4 * Copyright (C) 2012 VMware, Inc. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation version 2 and no later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 #include <linux/vmw_vmci_defs.h>
17 #include <linux/vmw_vmci_api.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/bug.h>
23 #include "vmci_datagram.h"
24 #include "vmci_resource.h"
25 #include "vmci_context.h"
26 #include "vmci_driver.h"
27 #include "vmci_event.h"
28 #include "vmci_route.h"
31 * struct datagram_entry describes the datagram entity. It is used for datagram
32 * entities created only on the host.
34 struct datagram_entry {
35 struct vmci_resource resource;
38 vmci_datagram_recv_cb recv_cb;
43 struct delayed_datagram_info {
44 struct datagram_entry *entry;
45 struct vmci_datagram msg;
46 struct work_struct work;
47 bool in_dg_host_queue;
50 /* Number of in-flight host->host datagrams */
51 static atomic_t delayed_dg_host_queue_size = ATOMIC_INIT(0);
54 * Create a datagram entry given a handle pointer.
56 static int dg_create_handle(u32 resource_id,
59 vmci_datagram_recv_cb recv_cb,
60 void *client_data, struct vmci_handle *out_handle)
64 struct vmci_handle handle;
65 struct datagram_entry *entry;
67 if ((flags & VMCI_FLAG_WELLKNOWN_DG_HND) != 0)
68 return VMCI_ERROR_INVALID_ARGS;
70 if ((flags & VMCI_FLAG_ANYCID_DG_HND) != 0) {
71 context_id = VMCI_INVALID_ID;
73 context_id = vmci_get_context_id();
74 if (context_id == VMCI_INVALID_ID)
75 return VMCI_ERROR_NO_RESOURCES;
78 handle = vmci_make_handle(context_id, resource_id);
80 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
82 pr_warn("Failed allocating memory for datagram entry\n");
83 return VMCI_ERROR_NO_MEM;
86 entry->run_delayed = (flags & VMCI_FLAG_DG_DELAYED_CB) ? true : false;
88 entry->recv_cb = recv_cb;
89 entry->client_data = client_data;
90 entry->priv_flags = priv_flags;
92 /* Make datagram resource live. */
93 result = vmci_resource_add(&entry->resource,
94 VMCI_RESOURCE_TYPE_DATAGRAM,
96 if (result != VMCI_SUCCESS) {
97 pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d\n",
98 handle.context, handle.resource, result);
103 *out_handle = vmci_resource_handle(&entry->resource);
108 * Internal utility function with the same purpose as
109 * vmci_datagram_get_priv_flags that also takes a context_id.
111 static int vmci_datagram_get_priv_flags(u32 context_id,
112 struct vmci_handle handle,
115 if (context_id == VMCI_INVALID_ID)
116 return VMCI_ERROR_INVALID_ARGS;
118 if (context_id == VMCI_HOST_CONTEXT_ID) {
119 struct datagram_entry *src_entry;
120 struct vmci_resource *resource;
122 resource = vmci_resource_by_handle(handle,
123 VMCI_RESOURCE_TYPE_DATAGRAM);
125 return VMCI_ERROR_INVALID_ARGS;
127 src_entry = container_of(resource, struct datagram_entry,
129 *priv_flags = src_entry->priv_flags;
130 vmci_resource_put(resource);
131 } else if (context_id == VMCI_HYPERVISOR_CONTEXT_ID)
132 *priv_flags = VMCI_MAX_PRIVILEGE_FLAGS;
134 *priv_flags = vmci_context_get_priv_flags(context_id);
140 * Calls the specified callback in a delayed context.
142 static void dg_delayed_dispatch(struct work_struct *work)
144 struct delayed_datagram_info *dg_info =
145 container_of(work, struct delayed_datagram_info, work);
147 dg_info->entry->recv_cb(dg_info->entry->client_data, &dg_info->msg);
149 vmci_resource_put(&dg_info->entry->resource);
151 if (dg_info->in_dg_host_queue)
152 atomic_dec(&delayed_dg_host_queue_size);
158 * Dispatch datagram as a host, to the host, or other vm context. This
159 * function cannot dispatch to hypervisor context handlers. This should
160 * have been handled before we get here by vmci_datagram_dispatch.
161 * Returns number of bytes sent on success, error code otherwise.
163 static int dg_dispatch_as_host(u32 context_id, struct vmci_datagram *dg)
169 dg_size = VMCI_DG_SIZE(dg);
171 /* Host cannot send to the hypervisor. */
172 if (dg->dst.context == VMCI_HYPERVISOR_CONTEXT_ID)
173 return VMCI_ERROR_DST_UNREACHABLE;
175 /* Check that source handle matches sending context. */
176 if (dg->src.context != context_id) {
177 pr_devel("Sender context (ID=0x%x) is not owner of src datagram entry (handle=0x%x:0x%x)\n",
178 context_id, dg->src.context, dg->src.resource);
179 return VMCI_ERROR_NO_ACCESS;
182 /* Get hold of privileges of sending endpoint. */
183 retval = vmci_datagram_get_priv_flags(context_id, dg->src,
185 if (retval != VMCI_SUCCESS) {
186 pr_warn("Couldn't get privileges (handle=0x%x:0x%x)\n",
187 dg->src.context, dg->src.resource);
191 /* Determine if we should route to host or guest destination. */
192 if (dg->dst.context == VMCI_HOST_CONTEXT_ID) {
193 /* Route to host datagram entry. */
194 struct datagram_entry *dst_entry;
195 struct vmci_resource *resource;
197 if (dg->src.context == VMCI_HYPERVISOR_CONTEXT_ID &&
198 dg->dst.resource == VMCI_EVENT_HANDLER) {
199 return vmci_event_dispatch(dg);
202 resource = vmci_resource_by_handle(dg->dst,
203 VMCI_RESOURCE_TYPE_DATAGRAM);
205 pr_devel("Sending to invalid destination (handle=0x%x:0x%x)\n",
206 dg->dst.context, dg->dst.resource);
207 return VMCI_ERROR_INVALID_RESOURCE;
209 dst_entry = container_of(resource, struct datagram_entry,
211 if (vmci_deny_interaction(src_priv_flags,
212 dst_entry->priv_flags)) {
213 vmci_resource_put(resource);
214 return VMCI_ERROR_NO_ACCESS;
218 * If a VMCI datagram destined for the host is also sent by the
219 * host, we always run it delayed. This ensures that no locks
220 * are held when the datagram callback runs.
222 if (dst_entry->run_delayed ||
223 dg->src.context == VMCI_HOST_CONTEXT_ID) {
224 struct delayed_datagram_info *dg_info;
226 if (atomic_add_return(1, &delayed_dg_host_queue_size)
227 == VMCI_MAX_DELAYED_DG_HOST_QUEUE_SIZE) {
228 atomic_dec(&delayed_dg_host_queue_size);
229 vmci_resource_put(resource);
230 return VMCI_ERROR_NO_MEM;
233 dg_info = kmalloc(sizeof(*dg_info) +
234 (size_t) dg->payload_size, GFP_ATOMIC);
236 atomic_dec(&delayed_dg_host_queue_size);
237 vmci_resource_put(resource);
238 return VMCI_ERROR_NO_MEM;
241 dg_info->in_dg_host_queue = true;
242 dg_info->entry = dst_entry;
243 memcpy(&dg_info->msg, dg, dg_size);
245 INIT_WORK(&dg_info->work, dg_delayed_dispatch);
246 schedule_work(&dg_info->work);
247 retval = VMCI_SUCCESS;
250 retval = dst_entry->recv_cb(dst_entry->client_data, dg);
251 vmci_resource_put(resource);
252 if (retval < VMCI_SUCCESS)
256 /* Route to destination VM context. */
257 struct vmci_datagram *new_dg;
259 if (context_id != dg->dst.context) {
260 if (vmci_deny_interaction(src_priv_flags,
261 vmci_context_get_priv_flags
262 (dg->dst.context))) {
263 return VMCI_ERROR_NO_ACCESS;
264 } else if (VMCI_CONTEXT_IS_VM(context_id)) {
266 * If the sending context is a VM, it
267 * cannot reach another VM.
270 pr_devel("Datagram communication between VMs not supported (src=0x%x, dst=0x%x)\n",
271 context_id, dg->dst.context);
272 return VMCI_ERROR_DST_UNREACHABLE;
276 /* We make a copy to enqueue. */
277 new_dg = kmalloc(dg_size, GFP_KERNEL);
279 return VMCI_ERROR_NO_MEM;
281 memcpy(new_dg, dg, dg_size);
282 retval = vmci_ctx_enqueue_datagram(dg->dst.context, new_dg);
283 if (retval < VMCI_SUCCESS) {
290 * We currently truncate the size to signed 32 bits. This doesn't
291 * matter for this handler as it only support 4Kb messages.
297 * Dispatch datagram as a guest, down through the VMX and potentially to
299 * Returns number of bytes sent on success, error code otherwise.
301 static int dg_dispatch_as_guest(struct vmci_datagram *dg)
304 struct vmci_resource *resource;
306 resource = vmci_resource_by_handle(dg->src,
307 VMCI_RESOURCE_TYPE_DATAGRAM);
309 return VMCI_ERROR_NO_HANDLE;
311 retval = vmci_send_datagram(dg);
312 vmci_resource_put(resource);
317 * Dispatch datagram. This will determine the routing for the datagram
318 * and dispatch it accordingly.
319 * Returns number of bytes sent on success, error code otherwise.
321 int vmci_datagram_dispatch(u32 context_id,
322 struct vmci_datagram *dg, bool from_guest)
325 enum vmci_route route;
327 BUILD_BUG_ON(sizeof(struct vmci_datagram) != 24);
329 if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE) {
330 pr_devel("Payload (size=%llu bytes) too big to send\n",
331 (unsigned long long)dg->payload_size);
332 return VMCI_ERROR_INVALID_ARGS;
335 retval = vmci_route(&dg->src, &dg->dst, from_guest, &route);
336 if (retval < VMCI_SUCCESS) {
337 pr_devel("Failed to route datagram (src=0x%x, dst=0x%x, err=%d)\n",
338 dg->src.context, dg->dst.context, retval);
342 if (VMCI_ROUTE_AS_HOST == route) {
343 if (VMCI_INVALID_ID == context_id)
344 context_id = VMCI_HOST_CONTEXT_ID;
345 return dg_dispatch_as_host(context_id, dg);
348 if (VMCI_ROUTE_AS_GUEST == route)
349 return dg_dispatch_as_guest(dg);
351 pr_warn("Unknown route (%d) for datagram\n", route);
352 return VMCI_ERROR_DST_UNREACHABLE;
356 * Invoke the handler for the given datagram. This is intended to be
357 * called only when acting as a guest and receiving a datagram from the
360 int vmci_datagram_invoke_guest_handler(struct vmci_datagram *dg)
362 struct vmci_resource *resource;
363 struct datagram_entry *dst_entry;
365 resource = vmci_resource_by_handle(dg->dst,
366 VMCI_RESOURCE_TYPE_DATAGRAM);
368 pr_devel("destination (handle=0x%x:0x%x) doesn't exist\n",
369 dg->dst.context, dg->dst.resource);
370 return VMCI_ERROR_NO_HANDLE;
373 dst_entry = container_of(resource, struct datagram_entry, resource);
374 if (dst_entry->run_delayed) {
375 struct delayed_datagram_info *dg_info;
377 dg_info = kmalloc(sizeof(*dg_info) + (size_t)dg->payload_size,
380 vmci_resource_put(resource);
381 return VMCI_ERROR_NO_MEM;
384 dg_info->in_dg_host_queue = false;
385 dg_info->entry = dst_entry;
386 memcpy(&dg_info->msg, dg, VMCI_DG_SIZE(dg));
388 INIT_WORK(&dg_info->work, dg_delayed_dispatch);
389 schedule_work(&dg_info->work);
391 dst_entry->recv_cb(dst_entry->client_data, dg);
392 vmci_resource_put(resource);
399 * vmci_datagram_create_handle_priv() - Create host context datagram endpoint
400 * @resource_id: The resource ID.
401 * @flags: Datagram Flags.
402 * @priv_flags: Privilege Flags.
403 * @recv_cb: Callback when receiving datagrams.
404 * @client_data: Pointer for a datagram_entry struct
405 * @out_handle: vmci_handle that is populated as a result of this function.
407 * Creates a host context datagram endpoint and returns a handle to it.
409 int vmci_datagram_create_handle_priv(u32 resource_id,
412 vmci_datagram_recv_cb recv_cb,
414 struct vmci_handle *out_handle)
416 if (out_handle == NULL)
417 return VMCI_ERROR_INVALID_ARGS;
419 if (recv_cb == NULL) {
420 pr_devel("Client callback needed when creating datagram\n");
421 return VMCI_ERROR_INVALID_ARGS;
424 if (priv_flags & ~VMCI_PRIVILEGE_ALL_FLAGS)
425 return VMCI_ERROR_INVALID_ARGS;
427 return dg_create_handle(resource_id, flags, priv_flags, recv_cb,
428 client_data, out_handle);
430 EXPORT_SYMBOL_GPL(vmci_datagram_create_handle_priv);
433 * vmci_datagram_create_handle() - Create host context datagram endpoint
434 * @resource_id: Resource ID.
435 * @flags: Datagram Flags.
436 * @recv_cb: Callback when receiving datagrams.
437 * @client_ata: Pointer for a datagram_entry struct
438 * @out_handle: vmci_handle that is populated as a result of this function.
440 * Creates a host context datagram endpoint and returns a handle to
441 * it. Same as vmci_datagram_create_handle_priv without the priviledge
444 int vmci_datagram_create_handle(u32 resource_id,
446 vmci_datagram_recv_cb recv_cb,
448 struct vmci_handle *out_handle)
450 return vmci_datagram_create_handle_priv(
452 VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS,
453 recv_cb, client_data,
456 EXPORT_SYMBOL_GPL(vmci_datagram_create_handle);
459 * vmci_datagram_destroy_handle() - Destroys datagram handle
460 * @handle: vmci_handle to be destroyed and reaped.
462 * Use this function to destroy any datagram handles created by
463 * vmci_datagram_create_handle{,Priv} functions.
465 int vmci_datagram_destroy_handle(struct vmci_handle handle)
467 struct datagram_entry *entry;
468 struct vmci_resource *resource;
470 resource = vmci_resource_by_handle(handle, VMCI_RESOURCE_TYPE_DATAGRAM);
472 pr_devel("Failed to destroy datagram (handle=0x%x:0x%x)\n",
473 handle.context, handle.resource);
474 return VMCI_ERROR_NOT_FOUND;
477 entry = container_of(resource, struct datagram_entry, resource);
479 vmci_resource_put(&entry->resource);
480 vmci_resource_remove(&entry->resource);
485 EXPORT_SYMBOL_GPL(vmci_datagram_destroy_handle);
488 * vmci_datagram_send() - Send a datagram
489 * @msg: The datagram to send.
491 * Sends the provided datagram on its merry way.
493 int vmci_datagram_send(struct vmci_datagram *msg)
496 return VMCI_ERROR_INVALID_ARGS;
498 return vmci_datagram_dispatch(VMCI_INVALID_ID, msg, false);
500 EXPORT_SYMBOL_GPL(vmci_datagram_send);