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 | */ |
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 | */ |
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(lock: &vmci_vsock_mutex); |
89 | return err; |
90 | } |
91 | EXPORT_SYMBOL_GPL(vmci_register_vsock_callback); |
92 | |
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(lock: &vmci_vsock_mutex); |
113 | } |
114 | |
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 | |
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 | |