diff options
Diffstat (limited to 'drivers/iommu/iommufd/eventq.c')
| -rw-r--r-- | drivers/iommu/iommufd/eventq.c | 552 |
1 files changed, 552 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/eventq.c b/drivers/iommu/iommufd/eventq.c new file mode 100644 index 000000000000..e373b9eec7f5 --- /dev/null +++ b/drivers/iommu/iommufd/eventq.c @@ -0,0 +1,552 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (C) 2024 Intel Corporation + */ +#define pr_fmt(fmt) "iommufd: " fmt + +#include <linux/anon_inodes.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/iommufd.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/poll.h> +#include <uapi/linux/iommufd.h> + +#include "../iommu-priv.h" +#include "iommufd_private.h" + +/* IOMMUFD_OBJ_FAULT Functions */ +void iommufd_auto_response_faults(struct iommufd_hw_pagetable *hwpt, + struct iommufd_attach_handle *handle) +{ + struct iommufd_fault *fault = hwpt->fault; + struct iopf_group *group, *next; + struct list_head free_list; + unsigned long index; + + if (!fault || !handle) + return; + INIT_LIST_HEAD(&free_list); + + mutex_lock(&fault->mutex); + spin_lock(&fault->common.lock); + list_for_each_entry_safe(group, next, &fault->common.deliver, node) { + if (group->attach_handle != &handle->handle) + continue; + list_move(&group->node, &free_list); + } + spin_unlock(&fault->common.lock); + + list_for_each_entry_safe(group, next, &free_list, node) { + list_del(&group->node); + iopf_group_response(group, IOMMU_PAGE_RESP_INVALID); + iopf_free_group(group); + } + + xa_for_each(&fault->response, index, group) { + if (group->attach_handle != &handle->handle) + continue; + xa_erase(&fault->response, index); + iopf_group_response(group, IOMMU_PAGE_RESP_INVALID); + iopf_free_group(group); + } + mutex_unlock(&fault->mutex); +} + +void iommufd_fault_destroy(struct iommufd_object *obj) +{ + struct iommufd_eventq *eventq = + container_of(obj, struct iommufd_eventq, obj); + struct iommufd_fault *fault = eventq_to_fault(eventq); + struct iopf_group *group, *next; + unsigned long index; + + /* + * The iommufd object's reference count is zero at this point. + * We can be confident that no other threads are currently + * accessing this pointer. Therefore, acquiring the mutex here + * is unnecessary. + */ + list_for_each_entry_safe(group, next, &fault->common.deliver, node) { + list_del(&group->node); + iopf_group_response(group, IOMMU_PAGE_RESP_INVALID); + iopf_free_group(group); + } + xa_for_each(&fault->response, index, group) { + xa_erase(&fault->response, index); + iopf_group_response(group, IOMMU_PAGE_RESP_INVALID); + iopf_free_group(group); + } + xa_destroy(&fault->response); + mutex_destroy(&fault->mutex); +} + +static void iommufd_compose_fault_message(struct iommu_fault *fault, + struct iommu_hwpt_pgfault *hwpt_fault, + struct iommufd_device *idev, + u32 cookie) +{ + hwpt_fault->flags = fault->prm.flags; + hwpt_fault->dev_id = idev->obj.id; + hwpt_fault->pasid = fault->prm.pasid; + hwpt_fault->grpid = fault->prm.grpid; + hwpt_fault->perm = fault->prm.perm; + hwpt_fault->addr = fault->prm.addr; + hwpt_fault->length = 0; + hwpt_fault->cookie = cookie; +} + +/* Fetch the first node out of the fault->deliver list */ +static struct iopf_group * +iommufd_fault_deliver_fetch(struct iommufd_fault *fault) +{ + struct list_head *list = &fault->common.deliver; + struct iopf_group *group = NULL; + + spin_lock(&fault->common.lock); + if (!list_empty(list)) { + group = list_first_entry(list, struct iopf_group, node); + list_del(&group->node); + } + spin_unlock(&fault->common.lock); + return group; +} + +/* Restore a node back to the head of the fault->deliver list */ +static void iommufd_fault_deliver_restore(struct iommufd_fault *fault, + struct iopf_group *group) +{ + spin_lock(&fault->common.lock); + list_add(&group->node, &fault->common.deliver); + spin_unlock(&fault->common.lock); +} + +static ssize_t iommufd_fault_fops_read(struct file *filep, char __user *buf, + size_t count, loff_t *ppos) +{ + size_t fault_size = sizeof(struct iommu_hwpt_pgfault); + struct iommufd_eventq *eventq = filep->private_data; + struct iommufd_fault *fault = eventq_to_fault(eventq); + struct iommu_hwpt_pgfault data = {}; + struct iommufd_device *idev; + struct iopf_group *group; + struct iopf_fault *iopf; + size_t done = 0; + int rc = 0; + + if (*ppos || count % fault_size) + return -ESPIPE; + + mutex_lock(&fault->mutex); + while ((group = iommufd_fault_deliver_fetch(fault))) { + if (done >= count || + group->fault_count * fault_size > count - done) { + iommufd_fault_deliver_restore(fault, group); + break; + } + + rc = xa_alloc(&fault->response, &group->cookie, group, + xa_limit_32b, GFP_KERNEL); + if (rc) { + iommufd_fault_deliver_restore(fault, group); + break; + } + + idev = to_iommufd_handle(group->attach_handle)->idev; + list_for_each_entry(iopf, &group->faults, list) { + iommufd_compose_fault_message(&iopf->fault, + &data, idev, + group->cookie); + if (copy_to_user(buf + done, &data, fault_size)) { + xa_erase(&fault->response, group->cookie); + iommufd_fault_deliver_restore(fault, group); + rc = -EFAULT; + break; + } + done += fault_size; + } + } + mutex_unlock(&fault->mutex); + + return done == 0 ? rc : done; +} + +static ssize_t iommufd_fault_fops_write(struct file *filep, const char __user *buf, + size_t count, loff_t *ppos) +{ + size_t response_size = sizeof(struct iommu_hwpt_page_response); + struct iommufd_eventq *eventq = filep->private_data; + struct iommufd_fault *fault = eventq_to_fault(eventq); + struct iommu_hwpt_page_response response; + struct iopf_group *group; + size_t done = 0; + int rc = 0; + + if (*ppos || count % response_size) + return -ESPIPE; + + mutex_lock(&fault->mutex); + while (count > done) { + rc = copy_from_user(&response, buf + done, response_size); + if (rc) + break; + + static_assert((int)IOMMUFD_PAGE_RESP_SUCCESS == + (int)IOMMU_PAGE_RESP_SUCCESS); + static_assert((int)IOMMUFD_PAGE_RESP_INVALID == + (int)IOMMU_PAGE_RESP_INVALID); + if (response.code != IOMMUFD_PAGE_RESP_SUCCESS && + response.code != IOMMUFD_PAGE_RESP_INVALID) { + rc = -EINVAL; + break; + } + + group = xa_erase(&fault->response, response.cookie); + if (!group) { + rc = -EINVAL; + break; + } + + iopf_group_response(group, response.code); + iopf_free_group(group); + done += response_size; + } + mutex_unlock(&fault->mutex); + + return done == 0 ? rc : done; +} + +/* IOMMUFD_OBJ_VEVENTQ Functions */ + +void iommufd_veventq_abort(struct iommufd_object *obj) +{ + struct iommufd_eventq *eventq = + container_of(obj, struct iommufd_eventq, obj); + struct iommufd_veventq *veventq = eventq_to_veventq(eventq); + struct iommufd_viommu *viommu = veventq->viommu; + struct iommufd_vevent *cur, *next; + + lockdep_assert_held_write(&viommu->veventqs_rwsem); + + list_for_each_entry_safe(cur, next, &eventq->deliver, node) { + list_del(&cur->node); + if (cur != &veventq->lost_events_header) + kfree(cur); + } + + refcount_dec(&viommu->obj.users); + list_del(&veventq->node); +} + +void iommufd_veventq_destroy(struct iommufd_object *obj) +{ + struct iommufd_veventq *veventq = eventq_to_veventq( + container_of(obj, struct iommufd_eventq, obj)); + + down_write(&veventq->viommu->veventqs_rwsem); + iommufd_veventq_abort(obj); + up_write(&veventq->viommu->veventqs_rwsem); +} + +static struct iommufd_vevent * +iommufd_veventq_deliver_fetch(struct iommufd_veventq *veventq) +{ + struct iommufd_eventq *eventq = &veventq->common; + struct list_head *list = &eventq->deliver; + struct iommufd_vevent *vevent = NULL; + + spin_lock(&eventq->lock); + if (!list_empty(list)) { + struct iommufd_vevent *next; + + next = list_first_entry(list, struct iommufd_vevent, node); + /* Make a copy of the lost_events_header for copy_to_user */ + if (next == &veventq->lost_events_header) { + vevent = kzalloc(sizeof(*vevent), GFP_ATOMIC); + if (!vevent) + goto out_unlock; + } + list_del(&next->node); + if (vevent) + memcpy(vevent, next, sizeof(*vevent)); + else + vevent = next; + } +out_unlock: + spin_unlock(&eventq->lock); + return vevent; +} + +static void iommufd_veventq_deliver_restore(struct iommufd_veventq *veventq, + struct iommufd_vevent *vevent) +{ + struct iommufd_eventq *eventq = &veventq->common; + struct list_head *list = &eventq->deliver; + + spin_lock(&eventq->lock); + if (vevent_for_lost_events_header(vevent)) { + /* Remove the copy of the lost_events_header */ + kfree(vevent); + vevent = NULL; + /* An empty list needs the lost_events_header back */ + if (list_empty(list)) + vevent = &veventq->lost_events_header; + } + if (vevent) + list_add(&vevent->node, list); + spin_unlock(&eventq->lock); +} + +static ssize_t iommufd_veventq_fops_read(struct file *filep, char __user *buf, + size_t count, loff_t *ppos) +{ + struct iommufd_eventq *eventq = filep->private_data; + struct iommufd_veventq *veventq = eventq_to_veventq(eventq); + struct iommufd_vevent_header *hdr; + struct iommufd_vevent *cur; + size_t done = 0; + int rc = 0; + + if (*ppos) + return -ESPIPE; + + while ((cur = iommufd_veventq_deliver_fetch(veventq))) { + /* Validate the remaining bytes against the header size */ + if (done >= count || sizeof(*hdr) > count - done) { + iommufd_veventq_deliver_restore(veventq, cur); + break; + } + hdr = &cur->header; + + /* If being a normal vEVENT, validate against the full size */ + if (!vevent_for_lost_events_header(cur) && + sizeof(hdr) + cur->data_len > count - done) { + iommufd_veventq_deliver_restore(veventq, cur); + break; + } + + if (copy_to_user(buf + done, hdr, sizeof(*hdr))) { + iommufd_veventq_deliver_restore(veventq, cur); + rc = -EFAULT; + break; + } + done += sizeof(*hdr); + + if (cur->data_len && + copy_to_user(buf + done, cur->event_data, cur->data_len)) { + iommufd_veventq_deliver_restore(veventq, cur); + rc = -EFAULT; + break; + } + spin_lock(&eventq->lock); + if (!vevent_for_lost_events_header(cur)) + veventq->num_events--; + spin_unlock(&eventq->lock); + done += cur->data_len; + kfree(cur); + } + + return done == 0 ? rc : done; +} + +/* Common Event Queue Functions */ + +static __poll_t iommufd_eventq_fops_poll(struct file *filep, + struct poll_table_struct *wait) +{ + struct iommufd_eventq *eventq = filep->private_data; + __poll_t pollflags = 0; + + if (eventq->obj.type == IOMMUFD_OBJ_FAULT) + pollflags |= EPOLLOUT; + + poll_wait(filep, &eventq->wait_queue, wait); + spin_lock(&eventq->lock); + if (!list_empty(&eventq->deliver)) + pollflags |= EPOLLIN | EPOLLRDNORM; + spin_unlock(&eventq->lock); + + return pollflags; +} + +static int iommufd_eventq_fops_release(struct inode *inode, struct file *filep) +{ + struct iommufd_eventq *eventq = filep->private_data; + + refcount_dec(&eventq->obj.users); + iommufd_ctx_put(eventq->ictx); + return 0; +} + +#define INIT_EVENTQ_FOPS(read_op, write_op) \ + ((const struct file_operations){ \ + .owner = THIS_MODULE, \ + .open = nonseekable_open, \ + .read = read_op, \ + .write = write_op, \ + .poll = iommufd_eventq_fops_poll, \ + .release = iommufd_eventq_fops_release, \ + }) + +static int iommufd_eventq_init(struct iommufd_eventq *eventq, char *name, + struct iommufd_ctx *ictx, + const struct file_operations *fops) +{ + struct file *filep; + int fdno; + + spin_lock_init(&eventq->lock); + INIT_LIST_HEAD(&eventq->deliver); + init_waitqueue_head(&eventq->wait_queue); + + filep = anon_inode_getfile(name, fops, eventq, O_RDWR); + if (IS_ERR(filep)) + return PTR_ERR(filep); + + eventq->ictx = ictx; + iommufd_ctx_get(eventq->ictx); + eventq->filep = filep; + refcount_inc(&eventq->obj.users); + + fdno = get_unused_fd_flags(O_CLOEXEC); + if (fdno < 0) + fput(filep); + return fdno; +} + +static const struct file_operations iommufd_fault_fops = + INIT_EVENTQ_FOPS(iommufd_fault_fops_read, iommufd_fault_fops_write); + +int iommufd_fault_alloc(struct iommufd_ucmd *ucmd) +{ + struct iommu_fault_alloc *cmd = ucmd->cmd; + struct iommufd_fault *fault; + int fdno; + int rc; + + if (cmd->flags) + return -EOPNOTSUPP; + + fault = __iommufd_object_alloc(ucmd->ictx, fault, IOMMUFD_OBJ_FAULT, + common.obj); + if (IS_ERR(fault)) + return PTR_ERR(fault); + + xa_init_flags(&fault->response, XA_FLAGS_ALLOC1); + mutex_init(&fault->mutex); + + fdno = iommufd_eventq_init(&fault->common, "[iommufd-pgfault]", + ucmd->ictx, &iommufd_fault_fops); + if (fdno < 0) { + rc = fdno; + goto out_abort; + } + + cmd->out_fault_id = fault->common.obj.id; + cmd->out_fault_fd = fdno; + + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_put_fdno; + iommufd_object_finalize(ucmd->ictx, &fault->common.obj); + + fd_install(fdno, fault->common.filep); + + return 0; +out_put_fdno: + put_unused_fd(fdno); + fput(fault->common.filep); +out_abort: + iommufd_object_abort_and_destroy(ucmd->ictx, &fault->common.obj); + + return rc; +} + +int iommufd_fault_iopf_handler(struct iopf_group *group) +{ + struct iommufd_hw_pagetable *hwpt; + struct iommufd_fault *fault; + + hwpt = group->attach_handle->domain->iommufd_hwpt; + fault = hwpt->fault; + + spin_lock(&fault->common.lock); + list_add_tail(&group->node, &fault->common.deliver); + spin_unlock(&fault->common.lock); + + wake_up_interruptible(&fault->common.wait_queue); + + return 0; +} + +static const struct file_operations iommufd_veventq_fops = + INIT_EVENTQ_FOPS(iommufd_veventq_fops_read, NULL); + +int iommufd_veventq_alloc(struct iommufd_ucmd *ucmd) +{ + struct iommu_veventq_alloc *cmd = ucmd->cmd; + struct iommufd_veventq *veventq; + struct iommufd_viommu *viommu; + int fdno; + int rc; + + if (cmd->flags || cmd->__reserved || + cmd->type == IOMMU_VEVENTQ_TYPE_DEFAULT) + return -EOPNOTSUPP; + if (!cmd->veventq_depth) + return -EINVAL; + + viommu = iommufd_get_viommu(ucmd, cmd->viommu_id); + if (IS_ERR(viommu)) + return PTR_ERR(viommu); + + down_write(&viommu->veventqs_rwsem); + + if (iommufd_viommu_find_veventq(viommu, cmd->type)) { + rc = -EEXIST; + goto out_unlock_veventqs; + } + + veventq = __iommufd_object_alloc(ucmd->ictx, veventq, + IOMMUFD_OBJ_VEVENTQ, common.obj); + if (IS_ERR(veventq)) { + rc = PTR_ERR(veventq); + goto out_unlock_veventqs; + } + + veventq->type = cmd->type; + veventq->viommu = viommu; + refcount_inc(&viommu->obj.users); + veventq->depth = cmd->veventq_depth; + list_add_tail(&veventq->node, &viommu->veventqs); + veventq->lost_events_header.header.flags = + IOMMU_VEVENTQ_FLAG_LOST_EVENTS; + + fdno = iommufd_eventq_init(&veventq->common, "[iommufd-viommu-event]", + ucmd->ictx, &iommufd_veventq_fops); + if (fdno < 0) { + rc = fdno; + goto out_abort; + } + + cmd->out_veventq_id = veventq->common.obj.id; + cmd->out_veventq_fd = fdno; + + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_put_fdno; + + iommufd_object_finalize(ucmd->ictx, &veventq->common.obj); + fd_install(fdno, veventq->common.filep); + goto out_unlock_veventqs; + +out_put_fdno: + put_unused_fd(fdno); + fput(veventq->common.filep); +out_abort: + iommufd_object_abort_and_destroy(ucmd->ictx, &veventq->common.obj); +out_unlock_veventqs: + up_write(&viommu->veventqs_rwsem); + iommufd_put_object(ucmd->ictx, &viommu->obj); + return rc; +} |