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
18 static bool vmci_disable_host;
19 module_param_named(disable_host, vmci_disable_host, bool, 0);
20 MODULE_PARM_DESC(disable_host,
21 "Disable driver host personality (default=enabled)");
22
23 static bool vmci_disable_guest;
24 module_param_named(disable_guest, vmci_disable_guest, bool, 0);
25 MODULE_PARM_DESC(disable_guest,
26 "Disable driver guest personality (default=enabled)");
27
28 static bool vmci_guest_personality_initialized;
29 static bool vmci_host_personality_initialized;
30
31 static DEFINE_MUTEX(vmci_vsock_mutex); /* protects vmci_vsock_transport_cb */
32 static vmci_vsock_cb vmci_vsock_transport_cb;
33 static 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 */
vmci_get_context_id(void)41 u32 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 }
50 EXPORT_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 */
vmci_register_vsock_callback(vmci_vsock_cb callback)61 int 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
87 out:
88 mutex_unlock(&vmci_vsock_mutex);
89 return err;
90 }
91 EXPORT_SYMBOL_GPL(vmci_register_vsock_callback);
92
vmci_call_vsock_callback(bool is_host)93 void 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);
111 out:
112 mutex_unlock(&vmci_vsock_mutex);
113 }
114
vmci_drv_init(void)115 static 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 }
159 module_init(vmci_drv_init);
160
vmci_drv_exit(void)161 static 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 }
171 module_exit(vmci_drv_exit);
172
173 MODULE_AUTHOR("VMware, Inc.");
174 MODULE_DESCRIPTION("VMware Virtual Machine Communication Interface.");
175 MODULE_VERSION("1.1.6.0-k");
176 MODULE_LICENSE("GPL v2");
177