// SPDX-License-Identifier: GPL-2.0-only /* * VMware VMCI Driver * * Copyright (C) 2012 VMware, Inc. All rights reserved. */ #include <linux/vmw_vmci_defs.h> #include <linux/vmw_vmci_api.h> #include <linux/highmem.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/cred.h> #include <linux/slab.h> #include "vmci_queue_pair.h" #include "vmci_datagram.h" #include "vmci_doorbell.h" #include "vmci_context.h" #include "vmci_driver.h" #include "vmci_event.h" /* Use a wide upper bound for the maximum contexts. */ #define VMCI_MAX_CONTEXTS 2000 /* * List of current VMCI contexts. Contexts can be added by * vmci_ctx_create() and removed via vmci_ctx_destroy(). * These, along with context lookup, are protected by the * list structure's lock. */ static struct { struct list_head head; spinlock_t lock; /* Spinlock for context list operations */ } ctx_list = { .head = LIST_HEAD_INIT(ctx_list.head), .lock = __SPIN_LOCK_UNLOCKED(ctx_list.lock), }; /* Used by contexts that did not set up notify flag pointers */ static bool ctx_dummy_notify; static void ctx_signal_notify(struct vmci_ctx *context) { *context->notify = true; } static void ctx_clear_notify(struct vmci_ctx *context) { *context->notify = false; } /* * If nothing requires the attention of the guest, clears both * notify flag and call. */ static void ctx_clear_notify_call(struct vmci_ctx *context) { if (context->pending_datagrams == 0 && vmci_handle_arr_get_size(context->pending_doorbell_array) == 0) ctx_clear_notify(context); } /* * Sets the context's notify flag iff datagrams are pending for this * context. Called from vmci_setup_notify(). */ void vmci_ctx_check_signal_notify(struct vmci_ctx *context) { spin_lock(&context->lock); if (context->pending_datagrams) ctx_signal_notify(context); spin_unlock(&context->lock); } /* * Allocates and initializes a VMCI context. */ struct vmci_ctx *vmci_ctx_create(u32 cid, u32 priv_flags, uintptr_t event_hnd, int user_version, const struct cred *cred) { struct vmci_ctx *context; int error; if (cid == VMCI_INVALID_ID) { pr_devel("Invalid context ID for VMCI context\n"); error = -EINVAL; goto err_out; } if (priv_flags & ~VMCI_PRIVILEGE_ALL_FLAGS) { pr_devel("Invalid flag (flags=0x%x) for VMCI context\n", priv_flags); error = -EINVAL; goto err_out; } if (user_version == 0) { pr_devel("Invalid suer_version %d\n", user_version); error = -EINVAL; goto err_out; } context = kzalloc(sizeof(*context), GFP_KERNEL); if (!context) { pr_warn("Failed to allocate memory for VMCI context\n"); error = -EINVAL; goto err_out; } kref_init(&context->kref); spin_lock_init(&context->lock); INIT_LIST_HEAD(&context->list_item); INIT_LIST_HEAD(&context->datagram_queue); INIT_LIST_HEAD(&context->notifier_list); /* Initialize host-specific VMCI context. */ init_waitqueue_head(&context->host_context.wait_queue); context->queue_pair_array = vmci_handle_arr_create(0, VMCI_MAX_GUEST_QP_COUNT); if (!context->queue_pair_array) { error = -ENOMEM; goto err_free_ctx; } context->doorbell_array = vmci_handle_arr_create(0, VMCI_MAX_GUEST_DOORBELL_COUNT); if (!context->doorbell_array) { error = -ENOMEM; goto err_free_qp_array; } context->pending_doorbell_array = vmci_handle_arr_create(0, VMCI_MAX_GUEST_DOORBELL_COUNT); if (!context->pending_doorbell_array) { error = -ENOMEM; goto err_free_db_array; } context->user_version = user_version; context->priv_flags = priv_flags; if (cred) context->cred = get_cred(cred); context->notify = &ctx_dummy_notify; context->notify_page = NULL; /* * If we collide with an existing context we generate a new * and use it instead. The VMX will determine if regeneration * is okay. Since there isn't 4B - 16 VMs running on a given * host, the below loop will terminate. */ spin_lock(&ctx_list.lock); while (vmci_ctx_exists(cid)) { /* We reserve the lowest 16 ids for fixed contexts. */ cid = max(cid, VMCI_RESERVED_CID_LIMIT - 1) + 1; if (cid == VMCI_INVALID_ID) cid = VMCI_RESERVED_CID_LIMIT; } context->cid = cid; list_add_tail_rcu(&context->list_item, &ctx_list.head); spin_unlock(&ctx_list.lock); return context; err_free_db_array: vmci_handle_arr_destroy(context->doorbell_array); err_free_qp_array: vmci_handle_arr_destroy(context->queue_pair_array); err_free_ctx: kfree(context); err_out: return ERR_PTR(error); } /* * Destroy VMCI context. */ void vmci_ctx_destroy(struct vmci_ctx *context) { spin_lock(&ctx_list.lock); list_del_rcu(&context->list_item); spin_unlock(&ctx_list.lock); synchronize_rcu(); vmci_ctx_put(context); } /* * Fire notification for all contexts interested in given cid. */ static int ctx_fire_notification(u32 context_id, u32 priv_flags) { u32 i, array_size; struct vmci_ctx *sub_ctx; struct vmci_handle_arr *subscriber_array; struct vmci_handle context_handle = vmci_make_handle(context_id, VMCI_EVENT_HANDLER); /* * We create an array to hold the subscribers we find when * scanning through all contexts. */ subscriber_array = vmci_handle_arr_create(0, VMCI_MAX_CONTEXTS); if (subscriber_array == NULL) return VMCI_ERROR_NO_MEM; /* * Scan all contexts to find who is interested in being * notified about given contextID. */ rcu_read_lock(); list_for_each_entry_rcu(sub_ctx, &ctx_list.head, list_item) { struct vmci_handle_list *node; /* * We only deliver notifications of the removal of * contexts, if the two contexts are allowed to * interact. */ if (vmci_deny_interaction(priv_flags, sub_ctx->priv_flags)) continue; list_for_each_entry_rcu(node, &sub_ctx->notifier_list, node) { if (!vmci_handle_is_equal(node->handle, context_handle)) continue; vmci_handle_arr_append_entry(&subscriber_array, vmci_make_handle(sub_ctx->cid, VMCI_EVENT_HANDLER)); } } rcu_read_unlock(); /* Fire event to all subscribers. */ array_size = vmci_handle_arr_get_size(subscriber_array); for (i = 0; i < array_size; i++) { int result; struct vmci_event_ctx ev; ev.msg.hdr.dst = vmci_handle_arr_get_entry(subscriber_array, i); ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_CONTEXT_RESOURCE_ID); ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr); ev.msg.event_data.event = VMCI_EVENT_CTX_REMOVED; ev.payload.context_id = context_id; result = vmci_datagram_dispatch(VMCI_HYPERVISOR_CONTEXT_ID, &ev.msg.hdr, false); if (result < VMCI_SUCCESS) { pr_devel("Failed to enqueue event datagram (type=%d) for context (ID=0x%x)\n", ev.msg.event_data.event, ev.msg.hdr.dst.context); /* We continue to enqueue on next subscriber. */ } } vmci_handle_arr_destroy(subscriber_array); return VMCI_SUCCESS; } /* * Returns the current number of pending datagrams. The call may * also serve as a synchronization point for the datagram queue, * as no enqueue operations can occur concurrently. */ int vmci_ctx_pending_datagrams(u32 cid, u32 *pending) { struct vmci_ctx *context; context = vmci_ctx_get(cid); if (context == NULL) return VMCI_ERROR_INVALID_ARGS; spin_lock(&context->lock); if (pending) *pending = context->pending_datagrams; spin_unlock(&context->lock); vmci_ctx_put(context); return VMCI_SUCCESS; } /* * Queues a VMCI datagram for the appropriate target VM context. */ int vmci_ctx_enqueue_datagram(u32 cid, struct vmci_datagram *dg) { struct vmci_datagram_queue_entry *dq_entry; struct vmci_ctx *context; struct vmci_handle dg_src; size_t vmci_dg_size; vmci_dg_size = VMCI_DG_SIZE(dg); if (vmci_dg_size > VMCI_MAX_DG_SIZE) { pr_devel("Datagram too large (bytes=%zu)\n", vmci_dg_size); return VMCI_ERROR_INVALID_ARGS; } /* Get the target VM's VMCI context. */ context = vmci_ctx_get(cid); if (!context) { pr_devel("Invalid context (ID=0x%x)\n", cid); return VMCI_ERROR_INVALID_ARGS; } /* Allocate guest call entry and add it to the target VM's queue. */ dq_entry = kmalloc(sizeof(*dq_entry), GFP_KERNEL); if (dq_entry == NULL) { pr_warn("Failed to allocate memory for datagram\n"); vmci_ctx_put(context); return VMCI_ERROR_NO_MEM; } dq_entry->dg = dg; dq_entry->dg_size = vmci_dg_size; dg_src = dg->src; INIT_LIST_HEAD(&dq_entry->list_item); spin_lock(&context->lock); /* * We put a higher limit on datagrams from the hypervisor. If * the pending datagram is not from hypervisor, then we check * if enqueueing it would exceed the * VMCI_MAX_DATAGRAM_QUEUE_SIZE limit on the destination. If * the pending datagram is from hypervisor, we allow it to be * queued at the destination side provided we don't reach the * VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE limit. */ if (context->datagram_queue_size + vmci_dg_size >= VMCI_MAX_DATAGRAM_QUEUE_SIZE && (!vmci_handle_is_equal(dg_src, vmci_make_handle (VMCI_HYPERVISOR_CONTEXT_ID, VMCI_CONTEXT_RESOURCE_ID)) || context->datagram_queue_size + vmci_dg_size >= VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE)) { spin_unlock(&context->lock); vmci_ctx_put(context); kfree(dq_entry); pr_devel("Context (ID=0x%x) receive queue is full\n", cid); return VMCI_ERROR_NO_RESOURCES; } list_add(&dq_entry->list_item, &context->datagram_queue); context->pending_datagrams++; context->datagram_queue_size += vmci_dg_size; ctx_signal_notify(context); wake_up(&context->host_context.wait_queue); spin_unlock(&context->lock); vmci_ctx_put(context); return vmci_dg_size; } /* * Verifies whether a context with the specified context ID exists. * FIXME: utility is dubious as no decisions can be reliably made * using this data as context can appear and disappear at any time. */ bool vmci_ctx_exists(u32 cid) { struct vmci_ctx *context; bool exists = false; rcu_read_lock(); list_for_each_entry_rcu(context, &ctx_list.head, list_item) { if (context->cid == cid) { exists = true; break; } } rcu_read_unlock(); return exists; } /* * Retrieves VMCI context corresponding to the given cid. */ struct vmci_ctx *vmci_ctx_get(u32 cid) { struct vmci_ctx *c, *context = NULL; if (cid == VMCI_INVALID_ID) return NULL; rcu_read_lock(); list_for_each_entry_rcu(c, &ctx_list.head, list_item) { if (c->cid == cid) { /* * The context owner drops its own reference to the * context only after removing it from the list and * waiting for RCU grace period to expire. This * means that we are not about to increase the * reference count of something that is in the * process of being destroyed. */ context = c; kref_get(&context->kref); break; } } rcu_read_unlock(); return context; } /* * Deallocates all parts of a context data structure. This * function doesn't lock the context, because it assumes that * the caller was holding the last reference to context. */ static void ctx_free_ctx(struct kref *kref) { struct vmci_ctx *context = container_of(kref, struct vmci_ctx, kref); struct vmci_datagram_queue_entry *dq_entry, *dq_entry_tmp; struct vmci_handle temp_handle; struct vmci_handle_list *notifier, *tmp; /* * Fire event to all contexts interested in knowing this * context is dying. */ ctx_fire_notification(context->cid, context->priv_flags); /* * Cleanup all queue pair resources attached to context. If * the VM dies without cleaning up, this code will make sure * that no resources are leaked. */ temp_handle = vmci_handle_arr_get_entry(context->queue_pair_array, 0); while (!vmci_handle_is_equal(temp_handle, VMCI_INVALID_HANDLE)) { if (vmci_qp_broker_detach(temp_handle, context) < VMCI_SUCCESS) { /* * When vmci_qp_broker_detach() succeeds it * removes the handle from the array. If * detach fails, we must remove the handle * ourselves. */ vmci_handle_arr_remove_entry(context->queue_pair_array, temp_handle); } temp_handle = vmci_handle_arr_get_entry(context->queue_pair_array, 0); } /* * It is fine to destroy this without locking the callQueue, as * this is the only thread having a reference to the context. */ list_for_each_entry_safe(dq_entry, dq_entry_tmp, &context->datagram_queue, list_item) { WARN_ON(dq_entry->dg_size != VMCI_DG_SIZE(dq_entry->dg)); list_del(&dq_entry->list_item); kfree(dq_entry->dg); kfree(dq_entry); } list_for_each_entry_safe(notifier, tmp, &context->notifier_list, node) { list_del(¬ifier->node); kfree(notifier); } vmci_handle_arr_destroy(context->queue_pair_array); vmci_handle_arr_destroy(context->doorbell_array); vmci_handle_arr_destroy(context->pending_doorbell_array); vmci_ctx_unset_notify(context); if (context->cred) put_cred(context->cred); kfree(context); } /* * Drops reference to VMCI context. If this is the last reference to * the context it will be deallocated. A context is created with * a reference count of one, and on destroy, it is removed from * the context list before its reference count is decremented. Thus, * if we reach zero, we are sure that nobody else are about to increment * it (they need the entry in the context list for that), and so there * is no need for locking. */ void vmci_ctx_put(struct vmci_ctx *context) { kref_put(&context->kref, ctx_free_ctx); } /* * Dequeues the next datagram and returns it to caller. * The caller passes in a pointer to the max size datagram * it can handle and the datagram is only unqueued if the * size is less than max_size. If larger max_size is set to * the size of the datagram to give the caller a chance to * set up a larger buffer for the guestcall. */ int vmci_ctx_dequeue_datagram(struct vmci_ctx *context, size_t *max_size, struct vmci_datagram **dg) { struct vmci_datagram_queue_entry *dq_entry; struct list_head *list_item; int rv; /* Dequeue the next datagram entry. */ spin_lock(&context->lock); if (context->pending_datagrams == 0) { ctx_clear_notify_call(context); spin_unlock(&context->lock); pr_devel("No datagrams pending\n"); return VMCI_ERROR_NO_MORE_DATAGRAMS; } list_item = context->datagram_queue.next; dq_entry = list_entry(list_item, struct vmci_datagram_queue_entry, list_item); /* Check size of caller's buffer. */ if (*max_size < dq_entry->dg_size) { *max_size = dq_entry->dg_size; spin_unlock(&context->lock); pr_devel("Caller's buffer should be at least (size=%u bytes)\n", (u32) *max_size); return VMCI_ERROR_NO_MEM; } list_del(list_item); context->pending_datagrams--; context->datagram_queue_size -= dq_entry->dg_size; if (context->pending_datagrams == 0) { ctx_clear_notify_call(context); rv = VMCI_SUCCESS; } else { /* * Return the size of the next datagram. */ struct vmci_datagram_queue_entry *next_entry; list_item = context->datagram_queue.next; next_entry = list_entry(list_item, struct vmci_datagram_queue_entry, list_item); /* * The following size_t -> int truncation is fine as * the maximum size of a (routable) datagram is 68KB. */ rv = (int)next_entry->dg_size; } spin_unlock(&context->lock); /* Caller must free datagram. */ *dg = dq_entry->dg; dq_entry->dg = NULL; kfree(dq_entry); return rv; } /* * Reverts actions set up by vmci_setup_notify(). Unmaps and unlocks the * page mapped/locked by vmci_setup_notify(). */ void vmci_ctx_unset_notify(struct vmci_ctx *context) { struct page *notify_page; spin_lock(&context->lock); notify_page = context->notify_page; context->notify = &ctx_dummy_notify; context->notify_page = NULL; spin_unlock(&context->lock); if (notify_page) { kunmap(notify_page); put_page(notify_page); } } /* * Add remote_cid to list of contexts current contexts wants * notifications from/about. */ int vmci_ctx_add_notification(u32 context_id, u32 remote_cid) { struct vmci_ctx *context; struct vmci_handle_list *notifier, *n; int result; bool exists = false; context = vmci_ctx_get(context_id); if (!context) return VMCI_ERROR_NOT_FOUND; if (VMCI_CONTEXT_IS_VM(context_id) && VMCI_CONTEXT_IS_VM(remote_cid)) { pr_devel("Context removed notifications for other VMs not supported (src=0x%x, remote=0x%x)\n", context_id, remote_cid); result = VMCI_ERROR_DST_UNREACHABLE; goto out; } if (context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED) { result = VMCI_ERROR_NO_ACCESS; goto out; } notifier = kmalloc(sizeof(struct vmci_handle_list), GFP_KERNEL); if (!notifier) { result = VMCI_ERROR_NO_MEM; goto out; } INIT_LIST_HEAD(¬ifier->node); notifier->handle = vmci_make_handle(remote_cid, VMCI_EVENT_HANDLER); spin_lock(&context->lock); if (context->n_notifiers < VMCI_MAX_CONTEXTS) { list_for_each_entry(n, &context->notifier_list, node) { if (vmci_handle_is_equal(n->handle, notifier->handle)) { exists = true; break; } } if (exists) { kfree(notifier); result = VMCI_ERROR_ALREADY_EXISTS; } else { list_add_tail_rcu(¬ifier->node, &context->notifier_list); context->n_notifiers++; result = VMCI_SUCCESS; } } else { kfree(notifier); result = VMCI_ERROR_NO_MEM; } spin_unlock(&context->lock); out: vmci_ctx_put(context); return result; } /* * Remove remote_cid from current context's list of contexts it is * interested in getting notifications from/about. */ int vmci_ctx_remove_notification(u32 context_id, u32 remote_cid) { struct vmci_ctx *context; struct vmci_handle_list *notifier, *tmp; struct vmci_handle handle; bool found = false; context = vmci_ctx_get(context_id); if (!context) return VMCI_ERROR_NOT_FOUND; handle = vmci_make_handle(remote_cid, VMCI_EVENT_HANDLER); spin_lock(&context->lock); list_for_each_entry_safe(notifier, tmp, &context->notifier_list, node) { if (vmci_handle_is_equal(notifier->handle, handle)) { list_del_rcu(¬ifier->node); context->n_notifiers--; found = true; break; } } spin_unlock(&context->lock); if (found) { synchronize_rcu(); kfree(notifier); } vmci_ctx_put(context); return found ? VMCI_SUCCESS : VMCI_ERROR_NOT_FOUND; } static int vmci_ctx_get_chkpt_notifiers(struct vmci_ctx *context, u32 *buf_size, void **pbuf) { u32 *notifiers; size_t data_size; struct vmci_handle_list *entry; int i = 0; if (context->n_notifiers == 0) { *buf_size = 0; *pbuf = NULL; return VMCI_SUCCESS; } data_size = context->n_notifiers * sizeof(*notifiers); if (*buf_size < data_size) { *buf_size = data_size; return VMCI_ERROR_MORE_DATA; } notifiers = kmalloc(data_size, GFP_ATOMIC); /* FIXME: want GFP_KERNEL */ if (!notifiers) return VMCI_ERROR_NO_MEM; list_for_each_entry(entry, &context->notifier_list, node) notifiers[i++] = entry->handle.context; *buf_size = data_size; *pbuf = notifiers; return VMCI_SUCCESS; } static int vmci_ctx_get_chkpt_doorbells(struct vmci_ctx *context, u32 *buf_size, void **pbuf) { struct dbell_cpt_state *dbells; u32 i, n_doorbells; n_doorbells = vmci_handle_arr_get_size(context->doorbell_array); if (n_doorbells > 0) { size_t data_size = n_doorbells * sizeof(*dbells); if (*buf_size < data_size) { *buf_size = data_size; return VMCI_ERROR_MORE_DATA; } dbells = kmalloc(data_size, GFP_ATOMIC); if (!dbells) return VMCI_ERROR_NO_MEM; for (i = 0; i < n_doorbells; i++) dbells[i].handle = vmci_handle_arr_get_entry( context->doorbell_array, i); *buf_size = data_size; *pbuf = dbells; } else { *buf_size = 0; *pbuf = NULL; } return VMCI_SUCCESS; } /* * Get current context's checkpoint state of given type. */ int vmci_ctx_get_chkpt_state(u32 context_id, u32 cpt_type, u32 *buf_size, void **pbuf) { struct vmci_ctx *context; int result; context = vmci_ctx_get(context_id); if (!context) return VMCI_ERROR_NOT_FOUND; spin_lock(&context->lock); switch (cpt_type) { case VMCI_NOTIFICATION_CPT_STATE: result = vmci_ctx_get_chkpt_notifiers(context, buf_size, pbuf); break; case VMCI_WELLKNOWN_CPT_STATE: /* * For compatibility with VMX'en with VM to VM communication, we * always return zero wellknown handles. */ *buf_size = 0; *pbuf = NULL; result = VMCI_SUCCESS; break; case VMCI_DOORBELL_CPT_STATE: result = vmci_ctx_get_chkpt_doorbells(context, buf_size, pbuf); break; default: pr_devel("Invalid cpt state (type=%d)\n", cpt_type); result = VMCI_ERROR_INVALID_ARGS; break; } spin_unlock(&context->lock); vmci_ctx_put(context); return result; } /* * Set current context's checkpoint state of given type. */ int vmci_ctx_set_chkpt_state(u32 context_id, u32 cpt_type, u32 buf_size, void *cpt_buf) { u32 i; u32 current_id; int result = VMCI_SUCCESS; u32 num_ids = buf_size / sizeof(u32); if (cpt_type == VMCI_WELLKNOWN_CPT_STATE && num_ids > 0) { /* * We would end up here if VMX with VM to VM communication * attempts to restore a checkpoint with wellknown handles. */ pr_warn("Attempt to restore checkpoint with obsolete wellknown handles\n"); return VMCI_ERROR_OBSOLETE; } if (cpt_type != VMCI_NOTIFICATION_CPT_STATE) { pr_devel("Invalid cpt state (type=%d)\n", cpt_type); return VMCI_ERROR_INVALID_ARGS; } for (i = 0; i < num_ids && result == VMCI_SUCCESS; i++) { current_id = ((u32 *)cpt_buf)[i]; result = vmci_ctx_add_notification(context_id, current_id); if (result != VMCI_SUCCESS) break; } if (result != VMCI_SUCCESS) pr_devel("Failed to set cpt state (type=%d) (error=%d)\n", cpt_type, result); return result; } /* * Retrieves the specified context's pending notifications in the * form of a handle array. The handle arrays returned are the * actual data - not a copy and should not be modified by the * caller. They must be released using * vmci_ctx_rcv_notifications_release. */ int vmci_ctx_rcv_notifications_get(u32 context_id, struct vmci_handle_arr **db_handle_array, struct vmci_handle_arr **qp_handle_array) { struct vmci_ctx *context; int result = VMCI_SUCCESS; context = vmci_ctx_get(context_id); if (context == NULL) return VMCI_ERROR_NOT_FOUND; spin_lock(&context->lock); *db_handle_array = context->pending_doorbell_array; context->pending_doorbell_array = vmci_handle_arr_create(0, VMCI_MAX_GUEST_DOORBELL_COUNT); if (!context->pending_doorbell_array) { context->pending_doorbell_array = *db_handle_array; *db_handle_array = NULL; result = VMCI_ERROR_NO_MEM; } *qp_handle_array = NULL; spin_unlock(&context->lock); vmci_ctx_put(context); return result; } /* * Releases handle arrays with pending notifications previously * retrieved using vmci_ctx_rcv_notifications_get. If the * notifications were not successfully handed over to the guest, * success must be false. */ void vmci_ctx_rcv_notifications_release(u32 context_id, struct vmci_handle_arr *db_handle_array, struct vmci_handle_arr *qp_handle_array, bool success) { struct vmci_ctx *context = vmci_ctx_get(context_id); spin_lock(&context->lock); if (!success) { struct vmci_handle handle; /* * New notifications may have been added while we were not * holding the context lock, so we transfer any new pending * doorbell notifications to the old array, and reinstate the * old array. */ handle = vmci_handle_arr_remove_tail( context->pending_doorbell_array); while (!vmci_handle_is_invalid(handle)) { if (!vmci_handle_arr_has_entry(db_handle_array, handle)) { vmci_handle_arr_append_entry( &db_handle_array, handle); } handle = vmci_handle_arr_remove_tail( context->pending_doorbell_array); } vmci_handle_arr_destroy(context->pending_doorbell_array); context->pending_doorbell_array = db_handle_array; db_handle_array = NULL; } else { ctx_clear_notify_call(context); } spin_unlock(&context->lock); vmci_ctx_put(context); if (db_handle_array) vmci_handle_arr_destroy(db_handle_array); if (qp_handle_array) vmci_handle_arr_destroy(qp_handle_array); } /* * Registers that a new doorbell handle has been allocated by the * context. Only doorbell handles registered can be notified. */ int vmci_ctx_dbell_create(u32 context_id, struct vmci_handle handle) { struct vmci_ctx *context; int result; if (context_id == VMCI_INVALID_ID || vmci_handle_is_invalid(handle)) return VMCI_ERROR_INVALID_ARGS; context = vmci_ctx_get(context_id); if (context == NULL) return VMCI_ERROR_NOT_FOUND; spin_lock(&context->lock); if (!vmci_handle_arr_has_entry(context->doorbell_array, handle)) result = vmci_handle_arr_append_entry(&context->doorbell_array, handle); else result = VMCI_ERROR_DUPLICATE_ENTRY; spin_unlock(&context->lock); vmci_ctx_put(context); return result; } /* * Unregisters a doorbell handle that was previously registered * with vmci_ctx_dbell_create. */ int vmci_ctx_dbell_destroy(u32 context_id, struct vmci_handle handle) { struct vmci_ctx *context; struct vmci_handle removed_handle; if (context_id == VMCI_INVALID_ID || vmci_handle_is_invalid(handle)) return VMCI_ERROR_INVALID_ARGS; context = vmci_ctx_get(context_id); if (context == NULL) return VMCI_ERROR_NOT_FOUND; spin_lock(&context->lock); removed_handle = vmci_handle_arr_remove_entry(context->doorbell_array, handle); vmci_handle_arr_remove_entry(context->pending_doorbell_array, handle); spin_unlock(&context->lock); vmci_ctx_put(context); return vmci_handle_is_invalid(removed_handle) ? VMCI_ERROR_NOT_FOUND : VMCI_SUCCESS; } /* * Unregisters all doorbell handles that were previously * registered with vmci_ctx_dbell_create. */ int vmci_ctx_dbell_destroy_all(u32 context_id) { struct vmci_ctx *context; struct vmci_handle handle; if (context_id == VMCI_INVALID_ID) return VMCI_ERROR_INVALID_ARGS; context = vmci_ctx_get(context_id); if (context == NULL) return VMCI_ERROR_NOT_FOUND; spin_lock(&context->lock); do { struct vmci_handle_arr *arr = context->doorbell_array; handle = vmci_handle_arr_remove_tail(arr); } while (!vmci_handle_is_invalid(handle)); do { struct vmci_handle_arr *arr = context->pending_doorbell_array; handle = vmci_handle_arr_remove_tail(arr); } while (!vmci_handle_is_invalid(handle)); spin_unlock(&context->lock); vmci_ctx_put(context); return VMCI_SUCCESS; } /* * Registers a notification of a doorbell handle initiated by the * specified source context. The notification of doorbells are * subject to the same isolation rules as datagram delivery. To * allow host side senders of notifications a finer granularity * of sender rights than those assigned to the sending context * itself, the host context is required to specify a different * set of privilege flags that will override the privileges of * the source context. */ int vmci_ctx_notify_dbell(u32 src_cid, struct vmci_handle handle, u32 src_priv_flags) { struct vmci_ctx *dst_context; int result; if (vmci_handle_is_invalid(handle)) return VMCI_ERROR_INVALID_ARGS; /* Get the target VM's VMCI context. */ dst_context = vmci_ctx_get(handle.context); if (!dst_context) { pr_devel("Invalid context (ID=0x%x)\n", handle.context); return VMCI_ERROR_NOT_FOUND; } if (src_cid != handle.context) { u32 dst_priv_flags; if (VMCI_CONTEXT_IS_VM(src_cid) && VMCI_CONTEXT_IS_VM(handle.context)) { pr_devel("Doorbell notification from VM to VM not supported (src=0x%x, dst=0x%x)\n", src_cid, handle.context); result = VMCI_ERROR_DST_UNREACHABLE; goto out; } result = vmci_dbell_get_priv_flags(handle, &dst_priv_flags); if (result < VMCI_SUCCESS) { pr_warn("Failed to get privilege flags for destination (handle=0x%x:0x%x)\n", handle.context, handle.resource); goto out; } if (src_cid != VMCI_HOST_CONTEXT_ID || src_priv_flags == VMCI_NO_PRIVILEGE_FLAGS) { src_priv_flags = vmci_context_get_priv_flags(src_cid); } if (vmci_deny_interaction(src_priv_flags, dst_priv_flags)) { result = VMCI_ERROR_NO_ACCESS; goto out; } } if (handle.context == VMCI_HOST_CONTEXT_ID) { result = vmci_dbell_host_context_notify(src_cid, handle); } else { spin_lock(&dst_context->lock); if (!vmci_handle_arr_has_entry(dst_context->doorbell_array, handle)) { result = VMCI_ERROR_NOT_FOUND; } else { if (!vmci_handle_arr_has_entry( dst_context->pending_doorbell_array, handle)) { result = vmci_handle_arr_append_entry( &dst_context->pending_doorbell_array, handle); if (result == VMCI_SUCCESS) { ctx_signal_notify(dst_context); wake_up(&dst_context->host_context.wait_queue); } } else { result = VMCI_SUCCESS; } } spin_unlock(&dst_context->lock); } out: vmci_ctx_put(dst_context); return result; } bool vmci_ctx_supports_host_qp(struct vmci_ctx *context) { return context && context->user_version >= VMCI_VERSION_HOSTQP; } /* * Registers that a new queue pair handle has been allocated by * the context. */ int vmci_ctx_qp_create(struct vmci_ctx *context, struct vmci_handle handle) { int result; if (context == NULL || vmci_handle_is_invalid(handle)) return VMCI_ERROR_INVALID_ARGS; if (!vmci_handle_arr_has_entry(context->queue_pair_array, handle)) result = vmci_handle_arr_append_entry( &context->queue_pair_array, handle); else result = VMCI_ERROR_DUPLICATE_ENTRY; return result; } /* * Unregisters a queue pair handle that was previously registered * with vmci_ctx_qp_create. */ int vmci_ctx_qp_destroy(struct vmci_ctx *context, struct vmci_handle handle) { struct vmci_handle hndl; if (context == NULL || vmci_handle_is_invalid(handle)) return VMCI_ERROR_INVALID_ARGS; hndl = vmci_handle_arr_remove_entry(context->queue_pair_array, handle); return vmci_handle_is_invalid(hndl) ? VMCI_ERROR_NOT_FOUND : VMCI_SUCCESS; } /* * Determines whether a given queue pair handle is registered * with the given context. */ bool vmci_ctx_qp_exists(struct vmci_ctx *context, struct vmci_handle handle) { if (context == NULL || vmci_handle_is_invalid(handle)) return false; return vmci_handle_arr_has_entry(context->queue_pair_array, handle); } /* * vmci_context_get_priv_flags() - Retrieve privilege flags. * @context_id: The context ID of the VMCI context. * * Retrieves privilege flags of the given VMCI context ID. */ u32 vmci_context_get_priv_flags(u32 context_id) { if (vmci_host_code_active()) { u32 flags; struct vmci_ctx *context; context = vmci_ctx_get(context_id); if (!context) return VMCI_LEAST_PRIVILEGE_FLAGS; flags = context->priv_flags; vmci_ctx_put(context); return flags; } return VMCI_NO_PRIVILEGE_FLAGS; } EXPORT_SYMBOL_GPL(vmci_context_get_priv_flags); /* * vmci_is_context_owner() - Determimnes if user is the context owner * @context_id: The context ID of the VMCI context. * @uid: The host user id (real kernel value). * * Determines whether a given UID is the owner of given VMCI context. */ bool vmci_is_context_owner(u32 context_id, kuid_t uid) { bool is_owner = false; if (vmci_host_code_active()) { struct vmci_ctx *context = vmci_ctx_get(context_id); if (context) { if (context->cred) is_owner = uid_eq(context->cred->uid, uid); vmci_ctx_put(context); } } return is_owner; } EXPORT_SYMBOL_GPL(vmci_is_context_owner);