// SPDX-License-Identifier: GPL-2.0-only /* * VFIO core * * Copyright (C) 2012 Red Hat, Inc. All rights reserved. * Author: Alex Williamson * * Derived from original vfio: * Copyright 2010 Cisco Systems, Inc. All rights reserved. * Author: Tom Lyon, pugs@cisco.com */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "vfio.h" #define DRIVER_VERSION "0.3" #define DRIVER_AUTHOR "Alex Williamson " #define DRIVER_DESC "VFIO - User Level meta-driver" static struct vfio { struct class *device_class; struct ida device_ida; } vfio; static DEFINE_XARRAY(vfio_device_set_xa); 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); /* * Device objects - create, release, get, put, search */ /* Device reference always implies a group reference */ void vfio_device_put_registration(struct vfio_device *device) { if (refcount_dec_and_test(&device->refcount)) complete(&device->comp); } bool vfio_device_try_get_registration(struct vfio_device *device) { return refcount_inc_not_zero(&device->refcount); } /* * 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); if (device->ops->release) device->ops->release(device); kvfree(device); } static int vfio_init_device(struct vfio_device *device, struct device *dev, const struct vfio_device_ops *ops); /* * 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. */ static 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; } static int __vfio_register_dev(struct vfio_device *device, enum vfio_group_type type) { int ret; if (WARN_ON(device->ops->bind_iommufd && (!device->ops->unbind_iommufd || !device->ops->attach_ioas))) return -EINVAL; /* * 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); ret = dev_set_name(&device->device, "vfio%d", device->index); if (ret) return ret; ret = vfio_device_set_group(device, type); if (ret) return ret; ret = device_add(&device->device); if (ret) goto err_out; /* Refcounting can't start until the driver calls register */ refcount_set(&device->refcount, 1); vfio_device_group_register(device); 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_IOMMU); } 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_EMULATED_IOMMU); } EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev); /* * 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) { 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)); } } } 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); /* 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, struct iommufd_ctx *iommufd, struct kvm *kvm) { int ret; lockdep_assert_held(&device->dev_set->lock); if (!try_module_get(device->dev->driver->owner)) return -ENODEV; if (iommufd) ret = vfio_iommufd_bind(device, iommufd); else ret = vfio_device_group_use_iommu(device); if (ret) goto err_module_put; device->kvm = kvm; if (device->ops->open_device) { ret = device->ops->open_device(device); if (ret) goto err_unuse_iommu; } return 0; err_unuse_iommu: device->kvm = NULL; if (iommufd) vfio_iommufd_unbind(device); else vfio_device_group_unuse_iommu(device); err_module_put: module_put(device->dev->driver->owner); return ret; } static void vfio_device_last_close(struct vfio_device *device, struct iommufd_ctx *iommufd) { lockdep_assert_held(&device->dev_set->lock); if (device->ops->close_device) device->ops->close_device(device); device->kvm = NULL; if (iommufd) vfio_iommufd_unbind(device); else vfio_device_group_unuse_iommu(device); module_put(device->dev->driver->owner); } int vfio_device_open(struct vfio_device *device, struct iommufd_ctx *iommufd, struct kvm *kvm) { int ret = 0; mutex_lock(&device->dev_set->lock); device->open_count++; if (device->open_count == 1) { ret = vfio_device_first_open(device, iommufd, kvm); if (ret) device->open_count--; } mutex_unlock(&device->dev_set->lock); return ret; } 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, iommufd); device->open_count--; mutex_unlock(&device->dev_set->lock); } /* * 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; vfio_device_group_close(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_PRE_COPY_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 * * If precopy is supported then the driver must support these additional * FSM arcs: * RUNNING -> PRE_COPY * PRE_COPY -> RUNNING * PRE_COPY -> STOP_COPY * However, if precopy and P2P are supported together then the driver * must support these additional arcs beyond the P2P arcs above: * PRE_COPY -> RUNNING * PRE_COPY -> PRE_COPY_P2P * PRE_COPY_P2P -> PRE_COPY * PRE_COPY_P2P -> RUNNING_P2P * PRE_COPY_P2P -> STOP_COPY * RUNNING -> PRE_COPY * RUNNING_P2P -> PRE_COPY_P2P * * Without P2P and precopy 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: * PRE_COPY -> PRE_COPY_P2P -> STOP_COPY * PRE_COPY -> RUNNING -> RUNNING_P2P * PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP * PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP -> RESUMING * PRE_COPY_P2P -> RUNNING_P2P -> RUNNING * PRE_COPY_P2P -> RUNNING_P2P -> STOP * PRE_COPY_P2P -> RUNNING_P2P -> STOP -> RESUMING * RESUMING -> STOP -> RUNNING_P2P * RESUMING -> STOP -> RUNNING_P2P -> PRE_COPY_P2P * RESUMING -> STOP -> RUNNING_P2P -> RUNNING * RESUMING -> STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY * RESUMING -> STOP -> STOP_COPY * RUNNING -> RUNNING_P2P -> PRE_COPY_P2P * RUNNING -> RUNNING_P2P -> STOP * RUNNING -> RUNNING_P2P -> STOP -> RESUMING * RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY * RUNNING_P2P -> RUNNING -> PRE_COPY * RUNNING_P2P -> STOP -> RESUMING * RUNNING_P2P -> STOP -> STOP_COPY * STOP -> RUNNING_P2P -> PRE_COPY_P2P * STOP -> RUNNING_P2P -> RUNNING * STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY * STOP_COPY -> STOP -> RESUMING * STOP_COPY -> STOP -> RUNNING_P2P * STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING * * The following transitions are blocked: * STOP_COPY -> PRE_COPY * STOP_COPY -> PRE_COPY_P2P */ 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_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = 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_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, [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_PRE_COPY] = { [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING, [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING, [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P, [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_PRE_COPY_P2P, [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING, [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING, [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, }, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = { [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P, [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P, [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P, [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, [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_PRE_COPY] = VFIO_DEVICE_STATE_ERROR, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_ERROR, [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_PRE_COPY] = VFIO_DEVICE_STATE_STOP, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = 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_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P, [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_PRE_COPY] = VFIO_DEVICE_STATE_ERROR, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = 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_PRE_COPY] = VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_PRE_COPY, [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P | VFIO_MIGRATION_PRE_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_data_size(struct vfio_device *device, u32 flags, void __user *arg, size_t argsz) { struct vfio_device_feature_mig_data_size data_size = {}; unsigned long stop_copy_length; int ret; if (!device->mig_ops) return -ENOTTY; ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET, sizeof(data_size)); if (ret != 1) return ret; ret = device->mig_ops->migration_get_data_size(device, &stop_copy_length); if (ret) return ret; data_size.stop_copy_length = stop_copy_length; if (copy_to_user(arg, &data_size, sizeof(data_size))) return -EFAULT; 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); case VFIO_DEVICE_FEATURE_MIG_DATA_SIZE: return vfio_ioctl_device_feature_migration_data_size( 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); } 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, }; /* * 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); /* * Pin contiguous user pages and return their associated host pages for local * domain only. * @device [in] : device * @iova [in] : starting IOVA of user pages to be pinned. * @npage [in] : count of pages to be pinned. This count should not * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. * @prot [in] : protection flags * @pages[out] : array of host pages * 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_device_container_pin_pages(). */ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, int npage, int prot, struct page **pages) { /* group->container cannot change while a vfio device is open */ if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device))) return -EINVAL; if (vfio_device_has_container(device)) return vfio_device_container_pin_pages(device, iova, npage, prot, pages); if (device->iommufd_access) { int ret; if (iova > ULONG_MAX) return -EINVAL; /* * VFIO ignores the sub page offset, npages is from the start of * a PAGE_SIZE chunk of IOVA. The caller is expected to recover * the sub page offset by doing: * pages[0] + (iova % PAGE_SIZE) */ ret = iommufd_access_pin_pages( device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE), npage * PAGE_SIZE, pages, (prot & IOMMU_WRITE) ? IOMMUFD_ACCESS_RW_WRITE : 0); if (ret) return ret; return npage; } return -EINVAL; } EXPORT_SYMBOL(vfio_pin_pages); /* * Unpin contiguous host pages for local domain only. * @device [in] : device * @iova [in] : starting address of user pages to be unpinned. * @npage [in] : count of pages to be unpinned. This count should not * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. */ void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage) { if (WARN_ON(!vfio_assert_device_open(device))) return; if (vfio_device_has_container(device)) { vfio_device_container_unpin_pages(device, iova, npage); return; } if (device->iommufd_access) { if (WARN_ON(iova > ULONG_MAX)) return; iommufd_access_unpin_pages(device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE), npage * PAGE_SIZE); return; } } EXPORT_SYMBOL(vfio_unpin_pages); /* * This interface allows the CPUs to perform some sort of virtual DMA on * behalf of the device. * * CPUs read/write from/into a range of IOVAs pointing to user space memory * into/from a kernel buffer. * * As the read/write of user space memory is conducted via the CPUs and is * not a real device DMA, it is not necessary to pin the user space memory. * * @device [in] : VFIO device * @iova [in] : base IOVA of a user space buffer * @data [in] : pointer to kernel buffer * @len [in] : kernel buffer length * @write : indicate read or write * Return error code on failure or 0 on success. */ int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data, size_t len, bool write) { if (!data || len <= 0 || !vfio_assert_device_open(device)) return -EINVAL; if (vfio_device_has_container(device)) return vfio_device_container_dma_rw(device, iova, data, len, write); if (device->iommufd_access) { unsigned int flags = 0; if (iova > ULONG_MAX) return -EINVAL; /* VFIO historically tries to auto-detect a kthread */ if (!current->mm) flags |= IOMMUFD_ACCESS_RW_KTHREAD; if (write) flags |= IOMMUFD_ACCESS_RW_WRITE; return iommufd_access_rw(device->iommufd_access, iova, data, len, flags); } return -EINVAL; } EXPORT_SYMBOL(vfio_dma_rw); /* * Module/class support */ static int __init vfio_init(void) { int ret; ida_init(&vfio.device_ida); ret = vfio_group_init(); if (ret) return ret; ret = vfio_virqfd_init(); if (ret) goto err_virqfd; /* /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; } pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); return 0; err_dev_class: vfio_virqfd_exit(); err_virqfd: vfio_group_cleanup(); return ret; } static void __exit vfio_cleanup(void) { ida_destroy(&vfio.device_ida); class_destroy(vfio.device_class); vfio.device_class = NULL; vfio_virqfd_exit(); vfio_group_cleanup(); 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_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce");