +} +EXPORT_SYMBOL_GPL(vfio_assign_device_set); + +static void vfio_release_device_set(struct vfio_device *device) +{ + struct vfio_device_set *dev_set = device->dev_set; + + if (!dev_set) + return; + + mutex_lock(&dev_set->lock); + list_del(&device->dev_set_list); + mutex_unlock(&dev_set->lock); + + xa_lock(&vfio_device_set_xa); + if (!--dev_set->device_count) { + __xa_erase(&vfio_device_set_xa, + (unsigned long)dev_set->set_id); + mutex_destroy(&dev_set->lock); + kfree(dev_set); + } + xa_unlock(&vfio_device_set_xa); +} + +unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set) +{ + struct vfio_device *cur; + unsigned int open_count = 0; + + lockdep_assert_held(&dev_set->lock); + + list_for_each_entry(cur, &dev_set->device_list, dev_set_list) + open_count += cur->open_count; + return open_count; +} +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) +{ + if (refcount_dec_and_test(&device->refcount)) + complete(&device->comp); +} + +static 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 + */ +/* Release helper called by vfio_put_device() */ +static void vfio_device_release(struct device *dev) +{ + struct vfio_device *device = + container_of(dev, struct vfio_device, device); + + vfio_release_device_set(device); + ida_free(&vfio.device_ida, device->index); + + /* + * kvfree() cannot be done here due to a life cycle mess in + * vfio-ccw. Before the ccw part is fixed all drivers are + * required to support @release and call vfio_free_device() + * from there. + */ + device->ops->release(device); +} + +/* + * Allocate and initialize vfio_device so it can be registered to vfio + * core. + * + * Drivers should use the wrapper vfio_alloc_device() for allocation. + * @size is the size of the structure to be allocated, including any + * private data used by the driver. + * + * Driver may provide an @init callback to cover device private data. + * + * Use vfio_put_device() to release the structure after success return. + */ +struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, + const struct vfio_device_ops *ops) +{ + struct vfio_device *device; + int ret; + + if (WARN_ON(size < sizeof(struct vfio_device))) + return ERR_PTR(-EINVAL); + + device = kvzalloc(size, GFP_KERNEL); + if (!device) + return ERR_PTR(-ENOMEM); + + ret = vfio_init_device(device, dev, ops); + if (ret) + goto out_free; + return device; + +out_free: + kvfree(device); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(_vfio_alloc_device); + +/* + * Initialize a vfio_device so it can be registered to vfio core. + * + * Only vfio-ccw driver should call this interface. + */ +int vfio_init_device(struct vfio_device *device, struct device *dev, + const struct vfio_device_ops *ops) +{ + int ret; + + ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); + if (ret < 0) { + dev_dbg(dev, "Error to alloc index\n"); + return ret; + } + + device->index = ret; + init_completion(&device->comp); + device->dev = dev; + device->ops = ops; + + if (ops->init) { + ret = ops->init(device); + if (ret) + goto out_uninit; + } + + device_initialize(&device->device); + device->device.release = vfio_device_release; + device->device.class = vfio.device_class; + device->device.parent = device->dev; + return 0; + +out_uninit: + vfio_release_device_set(device); + ida_free(&vfio.device_ida, device->index); + return ret; +} +EXPORT_SYMBOL_GPL(vfio_init_device); + +/* + * The helper called by driver @release callback to free the device + * structure. Drivers which don't have private data to clean can + * simply use this helper as its @release. + */ +void vfio_free_device(struct vfio_device *device) +{ + kvfree(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) +{ + 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 the driver doesn't specify a set then the device is added to a + * singleton set just for itself. + */ + 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; + + ret = device_add(&device->device); + if (ret) + goto err_out; + + /* 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); + + return 0; +err_out: + vfio_device_remove_group(device); + return ret; +} + +int vfio_register_group_dev(struct vfio_device *device) +{ + return __vfio_register_dev(device, + vfio_group_find_or_alloc(device->dev)); +} +EXPORT_SYMBOL_GPL(vfio_register_group_dev); + +/* + * Register a virtual device without IOMMU backing. The user of this + * device must not be able to directly trigger unmediated DMA. + */ +int vfio_register_emulated_iommu_dev(struct vfio_device *device) +{ + return __vfio_register_dev(device, + vfio_noiommu_group_alloc(device->dev, 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; + + vfio_device_put_registration(device); + rc = try_wait_for_completion(&device->comp); + while (rc <= 0) { + if (device->ops->request) + device->ops->request(device, i++); + + if (interrupted) { + rc = wait_for_completion_timeout(&device->comp, + HZ * 10); + } else { + rc = wait_for_completion_interruptible_timeout( + &device->comp, HZ * 10); + if (rc < 0) { + interrupted = true; + dev_warn(device->dev, + "Device is currently in use, task" + " \"%s\" (%d) " + "blocked until device is released", + current->comm, task_pid_nr(current)); + } + } + } + + mutex_lock(&group->device_lock); + list_del(&device->group_next); + mutex_unlock(&group->device_lock); + + /* Balances device_add in register path */ + device_del(&device->device); + + vfio_device_remove_group(device); +} +EXPORT_SYMBOL_GPL(vfio_unregister_group_dev); + +/* + * VFIO Group fd, /dev/vfio/$GROUP + */ +/* + * 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 (!group->container) { + ret = -EINVAL; + goto out_unlock; + } + if (group->container_users != 1) { + ret = -EBUSY; + goto out_unlock; + } + vfio_group_detach_container(group); + +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 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 (group->container || WARN_ON(group->container_users)) { + ret = -EINVAL; + goto out_unlock; + } + if (!group->iommu_group) { + ret = -ENODEV; + goto out_unlock; + } + + container = vfio_container_from_file(f.file); + ret = -EINVAL; + if (container) { + ret = vfio_container_attach_group(container, group); + goto out_unlock; + } + +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() */ +bool vfio_assert_device_open(struct vfio_device *device) +{ + return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); +} + +static struct file *vfio_device_open(struct vfio_device *device) +{ + struct file *filep; + int ret; + + mutex_lock(&device->group->group_lock); + ret = vfio_device_assign_container(device); + mutex_unlock(&device->group->group_lock); + if (ret) + return ERR_PTR(ret); + + if (!try_module_get(device->dev->driver->owner)) { + ret = -ENODEV; + goto err_unassign_container; + } + + mutex_lock(&device->dev_set->lock); + device->open_count++; + if (device->open_count == 1) { + /* + * Here we pass the KVM pointer with the group under the read + * 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); + device->kvm = device->group->kvm; + + if (device->ops->open_device) { + ret = device->ops->open_device(device); + if (ret) + goto err_undo_count; + } + vfio_device_container_register(device); + mutex_unlock(&device->group->group_lock); + } + 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; + +err_close_device: + mutex_lock(&device->dev_set->lock); + mutex_lock(&device->group->group_lock); + if (device->open_count == 1) { + if (device->ops->close_device) + device->ops->close_device(device); + + vfio_device_container_unregister(device); + } +err_undo_count: + mutex_unlock(&device->group->group_lock); + device->open_count--; + if (device->open_count == 0 && device->kvm) + device->kvm = NULL; + mutex_unlock(&device->dev_set->lock); + module_put(device->dev->driver->owner); +err_unassign_container: + vfio_device_unassign_container(device); + 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; + } + + if (group->container) + 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); + 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. + */ +static inline int vfio_device_pm_runtime_get(struct vfio_device *device) +{ + struct device *dev = device->dev; + + if (dev->driver && dev->driver->pm) { + int ret; + + ret = pm_runtime_resume_and_get(dev); + if (ret) { + dev_info_ratelimited(dev, + "vfio: runtime resume failed %d\n", ret); + return -EIO; + } + } + + return 0; +} + +/* + * Wrapper around pm_runtime_put(). + */ +static inline void vfio_device_pm_runtime_put(struct vfio_device *device) +{ + struct device *dev = device->dev; + + if (dev->driver && dev->driver->pm) + pm_runtime_put(dev); +} + +/* + * VFIO Device fd + */ +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); + mutex_lock(&device->group->group_lock); + if (device->open_count == 1) { + if (device->ops->close_device) + device->ops->close_device(device); + + vfio_device_container_unregister(device); + } + mutex_unlock(&device->group->group_lock); + device->open_count--; + if (device->open_count == 0) + device->kvm = NULL; + mutex_unlock(&device->dev_set->lock); + + module_put(device->dev->driver->owner); + + vfio_device_unassign_container(device); + + vfio_device_put_registration(device); + + return 0; +} + +/* + * vfio_mig_get_next_state - Compute the next step in the FSM + * @cur_fsm - The current state the device is in + * @new_fsm - The target state to reach + * @next_fsm - Pointer to the next step to get to new_fsm + * + * Return 0 upon success, otherwise -errno + * Upon success the next step in the state progression between cur_fsm and + * new_fsm will be set in next_fsm. + * + * This breaks down requests for combination transitions into smaller steps and + * returns the next step to get to new_fsm. The function may need to be called + * multiple times before reaching new_fsm. + * + */ +int vfio_mig_get_next_state(struct vfio_device *device, + enum vfio_device_mig_state cur_fsm, + enum vfio_device_mig_state new_fsm, + enum vfio_device_mig_state *next_fsm) +{ + enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_RUNNING_P2P + 1 }; + /* + * The coding in this table requires the driver to implement the + * following FSM arcs: + * RESUMING -> STOP + * STOP -> RESUMING + * STOP -> STOP_COPY + * STOP_COPY -> STOP + * + * If P2P is supported then the driver must also implement these FSM + * arcs: + * RUNNING -> RUNNING_P2P + * RUNNING_P2P -> RUNNING + * RUNNING_P2P -> STOP + * STOP -> RUNNING_P2P + * Without P2P the driver must implement: + * RUNNING -> STOP + * STOP -> RUNNING + * + * The coding will step through multiple states for some combination + * transitions; if all optional features are supported, this means the + * following ones: + * RESUMING -> STOP -> RUNNING_P2P + * RESUMING -> STOP -> RUNNING_P2P -> RUNNING + * RESUMING -> STOP -> STOP_COPY + * RUNNING -> RUNNING_P2P -> STOP + * RUNNING -> RUNNING_P2P -> STOP -> RESUMING + * RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY + * RUNNING_P2P -> STOP -> RESUMING + * RUNNING_P2P -> STOP -> STOP_COPY + * STOP -> RUNNING_P2P -> RUNNING + * STOP_COPY -> STOP -> RESUMING + * STOP_COPY -> STOP -> RUNNING_P2P + * STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING + */ + static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = { + [VFIO_DEVICE_STATE_STOP] = { + [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P, + [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, + [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING, + [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, + [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, + }, + [VFIO_DEVICE_STATE_RUNNING] = { + [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P, + [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING, + [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P, + [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P, + [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, + [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, + }, + [VFIO_DEVICE_STATE_STOP_COPY] = { + [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, + [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, + }, + [VFIO_DEVICE_STATE_RESUMING] = { + [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING, + [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, + }, + [VFIO_DEVICE_STATE_RUNNING_P2P] = { + [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING, + [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP, + [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, + [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, + }, + [VFIO_DEVICE_STATE_ERROR] = { + [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR, + [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR, + [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR, + [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR, + [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR, + [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, + }, + }; + + static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = { + [VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY, + [VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY, + [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY, + [VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY, + [VFIO_DEVICE_STATE_RUNNING_P2P] = + VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P, + [VFIO_DEVICE_STATE_ERROR] = ~0U, + }; + + if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) || + (state_flags_table[cur_fsm] & device->migration_flags) != + state_flags_table[cur_fsm])) + return -EINVAL; + + if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) || + (state_flags_table[new_fsm] & device->migration_flags) != + state_flags_table[new_fsm]) + return -EINVAL; + + /* + * Arcs touching optional and unsupported states are skipped over. The + * driver will instead see an arc from the original state to the next + * logical state, as per the above comment. + */ + *next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm]; + while ((state_flags_table[*next_fsm] & device->migration_flags) != + state_flags_table[*next_fsm]) + *next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm]; + + return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL; +} +EXPORT_SYMBOL_GPL(vfio_mig_get_next_state); + +/* + * Convert the drivers's struct file into a FD number and return it to userspace + */ +static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg, + struct vfio_device_feature_mig_state *mig) +{ + int ret; + int fd; + + fd = get_unused_fd_flags(O_CLOEXEC); + if (fd < 0) { + ret = fd; + goto out_fput; + } + + mig->data_fd = fd; + if (copy_to_user(arg, mig, sizeof(*mig))) { + ret = -EFAULT; + goto out_put_unused; + } + fd_install(fd, filp); + return 0; + +out_put_unused: + put_unused_fd(fd); +out_fput: + fput(filp); + return ret; +} + +static int +vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + size_t minsz = + offsetofend(struct vfio_device_feature_mig_state, data_fd); + struct vfio_device_feature_mig_state mig; + struct file *filp = NULL; + int ret; + + if (!device->mig_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, + VFIO_DEVICE_FEATURE_SET | + VFIO_DEVICE_FEATURE_GET, + sizeof(mig)); + if (ret != 1) + return ret; + + if (copy_from_user(&mig, arg, minsz)) + return -EFAULT; + + if (flags & VFIO_DEVICE_FEATURE_GET) { + enum vfio_device_mig_state curr_state; + + ret = device->mig_ops->migration_get_state(device, + &curr_state); + if (ret) + return ret; + mig.device_state = curr_state; + goto out_copy; + } + + /* Handle the VFIO_DEVICE_FEATURE_SET */ + filp = device->mig_ops->migration_set_state(device, mig.device_state); + if (IS_ERR(filp) || !filp) + goto out_copy; + + return vfio_ioct_mig_return_fd(filp, arg, &mig); +out_copy: + mig.data_fd = -1; + if (copy_to_user(arg, &mig, sizeof(mig))) + return -EFAULT; + if (IS_ERR(filp)) + return PTR_ERR(filp); + return 0; +} + +static int vfio_ioctl_device_feature_migration(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + struct vfio_device_feature_migration mig = { + .flags = device->migration_flags, + }; + int ret; + + if (!device->mig_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET, + sizeof(mig)); + if (ret != 1) + return ret; + if (copy_to_user(arg, &mig, sizeof(mig))) + return -EFAULT; + return 0; +} + +/* Ranges should fit into a single kernel page */ +#define LOG_MAX_RANGES \ + (PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range)) + +static int +vfio_ioctl_device_feature_logging_start(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + size_t minsz = + offsetofend(struct vfio_device_feature_dma_logging_control, + ranges); + struct vfio_device_feature_dma_logging_range __user *ranges; + struct vfio_device_feature_dma_logging_control control; + struct vfio_device_feature_dma_logging_range range; + struct rb_root_cached root = RB_ROOT_CACHED; + struct interval_tree_node *nodes; + u64 iova_end; + u32 nnodes; + int i, ret; + + if (!device->log_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, + VFIO_DEVICE_FEATURE_SET, + sizeof(control)); + if (ret != 1) + return ret; + + if (copy_from_user(&control, arg, minsz)) + return -EFAULT; + + nnodes = control.num_ranges; + if (!nnodes) + return -EINVAL; + + if (nnodes > LOG_MAX_RANGES) + return -E2BIG; + + ranges = u64_to_user_ptr(control.ranges); + nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node), + GFP_KERNEL); + if (!nodes) + return -ENOMEM; + + for (i = 0; i < nnodes; i++) { + if (copy_from_user(&range, &ranges[i], sizeof(range))) { + ret = -EFAULT; + goto end; + } + if (!IS_ALIGNED(range.iova, control.page_size) || + !IS_ALIGNED(range.length, control.page_size)) { + ret = -EINVAL; + goto end; + } + + if (check_add_overflow(range.iova, range.length, &iova_end) || + iova_end > ULONG_MAX) { + ret = -EOVERFLOW; + goto end; + } + + nodes[i].start = range.iova; + nodes[i].last = range.iova + range.length - 1; + if (interval_tree_iter_first(&root, nodes[i].start, + nodes[i].last)) { + /* Range overlapping */ + ret = -EINVAL; + goto end; + } + interval_tree_insert(nodes + i, &root); + } + + ret = device->log_ops->log_start(device, &root, nnodes, + &control.page_size); + if (ret) + goto end; + + if (copy_to_user(arg, &control, sizeof(control))) { + ret = -EFAULT; + device->log_ops->log_stop(device); + } + +end: + kfree(nodes); + return ret; +} + +static int +vfio_ioctl_device_feature_logging_stop(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + int ret; + + if (!device->log_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, + VFIO_DEVICE_FEATURE_SET, 0); + if (ret != 1) + return ret; + + return device->log_ops->log_stop(device); +} + +static int vfio_device_log_read_and_clear(struct iova_bitmap *iter, + unsigned long iova, size_t length, + void *opaque) +{ + struct vfio_device *device = opaque; + + return device->log_ops->log_read_and_clear(device, iova, length, iter); +} + +static int +vfio_ioctl_device_feature_logging_report(struct vfio_device *device, + u32 flags, void __user *arg, + size_t argsz) +{ + size_t minsz = + offsetofend(struct vfio_device_feature_dma_logging_report, + bitmap); + struct vfio_device_feature_dma_logging_report report; + struct iova_bitmap *iter; + u64 iova_end; + int ret; + + if (!device->log_ops) + return -ENOTTY; + + ret = vfio_check_feature(flags, argsz, + VFIO_DEVICE_FEATURE_GET, + sizeof(report)); + if (ret != 1) + return ret; + + if (copy_from_user(&report, arg, minsz)) + return -EFAULT; + + if (report.page_size < SZ_4K || !is_power_of_2(report.page_size)) + return -EINVAL; + + if (check_add_overflow(report.iova, report.length, &iova_end) || + iova_end > ULONG_MAX) + return -EOVERFLOW; + + iter = iova_bitmap_alloc(report.iova, report.length, + report.page_size, + u64_to_user_ptr(report.bitmap)); + if (IS_ERR(iter)) + return PTR_ERR(iter); + + ret = iova_bitmap_for_each(iter, device, + vfio_device_log_read_and_clear); + + iova_bitmap_free(iter); + return ret; +} + +static int vfio_ioctl_device_feature(struct vfio_device *device, + struct vfio_device_feature __user *arg) +{ + size_t minsz = offsetofend(struct vfio_device_feature, flags); + struct vfio_device_feature feature; + + if (copy_from_user(&feature, arg, minsz)) + return -EFAULT; + + if (feature.argsz < minsz) + return -EINVAL; + + /* Check unknown flags */ + if (feature.flags & + ~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET | + VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE)) + return -EINVAL; + + /* GET & SET are mutually exclusive except with PROBE */ + if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) && + (feature.flags & VFIO_DEVICE_FEATURE_SET) && + (feature.flags & VFIO_DEVICE_FEATURE_GET)) + return -EINVAL; + + switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) { + case VFIO_DEVICE_FEATURE_MIGRATION: + return vfio_ioctl_device_feature_migration( + device, feature.flags, arg->data, + feature.argsz - minsz); + case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE: + return vfio_ioctl_device_feature_mig_device_state( + device, feature.flags, arg->data, + feature.argsz - minsz); + case VFIO_DEVICE_FEATURE_DMA_LOGGING_START: + return vfio_ioctl_device_feature_logging_start( + device, feature.flags, arg->data, + feature.argsz - minsz); + case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP: + return vfio_ioctl_device_feature_logging_stop( + device, feature.flags, arg->data, + feature.argsz - minsz); + case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT: + return vfio_ioctl_device_feature_logging_report( + device, feature.flags, arg->data, + feature.argsz - minsz); + default: + if (unlikely(!device->ops->device_feature)) + return -EINVAL; + return device->ops->device_feature(device, feature.flags, + arg->data, + feature.argsz - minsz); + } +} + +static long vfio_device_fops_unl_ioctl(struct file *filep, + unsigned int cmd, unsigned long arg) +{ + struct vfio_device *device = filep->private_data; + int ret; + + ret = vfio_device_pm_runtime_get(device); + if (ret) + return ret; + + switch (cmd) { + case VFIO_DEVICE_FEATURE: + ret = vfio_ioctl_device_feature(device, (void __user *)arg); + break; + + default: + if (unlikely(!device->ops->ioctl)) + ret = -EINVAL; + else + ret = device->ops->ioctl(device, cmd, arg); + break; + } + + vfio_device_pm_runtime_put(device); + return ret; +} + +static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf, + size_t count, loff_t *ppos) +{ + struct vfio_device *device = filep->private_data; + + if (unlikely(!device->ops->read)) + return -EINVAL; + + return device->ops->read(device, buf, count, ppos); +} + +static ssize_t vfio_device_fops_write(struct file *filep, + const char __user *buf, + size_t count, loff_t *ppos) +{ + struct vfio_device *device = filep->private_data; + + if (unlikely(!device->ops->write)) + return -EINVAL; + + return device->ops->write(device, buf, count, ppos); +} + +static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma) +{ + struct vfio_device *device = filep->private_data; + + if (unlikely(!device->ops->mmap)) + return -EINVAL; + + return device->ops->mmap(device, vma); +} + +static const struct file_operations vfio_device_fops = { + .owner = THIS_MODULE, + .release = vfio_device_fops_release, + .read = vfio_device_fops_read, + .write = vfio_device_fops_write, + .unlocked_ioctl = vfio_device_fops_unl_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .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; + bool ret; + + if (!vfio_file_is_group(file)) + return true; + + mutex_lock(&group->group_lock); + if (group->container) { + ret = vfio_container_ioctl_check_extension(group->container, + VFIO_DMA_CC_IOMMU); + } else { + /* + * Since the coherency state is determined only once a container + * is attached the user must do so before they can prove they + * have permission. + */ + ret = true; + } + mutex_unlock(&group->group_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 + */ +/* + * Helper for managing a buffer of info chain capabilities, allocate or + * reallocate a buffer with additional @size, filling in @id and @version + * of the capability. A pointer to the new capability is returned. + * + * NB. The chain is based at the head of the buffer, so new entries are + * added to the tail, vfio_info_cap_shift() should be called to fixup the + * next offsets prior to copying to the user buffer. + */ +struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, + size_t size, u16 id, u16 version) +{ + void *buf; + struct vfio_info_cap_header *header, *tmp; + + buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL); + if (!buf) { + kfree(caps->buf); + caps->buf = NULL; + caps->size = 0; + return ERR_PTR(-ENOMEM); + } + + caps->buf = buf; + header = buf + caps->size; + + /* Eventually copied to user buffer, zero */ + memset(header, 0, size); + + header->id = id; + header->version = version; + + /* Add to the end of the capability chain */ + for (tmp = buf; tmp->next; tmp = buf + tmp->next) + ; /* nothing */ + + tmp->next = caps->size; + caps->size += size; + + return header; +} +EXPORT_SYMBOL_GPL(vfio_info_cap_add); + +void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset) +{ + struct vfio_info_cap_header *tmp; + void *buf = (void *)caps->buf; + + for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset) + tmp->next += offset; +} +EXPORT_SYMBOL(vfio_info_cap_shift); + +int vfio_info_add_capability(struct vfio_info_cap *caps, + struct vfio_info_cap_header *cap, size_t size) +{ + struct vfio_info_cap_header *header; + + header = vfio_info_cap_add(caps, size, cap->id, cap->version); + if (IS_ERR(header)) + return PTR_ERR(header); + + memcpy(header + 1, cap + 1, size - sizeof(*header)); + + return 0; +} +EXPORT_SYMBOL(vfio_info_add_capability); + +int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs, + int max_irq_type, size_t *data_size) +{ + unsigned long minsz; + size_t size; + + minsz = offsetofend(struct vfio_irq_set, count); + + if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) || + (hdr->count >= (U32_MAX - hdr->start)) || + (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK | + VFIO_IRQ_SET_ACTION_TYPE_MASK))) + return -EINVAL; + + if (data_size) + *data_size = 0; + + if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs) + return -EINVAL; + + switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) { + case VFIO_IRQ_SET_DATA_NONE: + size = 0; + break; + case VFIO_IRQ_SET_DATA_BOOL: + size = sizeof(uint8_t); + break; + case VFIO_IRQ_SET_DATA_EVENTFD: + size = sizeof(int32_t); + break; + default: + return -EINVAL; + } + + if (size) { + if (hdr->argsz - minsz < hdr->count * size) + return -EINVAL; + + if (!data_size) + return -EINVAL; + + *data_size = hdr->count * size; + } + + return 0; +} +EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); + +/* + * 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(); + 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)) { + ret = PTR_ERR(vfio.device_class); + 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(); + 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; + xa_destroy(&vfio_device_set_xa); +} + +module_init(vfio_init); +module_exit(vfio_cleanup); + +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_ALIAS_MISCDEV(VFIO_MINOR); +MODULE_ALIAS("devname:vfio/vfio"); +MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce"); |