linux/drivers/misc/vmw_vmci/vmci_context.c

// 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

/*
 * 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 {} ctx_list =;

/* 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)
{}

static void ctx_clear_notify(struct vmci_ctx *context)
{}

/*
 * If nothing requires the attention of the guest, clears both
 * notify flag and call.
 */
static void ctx_clear_notify_call(struct vmci_ctx *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)
{}

/*
 * 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)
{}

/*
 * Destroy VMCI context.
 */
void vmci_ctx_destroy(struct vmci_ctx *context)
{}

/*
 * Fire notification for all contexts interested in given cid.
 */
static int ctx_fire_notification(u32 context_id, u32 priv_flags)
{}

/*
 * 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)
{}

/*
 * Queues a VMCI datagram for the appropriate target VM context.
 */
int vmci_ctx_enqueue_datagram(u32 cid, struct vmci_datagram *dg)
{}

/*
 * 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)
{}

/*
 * Retrieves VMCI context corresponding to the given cid.
 */
struct vmci_ctx *vmci_ctx_get(u32 cid)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * Add remote_cid to list of contexts current contexts wants
 * notifications from/about.
 */
int vmci_ctx_add_notification(u32 context_id, u32 remote_cid)
{}

/*
 * 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)
{}

static int vmci_ctx_get_chkpt_notifiers(struct vmci_ctx *context,
					u32 *buf_size, void **pbuf)
{}

static int vmci_ctx_get_chkpt_doorbells(struct vmci_ctx *context,
					u32 *buf_size, void **pbuf)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * Unregisters all doorbell handles that were previously
 * registered with vmci_ctx_dbell_create.
 */
int vmci_ctx_dbell_destroy_all(u32 context_id)
{}

/*
 * 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)
{}

bool vmci_ctx_supports_host_qp(struct vmci_ctx *context)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}

/*
 * 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)
{}
EXPORT_SYMBOL_GPL();

/*
 * 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)
{}
EXPORT_SYMBOL_GPL();