--- /dev/null
+/*
+ * VMware VMCI Driver
+ *
+ * Copyright (C) 2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation version 2 and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#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/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"
+
+/*
+ * 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);
+ if (!context->queue_pair_array) {
+ error = -ENOMEM;
+ goto err_free_ctx;
+ }
+
+ context->doorbell_array = vmci_handle_arr_create(0);
+ if (!context->doorbell_array) {
+ error = -ENOMEM;
+ goto err_free_qp_array;
+ }
+
+ context->pending_doorbell_array = vmci_handle_arr_create(0);
+ 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);
+ 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);
+
+ 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;
+ }
+
+ 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;
+ size_t n_doorbells;
+ int i;
+
+ 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);
+ 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)) {
+ vmci_handle_arr_append_entry(&context->doorbell_array, handle);
+ result = VMCI_SUCCESS;
+ } 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)) {
+ vmci_handle_arr_append_entry(
+ &dst_context->pending_doorbell_array,
+ handle);
+
+ ctx_signal_notify(dst_context);
+ wake_up(&dst_context->host_context.wait_queue);
+
+ }
+ 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)) {
+ vmci_handle_arr_append_entry(&context->queue_pair_array,
+ handle);
+ result = VMCI_SUCCESS;
+ } 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);
Code Review / kvmfornfv.git / blobdiff