[PATCH 01/10] VMCI: context implementation.

George Zhang
2012-10-16T00:38:54Z

VMCI Context code maintains state for vmci and allows the driver to
communicate with multiple VMs.

Signed-off-by: George Zhang <georgezhang@vmware.com>
---
drivers/misc/vmw_vmci/vmci_context.c | 1291 ++++++++++++++++++++++++++++++++++
drivers/misc/vmw_vmci/vmci_context.h | 177 +++++
2 files changed, 1468 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/vmw_vmci/vmci_context.c
create mode 100644 drivers/misc/vmw_vmci/vmci_context.h

diff --git a/drivers/misc/vmw_vmci/vmci_context.c b/drivers/misc/vmw_vmci/vmci_context.c
new file mode 100644
index 0000000..c552dd3
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_context.c
@@ -0,0 +1,1291 @@
+/*
+ * 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_common_int.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.
+ */
+static struct {
+ struct list_head head;
+ spinlock_t lock; /* Spinlock for context list operations */
+} ctx_list;
+
+static void ctx_signal_notify(struct vmci_ctx *context)
+{
+ if (context->notify)
+ *context->notify = true;
+}
+
+static void ctx_clear_notify(struct vmci_ctx *context)
+{
+ if (context->notify)
+ *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)
+{
+ ASSERT(context);
+
+ spin_lock(&context->lock);
+ if (context->pending_datagrams)
+ ctx_signal_notify(context);
+ spin_unlock(&context->lock);
+}
+
+int __init vmci_ctx_init(void)
+{
+ INIT_LIST_HEAD(&ctx_list.head);
+ spin_lock_init(&ctx_list.lock);
+
+ return VMCI_SUCCESS;
+}
+
+/*
+ * Allocates and initializes a VMCI context.
+ */
+int vmci_ctx_init_ctx(u32 cid,
+ u32 priv_flags,
+ uintptr_t event_hnd,
+ int user_version,
+ const struct cred *cred,
+ struct vmci_ctx **out_context)
+{
+ struct vmci_ctx *context;
+ int result;
+
+ if (priv_flags & ~VMCI_PRIVILEGE_ALL_FLAGS) {
+ pr_devel("Invalid flag (flags=0x%x) for VMCI context.",
+ priv_flags);
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+
+ if (user_version == 0)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ context = kzalloc(sizeof(*context), GFP_KERNEL);
+ if (context == NULL) {
+ pr_warn("Failed to allocate memory for VMCI context.");
+ return VMCI_ERROR_NO_MEM;
+ }
+
+ INIT_LIST_HEAD(&context->list_item);
+ INIT_LIST_HEAD(&context->datagram_queue);
+
+ context->user_version = user_version;
+
+ context->queue_pair_array = vmci_handle_arr_create(0);
+ if (!context->queue_pair_array) {
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+
+ context->doorbell_array = vmci_handle_arr_create(0);
+ if (!context->doorbell_array) {
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+
+ context->pending_doorbell_array = vmci_handle_arr_create(0);
+ if (!context->pending_doorbell_array) {
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+
+ INIT_LIST_HEAD(&context->notifier_list);
+
+ spin_lock_init(&context->lock);
+
+ kref_init(&context->kref);
+
+ /* Inititialize host-specific VMCI context. */
+ init_waitqueue_head(&context->host_context.wait_queue);
+
+ context->priv_flags = priv_flags;
+
+ if (cred)
+ context->cred = get_cred(cred);
+
+ context->notify = NULL;
+ 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);
+
+ ASSERT(cid != VMCI_INVALID_ID);
+ while (vmci_ctx_exists(cid)) {
+
+ /*
+ * If the cid is below our limit and we collide we are
+ * creating duplicate contexts internally so we want
+ * to assert fail in that case.
+ */
+ ASSERT(cid >= VMCI_RESERVED_CID_LIMIT);
+
+ /* 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;
+ }
+ ASSERT(!vmci_ctx_exists(cid));
+ context->cid = cid;
+
+ list_add_tail_rcu(&context->list_item, &ctx_list.head);
+ spin_unlock(&ctx_list.lock);
+
+ *out_context = context;
+ return VMCI_SUCCESS;
+
+ error:
+ if (context->queue_pair_array)
+ vmci_handle_arr_destroy(context->queue_pair_array);
+ if (context->doorbell_array)
+ vmci_handle_arr_destroy(context->doorbell_array);
+ if (context->pending_doorbell_array)
+ vmci_handle_arr_destroy(context->pending_doorbell_array);
+ kfree(context);
+ return result;
+}
+
+/*
+ * Dequeue VMCI context.
+ */
+void vmci_ctx_release_ctx(struct vmci_ctx *context)
+{
+ spin_lock(&ctx_list.lock);
+ list_del_rcu(&context->list_item);
+ spin_unlock(&ctx_list.lock);
+ synchronize_rcu();
+
+ vmci_ctx_release(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_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_msg *e_msg;
+ struct vmci_event_payld_ctx *ev_payload;
+ char buf[sizeof(*e_msg) + sizeof(*ev_payload)];
+
+ e_msg = (struct vmci_event_msg *)buf;
+
+ /* Clear out any garbage. */
+ memset(e_msg, 0, sizeof(*e_msg) + sizeof(*ev_payload));
+ e_msg->hdr.dst = vmci_handle_arr_get_entry(subscriber_array, i);
+ e_msg->hdr.src =
+ vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
+ VMCI_CONTEXT_RESOURCE_ID);
+ e_msg->hdr.payload_size =
+ sizeof(*e_msg) + sizeof(*ev_payload) - sizeof(e_msg->hdr);
+ e_msg->event_data.event = VMCI_EVENT_CTX_REMOVED;
+ ev_payload = vmci_event_data_payload(&e_msg->event_data);
+ ev_payload->context_id = context_id;
+
+ result = vmci_datagram_dispatch(VMCI_HYPERVISOR_CONTEXT_ID,
+ (struct vmci_datagram *)
+ e_msg, false);
+ if (result < VMCI_SUCCESS) {
+ pr_devel("Failed to enqueue event datagram "
+ "(type=%d) for context (ID=0x%x).",
+ e_msg->event_data.event,
+ e_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_release(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;
+
+ ASSERT(dg);
+ vmci_dg_size = VMCI_DG_SIZE(dg);
+ ASSERT(vmci_dg_size <= VMCI_MAX_DG_SIZE);
+
+ /* Get the target VM's VMCI context. */
+ context = vmci_ctx_get(cid);
+ if (context == NULL) {
+ pr_devel("Invalid context (ID=0x%x).", 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.");
+ vmci_ctx_release(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_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_release(context);
+ kfree(dq_entry);
+ pr_devel("Context (ID=0x%x) receive queue is full.", 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_release(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 *context = NULL;
+
+ if (cid == VMCI_INVALID_ID)
+ return NULL;
+
+ spin_lock(&ctx_list.lock);
+ list_for_each_entry(context, &ctx_list.head, list_item) {
+ if (context->cid == cid) {
+ /*
+ * At this point, we are sure that the
+ * reference count is larger already than
+ * zero. When starting the destruction of a
+ * context, we always remove it from the
+ * context list before decreasing the
+ * reference count. As we found the context
+ * here, it hasn't been destroyed yet. This
+ * means that we are not about to increase the
+ * reference count of something that is in the
+ * process of being destroyed.
+ */
+
+ kref_get(&context->kref);
+ break;
+ }
+ }
+ spin_unlock(&ctx_list.lock);
+
+ return (context && context->cid == cid) ? context : NULL;
+}
+
+/*
+ * Deallocates all parts of a context datastructure. This
+ * functions doesn't lock the context, because it assumes that
+ * the caller is 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_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) {
+ ASSERT(dq_entry->dg);
+ ASSERT(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(&notifier->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);
+}
+
+/*
+ * Releases the 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). This function musn't be called with a
+ * lock held.
+ */
+void vmci_ctx_release(struct vmci_ctx *context)
+{
+ ASSERT(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;
+
+ ASSERT(context && dg);
+
+ /* 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.");
+ return VMCI_ERROR_NO_MORE_DATAGRAMS;
+ }
+
+ list_item = context->datagram_queue.next;
+ ASSERT(!list_empty(&context->datagram_queue));
+
+ dq_entry =
+ list_entry(list_item, struct vmci_datagram_queue_entry, list_item);
+ ASSERT(dq_entry->dg);
+
+ /* 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).", (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;
+ ASSERT(!list_empty(&context->datagram_queue));
+ next_entry =
+ list_entry(list_item, struct vmci_datagram_queue_entry,
+ list_item);
+ ASSERT(next_entry && next_entry->dg);
+
+ /*
+ * 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. */
+ ASSERT(dq_entry->dg_size == VMCI_DG_SIZE(dq_entry->dg));
+ *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 = context->notify_page;
+
+ if (!notify_page)
+ return;
+
+ context->notify = NULL;
+ context->notify_page = NULL;
+ kunmap(notify_page);
+ put_page(notify_page);
+
+}
+
+u32 vmci_ctx_get_id(struct vmci_ctx *context)
+{
+ if (!context)
+ return VMCI_INVALID_ID;
+
+ ASSERT(context->cid != VMCI_INVALID_ID);
+ return context->cid;
+}
+
+/*
+ * 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).",
+ 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(&notifier->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_EQUAL(n->handle, notifier->handle)) {
+ exists = true;
+ break;
+ }
+ }
+
+ if (exists) {
+ kfree(notifier);
+ result = VMCI_ERROR_ALREADY_EXISTS;
+ } else {
+ list_add_tail_rcu(&notifier->node, &context->notifier_list);
+ context->n_notifiers++;
+ result = VMCI_SUCCESS;
+ }
+
+ spin_unlock(&context->lock);
+
+ out:
+ vmci_ctx_release(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_EQUAL(notifier->handle, handle)) {
+ list_del_rcu(&notifier->node);
+ context->n_notifiers--;
+ found = true;
+ break;
+ }
+ }
+ spin_unlock(&context->lock);
+
+ if (found) {
+ synchronize_rcu();
+ kfree(notifier);
+ }
+
+ vmci_ctx_release(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;
+
+ ASSERT(context->doorbell_array);
+
+ 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;
+
+ ASSERT(buf_size && pbuf);
+
+ 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).", cpt_type);
+ result = VMCI_ERROR_INVALID_ARGS;
+ break;
+ }
+
+ spin_unlock(&context->lock);
+ vmci_ctx_release(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);
+ ASSERT(cpt_buf);
+
+ 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.");
+ return VMCI_ERROR_OBSOLETE;
+ }
+
+ if (cpt_type != VMCI_NOTIFICATION_CPT_STATE) {
+ pr_devel("Invalid cpt state (type=%d).", 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).", 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;
+
+ ASSERT(db_handle_array && qp_handle_array);
+
+ 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_release(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);
+
+ if (!context) {
+ /*
+ * The OS driver part is holding on to the context for the
+ * duration of the receive notification ioctl, so it should
+ * still be here.
+ */
+ ASSERT(false);
+ }
+
+ 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_INVALID(handle)) {
+ ASSERT(vmci_handle_arr_has_entry
+ (context->doorbell_array, 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_release(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_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_release(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_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_release(context);
+
+ return VMCI_HANDLE_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_INVALID(handle));
+ do {
+ struct vmci_handle_arr *arr = context->pending_doorbell_array;
+ handle = vmci_handle_arr_remove_tail(arr);
+ } while (!VMCI_HANDLE_INVALID(handle));
+ spin_unlock(&context->lock);
+
+ vmci_ctx_release(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_INVALID(handle))
+ return VMCI_ERROR_INVALID_ARGS;
+
+ /* Get the target VM's VMCI context. */
+ dst_context = vmci_ctx_get(handle.context);
+ if (dst_context == NULL) {
+ pr_devel("Invalid context (ID=0x%x).", 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).", 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).",
+ 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_release(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_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_INVALID(handle))
+ return VMCI_ERROR_INVALID_ARGS;
+
+ hndl = vmci_handle_arr_remove_entry(context->queue_pair_array, handle);
+
+ return VMCI_HANDLE_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_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_release(context);
+ return flags;
+ }
+ return VMCI_NO_PRIVILEGE_FLAGS;
+}
+EXPORT_SYMBOL(vmci_context_get_priv_flags);
+
+/*
+ * vmci_context_id_to_host_vmid() - Map CID to HostID
+ * @context_id: Context ID of VMCI context.
+ * @host_vmid: Host VM ID data
+ * @host_vmid_len: Length of Host VM ID Data.
+ *
+ * Maps a context ID to the host specific (process/world) ID
+ * of the VM/VMX. This function is not used on Linux systems
+ * and should be ignored.
+ */
+int vmci_context_id_to_host_vmid(u32 context_id,
+ void *host_vmid, size_t host_vmid_len)
+{
+ return VMCI_ERROR_UNAVAILABLE;
+}
+EXPORT_SYMBOL(vmci_context_id_to_host_vmid);
+
+/*
+ * 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_release(context);
+ }
+ }
+
+ return is_owner;
+}
+EXPORT_SYMBOL(vmci_is_context_owner);
diff --git a/drivers/misc/vmw_vmci/vmci_context.h b/drivers/misc/vmw_vmci/vmci_context.h
new file mode 100644
index 0000000..b997b7d
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_context.h
@@ -0,0 +1,177 @@
+/*
+ * VMware VMCI driver (vmciContext.h)
+ *
+ * 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.
+ */
+
+#ifndef _VMCI_CONTEXT_H_
+#define _VMCI_CONTEXT_H_
+
+#include <linux/vmw_vmci_defs.h>
+#include <linux/atomic.h>
+#include <linux/kref.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#include "vmci_handle_array.h"
+#include "vmci_common_int.h"
+#include "vmci_datagram.h"
+
+/* Used to determine what checkpoint state to get and set. */
+enum {
+ VMCI_NOTIFICATION_CPT_STATE = 1,
+ VMCI_WELLKNOWN_CPT_STATE = 2,
+ VMCI_DG_OUT_STATE = 3,
+ VMCI_DG_IN_STATE = 4,
+ VMCI_DG_IN_SIZE_STATE = 5,
+ VMCI_DOORBELL_CPT_STATE = 6,
+};
+
+/* Host specific struct used for signalling */
+struct vmci_host {
+ wait_queue_head_t wait_queue;
+};
+
+struct vmci_handle_list {
+ struct list_head node;
+ struct vmci_handle handle;
+};
+
+struct vmci_ctx {
+ struct list_head list_item; /* For global VMCI list. */
+ u32 cid;
+ struct kref kref;
+ struct list_head datagram_queue; /* Head of per VM queue. */
+ u32 pending_datagrams;
+ size_t datagram_queue_size; /* Size of datagram queue in bytes. */
+
+ /*
+ * Version of the code that created
+ * this context; e.g., VMX.
+ */
+ int user_version;
+ spinlock_t lock; /* Locks callQueue and handle_arrays. */
+
+ /*
+ * queue_pairs attached to. The array of
+ * handles for queue pairs is accessed
+ * from the code for QP API, and there
+ * it is protected by the QP lock. It
+ * is also accessed from the context
+ * clean up path, which does not
+ * require a lock. VMCILock is not
+ * used to protect the QP array field.
+ */
+ struct vmci_handle_arr *queue_pair_array;
+
+ /* Doorbells created by context. */
+ struct vmci_handle_arr *doorbell_array;
+
+ /* Doorbells pending for context. */
+ struct vmci_handle_arr *pending_doorbell_array;
+
+ /* Contexts current context is subscribing to. */
+ struct list_head notifier_list;
+ unsigned int n_notifiers;
+
+ struct vmci_host host_context;
+ u32 priv_flags;
+
+ const struct cred *cred;
+ bool *notify; /* Notify flag pointer - hosted only. */
+ struct page *notify_page; /* Page backing the notify UVA. */
+};
+
+/* VMCINotifyAddRemoveInfo: Used to add/remove remote context notifications. */
+struct vmci_ctx_info {
+ u32 remote_cid;
+ int result;
+};
+
+/* VMCICptBufInfo: Used to set/get current context's checkpoint state. */
+struct vmci_ctx_chkpt_buf_info {
+ u64 cpt_buf;
+ u32 cpt_type;
+ u32 buf_size;
+ s32 result;
+ u32 _pad;
+};
+
+/*
+ * VMCINotificationReceiveInfo: Used to recieve pending notifications
+ * for doorbells and queue pairs.
+ */
+struct vmci_ctx_notify_recv_info {
+ u64 db_handle_buf_uva;
+ u64 db_handle_buf_size;
+ u64 qp_handle_buf_uva;
+ u64 qp_handle_buf_size;
+ s32 result;
+ u32 _pad;
+};
+
+/*
+ * Utilility function that checks whether two entities are allowed
+ * to interact. If one of them is restricted, the other one must
+ * be trusted.
+ */
+static inline bool vmci_deny_interaction(u32 part_one, u32 part_two)
+{
+ return ((part_one & VMCI_PRIVILEGE_FLAG_RESTRICTED) &&
+ !(part_two & VMCI_PRIVILEGE_FLAG_TRUSTED)) ||
+ ((part_two & VMCI_PRIVILEGE_FLAG_RESTRICTED) &&
+ !(part_one & VMCI_PRIVILEGE_FLAG_TRUSTED));
+}
+
+int vmci_ctx_init(void);
+int vmci_ctx_init_ctx(u32 cid, u32 flags,
+ uintptr_t event_hnd, int version,
+ const struct cred *cred, struct vmci_ctx **context);
+
+bool vmci_ctx_supports_host_qp(struct vmci_ctx *context);
+void vmci_ctx_release_ctx(struct vmci_ctx *context);
+int vmci_ctx_enqueue_datagram(u32 cid, struct vmci_datagram *dg);
+int vmci_ctx_dequeue_datagram(struct vmci_ctx *context,
+ size_t *max_size, struct vmci_datagram **dg);
+int vmci_ctx_pending_datagrams(u32 cid, u32 *pending);
+struct vmci_ctx *vmci_ctx_get(u32 cid);
+void vmci_ctx_release(struct vmci_ctx *context);
+bool vmci_ctx_exists(u32 cid);
+
+u32 vmci_ctx_get_id(struct vmci_ctx *context);
+int vmci_ctx_add_notification(u32 context_id, u32 remote_cid);
+int vmci_ctx_remove_notification(u32 context_id, u32 remote_cid);
+int vmci_ctx_get_chkpt_state(u32 context_id, u32 cpt_type,
+ u32 *num_cids, void **cpt_buf_ptr);
+int vmci_ctx_set_chkpt_state(u32 context_id, u32 cpt_type,
+ u32 num_cids, void *cpt_buf);
+
+int vmci_ctx_qp_create(struct vmci_ctx *context, struct vmci_handle handle);
+int vmci_ctx_qp_destroy(struct vmci_ctx *context, struct vmci_handle handle);
+bool vmci_ctx_qp_exists(struct vmci_ctx *context, struct vmci_handle handle);
+
+void vmci_ctx_check_signal_notify(struct vmci_ctx *context);
+void vmci_ctx_unset_notify(struct vmci_ctx *context);
+
+int vmci_ctx_dbell_create(u32 context_id, struct vmci_handle handle);
+int vmci_ctx_dbell_destroy(u32 context_id, struct vmci_handle handle);
+int vmci_ctx_dbell_destroy_all(u32 context_id);
+int vmci_ctx_notify_dbell(u32 cid, struct vmci_handle handle,
+ u32 src_priv_flags);
+
+int vmci_ctx_rcv_notifications_get(u32 context_id, struct vmci_handle_arr
+ **db_handle_array, struct vmci_handle_arr
+ **qp_handle_array);
+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);
+#endif /* _VMCI_CONTEXT_H_ */