1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * VMware VMCI Driver
4 *
5 * Copyright (C) 2012 VMware, Inc. All rights reserved.
6 */
7
8#include <linux/vmw_vmci_defs.h>
9#include <linux/vmw_vmci_api.h>
10#include <linux/atomic.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/init.h>
14
15#include "vmci_driver.h"
16#include "vmci_event.h"
17
18static bool vmci_disable_host;
19module_param_named(disable_host, vmci_disable_host, bool, 0);
20MODULE_PARM_DESC(disable_host,
21		 "Disable driver host personality (default=enabled)");
22
23static bool vmci_disable_guest;
24module_param_named(disable_guest, vmci_disable_guest, bool, 0);
25MODULE_PARM_DESC(disable_guest,
26		 "Disable driver guest personality (default=enabled)");
27
28static bool vmci_guest_personality_initialized;
29static bool vmci_host_personality_initialized;
30
31static DEFINE_MUTEX(vmci_vsock_mutex); /* protects vmci_vsock_transport_cb */
32static vmci_vsock_cb vmci_vsock_transport_cb;
33static bool vmci_vsock_cb_host_called;
34
35/*
36 * vmci_get_context_id() - Gets the current context ID.
37 *
38 * Returns the current context ID.  Note that since this is accessed only
39 * from code running in the host, this always returns the host context ID.
40 */
41u32 vmci_get_context_id(void)
42{
43	if (vmci_guest_code_active())
44		return vmci_get_vm_context_id();
45	else if (vmci_host_code_active())
46		return VMCI_HOST_CONTEXT_ID;
47
48	return VMCI_INVALID_ID;
49}
50EXPORT_SYMBOL_GPL(vmci_get_context_id);
51
52/*
53 * vmci_register_vsock_callback() - Register the VSOCK vmci_transport callback.
54 *
55 * The callback will be called when the first host or guest becomes active,
56 * or if they are already active when this function is called.
57 * To unregister the callback, call this function with NULL parameter.
58 *
59 * Returns 0 on success. -EBUSY if a callback is already registered.
60 */
61int vmci_register_vsock_callback(vmci_vsock_cb callback)
62{
63	int err = 0;
64
65	mutex_lock(&vmci_vsock_mutex);
66
67	if (vmci_vsock_transport_cb && callback) {
68		err = -EBUSY;
69		goto out;
70	}
71
72	vmci_vsock_transport_cb = callback;
73
74	if (!vmci_vsock_transport_cb) {
75		vmci_vsock_cb_host_called = false;
76		goto out;
77	}
78
79	if (vmci_guest_code_active())
80		vmci_vsock_transport_cb(false);
81
82	if (vmci_host_users() > 0) {
83		vmci_vsock_cb_host_called = true;
84		vmci_vsock_transport_cb(true);
85	}
86
87out:
88	mutex_unlock(&vmci_vsock_mutex);
89	return err;
90}
91EXPORT_SYMBOL_GPL(vmci_register_vsock_callback);
92
93void vmci_call_vsock_callback(bool is_host)
94{
95	mutex_lock(&vmci_vsock_mutex);
96
97	if (!vmci_vsock_transport_cb)
98		goto out;
99
100	/* In the host, this function could be called multiple times,
101	 * but we want to register it only once.
102	 */
103	if (is_host) {
104		if (vmci_vsock_cb_host_called)
105			goto out;
106
107		vmci_vsock_cb_host_called = true;
108	}
109
110	vmci_vsock_transport_cb(is_host);
111out:
112	mutex_unlock(&vmci_vsock_mutex);
113}
114
115static int __init vmci_drv_init(void)
116{
117	int vmci_err;
118	int error;
119
120	vmci_err = vmci_event_init();
121	if (vmci_err < VMCI_SUCCESS) {
122		pr_err("Failed to initialize VMCIEvent (result=%d)\n",
123		       vmci_err);
124		return -EINVAL;
125	}
126
127	if (!vmci_disable_guest) {
128		error = vmci_guest_init();
129		if (error) {
130			pr_warn("Failed to initialize guest personality (err=%d)\n",
131				error);
132		} else {
133			vmci_guest_personality_initialized = true;
134			pr_info("Guest personality initialized and is %s\n",
135				vmci_guest_code_active() ?
136				"active" : "inactive");
137		}
138	}
139
140	if (!vmci_disable_host) {
141		error = vmci_host_init();
142		if (error) {
143			pr_warn("Unable to initialize host personality (err=%d)\n",
144				error);
145		} else {
146			vmci_host_personality_initialized = true;
147			pr_info("Initialized host personality\n");
148		}
149	}
150
151	if (!vmci_guest_personality_initialized &&
152	    !vmci_host_personality_initialized) {
153		vmci_event_exit();
154		return -ENODEV;
155	}
156
157	return 0;
158}
159module_init(vmci_drv_init);
160
161static void __exit vmci_drv_exit(void)
162{
163	if (vmci_guest_personality_initialized)
164		vmci_guest_exit();
165
166	if (vmci_host_personality_initialized)
167		vmci_host_exit();
168
169	vmci_event_exit();
170}
171module_exit(vmci_drv_exit);
172
173MODULE_AUTHOR("VMware, Inc.");
174MODULE_DESCRIPTION("VMware Virtual Machine Communication Interface.");
175MODULE_VERSION("1.1.6.0-k");
176MODULE_LICENSE("GPL v2");
177