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 #ifndef _VMW_VMCI_DEF_H_
9 #define _VMW_VMCI_DEF_H_
10
11 #include <linux/atomic.h>
12 #include <linux/bits.h>
13
14 /* Register offsets. */
15 #define VMCI_STATUS_ADDR 0x00
16 #define VMCI_CONTROL_ADDR 0x04
17 #define VMCI_ICR_ADDR 0x08
18 #define VMCI_IMR_ADDR 0x0c
19 #define VMCI_DATA_OUT_ADDR 0x10
20 #define VMCI_DATA_IN_ADDR 0x14
21 #define VMCI_CAPS_ADDR 0x18
22 #define VMCI_RESULT_LOW_ADDR 0x1c
23 #define VMCI_RESULT_HIGH_ADDR 0x20
24 #define VMCI_DATA_OUT_LOW_ADDR 0x24
25 #define VMCI_DATA_OUT_HIGH_ADDR 0x28
26 #define VMCI_DATA_IN_LOW_ADDR 0x2c
27 #define VMCI_DATA_IN_HIGH_ADDR 0x30
28 #define VMCI_GUEST_PAGE_SHIFT 0x34
29
30 /* Max number of devices. */
31 #define VMCI_MAX_DEVICES 1
32
33 /* Status register bits. */
34 #define VMCI_STATUS_INT_ON BIT(0)
35
36 /* Control register bits. */
37 #define VMCI_CONTROL_RESET BIT(0)
38 #define VMCI_CONTROL_INT_ENABLE BIT(1)
39 #define VMCI_CONTROL_INT_DISABLE BIT(2)
40
41 /* Capabilities register bits. */
42 #define VMCI_CAPS_HYPERCALL BIT(0)
43 #define VMCI_CAPS_GUESTCALL BIT(1)
44 #define VMCI_CAPS_DATAGRAM BIT(2)
45 #define VMCI_CAPS_NOTIFICATIONS BIT(3)
46 #define VMCI_CAPS_PPN64 BIT(4)
47 #define VMCI_CAPS_DMA_DATAGRAM BIT(5)
48
49 /* Interrupt Cause register bits. */
50 #define VMCI_ICR_DATAGRAM BIT(0)
51 #define VMCI_ICR_NOTIFICATION BIT(1)
52 #define VMCI_ICR_DMA_DATAGRAM BIT(2)
53
54 /* Interrupt Mask register bits. */
55 #define VMCI_IMR_DATAGRAM BIT(0)
56 #define VMCI_IMR_NOTIFICATION BIT(1)
57 #define VMCI_IMR_DMA_DATAGRAM BIT(2)
58
59 /*
60 * Maximum MSI/MSI-X interrupt vectors in the device.
61 * If VMCI_CAPS_DMA_DATAGRAM is supported by the device,
62 * VMCI_MAX_INTRS_DMA_DATAGRAM vectors are available,
63 * otherwise only VMCI_MAX_INTRS_NOTIFICATION.
64 */
65 #define VMCI_MAX_INTRS_NOTIFICATION 2
66 #define VMCI_MAX_INTRS_DMA_DATAGRAM 3
67 #define VMCI_MAX_INTRS VMCI_MAX_INTRS_DMA_DATAGRAM
68
69 /*
70 * Supported interrupt vectors. There is one for each ICR value above,
71 * but here they indicate the position in the vector array/message ID.
72 */
73 enum {
74 VMCI_INTR_DATAGRAM = 0,
75 VMCI_INTR_NOTIFICATION = 1,
76 VMCI_INTR_DMA_DATAGRAM = 2,
77 };
78
79 /*
80 * A single VMCI device has an upper limit of 128MB on the amount of
81 * memory that can be used for queue pairs. Since each queue pair
82 * consists of at least two pages, the memory limit also dictates the
83 * number of queue pairs a guest can create.
84 */
85 #define VMCI_MAX_GUEST_QP_MEMORY ((size_t)(128 * 1024 * 1024))
86 #define VMCI_MAX_GUEST_QP_COUNT (VMCI_MAX_GUEST_QP_MEMORY / PAGE_SIZE / 2)
87
88 /*
89 * There can be at most PAGE_SIZE doorbells since there is one doorbell
90 * per byte in the doorbell bitmap page.
91 */
92 #define VMCI_MAX_GUEST_DOORBELL_COUNT PAGE_SIZE
93
94 /*
95 * Queues with pre-mapped data pages must be small, so that we don't pin
96 * too much kernel memory (especially on vmkernel). We limit a queuepair to
97 * 32 KB, or 16 KB per queue for symmetrical pairs.
98 */
99 #define VMCI_MAX_PINNED_QP_MEMORY ((size_t)(32 * 1024))
100
101 /*
102 * The version of the VMCI device that supports MMIO access to registers
103 * requests 256KB for BAR1 whereas the version of VMCI that supports
104 * MSI/MSI-X only requests 8KB. The layout of the larger 256KB region is:
105 * - the first 128KB are used for MSI/MSI-X.
106 * - the following 64KB are used for MMIO register access.
107 * - the remaining 64KB are unused.
108 */
109 #define VMCI_WITH_MMIO_ACCESS_BAR_SIZE ((size_t)(256 * 1024))
110 #define VMCI_MMIO_ACCESS_OFFSET ((size_t)(128 * 1024))
111 #define VMCI_MMIO_ACCESS_SIZE ((size_t)(64 * 1024))
112
113 /*
114 * For VMCI devices supporting the VMCI_CAPS_DMA_DATAGRAM capability, the
115 * sending and receiving of datagrams can be performed using DMA to/from
116 * a driver allocated buffer.
117 * Sending and receiving will be handled as follows:
118 * - when sending datagrams, the driver initializes the buffer where the
119 * data part will refer to the outgoing VMCI datagram, sets the busy flag
120 * to 1 and writes the address of the buffer to VMCI_DATA_OUT_HIGH_ADDR
121 * and VMCI_DATA_OUT_LOW_ADDR. Writing to VMCI_DATA_OUT_LOW_ADDR triggers
122 * the device processing of the buffer. When the device has processed the
123 * buffer, it will write the result value to the buffer and then clear the
124 * busy flag.
125 * - when receiving datagrams, the driver initializes the buffer where the
126 * data part will describe the receive buffer, clears the busy flag and
127 * writes the address of the buffer to VMCI_DATA_IN_HIGH_ADDR and
128 * VMCI_DATA_IN_LOW_ADDR. Writing to VMCI_DATA_IN_LOW_ADDR triggers the
129 * device processing of the buffer. The device will copy as many available
130 * datagrams into the buffer as possible, and then sets the busy flag.
131 * When the busy flag is set, the driver will process the datagrams in the
132 * buffer.
133 */
134 struct vmci_data_in_out_header {
135 uint32_t busy;
136 uint32_t opcode;
137 uint32_t size;
138 uint32_t rsvd;
139 uint64_t result;
140 };
141
142 struct vmci_sg_elem {
143 uint64_t addr;
144 uint64_t size;
145 };
146
147 /*
148 * We have a fixed set of resource IDs available in the VMX.
149 * This allows us to have a very simple implementation since we statically
150 * know how many will create datagram handles. If a new caller arrives and
151 * we have run out of slots we can manually increment the maximum size of
152 * available resource IDs.
153 *
154 * VMCI reserved hypervisor datagram resource IDs.
155 */
156 enum {
157 VMCI_RESOURCES_QUERY = 0,
158 VMCI_GET_CONTEXT_ID = 1,
159 VMCI_SET_NOTIFY_BITMAP = 2,
160 VMCI_DOORBELL_LINK = 3,
161 VMCI_DOORBELL_UNLINK = 4,
162 VMCI_DOORBELL_NOTIFY = 5,
163 /*
164 * VMCI_DATAGRAM_REQUEST_MAP and VMCI_DATAGRAM_REMOVE_MAP are
165 * obsoleted by the removal of VM to VM communication.
166 */
167 VMCI_DATAGRAM_REQUEST_MAP = 6,
168 VMCI_DATAGRAM_REMOVE_MAP = 7,
169 VMCI_EVENT_SUBSCRIBE = 8,
170 VMCI_EVENT_UNSUBSCRIBE = 9,
171 VMCI_QUEUEPAIR_ALLOC = 10,
172 VMCI_QUEUEPAIR_DETACH = 11,
173
174 /*
175 * VMCI_VSOCK_VMX_LOOKUP was assigned to 12 for Fusion 3.0/3.1,
176 * WS 7.0/7.1 and ESX 4.1
177 */
178 VMCI_HGFS_TRANSPORT = 13,
179 VMCI_UNITY_PBRPC_REGISTER = 14,
180 VMCI_RPC_PRIVILEGED = 15,
181 VMCI_RPC_UNPRIVILEGED = 16,
182 VMCI_RESOURCE_MAX = 17,
183 };
184
185 /*
186 * struct vmci_handle - Ownership information structure
187 * @context: The VMX context ID.
188 * @resource: The resource ID (used for locating in resource hash).
189 *
190 * The vmci_handle structure is used to track resources used within
191 * vmw_vmci.
192 */
193 struct vmci_handle {
194 u32 context;
195 u32 resource;
196 };
197
198 #define vmci_make_handle(_cid, _rid) \
199 (struct vmci_handle){ .context = _cid, .resource = _rid }
200
vmci_handle_is_equal(struct vmci_handle h1,struct vmci_handle h2)201 static inline bool vmci_handle_is_equal(struct vmci_handle h1,
202 struct vmci_handle h2)
203 {
204 return h1.context == h2.context && h1.resource == h2.resource;
205 }
206
207 #define VMCI_INVALID_ID ~0
208 static const struct vmci_handle VMCI_INVALID_HANDLE = {
209 .context = VMCI_INVALID_ID,
210 .resource = VMCI_INVALID_ID
211 };
212
vmci_handle_is_invalid(struct vmci_handle h)213 static inline bool vmci_handle_is_invalid(struct vmci_handle h)
214 {
215 return vmci_handle_is_equal(h, VMCI_INVALID_HANDLE);
216 }
217
218 /*
219 * The below defines can be used to send anonymous requests.
220 * This also indicates that no response is expected.
221 */
222 #define VMCI_ANON_SRC_CONTEXT_ID VMCI_INVALID_ID
223 #define VMCI_ANON_SRC_RESOURCE_ID VMCI_INVALID_ID
224 static const struct vmci_handle __maybe_unused VMCI_ANON_SRC_HANDLE = {
225 .context = VMCI_ANON_SRC_CONTEXT_ID,
226 .resource = VMCI_ANON_SRC_RESOURCE_ID
227 };
228
229 /* The lowest 16 context ids are reserved for internal use. */
230 #define VMCI_RESERVED_CID_LIMIT ((u32) 16)
231
232 /*
233 * Hypervisor context id, used for calling into hypervisor
234 * supplied services from the VM.
235 */
236 #define VMCI_HYPERVISOR_CONTEXT_ID 0
237
238 /*
239 * Well-known context id, a logical context that contains a set of
240 * well-known services. This context ID is now obsolete.
241 */
242 #define VMCI_WELL_KNOWN_CONTEXT_ID 1
243
244 /*
245 * Context ID used by host endpoints.
246 */
247 #define VMCI_HOST_CONTEXT_ID 2
248
249 #define VMCI_CONTEXT_IS_VM(_cid) (VMCI_INVALID_ID != (_cid) && \
250 (_cid) > VMCI_HOST_CONTEXT_ID)
251
252 /*
253 * The VMCI_CONTEXT_RESOURCE_ID is used together with vmci_make_handle to make
254 * handles that refer to a specific context.
255 */
256 #define VMCI_CONTEXT_RESOURCE_ID 0
257
258 /*
259 * VMCI error codes.
260 */
261 enum {
262 VMCI_SUCCESS_QUEUEPAIR_ATTACH = 5,
263 VMCI_SUCCESS_QUEUEPAIR_CREATE = 4,
264 VMCI_SUCCESS_LAST_DETACH = 3,
265 VMCI_SUCCESS_ACCESS_GRANTED = 2,
266 VMCI_SUCCESS_ENTRY_DEAD = 1,
267 VMCI_SUCCESS = 0,
268 VMCI_ERROR_INVALID_RESOURCE = (-1),
269 VMCI_ERROR_INVALID_ARGS = (-2),
270 VMCI_ERROR_NO_MEM = (-3),
271 VMCI_ERROR_DATAGRAM_FAILED = (-4),
272 VMCI_ERROR_MORE_DATA = (-5),
273 VMCI_ERROR_NO_MORE_DATAGRAMS = (-6),
274 VMCI_ERROR_NO_ACCESS = (-7),
275 VMCI_ERROR_NO_HANDLE = (-8),
276 VMCI_ERROR_DUPLICATE_ENTRY = (-9),
277 VMCI_ERROR_DST_UNREACHABLE = (-10),
278 VMCI_ERROR_PAYLOAD_TOO_LARGE = (-11),
279 VMCI_ERROR_INVALID_PRIV = (-12),
280 VMCI_ERROR_GENERIC = (-13),
281 VMCI_ERROR_PAGE_ALREADY_SHARED = (-14),
282 VMCI_ERROR_CANNOT_SHARE_PAGE = (-15),
283 VMCI_ERROR_CANNOT_UNSHARE_PAGE = (-16),
284 VMCI_ERROR_NO_PROCESS = (-17),
285 VMCI_ERROR_NO_DATAGRAM = (-18),
286 VMCI_ERROR_NO_RESOURCES = (-19),
287 VMCI_ERROR_UNAVAILABLE = (-20),
288 VMCI_ERROR_NOT_FOUND = (-21),
289 VMCI_ERROR_ALREADY_EXISTS = (-22),
290 VMCI_ERROR_NOT_PAGE_ALIGNED = (-23),
291 VMCI_ERROR_INVALID_SIZE = (-24),
292 VMCI_ERROR_REGION_ALREADY_SHARED = (-25),
293 VMCI_ERROR_TIMEOUT = (-26),
294 VMCI_ERROR_DATAGRAM_INCOMPLETE = (-27),
295 VMCI_ERROR_INCORRECT_IRQL = (-28),
296 VMCI_ERROR_EVENT_UNKNOWN = (-29),
297 VMCI_ERROR_OBSOLETE = (-30),
298 VMCI_ERROR_QUEUEPAIR_MISMATCH = (-31),
299 VMCI_ERROR_QUEUEPAIR_NOTSET = (-32),
300 VMCI_ERROR_QUEUEPAIR_NOTOWNER = (-33),
301 VMCI_ERROR_QUEUEPAIR_NOTATTACHED = (-34),
302 VMCI_ERROR_QUEUEPAIR_NOSPACE = (-35),
303 VMCI_ERROR_QUEUEPAIR_NODATA = (-36),
304 VMCI_ERROR_BUSMEM_INVALIDATION = (-37),
305 VMCI_ERROR_MODULE_NOT_LOADED = (-38),
306 VMCI_ERROR_DEVICE_NOT_FOUND = (-39),
307 VMCI_ERROR_QUEUEPAIR_NOT_READY = (-40),
308 VMCI_ERROR_WOULD_BLOCK = (-41),
309
310 /* VMCI clients should return error code within this range */
311 VMCI_ERROR_CLIENT_MIN = (-500),
312 VMCI_ERROR_CLIENT_MAX = (-550),
313
314 /* Internal error codes. */
315 VMCI_SHAREDMEM_ERROR_BAD_CONTEXT = (-1000),
316 };
317
318 /* VMCI reserved events. */
319 enum {
320 /* Only applicable to guest endpoints */
321 VMCI_EVENT_CTX_ID_UPDATE = 0,
322
323 /* Applicable to guest and host */
324 VMCI_EVENT_CTX_REMOVED = 1,
325
326 /* Only applicable to guest endpoints */
327 VMCI_EVENT_QP_RESUMED = 2,
328
329 /* Applicable to guest and host */
330 VMCI_EVENT_QP_PEER_ATTACH = 3,
331
332 /* Applicable to guest and host */
333 VMCI_EVENT_QP_PEER_DETACH = 4,
334
335 /*
336 * Applicable to VMX and vmk. On vmk,
337 * this event has the Context payload type.
338 */
339 VMCI_EVENT_MEM_ACCESS_ON = 5,
340
341 /*
342 * Applicable to VMX and vmk. Same as
343 * above for the payload type.
344 */
345 VMCI_EVENT_MEM_ACCESS_OFF = 6,
346 VMCI_EVENT_MAX = 7,
347 };
348
349 /*
350 * Of the above events, a few are reserved for use in the VMX, and
351 * other endpoints (guest and host kernel) should not use them. For
352 * the rest of the events, we allow both host and guest endpoints to
353 * subscribe to them, to maintain the same API for host and guest
354 * endpoints.
355 */
356 #define VMCI_EVENT_VALID_VMX(_event) ((_event) == VMCI_EVENT_MEM_ACCESS_ON || \
357 (_event) == VMCI_EVENT_MEM_ACCESS_OFF)
358
359 #define VMCI_EVENT_VALID(_event) ((_event) < VMCI_EVENT_MAX && \
360 !VMCI_EVENT_VALID_VMX(_event))
361
362 /* Reserved guest datagram resource ids. */
363 #define VMCI_EVENT_HANDLER 0
364
365 /*
366 * VMCI coarse-grained privileges (per context or host
367 * process/endpoint. An entity with the restricted flag is only
368 * allowed to interact with the hypervisor and trusted entities.
369 */
370 enum {
371 VMCI_NO_PRIVILEGE_FLAGS = 0,
372 VMCI_PRIVILEGE_FLAG_RESTRICTED = 1,
373 VMCI_PRIVILEGE_FLAG_TRUSTED = 2,
374 VMCI_PRIVILEGE_ALL_FLAGS = (VMCI_PRIVILEGE_FLAG_RESTRICTED |
375 VMCI_PRIVILEGE_FLAG_TRUSTED),
376 VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS = VMCI_NO_PRIVILEGE_FLAGS,
377 VMCI_LEAST_PRIVILEGE_FLAGS = VMCI_PRIVILEGE_FLAG_RESTRICTED,
378 VMCI_MAX_PRIVILEGE_FLAGS = VMCI_PRIVILEGE_FLAG_TRUSTED,
379 };
380
381 /* 0 through VMCI_RESERVED_RESOURCE_ID_MAX are reserved. */
382 #define VMCI_RESERVED_RESOURCE_ID_MAX 1023
383
384 /*
385 * Driver version.
386 *
387 * Increment major version when you make an incompatible change.
388 * Compatibility goes both ways (old driver with new executable
389 * as well as new driver with old executable).
390 */
391
392 /* Never change VMCI_VERSION_SHIFT_WIDTH */
393 #define VMCI_VERSION_SHIFT_WIDTH 16
394 #define VMCI_MAKE_VERSION(_major, _minor) \
395 ((_major) << VMCI_VERSION_SHIFT_WIDTH | (u16) (_minor))
396
397 #define VMCI_VERSION_MAJOR(v) ((u32) (v) >> VMCI_VERSION_SHIFT_WIDTH)
398 #define VMCI_VERSION_MINOR(v) ((u16) (v))
399
400 /*
401 * VMCI_VERSION is always the current version. Subsequently listed
402 * versions are ways of detecting previous versions of the connecting
403 * application (i.e., VMX).
404 *
405 * VMCI_VERSION_NOVMVM: This version removed support for VM to VM
406 * communication.
407 *
408 * VMCI_VERSION_NOTIFY: This version introduced doorbell notification
409 * support.
410 *
411 * VMCI_VERSION_HOSTQP: This version introduced host end point support
412 * for hosted products.
413 *
414 * VMCI_VERSION_PREHOSTQP: This is the version prior to the adoption of
415 * support for host end-points.
416 *
417 * VMCI_VERSION_PREVERS2: This fictional version number is intended to
418 * represent the version of a VMX which doesn't call into the driver
419 * with ioctl VERSION2 and thus doesn't establish its version with the
420 * driver.
421 */
422
423 #define VMCI_VERSION VMCI_VERSION_NOVMVM
424 #define VMCI_VERSION_NOVMVM VMCI_MAKE_VERSION(11, 0)
425 #define VMCI_VERSION_NOTIFY VMCI_MAKE_VERSION(10, 0)
426 #define VMCI_VERSION_HOSTQP VMCI_MAKE_VERSION(9, 0)
427 #define VMCI_VERSION_PREHOSTQP VMCI_MAKE_VERSION(8, 0)
428 #define VMCI_VERSION_PREVERS2 VMCI_MAKE_VERSION(1, 0)
429
430 #define VMCI_SOCKETS_MAKE_VERSION(_p) \
431 ((((_p)[0] & 0xFF) << 24) | (((_p)[1] & 0xFF) << 16) | ((_p)[2]))
432
433 /*
434 * The VMCI IOCTLs. We use identity code 7, as noted in ioctl-number.h, and
435 * we start at sequence 9f. This gives us the same values that our shipping
436 * products use, starting at 1951, provided we leave out the direction and
437 * structure size. Note that VMMon occupies the block following us, starting
438 * at 2001.
439 */
440 #define IOCTL_VMCI_VERSION _IO(7, 0x9f) /* 1951 */
441 #define IOCTL_VMCI_INIT_CONTEXT _IO(7, 0xa0)
442 #define IOCTL_VMCI_QUEUEPAIR_SETVA _IO(7, 0xa4)
443 #define IOCTL_VMCI_NOTIFY_RESOURCE _IO(7, 0xa5)
444 #define IOCTL_VMCI_NOTIFICATIONS_RECEIVE _IO(7, 0xa6)
445 #define IOCTL_VMCI_VERSION2 _IO(7, 0xa7)
446 #define IOCTL_VMCI_QUEUEPAIR_ALLOC _IO(7, 0xa8)
447 #define IOCTL_VMCI_QUEUEPAIR_SETPAGEFILE _IO(7, 0xa9)
448 #define IOCTL_VMCI_QUEUEPAIR_DETACH _IO(7, 0xaa)
449 #define IOCTL_VMCI_DATAGRAM_SEND _IO(7, 0xab)
450 #define IOCTL_VMCI_DATAGRAM_RECEIVE _IO(7, 0xac)
451 #define IOCTL_VMCI_CTX_ADD_NOTIFICATION _IO(7, 0xaf)
452 #define IOCTL_VMCI_CTX_REMOVE_NOTIFICATION _IO(7, 0xb0)
453 #define IOCTL_VMCI_CTX_GET_CPT_STATE _IO(7, 0xb1)
454 #define IOCTL_VMCI_CTX_SET_CPT_STATE _IO(7, 0xb2)
455 #define IOCTL_VMCI_GET_CONTEXT_ID _IO(7, 0xb3)
456 #define IOCTL_VMCI_SOCKETS_VERSION _IO(7, 0xb4)
457 #define IOCTL_VMCI_SOCKETS_GET_AF_VALUE _IO(7, 0xb8)
458 #define IOCTL_VMCI_SOCKETS_GET_LOCAL_CID _IO(7, 0xb9)
459 #define IOCTL_VMCI_SET_NOTIFY _IO(7, 0xcb) /* 1995 */
460 /*IOCTL_VMMON_START _IO(7, 0xd1)*/ /* 2001 */
461
462 /*
463 * struct vmci_queue_header - VMCI Queue Header information.
464 *
465 * A Queue cannot stand by itself as designed. Each Queue's header
466 * contains a pointer into itself (the producer_tail) and into its peer
467 * (consumer_head). The reason for the separation is one of
468 * accessibility: Each end-point can modify two things: where the next
469 * location to enqueue is within its produce_q (producer_tail); and
470 * where the next dequeue location is in its consume_q (consumer_head).
471 *
472 * An end-point cannot modify the pointers of its peer (guest to
473 * guest; NOTE that in the host both queue headers are mapped r/w).
474 * But, each end-point needs read access to both Queue header
475 * structures in order to determine how much space is used (or left)
476 * in the Queue. This is because for an end-point to know how full
477 * its produce_q is, it needs to use the consumer_head that points into
478 * the produce_q but -that- consumer_head is in the Queue header for
479 * that end-points consume_q.
480 *
481 * Thoroughly confused? Sorry.
482 *
483 * producer_tail: the point to enqueue new entrants. When you approach
484 * a line in a store, for example, you walk up to the tail.
485 *
486 * consumer_head: the point in the queue from which the next element is
487 * dequeued. In other words, who is next in line is he who is at the
488 * head of the line.
489 *
490 * Also, producer_tail points to an empty byte in the Queue, whereas
491 * consumer_head points to a valid byte of data (unless producer_tail ==
492 * consumer_head in which case consumer_head does not point to a valid
493 * byte of data).
494 *
495 * For a queue of buffer 'size' bytes, the tail and head pointers will be in
496 * the range [0, size-1].
497 *
498 * If produce_q_header->producer_tail == consume_q_header->consumer_head
499 * then the produce_q is empty.
500 */
501 struct vmci_queue_header {
502 /* All fields are 64bit and aligned. */
503 struct vmci_handle handle; /* Identifier. */
504 u64 producer_tail; /* Offset in this queue. */
505 u64 consumer_head; /* Offset in peer queue. */
506 };
507
508 /*
509 * struct vmci_datagram - Base struct for vmci datagrams.
510 * @dst: A vmci_handle that tracks the destination of the datagram.
511 * @src: A vmci_handle that tracks the source of the datagram.
512 * @payload_size: The size of the payload.
513 *
514 * vmci_datagram structs are used when sending vmci datagrams. They include
515 * the necessary source and destination information to properly route
516 * the information along with the size of the package.
517 */
518 struct vmci_datagram {
519 struct vmci_handle dst;
520 struct vmci_handle src;
521 u64 payload_size;
522 };
523
524 /*
525 * Second flag is for creating a well-known handle instead of a per context
526 * handle. Next flag is for deferring datagram delivery, so that the
527 * datagram callback is invoked in a delayed context (not interrupt context).
528 */
529 #define VMCI_FLAG_DG_NONE 0
530 #define VMCI_FLAG_WELLKNOWN_DG_HND BIT(0)
531 #define VMCI_FLAG_ANYCID_DG_HND BIT(1)
532 #define VMCI_FLAG_DG_DELAYED_CB BIT(2)
533
534 /*
535 * Maximum supported size of a VMCI datagram for routable datagrams.
536 * Datagrams going to the hypervisor are allowed to be larger.
537 */
538 #define VMCI_MAX_DG_SIZE (17 * 4096)
539 #define VMCI_MAX_DG_PAYLOAD_SIZE (VMCI_MAX_DG_SIZE - \
540 sizeof(struct vmci_datagram))
541 #define VMCI_DG_PAYLOAD(_dg) (void *)((char *)(_dg) + \
542 sizeof(struct vmci_datagram))
543 #define VMCI_DG_HEADERSIZE sizeof(struct vmci_datagram)
544 #define VMCI_DG_SIZE(_dg) (VMCI_DG_HEADERSIZE + (size_t)(_dg)->payload_size)
545 #define VMCI_DG_SIZE_ALIGNED(_dg) ((VMCI_DG_SIZE(_dg) + 7) & (~((size_t) 0x7)))
546 #define VMCI_MAX_DATAGRAM_QUEUE_SIZE (VMCI_MAX_DG_SIZE * 2)
547
548 struct vmci_event_payload_qp {
549 struct vmci_handle handle; /* queue_pair handle. */
550 u32 peer_id; /* Context id of attaching/detaching VM. */
551 u32 _pad;
552 };
553
554 /* Flags for VMCI queue_pair API. */
555 enum {
556 /* Fail alloc if QP not created by peer. */
557 VMCI_QPFLAG_ATTACH_ONLY = 1 << 0,
558
559 /* Only allow attaches from local context. */
560 VMCI_QPFLAG_LOCAL = 1 << 1,
561
562 /* Host won't block when guest is quiesced. */
563 VMCI_QPFLAG_NONBLOCK = 1 << 2,
564
565 /* Pin data pages in ESX. Used with NONBLOCK */
566 VMCI_QPFLAG_PINNED = 1 << 3,
567
568 /* Update the following flag when adding new flags. */
569 VMCI_QP_ALL_FLAGS = (VMCI_QPFLAG_ATTACH_ONLY | VMCI_QPFLAG_LOCAL |
570 VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED),
571
572 /* Convenience flags */
573 VMCI_QP_ASYMM = (VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED),
574 VMCI_QP_ASYMM_PEER = (VMCI_QPFLAG_ATTACH_ONLY | VMCI_QP_ASYMM),
575 };
576
577 /*
578 * We allow at least 1024 more event datagrams from the hypervisor past the
579 * normally allowed datagrams pending for a given context. We define this
580 * limit on event datagrams from the hypervisor to guard against DoS attack
581 * from a malicious VM which could repeatedly attach to and detach from a queue
582 * pair, causing events to be queued at the destination VM. However, the rate
583 * at which such events can be generated is small since it requires a VM exit
584 * and handling of queue pair attach/detach call at the hypervisor. Event
585 * datagrams may be queued up at the destination VM if it has interrupts
586 * disabled or if it is not draining events for some other reason. 1024
587 * datagrams is a grossly conservative estimate of the time for which
588 * interrupts may be disabled in the destination VM, but at the same time does
589 * not exacerbate the memory pressure problem on the host by much (size of each
590 * event datagram is small).
591 */
592 #define VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE \
593 (VMCI_MAX_DATAGRAM_QUEUE_SIZE + \
594 1024 * (sizeof(struct vmci_datagram) + \
595 sizeof(struct vmci_event_data_max)))
596
597 /*
598 * Struct used for querying, via VMCI_RESOURCES_QUERY, the availability of
599 * hypervisor resources. Struct size is 16 bytes. All fields in struct are
600 * aligned to their natural alignment.
601 */
602 struct vmci_resource_query_hdr {
603 struct vmci_datagram hdr;
604 u32 num_resources;
605 u32 _padding;
606 };
607
608 /*
609 * Convenience struct for negotiating vectors. Must match layout of
610 * VMCIResourceQueryHdr minus the struct vmci_datagram header.
611 */
612 struct vmci_resource_query_msg {
613 u32 num_resources;
614 u32 _padding;
615 u32 resources[1];
616 };
617
618 /*
619 * The maximum number of resources that can be queried using
620 * VMCI_RESOURCE_QUERY is 31, as the result is encoded in the lower 31
621 * bits of a positive return value. Negative values are reserved for
622 * errors.
623 */
624 #define VMCI_RESOURCE_QUERY_MAX_NUM 31
625
626 /* Maximum size for the VMCI_RESOURCE_QUERY request. */
627 #define VMCI_RESOURCE_QUERY_MAX_SIZE \
628 (sizeof(struct vmci_resource_query_hdr) + \
629 sizeof(u32) * VMCI_RESOURCE_QUERY_MAX_NUM)
630
631 /*
632 * Struct used for setting the notification bitmap. All fields in
633 * struct are aligned to their natural alignment.
634 */
635 struct vmci_notify_bm_set_msg {
636 struct vmci_datagram hdr;
637 union {
638 u32 bitmap_ppn32;
639 u64 bitmap_ppn64;
640 };
641 };
642
643 /*
644 * Struct used for linking a doorbell handle with an index in the
645 * notify bitmap. All fields in struct are aligned to their natural
646 * alignment.
647 */
648 struct vmci_doorbell_link_msg {
649 struct vmci_datagram hdr;
650 struct vmci_handle handle;
651 u64 notify_idx;
652 };
653
654 /*
655 * Struct used for unlinking a doorbell handle from an index in the
656 * notify bitmap. All fields in struct are aligned to their natural
657 * alignment.
658 */
659 struct vmci_doorbell_unlink_msg {
660 struct vmci_datagram hdr;
661 struct vmci_handle handle;
662 };
663
664 /*
665 * Struct used for generating a notification on a doorbell handle. All
666 * fields in struct are aligned to their natural alignment.
667 */
668 struct vmci_doorbell_notify_msg {
669 struct vmci_datagram hdr;
670 struct vmci_handle handle;
671 };
672
673 /*
674 * This struct is used to contain data for events. Size of this struct is a
675 * multiple of 8 bytes, and all fields are aligned to their natural alignment.
676 */
677 struct vmci_event_data {
678 u32 event; /* 4 bytes. */
679 u32 _pad;
680 /* Event payload is put here. */
681 };
682
683 /*
684 * Define the different VMCI_EVENT payload data types here. All structs must
685 * be a multiple of 8 bytes, and fields must be aligned to their natural
686 * alignment.
687 */
688 struct vmci_event_payld_ctx {
689 u32 context_id; /* 4 bytes. */
690 u32 _pad;
691 };
692
693 struct vmci_event_payld_qp {
694 struct vmci_handle handle; /* queue_pair handle. */
695 u32 peer_id; /* Context id of attaching/detaching VM. */
696 u32 _pad;
697 };
698
699 /*
700 * We define the following struct to get the size of the maximum event
701 * data the hypervisor may send to the guest. If adding a new event
702 * payload type above, add it to the following struct too (inside the
703 * union).
704 */
705 struct vmci_event_data_max {
706 struct vmci_event_data event_data;
707 union {
708 struct vmci_event_payld_ctx context_payload;
709 struct vmci_event_payld_qp qp_payload;
710 } ev_data_payload;
711 };
712
713 /*
714 * Struct used for VMCI_EVENT_SUBSCRIBE/UNSUBSCRIBE and
715 * VMCI_EVENT_HANDLER messages. Struct size is 32 bytes. All fields
716 * in struct are aligned to their natural alignment.
717 */
718 struct vmci_event_msg {
719 struct vmci_datagram hdr;
720
721 /* Has event type and payload. */
722 struct vmci_event_data event_data;
723
724 /* Payload gets put here. */
725 };
726
727 /* Event with context payload. */
728 struct vmci_event_ctx {
729 struct vmci_event_msg msg;
730 struct vmci_event_payld_ctx payload;
731 };
732
733 /* Event with QP payload. */
734 struct vmci_event_qp {
735 struct vmci_event_msg msg;
736 struct vmci_event_payld_qp payload;
737 };
738
739 /*
740 * Structs used for queue_pair alloc and detach messages. We align fields of
741 * these structs to 64bit boundaries.
742 */
743 struct vmci_qp_alloc_msg {
744 struct vmci_datagram hdr;
745 struct vmci_handle handle;
746 u32 peer;
747 u32 flags;
748 u64 produce_size;
749 u64 consume_size;
750 u64 num_ppns;
751
752 /* List of PPNs placed here. */
753 };
754
755 struct vmci_qp_detach_msg {
756 struct vmci_datagram hdr;
757 struct vmci_handle handle;
758 };
759
760 /* VMCI Doorbell API. */
761 #define VMCI_FLAG_DELAYED_CB BIT(0)
762
763 typedef void (*vmci_callback) (void *client_data);
764
765 /*
766 * struct vmci_qp - A vmw_vmci queue pair handle.
767 *
768 * This structure is used as a handle to a queue pair created by
769 * VMCI. It is intentionally left opaque to clients.
770 */
771 struct vmci_qp;
772
773 /* Callback needed for correctly waiting on events. */
774 typedef int (*vmci_datagram_recv_cb) (void *client_data,
775 struct vmci_datagram *msg);
776
777 /* VMCI Event API. */
778 typedef void (*vmci_event_cb) (u32 sub_id, const struct vmci_event_data *ed,
779 void *client_data);
780
781 /*
782 * We use the following inline function to access the payload data
783 * associated with an event data.
784 */
785 static inline const void *
vmci_event_data_const_payload(const struct vmci_event_data * ev_data)786 vmci_event_data_const_payload(const struct vmci_event_data *ev_data)
787 {
788 return (const char *)ev_data + sizeof(*ev_data);
789 }
790
vmci_event_data_payload(struct vmci_event_data * ev_data)791 static inline void *vmci_event_data_payload(struct vmci_event_data *ev_data)
792 {
793 return (void *)vmci_event_data_const_payload(ev_data);
794 }
795
796 /*
797 * Helper to read a value from a head or tail pointer. For X86_32, the
798 * pointer is treated as a 32bit value, since the pointer value
799 * never exceeds a 32bit value in this case. Also, doing an
800 * atomic64_read on X86_32 uniprocessor systems may be implemented
801 * as a non locked cmpxchg8b, that may end up overwriting updates done
802 * by the VMCI device to the memory location. On 32bit SMP, the lock
803 * prefix will be used, so correctness isn't an issue, but using a
804 * 64bit operation still adds unnecessary overhead.
805 */
vmci_q_read_pointer(u64 * var)806 static inline u64 vmci_q_read_pointer(u64 *var)
807 {
808 return READ_ONCE(*(unsigned long *)var);
809 }
810
811 /*
812 * Helper to set the value of a head or tail pointer. For X86_32, the
813 * pointer is treated as a 32bit value, since the pointer value
814 * never exceeds a 32bit value in this case. On 32bit SMP, using a
815 * locked cmpxchg8b adds unnecessary overhead.
816 */
vmci_q_set_pointer(u64 * var,u64 new_val)817 static inline void vmci_q_set_pointer(u64 *var, u64 new_val)
818 {
819 /* XXX buggered on big-endian */
820 WRITE_ONCE(*(unsigned long *)var, (unsigned long)new_val);
821 }
822
823 /*
824 * Helper to add a given offset to a head or tail pointer. Wraps the
825 * value of the pointer around the max size of the queue.
826 */
vmci_qp_add_pointer(u64 * var,size_t add,u64 size)827 static inline void vmci_qp_add_pointer(u64 *var, size_t add, u64 size)
828 {
829 u64 new_val = vmci_q_read_pointer(var);
830
831 if (new_val >= size - add)
832 new_val -= size;
833
834 new_val += add;
835
836 vmci_q_set_pointer(var, new_val);
837 }
838
839 /*
840 * Helper routine to get the Producer Tail from the supplied queue.
841 */
842 static inline u64
vmci_q_header_producer_tail(const struct vmci_queue_header * q_header)843 vmci_q_header_producer_tail(const struct vmci_queue_header *q_header)
844 {
845 struct vmci_queue_header *qh = (struct vmci_queue_header *)q_header;
846 return vmci_q_read_pointer(&qh->producer_tail);
847 }
848
849 /*
850 * Helper routine to get the Consumer Head from the supplied queue.
851 */
852 static inline u64
vmci_q_header_consumer_head(const struct vmci_queue_header * q_header)853 vmci_q_header_consumer_head(const struct vmci_queue_header *q_header)
854 {
855 struct vmci_queue_header *qh = (struct vmci_queue_header *)q_header;
856 return vmci_q_read_pointer(&qh->consumer_head);
857 }
858
859 /*
860 * Helper routine to increment the Producer Tail. Fundamentally,
861 * vmci_qp_add_pointer() is used to manipulate the tail itself.
862 */
863 static inline void
vmci_q_header_add_producer_tail(struct vmci_queue_header * q_header,size_t add,u64 queue_size)864 vmci_q_header_add_producer_tail(struct vmci_queue_header *q_header,
865 size_t add,
866 u64 queue_size)
867 {
868 vmci_qp_add_pointer(&q_header->producer_tail, add, queue_size);
869 }
870
871 /*
872 * Helper routine to increment the Consumer Head. Fundamentally,
873 * vmci_qp_add_pointer() is used to manipulate the head itself.
874 */
875 static inline void
vmci_q_header_add_consumer_head(struct vmci_queue_header * q_header,size_t add,u64 queue_size)876 vmci_q_header_add_consumer_head(struct vmci_queue_header *q_header,
877 size_t add,
878 u64 queue_size)
879 {
880 vmci_qp_add_pointer(&q_header->consumer_head, add, queue_size);
881 }
882
883 /*
884 * Helper routine for getting the head and the tail pointer for a queue.
885 * Both the VMCIQueues are needed to get both the pointers for one queue.
886 */
887 static inline void
vmci_q_header_get_pointers(const struct vmci_queue_header * produce_q_header,const struct vmci_queue_header * consume_q_header,u64 * producer_tail,u64 * consumer_head)888 vmci_q_header_get_pointers(const struct vmci_queue_header *produce_q_header,
889 const struct vmci_queue_header *consume_q_header,
890 u64 *producer_tail,
891 u64 *consumer_head)
892 {
893 if (producer_tail)
894 *producer_tail = vmci_q_header_producer_tail(produce_q_header);
895
896 if (consumer_head)
897 *consumer_head = vmci_q_header_consumer_head(consume_q_header);
898 }
899
vmci_q_header_init(struct vmci_queue_header * q_header,const struct vmci_handle handle)900 static inline void vmci_q_header_init(struct vmci_queue_header *q_header,
901 const struct vmci_handle handle)
902 {
903 q_header->handle = handle;
904 q_header->producer_tail = 0;
905 q_header->consumer_head = 0;
906 }
907
908 /*
909 * Finds available free space in a produce queue to enqueue more
910 * data or reports an error if queue pair corruption is detected.
911 */
912 static s64
vmci_q_header_free_space(const struct vmci_queue_header * produce_q_header,const struct vmci_queue_header * consume_q_header,const u64 produce_q_size)913 vmci_q_header_free_space(const struct vmci_queue_header *produce_q_header,
914 const struct vmci_queue_header *consume_q_header,
915 const u64 produce_q_size)
916 {
917 u64 tail;
918 u64 head;
919 u64 free_space;
920
921 tail = vmci_q_header_producer_tail(produce_q_header);
922 head = vmci_q_header_consumer_head(consume_q_header);
923
924 if (tail >= produce_q_size || head >= produce_q_size)
925 return VMCI_ERROR_INVALID_SIZE;
926
927 /*
928 * Deduct 1 to avoid tail becoming equal to head which causes
929 * ambiguity. If head and tail are equal it means that the
930 * queue is empty.
931 */
932 if (tail >= head)
933 free_space = produce_q_size - (tail - head) - 1;
934 else
935 free_space = head - tail - 1;
936
937 return free_space;
938 }
939
940 /*
941 * vmci_q_header_free_space() does all the heavy lifting of
942 * determing the number of free bytes in a Queue. This routine,
943 * then subtracts that size from the full size of the Queue so
944 * the caller knows how many bytes are ready to be dequeued.
945 * Results:
946 * On success, available data size in bytes (up to MAX_INT64).
947 * On failure, appropriate error code.
948 */
949 static inline s64
vmci_q_header_buf_ready(const struct vmci_queue_header * consume_q_header,const struct vmci_queue_header * produce_q_header,const u64 consume_q_size)950 vmci_q_header_buf_ready(const struct vmci_queue_header *consume_q_header,
951 const struct vmci_queue_header *produce_q_header,
952 const u64 consume_q_size)
953 {
954 s64 free_space;
955
956 free_space = vmci_q_header_free_space(consume_q_header,
957 produce_q_header, consume_q_size);
958 if (free_space < VMCI_SUCCESS)
959 return free_space;
960
961 return consume_q_size - free_space - 1;
962 }
963
964
965 #endif /* _VMW_VMCI_DEF_H_ */
966