1 /******************************************************************************
2 * netif.h
3 *
4 * Unified network-device I/O interface for Xen guest OSes.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 *
24 * Copyright (c) 2003-2004, Keir Fraser
25 */
26
27 #ifndef __XEN_PUBLIC_IO_NETIF_H__
28 #define __XEN_PUBLIC_IO_NETIF_H__
29
30 #include "ring.h"
31 #include "../grant_table.h"
32
33 /*
34 * Older implementation of Xen network frontend / backend has an
35 * implicit dependency on the MAX_SKB_FRAGS as the maximum number of
36 * ring slots a skb can use. Netfront / netback may not work as
37 * expected when frontend and backend have different MAX_SKB_FRAGS.
38 *
39 * A better approach is to add mechanism for netfront / netback to
40 * negotiate this value. However we cannot fix all possible
41 * frontends, so we need to define a value which states the minimum
42 * slots backend must support.
43 *
44 * The minimum value derives from older Linux kernel's MAX_SKB_FRAGS
45 * (18), which is proved to work with most frontends. Any new backend
46 * which doesn't negotiate with frontend should expect frontend to
47 * send a valid packet using slots up to this value.
48 */
49 #define XEN_NETIF_NR_SLOTS_MIN 18
50
51 /*
52 * Notifications after enqueuing any type of message should be conditional on
53 * the appropriate req_event or rsp_event field in the shared ring.
54 * If the client sends notification for rx requests then it should specify
55 * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume
56 * that it cannot safely queue packets (as it may not be kicked to send them).
57 */
58
59 /*
60 * "feature-split-event-channels" is introduced to separate guest TX
61 * and RX notification. Backend either doesn't support this feature or
62 * advertises it via xenstore as 0 (disabled) or 1 (enabled).
63 *
64 * To make use of this feature, frontend should allocate two event
65 * channels for TX and RX, advertise them to backend as
66 * "event-channel-tx" and "event-channel-rx" respectively. If frontend
67 * doesn't want to use this feature, it just writes "event-channel"
68 * node as before.
69 */
70
71 /*
72 * Multiple transmit and receive queues:
73 * If supported, the backend will write the key "multi-queue-max-queues" to
74 * the directory for that vif, and set its value to the maximum supported
75 * number of queues.
76 * Frontends that are aware of this feature and wish to use it can write the
77 * key "multi-queue-num-queues", set to the number they wish to use, which
78 * must be greater than zero, and no more than the value reported by the backend
79 * in "multi-queue-max-queues".
80 *
81 * Queues replicate the shared rings and event channels.
82 * "feature-split-event-channels" may optionally be used when using
83 * multiple queues, but is not mandatory.
84 *
85 * Each queue consists of one shared ring pair, i.e. there must be the same
86 * number of tx and rx rings.
87 *
88 * For frontends requesting just one queue, the usual event-channel and
89 * ring-ref keys are written as before, simplifying the backend processing
90 * to avoid distinguishing between a frontend that doesn't understand the
91 * multi-queue feature, and one that does, but requested only one queue.
92 *
93 * Frontends requesting two or more queues must not write the toplevel
94 * event-channel (or event-channel-{tx,rx}) and {tx,rx}-ring-ref keys,
95 * instead writing those keys under sub-keys having the name "queue-N" where
96 * N is the integer ID of the queue for which those keys belong. Queues
97 * are indexed from zero. For example, a frontend with two queues and split
98 * event channels must write the following set of queue-related keys:
99 *
100 * /local/domain/1/device/vif/0/multi-queue-num-queues = "2"
101 * /local/domain/1/device/vif/0/queue-0 = ""
102 * /local/domain/1/device/vif/0/queue-0/tx-ring-ref = "<ring-ref-tx0>"
103 * /local/domain/1/device/vif/0/queue-0/rx-ring-ref = "<ring-ref-rx0>"
104 * /local/domain/1/device/vif/0/queue-0/event-channel-tx = "<evtchn-tx0>"
105 * /local/domain/1/device/vif/0/queue-0/event-channel-rx = "<evtchn-rx0>"
106 * /local/domain/1/device/vif/0/queue-1 = ""
107 * /local/domain/1/device/vif/0/queue-1/tx-ring-ref = "<ring-ref-tx1>"
108 * /local/domain/1/device/vif/0/queue-1/rx-ring-ref = "<ring-ref-rx1"
109 * /local/domain/1/device/vif/0/queue-1/event-channel-tx = "<evtchn-tx1>"
110 * /local/domain/1/device/vif/0/queue-1/event-channel-rx = "<evtchn-rx1>"
111 *
112 * If there is any inconsistency in the XenStore data, the backend may
113 * choose not to connect any queues, instead treating the request as an
114 * error. This includes scenarios where more (or fewer) queues were
115 * requested than the frontend provided details for.
116 *
117 * Mapping of packets to queues is considered to be a function of the
118 * transmitting system (backend or frontend) and is not negotiated
119 * between the two. Guests are free to transmit packets on any queue
120 * they choose, provided it has been set up correctly. Guests must be
121 * prepared to receive packets on any queue they have requested be set up.
122 */
123
124 /*
125 * "feature-no-csum-offload" should be used to turn IPv4 TCP/UDP checksum
126 * offload off or on. If it is missing then the feature is assumed to be on.
127 * "feature-ipv6-csum-offload" should be used to turn IPv6 TCP/UDP checksum
128 * offload on or off. If it is missing then the feature is assumed to be off.
129 */
130
131 /*
132 * "feature-gso-tcpv4" and "feature-gso-tcpv6" advertise the capability to
133 * handle large TCP packets (in IPv4 or IPv6 form respectively). Neither
134 * frontends nor backends are assumed to be capable unless the flags are
135 * present.
136 */
137
138 /*
139 * "feature-multicast-control" and "feature-dynamic-multicast-control"
140 * advertise the capability to filter ethernet multicast packets in the
141 * backend. If the frontend wishes to take advantage of this feature then
142 * it may set "request-multicast-control". If the backend only advertises
143 * "feature-multicast-control" then "request-multicast-control" must be set
144 * before the frontend moves into the connected state. The backend will
145 * sample the value on this state transition and any subsequent change in
146 * value will have no effect. However, if the backend also advertises
147 * "feature-dynamic-multicast-control" then "request-multicast-control"
148 * may be set by the frontend at any time. In this case, the backend will
149 * watch the value and re-sample on watch events.
150 *
151 * If the sampled value of "request-multicast-control" is set then the
152 * backend transmit side should no longer flood multicast packets to the
153 * frontend, it should instead drop any multicast packet that does not
154 * match in a filter list.
155 * The list is amended by the frontend by sending dummy transmit requests
156 * containing XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} extra-info fragments as
157 * specified below.
158 * Note that the filter list may be amended even if the sampled value of
159 * "request-multicast-control" is not set, however the filter should only
160 * be applied if it is set.
161 */
162
163 /*
164 * Control ring
165 * ============
166 *
167 * Some features, such as hashing (detailed below), require a
168 * significant amount of out-of-band data to be passed from frontend to
169 * backend. Use of xenstore is not suitable for large quantities of data
170 * because of quota limitations and so a dedicated 'control ring' is used.
171 * The ability of the backend to use a control ring is advertised by
172 * setting:
173 *
174 * /local/domain/X/backend/<domid>/<vif>/feature-ctrl-ring = "1"
175 *
176 * The frontend provides a control ring to the backend by setting:
177 *
178 * /local/domain/<domid>/device/vif/<vif>/ctrl-ring-ref = <gref>
179 * /local/domain/<domid>/device/vif/<vif>/event-channel-ctrl = <port>
180 *
181 * where <gref> is the grant reference of the shared page used to
182 * implement the control ring and <port> is an event channel to be used
183 * as a mailbox interrupt. These keys must be set before the frontend
184 * moves into the connected state.
185 *
186 * The control ring uses a fixed request/response message size and is
187 * balanced (i.e. one request to one response), so operationally it is much
188 * the same as a transmit or receive ring.
189 * Note that there is no requirement that responses are issued in the same
190 * order as requests.
191 */
192
193 /*
194 * Hash types
195 * ==========
196 *
197 * For the purposes of the definitions below, 'Packet[]' is an array of
198 * octets containing an IP packet without options, 'Array[X..Y]' means a
199 * sub-array of 'Array' containing bytes X thru Y inclusive, and '+' is
200 * used to indicate concatenation of arrays.
201 */
202
203 /*
204 * A hash calculated over an IP version 4 header as follows:
205 *
206 * Buffer[0..8] = Packet[12..15] (source address) +
207 * Packet[16..19] (destination address)
208 *
209 * Result = Hash(Buffer, 8)
210 */
211 #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4 0
212 #define XEN_NETIF_CTRL_HASH_TYPE_IPV4 \
213 (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4)
214
215 /*
216 * A hash calculated over an IP version 4 header and TCP header as
217 * follows:
218 *
219 * Buffer[0..12] = Packet[12..15] (source address) +
220 * Packet[16..19] (destination address) +
221 * Packet[20..21] (source port) +
222 * Packet[22..23] (destination port)
223 *
224 * Result = Hash(Buffer, 12)
225 */
226 #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP 1
227 #define XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP \
228 (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP)
229
230 /*
231 * A hash calculated over an IP version 6 header as follows:
232 *
233 * Buffer[0..32] = Packet[8..23] (source address ) +
234 * Packet[24..39] (destination address)
235 *
236 * Result = Hash(Buffer, 32)
237 */
238 #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6 2
239 #define XEN_NETIF_CTRL_HASH_TYPE_IPV6 \
240 (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6)
241
242 /*
243 * A hash calculated over an IP version 6 header and TCP header as
244 * follows:
245 *
246 * Buffer[0..36] = Packet[8..23] (source address) +
247 * Packet[24..39] (destination address) +
248 * Packet[40..41] (source port) +
249 * Packet[42..43] (destination port)
250 *
251 * Result = Hash(Buffer, 36)
252 */
253 #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP 3
254 #define XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP \
255 (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP)
256
257 /*
258 * Hash algorithms
259 * ===============
260 */
261
262 #define XEN_NETIF_CTRL_HASH_ALGORITHM_NONE 0
263
264 /*
265 * Toeplitz hash:
266 */
267
268 #define XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ 1
269
270 /*
271 * This algorithm uses a 'key' as well as the data buffer itself.
272 * (Buffer[] and Key[] are treated as shift-registers where the MSB of
273 * Buffer/Key[0] is considered 'left-most' and the LSB of Buffer/Key[N-1]
274 * is the 'right-most').
275 *
276 * Value = 0
277 * For number of bits in Buffer[]
278 * If (left-most bit of Buffer[] is 1)
279 * Value ^= left-most 32 bits of Key[]
280 * Key[] << 1
281 * Buffer[] << 1
282 *
283 * The code below is provided for convenience where an operating system
284 * does not already provide an implementation.
285 */
286 #ifdef XEN_NETIF_DEFINE_TOEPLITZ
xen_netif_toeplitz_hash(const uint8_t * key,unsigned int keylen,const uint8_t * buf,unsigned int buflen)287 static uint32_t xen_netif_toeplitz_hash(const uint8_t *key,
288 unsigned int keylen,
289 const uint8_t *buf,
290 unsigned int buflen)
291 {
292 unsigned int keyi, bufi;
293 uint64_t prefix = 0;
294 uint64_t hash = 0;
295
296 /* Pre-load prefix with the first 8 bytes of the key */
297 for (keyi = 0; keyi < 8; keyi++) {
298 prefix <<= 8;
299 prefix |= (keyi < keylen) ? key[keyi] : 0;
300 }
301
302 for (bufi = 0; bufi < buflen; bufi++) {
303 uint8_t byte = buf[bufi];
304 unsigned int bit;
305
306 for (bit = 0; bit < 8; bit++) {
307 if (byte & 0x80)
308 hash ^= prefix;
309 prefix <<= 1;
310 byte <<=1;
311 }
312
313 /*
314 * 'prefix' has now been left-shifted by 8, so
315 * OR in the next byte.
316 */
317 prefix |= (keyi < keylen) ? key[keyi] : 0;
318 keyi++;
319 }
320
321 /* The valid part of the hash is in the upper 32 bits. */
322 return hash >> 32;
323 }
324 #endif /* XEN_NETIF_DEFINE_TOEPLITZ */
325
326 /*
327 * Control requests (struct xen_netif_ctrl_request)
328 * ================================================
329 *
330 * All requests have the following format:
331 *
332 * 0 1 2 3 4 5 6 7 octet
333 * +-----+-----+-----+-----+-----+-----+-----+-----+
334 * | id | type | data[0] |
335 * +-----+-----+-----+-----+-----+-----+-----+-----+
336 * | data[1] | data[2] |
337 * +-----+-----+-----+-----+-----------------------+
338 *
339 * id: the request identifier, echoed in response.
340 * type: the type of request (see below)
341 * data[]: any data associated with the request (determined by type)
342 */
343
344 struct xen_netif_ctrl_request {
345 uint16_t id;
346 uint16_t type;
347
348 #define XEN_NETIF_CTRL_TYPE_INVALID 0
349 #define XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS 1
350 #define XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS 2
351 #define XEN_NETIF_CTRL_TYPE_SET_HASH_KEY 3
352 #define XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE 4
353 #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE 5
354 #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING 6
355 #define XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM 7
356 #define XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE 8
357 #define XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING 9
358 #define XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING 10
359
360 uint32_t data[3];
361 };
362
363 /*
364 * Control responses (struct xen_netif_ctrl_response)
365 * ==================================================
366 *
367 * All responses have the following format:
368 *
369 * 0 1 2 3 4 5 6 7 octet
370 * +-----+-----+-----+-----+-----+-----+-----+-----+
371 * | id | type | status |
372 * +-----+-----+-----+-----+-----+-----+-----+-----+
373 * | data |
374 * +-----+-----+-----+-----+
375 *
376 * id: the corresponding request identifier
377 * type: the type of the corresponding request
378 * status: the status of request processing
379 * data: any data associated with the response (determined by type and
380 * status)
381 */
382
383 struct xen_netif_ctrl_response {
384 uint16_t id;
385 uint16_t type;
386 uint32_t status;
387
388 #define XEN_NETIF_CTRL_STATUS_SUCCESS 0
389 #define XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED 1
390 #define XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER 2
391 #define XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW 3
392
393 uint32_t data;
394 };
395
396 /*
397 * Static Grants (struct xen_netif_gref)
398 * =====================================
399 *
400 * A frontend may provide a fixed set of grant references to be mapped on
401 * the backend. The message of type XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING
402 * prior its usage in the command ring allows for creation of these mappings.
403 * The backend will maintain a fixed amount of these mappings.
404 *
405 * XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE lets a frontend query how many
406 * of these mappings can be kept.
407 *
408 * Each entry in the XEN_NETIF_CTRL_TYPE_{ADD,DEL}_GREF_MAPPING input table has
409 * the following format:
410 *
411 * 0 1 2 3 4 5 6 7 octet
412 * +-----+-----+-----+-----+-----+-----+-----+-----+
413 * | grant ref | flags | status |
414 * +-----+-----+-----+-----+-----+-----+-----+-----+
415 *
416 * grant ref: grant reference (IN)
417 * flags: flags describing the control operation (IN)
418 * status: XEN_NETIF_CTRL_STATUS_* (OUT)
419 *
420 * 'status' is an output parameter which does not require to be set to zero
421 * prior to its usage in the corresponding control messages.
422 */
423
424 struct xen_netif_gref {
425 grant_ref_t ref;
426 uint16_t flags;
427
428 #define _XEN_NETIF_CTRLF_GREF_readonly 0
429 #define XEN_NETIF_CTRLF_GREF_readonly (1U<<_XEN_NETIF_CTRLF_GREF_readonly)
430
431 uint16_t status;
432 };
433
434 /*
435 * Control messages
436 * ================
437 *
438 * XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM
439 * --------------------------------------
440 *
441 * This is sent by the frontend to set the desired hash algorithm.
442 *
443 * Request:
444 *
445 * type = XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM
446 * data[0] = a XEN_NETIF_CTRL_HASH_ALGORITHM_* value
447 * data[1] = 0
448 * data[2] = 0
449 *
450 * Response:
451 *
452 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
453 * supported
454 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - The algorithm is not
455 * supported
456 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
457 *
458 * NOTE: Setting data[0] to XEN_NETIF_CTRL_HASH_ALGORITHM_NONE disables
459 * hashing and the backend is free to choose how it steers packets
460 * to queues (which is the default behaviour).
461 *
462 * XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS
463 * ----------------------------------
464 *
465 * This is sent by the frontend to query the types of hash supported by
466 * the backend.
467 *
468 * Request:
469 *
470 * type = XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS
471 * data[0] = 0
472 * data[1] = 0
473 * data[2] = 0
474 *
475 * Response:
476 *
477 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported
478 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
479 * data = supported hash types (if operation was successful)
480 *
481 * NOTE: A valid hash algorithm must be selected before this operation can
482 * succeed.
483 *
484 * XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS
485 * ----------------------------------
486 *
487 * This is sent by the frontend to set the types of hash that the backend
488 * should calculate. (See above for hash type definitions).
489 * Note that the 'maximal' type of hash should always be chosen. For
490 * example, if the frontend sets both IPV4 and IPV4_TCP hash types then
491 * the latter hash type should be calculated for any TCP packet and the
492 * former only calculated for non-TCP packets.
493 *
494 * Request:
495 *
496 * type = XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS
497 * data[0] = bitwise OR of XEN_NETIF_CTRL_HASH_TYPE_* values
498 * data[1] = 0
499 * data[2] = 0
500 *
501 * Response:
502 *
503 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
504 * supported
505 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - One or more flag
506 * value is invalid or
507 * unsupported
508 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
509 * data = 0
510 *
511 * NOTE: A valid hash algorithm must be selected before this operation can
512 * succeed.
513 * Also, setting data[0] to zero disables hashing and the backend
514 * is free to choose how it steers packets to queues.
515 *
516 * XEN_NETIF_CTRL_TYPE_SET_HASH_KEY
517 * --------------------------------
518 *
519 * This is sent by the frontend to set the key of the hash if the algorithm
520 * requires it. (See hash algorithms above).
521 *
522 * Request:
523 *
524 * type = XEN_NETIF_CTRL_TYPE_SET_HASH_KEY
525 * data[0] = grant reference of page containing the key (assumed to
526 * start at beginning of grant)
527 * data[1] = size of key in octets
528 * data[2] = 0
529 *
530 * Response:
531 *
532 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
533 * supported
534 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Key size is invalid
535 * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Key size is larger
536 * than the backend
537 * supports
538 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
539 * data = 0
540 *
541 * NOTE: Any key octets not specified are assumed to be zero (the key
542 * is assumed to be empty by default) and specifying a new key
543 * invalidates any previous key, hence specifying a key size of
544 * zero will clear the key (which ensures that the calculated hash
545 * will always be zero).
546 * The maximum size of key is algorithm and backend specific, but
547 * is also limited by the single grant reference.
548 * The grant reference may be read-only and must remain valid until
549 * the response has been processed.
550 *
551 * XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE
552 * -----------------------------------------
553 *
554 * This is sent by the frontend to query the maximum size of mapping
555 * table supported by the backend. The size is specified in terms of
556 * table entries.
557 *
558 * Request:
559 *
560 * type = XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE
561 * data[0] = 0
562 * data[1] = 0
563 * data[2] = 0
564 *
565 * Response:
566 *
567 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported
568 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
569 * data = maximum number of entries allowed in the mapping table
570 * (if operation was successful) or zero if a mapping table is
571 * not supported (i.e. hash mapping is done only by modular
572 * arithmetic).
573 *
574 * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE
575 * -------------------------------------
576 *
577 * This is sent by the frontend to set the actual size of the mapping
578 * table to be used by the backend. The size is specified in terms of
579 * table entries.
580 * Any previous table is invalidated by this message and any new table
581 * is assumed to be zero filled.
582 *
583 * Request:
584 *
585 * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE
586 * data[0] = number of entries in mapping table
587 * data[1] = 0
588 * data[2] = 0
589 *
590 * Response:
591 *
592 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
593 * supported
594 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size is invalid
595 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
596 * data = 0
597 *
598 * NOTE: Setting data[0] to 0 means that hash mapping should be done
599 * using modular arithmetic.
600 *
601 * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING
602 * ------------------------------------
603 *
604 * This is sent by the frontend to set the content of the table mapping
605 * hash value to queue number. The backend should calculate the hash from
606 * the packet header, use it as an index into the table (modulo the size
607 * of the table) and then steer the packet to the queue number found at
608 * that index.
609 *
610 * Request:
611 *
612 * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING
613 * data[0] = grant reference of page containing the mapping (sub-)table
614 * (assumed to start at beginning of grant)
615 * data[1] = size of (sub-)table in entries
616 * data[2] = offset, in entries, of sub-table within overall table
617 *
618 * Response:
619 *
620 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
621 * supported
622 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size or content
623 * is invalid
624 * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Table size is larger
625 * than the backend
626 * supports
627 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
628 * data = 0
629 *
630 * NOTE: The overall table has the following format:
631 *
632 * 0 1 2 3 4 5 6 7 octet
633 * +-----+-----+-----+-----+-----+-----+-----+-----+
634 * | mapping[0] | mapping[1] |
635 * +-----+-----+-----+-----+-----+-----+-----+-----+
636 * | . |
637 * | . |
638 * | . |
639 * +-----+-----+-----+-----+-----+-----+-----+-----+
640 * | mapping[N-2] | mapping[N-1] |
641 * +-----+-----+-----+-----+-----+-----+-----+-----+
642 *
643 * where N is specified by a XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE
644 * message and each mapping must specifies a queue between 0 and
645 * "multi-queue-num-queues" (see above).
646 * The backend may support a mapping table larger than can be
647 * mapped by a single grant reference. Thus sub-tables within a
648 * larger table can be individually set by sending multiple messages
649 * with differing offset values. Specifying a new sub-table does not
650 * invalidate any table data outside that range.
651 * The grant reference may be read-only and must remain valid until
652 * the response has been processed.
653 *
654 * XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE
655 * -----------------------------------------
656 *
657 * This is sent by the frontend to fetch the number of grefs that can be kept
658 * mapped in the backend.
659 *
660 * Request:
661 *
662 * type = XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE
663 * data[0] = queue index (assumed 0 for single queue)
664 * data[1] = 0
665 * data[2] = 0
666 *
667 * Response:
668 *
669 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
670 * supported
671 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - The queue index is
672 * out of range
673 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
674 * data = maximum number of entries allowed in the gref mapping table
675 * (if operation was successful) or zero if it is not supported.
676 *
677 * XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING
678 * ------------------------------------
679 *
680 * This is sent by the frontend for backend to map a list of grant
681 * references.
682 *
683 * Request:
684 *
685 * type = XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING
686 * data[0] = queue index
687 * data[1] = grant reference of page containing the mapping list
688 * (r/w and assumed to start at beginning of page)
689 * data[2] = size of list in entries
690 *
691 * Response:
692 *
693 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
694 * supported
695 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Operation failed
696 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
697 *
698 * NOTE: Each entry in the input table has the format outlined
699 * in struct xen_netif_gref.
700 * Contrary to XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING, the struct
701 * xen_netif_gref 'status' field is not used and therefore the response
702 * 'status' determines the success of this operation. In case of
703 * failure none of grants mappings get added in the backend.
704 *
705 * XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING
706 * ------------------------------------
707 *
708 * This is sent by the frontend for backend to unmap a list of grant
709 * references.
710 *
711 * Request:
712 *
713 * type = XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING
714 * data[0] = queue index
715 * data[1] = grant reference of page containing the mapping list
716 * (r/w and assumed to start at beginning of page)
717 * data[2] = size of list in entries
718 *
719 * Response:
720 *
721 * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
722 * supported
723 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Operation failed
724 * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
725 * data = number of entries that were unmapped
726 *
727 * NOTE: Each entry in the input table has the format outlined in struct
728 * xen_netif_gref.
729 * The struct xen_netif_gref 'status' field determines if the entry
730 * was successfully removed.
731 * The entries used are only the ones representing grant references that
732 * were previously the subject of a XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING
733 * operation. Any other entries will have their status set to
734 * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER upon completion.
735 */
736
737 DEFINE_RING_TYPES(xen_netif_ctrl,
738 struct xen_netif_ctrl_request,
739 struct xen_netif_ctrl_response);
740
741 /*
742 * Guest transmit
743 * ==============
744 *
745 * This is the 'wire' format for transmit (frontend -> backend) packets:
746 *
747 * Fragment 1: netif_tx_request_t - flags = NETTXF_*
748 * size = total packet size
749 * [Extra 1: netif_extra_info_t] - (only if fragment 1 flags include
750 * NETTXF_extra_info)
751 * ...
752 * [Extra N: netif_extra_info_t] - (only if extra N-1 flags include
753 * XEN_NETIF_EXTRA_MORE)
754 * ...
755 * Fragment N: netif_tx_request_t - (only if fragment N-1 flags include
756 * NETTXF_more_data - flags on preceding
757 * extras are not relevant here)
758 * flags = 0
759 * size = fragment size
760 *
761 * NOTE:
762 *
763 * This format slightly is different from that used for receive
764 * (backend -> frontend) packets. Specifically, in a multi-fragment
765 * packet the actual size of fragment 1 can only be determined by
766 * subtracting the sizes of fragments 2..N from the total packet size.
767 *
768 * Ring slot size is 12 octets, however not all request/response
769 * structs use the full size.
770 *
771 * tx request data (netif_tx_request_t)
772 * ------------------------------------
773 *
774 * 0 1 2 3 4 5 6 7 octet
775 * +-----+-----+-----+-----+-----+-----+-----+-----+
776 * | grant ref | offset | flags |
777 * +-----+-----+-----+-----+-----+-----+-----+-----+
778 * | id | size |
779 * +-----+-----+-----+-----+
780 *
781 * grant ref: Reference to buffer page.
782 * offset: Offset within buffer page.
783 * flags: NETTXF_*.
784 * id: request identifier, echoed in response.
785 * size: packet size in bytes.
786 *
787 * tx response (netif_tx_response_t)
788 * ---------------------------------
789 *
790 * 0 1 2 3 4 5 6 7 octet
791 * +-----+-----+-----+-----+-----+-----+-----+-----+
792 * | id | status | unused |
793 * +-----+-----+-----+-----+-----+-----+-----+-----+
794 * | unused |
795 * +-----+-----+-----+-----+
796 *
797 * id: reflects id in transmit request
798 * status: NETIF_RSP_*
799 *
800 * Guest receive
801 * =============
802 *
803 * This is the 'wire' format for receive (backend -> frontend) packets:
804 *
805 * Fragment 1: netif_rx_request_t - flags = NETRXF_*
806 * size = fragment size
807 * [Extra 1: netif_extra_info_t] - (only if fragment 1 flags include
808 * NETRXF_extra_info)
809 * ...
810 * [Extra N: netif_extra_info_t] - (only if extra N-1 flags include
811 * XEN_NETIF_EXTRA_MORE)
812 * ...
813 * Fragment N: netif_rx_request_t - (only if fragment N-1 flags include
814 * NETRXF_more_data - flags on preceding
815 * extras are not relevant here)
816 * flags = 0
817 * size = fragment size
818 *
819 * NOTE:
820 *
821 * This format slightly is different from that used for transmit
822 * (frontend -> backend) packets. Specifically, in a multi-fragment
823 * packet the size of the packet can only be determined by summing the
824 * sizes of fragments 1..N.
825 *
826 * Ring slot size is 8 octets.
827 *
828 * rx request (netif_rx_request_t)
829 * -------------------------------
830 *
831 * 0 1 2 3 4 5 6 7 octet
832 * +-----+-----+-----+-----+-----+-----+-----+-----+
833 * | id | pad | gref |
834 * +-----+-----+-----+-----+-----+-----+-----+-----+
835 *
836 * id: request identifier, echoed in response.
837 * gref: reference to incoming granted frame.
838 *
839 * rx response (netif_rx_response_t)
840 * ---------------------------------
841 *
842 * 0 1 2 3 4 5 6 7 octet
843 * +-----+-----+-----+-----+-----+-----+-----+-----+
844 * | id | offset | flags | status |
845 * +-----+-----+-----+-----+-----+-----+-----+-----+
846 *
847 * id: reflects id in receive request
848 * offset: offset in page of start of received packet
849 * flags: NETRXF_*
850 * status: -ve: NETIF_RSP_*; +ve: Rx'ed pkt size.
851 *
852 * NOTE: Historically, to support GSO on the frontend receive side, Linux
853 * netfront does not make use of the rx response id (because, as
854 * described below, extra info structures overlay the id field).
855 * Instead it assumes that responses always appear in the same ring
856 * slot as their corresponding request. Thus, to maintain
857 * compatibility, backends must make sure this is the case.
858 *
859 * Extra Info
860 * ==========
861 *
862 * Can be present if initial request or response has NET{T,R}XF_extra_info,
863 * or previous extra request has XEN_NETIF_EXTRA_MORE.
864 *
865 * The struct therefore needs to fit into either a tx or rx slot and
866 * is therefore limited to 8 octets.
867 *
868 * NOTE: Because extra info data overlays the usual request/response
869 * structures, there is no id information in the opposite direction.
870 * So, if an extra info overlays an rx response the frontend can
871 * assume that it is in the same ring slot as the request that was
872 * consumed to make the slot available, and the backend must ensure
873 * this assumption is true.
874 *
875 * extra info (netif_extra_info_t)
876 * -------------------------------
877 *
878 * General format:
879 *
880 * 0 1 2 3 4 5 6 7 octet
881 * +-----+-----+-----+-----+-----+-----+-----+-----+
882 * |type |flags| type specific data |
883 * +-----+-----+-----+-----+-----+-----+-----+-----+
884 * | padding for tx |
885 * +-----+-----+-----+-----+
886 *
887 * type: XEN_NETIF_EXTRA_TYPE_*
888 * flags: XEN_NETIF_EXTRA_FLAG_*
889 * padding for tx: present only in the tx case due to 8 octet limit
890 * from rx case. Not shown in type specific entries
891 * below.
892 *
893 * XEN_NETIF_EXTRA_TYPE_GSO:
894 *
895 * 0 1 2 3 4 5 6 7 octet
896 * +-----+-----+-----+-----+-----+-----+-----+-----+
897 * |type |flags| size |type | pad | features |
898 * +-----+-----+-----+-----+-----+-----+-----+-----+
899 *
900 * type: Must be XEN_NETIF_EXTRA_TYPE_GSO
901 * flags: XEN_NETIF_EXTRA_FLAG_*
902 * size: Maximum payload size of each segment. For example,
903 * for TCP this is just the path MSS.
904 * type: XEN_NETIF_GSO_TYPE_*: This determines the protocol of
905 * the packet and any extra features required to segment the
906 * packet properly.
907 * features: EN_NETIF_GSO_FEAT_*: This specifies any extra GSO
908 * features required to process this packet, such as ECN
909 * support for TCPv4.
910 *
911 * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}:
912 *
913 * 0 1 2 3 4 5 6 7 octet
914 * +-----+-----+-----+-----+-----+-----+-----+-----+
915 * |type |flags| addr |
916 * +-----+-----+-----+-----+-----+-----+-----+-----+
917 *
918 * type: Must be XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}
919 * flags: XEN_NETIF_EXTRA_FLAG_*
920 * addr: address to add/remove
921 *
922 * XEN_NETIF_EXTRA_TYPE_HASH:
923 *
924 * A backend that supports teoplitz hashing is assumed to accept
925 * this type of extra info in transmit packets.
926 * A frontend that enables hashing is assumed to accept
927 * this type of extra info in receive packets.
928 *
929 * 0 1 2 3 4 5 6 7 octet
930 * +-----+-----+-----+-----+-----+-----+-----+-----+
931 * |type |flags|htype| alg |LSB ---- value ---- MSB|
932 * +-----+-----+-----+-----+-----+-----+-----+-----+
933 *
934 * type: Must be XEN_NETIF_EXTRA_TYPE_HASH
935 * flags: XEN_NETIF_EXTRA_FLAG_*
936 * htype: Hash type (one of _XEN_NETIF_CTRL_HASH_TYPE_* - see above)
937 * alg: The algorithm used to calculate the hash (one of
938 * XEN_NETIF_CTRL_HASH_TYPE_ALGORITHM_* - see above)
939 * value: Hash value
940 */
941
942 /* Protocol checksum field is blank in the packet (hardware offload)? */
943 #define _NETTXF_csum_blank (0)
944 #define NETTXF_csum_blank (1U<<_NETTXF_csum_blank)
945
946 /* Packet data has been validated against protocol checksum. */
947 #define _NETTXF_data_validated (1)
948 #define NETTXF_data_validated (1U<<_NETTXF_data_validated)
949
950 /* Packet continues in the next request descriptor. */
951 #define _NETTXF_more_data (2)
952 #define NETTXF_more_data (1U<<_NETTXF_more_data)
953
954 /* Packet to be followed by extra descriptor(s). */
955 #define _NETTXF_extra_info (3)
956 #define NETTXF_extra_info (1U<<_NETTXF_extra_info)
957
958 #define XEN_NETIF_MAX_TX_SIZE 0xFFFF
959 struct netif_tx_request {
960 grant_ref_t gref;
961 uint16_t offset;
962 uint16_t flags;
963 uint16_t id;
964 uint16_t size;
965 };
966 typedef struct netif_tx_request netif_tx_request_t;
967
968 /* Types of netif_extra_info descriptors. */
969 #define XEN_NETIF_EXTRA_TYPE_NONE (0) /* Never used - invalid */
970 #define XEN_NETIF_EXTRA_TYPE_GSO (1) /* u.gso */
971 #define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2) /* u.mcast */
972 #define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3) /* u.mcast */
973 #define XEN_NETIF_EXTRA_TYPE_HASH (4) /* u.hash */
974 #define XEN_NETIF_EXTRA_TYPE_MAX (5)
975
976 /* netif_extra_info_t flags. */
977 #define _XEN_NETIF_EXTRA_FLAG_MORE (0)
978 #define XEN_NETIF_EXTRA_FLAG_MORE (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
979
980 /* GSO types */
981 #define XEN_NETIF_GSO_TYPE_NONE (0)
982 #define XEN_NETIF_GSO_TYPE_TCPV4 (1)
983 #define XEN_NETIF_GSO_TYPE_TCPV6 (2)
984
985 /*
986 * This structure needs to fit within both netif_tx_request_t and
987 * netif_rx_response_t for compatibility.
988 */
989 struct netif_extra_info {
990 uint8_t type;
991 uint8_t flags;
992 union {
993 struct {
994 uint16_t size;
995 uint8_t type;
996 uint8_t pad;
997 uint16_t features;
998 } gso;
999 struct {
1000 uint8_t addr[6];
1001 } mcast;
1002 struct {
1003 uint8_t type;
1004 uint8_t algorithm;
1005 uint8_t value[4];
1006 } hash;
1007 uint16_t pad[3];
1008 } u;
1009 };
1010 typedef struct netif_extra_info netif_extra_info_t;
1011
1012 struct netif_tx_response {
1013 uint16_t id;
1014 int16_t status;
1015 };
1016 typedef struct netif_tx_response netif_tx_response_t;
1017
1018 struct netif_rx_request {
1019 uint16_t id; /* Echoed in response message. */
1020 uint16_t pad;
1021 grant_ref_t gref;
1022 };
1023 typedef struct netif_rx_request netif_rx_request_t;
1024
1025 /* Packet data has been validated against protocol checksum. */
1026 #define _NETRXF_data_validated (0)
1027 #define NETRXF_data_validated (1U<<_NETRXF_data_validated)
1028
1029 /* Protocol checksum field is blank in the packet (hardware offload)? */
1030 #define _NETRXF_csum_blank (1)
1031 #define NETRXF_csum_blank (1U<<_NETRXF_csum_blank)
1032
1033 /* Packet continues in the next request descriptor. */
1034 #define _NETRXF_more_data (2)
1035 #define NETRXF_more_data (1U<<_NETRXF_more_data)
1036
1037 /* Packet to be followed by extra descriptor(s). */
1038 #define _NETRXF_extra_info (3)
1039 #define NETRXF_extra_info (1U<<_NETRXF_extra_info)
1040
1041 /* Packet has GSO prefix. Deprecated but included for compatibility */
1042 #define _NETRXF_gso_prefix (4)
1043 #define NETRXF_gso_prefix (1U<<_NETRXF_gso_prefix)
1044
1045 struct netif_rx_response {
1046 uint16_t id;
1047 uint16_t offset;
1048 uint16_t flags;
1049 int16_t status;
1050 };
1051 typedef struct netif_rx_response netif_rx_response_t;
1052
1053 /*
1054 * Generate netif ring structures and types.
1055 */
1056
1057 DEFINE_RING_TYPES(netif_tx, struct netif_tx_request, struct netif_tx_response);
1058 DEFINE_RING_TYPES(netif_rx, struct netif_rx_request, struct netif_rx_response);
1059
1060 #define NETIF_RSP_DROPPED -2
1061 #define NETIF_RSP_ERROR -1
1062 #define NETIF_RSP_OKAY 0
1063 /* No response: used for auxiliary requests (e.g., netif_extra_info_t). */
1064 #define NETIF_RSP_NULL 1
1065
1066 #endif
1067
1068 /*
1069 * Local variables:
1070 * mode: C
1071 * c-file-style: "BSD"
1072 * c-basic-offset: 4
1073 * tab-width: 4
1074 * indent-tabs-mode: nil
1075 * End:
1076 */
1077