1 | /* SPDX-License-Identifier: MIT */ |
2 | /****************************************************************************** |
3 | * xen_netif.h |
4 | * |
5 | * Unified network-device I/O interface for Xen guest OSes. |
6 | * |
7 | * Copyright (c) 2003-2004, Keir Fraser |
8 | */ |
9 | |
10 | #ifndef __XEN_PUBLIC_IO_XEN_NETIF_H__ |
11 | #define __XEN_PUBLIC_IO_XEN_NETIF_H__ |
12 | |
13 | #include "ring.h" |
14 | #include "../grant_table.h" |
15 | |
16 | /* |
17 | * Older implementation of Xen network frontend / backend has an |
18 | * implicit dependency on the MAX_SKB_FRAGS as the maximum number of |
19 | * ring slots a skb can use. Netfront / netback may not work as |
20 | * expected when frontend and backend have different MAX_SKB_FRAGS. |
21 | * |
22 | * A better approach is to add mechanism for netfront / netback to |
23 | * negotiate this value. However we cannot fix all possible |
24 | * frontends, so we need to define a value which states the minimum |
25 | * slots backend must support. |
26 | * |
27 | * The minimum value derives from older Linux kernel's MAX_SKB_FRAGS |
28 | * (18), which is proved to work with most frontends. Any new backend |
29 | * which doesn't negotiate with frontend should expect frontend to |
30 | * send a valid packet using slots up to this value. |
31 | */ |
32 | #define XEN_NETIF_NR_SLOTS_MIN 18 |
33 | |
34 | /* |
35 | * Notifications after enqueuing any type of message should be conditional on |
36 | * the appropriate req_event or rsp_event field in the shared ring. |
37 | * If the client sends notification for rx requests then it should specify |
38 | * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume |
39 | * that it cannot safely queue packets (as it may not be kicked to send them). |
40 | */ |
41 | |
42 | /* |
43 | * "feature-split-event-channels" is introduced to separate guest TX |
44 | * and RX notification. Backend either doesn't support this feature or |
45 | * advertises it via xenstore as 0 (disabled) or 1 (enabled). |
46 | * |
47 | * To make use of this feature, frontend should allocate two event |
48 | * channels for TX and RX, advertise them to backend as |
49 | * "event-channel-tx" and "event-channel-rx" respectively. If frontend |
50 | * doesn't want to use this feature, it just writes "event-channel" |
51 | * node as before. |
52 | */ |
53 | |
54 | /* |
55 | * Multiple transmit and receive queues: |
56 | * If supported, the backend will write the key "multi-queue-max-queues" to |
57 | * the directory for that vif, and set its value to the maximum supported |
58 | * number of queues. |
59 | * Frontends that are aware of this feature and wish to use it can write the |
60 | * key "multi-queue-num-queues", set to the number they wish to use, which |
61 | * must be greater than zero, and no more than the value reported by the backend |
62 | * in "multi-queue-max-queues". |
63 | * |
64 | * Queues replicate the shared rings and event channels. |
65 | * "feature-split-event-channels" may optionally be used when using |
66 | * multiple queues, but is not mandatory. |
67 | * |
68 | * Each queue consists of one shared ring pair, i.e. there must be the same |
69 | * number of tx and rx rings. |
70 | * |
71 | * For frontends requesting just one queue, the usual event-channel and |
72 | * ring-ref keys are written as before, simplifying the backend processing |
73 | * to avoid distinguishing between a frontend that doesn't understand the |
74 | * multi-queue feature, and one that does, but requested only one queue. |
75 | * |
76 | * Frontends requesting two or more queues must not write the toplevel |
77 | * event-channel (or event-channel-{tx,rx}) and {tx,rx}-ring-ref keys, |
78 | * instead writing those keys under sub-keys having the name "queue-N" where |
79 | * N is the integer ID of the queue for which those keys belong. Queues |
80 | * are indexed from zero. For example, a frontend with two queues and split |
81 | * event channels must write the following set of queue-related keys: |
82 | * |
83 | * /local/domain/1/device/vif/0/multi-queue-num-queues = "2" |
84 | * /local/domain/1/device/vif/0/queue-0 = "" |
85 | * /local/domain/1/device/vif/0/queue-0/tx-ring-ref = "<ring-ref-tx0>" |
86 | * /local/domain/1/device/vif/0/queue-0/rx-ring-ref = "<ring-ref-rx0>" |
87 | * /local/domain/1/device/vif/0/queue-0/event-channel-tx = "<evtchn-tx0>" |
88 | * /local/domain/1/device/vif/0/queue-0/event-channel-rx = "<evtchn-rx0>" |
89 | * /local/domain/1/device/vif/0/queue-1 = "" |
90 | * /local/domain/1/device/vif/0/queue-1/tx-ring-ref = "<ring-ref-tx1>" |
91 | * /local/domain/1/device/vif/0/queue-1/rx-ring-ref = "<ring-ref-rx1" |
92 | * /local/domain/1/device/vif/0/queue-1/event-channel-tx = "<evtchn-tx1>" |
93 | * /local/domain/1/device/vif/0/queue-1/event-channel-rx = "<evtchn-rx1>" |
94 | * |
95 | * If there is any inconsistency in the XenStore data, the backend may |
96 | * choose not to connect any queues, instead treating the request as an |
97 | * error. This includes scenarios where more (or fewer) queues were |
98 | * requested than the frontend provided details for. |
99 | * |
100 | * Mapping of packets to queues is considered to be a function of the |
101 | * transmitting system (backend or frontend) and is not negotiated |
102 | * between the two. Guests are free to transmit packets on any queue |
103 | * they choose, provided it has been set up correctly. Guests must be |
104 | * prepared to receive packets on any queue they have requested be set up. |
105 | */ |
106 | |
107 | /* |
108 | * "feature-no-csum-offload" should be used to turn IPv4 TCP/UDP checksum |
109 | * offload off or on. If it is missing then the feature is assumed to be on. |
110 | * "feature-ipv6-csum-offload" should be used to turn IPv6 TCP/UDP checksum |
111 | * offload on or off. If it is missing then the feature is assumed to be off. |
112 | */ |
113 | |
114 | /* |
115 | * "feature-gso-tcpv4" and "feature-gso-tcpv6" advertise the capability to |
116 | * handle large TCP packets (in IPv4 or IPv6 form respectively). Neither |
117 | * frontends nor backends are assumed to be capable unless the flags are |
118 | * present. |
119 | */ |
120 | |
121 | /* |
122 | * "feature-multicast-control" and "feature-dynamic-multicast-control" |
123 | * advertise the capability to filter ethernet multicast packets in the |
124 | * backend. If the frontend wishes to take advantage of this feature then |
125 | * it may set "request-multicast-control". If the backend only advertises |
126 | * "feature-multicast-control" then "request-multicast-control" must be set |
127 | * before the frontend moves into the connected state. The backend will |
128 | * sample the value on this state transition and any subsequent change in |
129 | * value will have no effect. However, if the backend also advertises |
130 | * "feature-dynamic-multicast-control" then "request-multicast-control" |
131 | * may be set by the frontend at any time. In this case, the backend will |
132 | * watch the value and re-sample on watch events. |
133 | * |
134 | * If the sampled value of "request-multicast-control" is set then the |
135 | * backend transmit side should no longer flood multicast packets to the |
136 | * frontend, it should instead drop any multicast packet that does not |
137 | * match in a filter list. |
138 | * The list is amended by the frontend by sending dummy transmit requests |
139 | * containing XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} extra-info fragments as |
140 | * specified below. |
141 | * Note that the filter list may be amended even if the sampled value of |
142 | * "request-multicast-control" is not set, however the filter should only |
143 | * be applied if it is set. |
144 | */ |
145 | |
146 | /* |
147 | * "xdp-headroom" is used to request that extra space is added |
148 | * for XDP processing. The value is measured in bytes and passed by |
149 | * the frontend to be consistent between both ends. |
150 | * If the value is greater than zero that means that |
151 | * an RX response is going to be passed to an XDP program for processing. |
152 | * XEN_NETIF_MAX_XDP_HEADROOM defines the maximum headroom offset in bytes |
153 | * |
154 | * "feature-xdp-headroom" is set to "1" by the netback side like other features |
155 | * so a guest can check if an XDP program can be processed. |
156 | */ |
157 | #define XEN_NETIF_MAX_XDP_HEADROOM 0x7FFF |
158 | |
159 | /* |
160 | * Control ring |
161 | * ============ |
162 | * |
163 | * Some features, such as hashing (detailed below), require a |
164 | * significant amount of out-of-band data to be passed from frontend to |
165 | * backend. Use of xenstore is not suitable for large quantities of data |
166 | * because of quota limitations and so a dedicated 'control ring' is used. |
167 | * The ability of the backend to use a control ring is advertised by |
168 | * setting: |
169 | * |
170 | * /local/domain/X/backend/<domid>/<vif>/feature-ctrl-ring = "1" |
171 | * |
172 | * The frontend provides a control ring to the backend by setting: |
173 | * |
174 | * /local/domain/<domid>/device/vif/<vif>/ctrl-ring-ref = <gref> |
175 | * /local/domain/<domid>/device/vif/<vif>/event-channel-ctrl = <port> |
176 | * |
177 | * where <gref> is the grant reference of the shared page used to |
178 | * implement the control ring and <port> is an event channel to be used |
179 | * as a mailbox interrupt. These keys must be set before the frontend |
180 | * moves into the connected state. |
181 | * |
182 | * The control ring uses a fixed request/response message size and is |
183 | * balanced (i.e. one request to one response), so operationally it is much |
184 | * the same as a transmit or receive ring. |
185 | * Note that there is no requirement that responses are issued in the same |
186 | * order as requests. |
187 | */ |
188 | |
189 | /* |
190 | * Hash types |
191 | * ========== |
192 | * |
193 | * For the purposes of the definitions below, 'Packet[]' is an array of |
194 | * octets containing an IP packet without options, 'Array[X..Y]' means a |
195 | * sub-array of 'Array' containing bytes X thru Y inclusive, and '+' is |
196 | * used to indicate concatenation of arrays. |
197 | */ |
198 | |
199 | /* |
200 | * A hash calculated over an IP version 4 header as follows: |
201 | * |
202 | * Buffer[0..8] = Packet[12..15] (source address) + |
203 | * Packet[16..19] (destination address) |
204 | * |
205 | * Result = Hash(Buffer, 8) |
206 | */ |
207 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4 0 |
208 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV4 \ |
209 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4) |
210 | |
211 | /* |
212 | * A hash calculated over an IP version 4 header and TCP header as |
213 | * follows: |
214 | * |
215 | * Buffer[0..12] = Packet[12..15] (source address) + |
216 | * Packet[16..19] (destination address) + |
217 | * Packet[20..21] (source port) + |
218 | * Packet[22..23] (destination port) |
219 | * |
220 | * Result = Hash(Buffer, 12) |
221 | */ |
222 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP 1 |
223 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP \ |
224 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP) |
225 | |
226 | /* |
227 | * A hash calculated over an IP version 6 header as follows: |
228 | * |
229 | * Buffer[0..32] = Packet[8..23] (source address ) + |
230 | * Packet[24..39] (destination address) |
231 | * |
232 | * Result = Hash(Buffer, 32) |
233 | */ |
234 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6 2 |
235 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV6 \ |
236 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6) |
237 | |
238 | /* |
239 | * A hash calculated over an IP version 6 header and TCP header as |
240 | * follows: |
241 | * |
242 | * Buffer[0..36] = Packet[8..23] (source address) + |
243 | * Packet[24..39] (destination address) + |
244 | * Packet[40..41] (source port) + |
245 | * Packet[42..43] (destination port) |
246 | * |
247 | * Result = Hash(Buffer, 36) |
248 | */ |
249 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP 3 |
250 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP \ |
251 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP) |
252 | |
253 | /* |
254 | * Hash algorithms |
255 | * =============== |
256 | */ |
257 | |
258 | #define XEN_NETIF_CTRL_HASH_ALGORITHM_NONE 0 |
259 | |
260 | /* |
261 | * Toeplitz hash: |
262 | */ |
263 | |
264 | #define XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ 1 |
265 | |
266 | /* |
267 | * This algorithm uses a 'key' as well as the data buffer itself. |
268 | * (Buffer[] and Key[] are treated as shift-registers where the MSB of |
269 | * Buffer/Key[0] is considered 'left-most' and the LSB of Buffer/Key[N-1] |
270 | * is the 'right-most'). |
271 | * |
272 | * Value = 0 |
273 | * For number of bits in Buffer[] |
274 | * If (left-most bit of Buffer[] is 1) |
275 | * Value ^= left-most 32 bits of Key[] |
276 | * Key[] << 1 |
277 | * Buffer[] << 1 |
278 | * |
279 | * The code below is provided for convenience where an operating system |
280 | * does not already provide an implementation. |
281 | */ |
282 | #ifdef XEN_NETIF_DEFINE_TOEPLITZ |
283 | static uint32_t xen_netif_toeplitz_hash(const uint8_t *key, |
284 | unsigned int keylen, |
285 | const uint8_t *buf, unsigned int buflen) |
286 | { |
287 | unsigned int keyi, bufi; |
288 | uint64_t prefix = 0; |
289 | uint64_t hash = 0; |
290 | |
291 | /* Pre-load prefix with the first 8 bytes of the key */ |
292 | for (keyi = 0; keyi < 8; keyi++) { |
293 | prefix <<= 8; |
294 | prefix |= (keyi < keylen) ? key[keyi] : 0; |
295 | } |
296 | |
297 | for (bufi = 0; bufi < buflen; bufi++) { |
298 | uint8_t byte = buf[bufi]; |
299 | unsigned int bit; |
300 | |
301 | for (bit = 0; bit < 8; bit++) { |
302 | if (byte & 0x80) |
303 | hash ^= prefix; |
304 | prefix <<= 1; |
305 | byte <<= 1; |
306 | } |
307 | |
308 | /* |
309 | * 'prefix' has now been left-shifted by 8, so |
310 | * OR in the next byte. |
311 | */ |
312 | prefix |= (keyi < keylen) ? key[keyi] : 0; |
313 | keyi++; |
314 | } |
315 | |
316 | /* The valid part of the hash is in the upper 32 bits. */ |
317 | return hash >> 32; |
318 | } |
319 | #endif /* XEN_NETIF_DEFINE_TOEPLITZ */ |
320 | |
321 | /* |
322 | * Control requests (struct xen_netif_ctrl_request) |
323 | * ================================================ |
324 | * |
325 | * All requests have the following format: |
326 | * |
327 | * 0 1 2 3 4 5 6 7 octet |
328 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
329 | * | id | type | data[0] | |
330 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
331 | * | data[1] | data[2] | |
332 | * +-----+-----+-----+-----+-----------------------+ |
333 | * |
334 | * id: the request identifier, echoed in response. |
335 | * type: the type of request (see below) |
336 | * data[]: any data associated with the request (determined by type) |
337 | */ |
338 | |
339 | struct xen_netif_ctrl_request { |
340 | uint16_t id; |
341 | uint16_t type; |
342 | |
343 | #define XEN_NETIF_CTRL_TYPE_INVALID 0 |
344 | #define XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS 1 |
345 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS 2 |
346 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_KEY 3 |
347 | #define XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE 4 |
348 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE 5 |
349 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING 6 |
350 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM 7 |
351 | |
352 | uint32_t data[3]; |
353 | }; |
354 | |
355 | /* |
356 | * Control responses (struct xen_netif_ctrl_response) |
357 | * ================================================== |
358 | * |
359 | * All responses have the following format: |
360 | * |
361 | * 0 1 2 3 4 5 6 7 octet |
362 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
363 | * | id | type | status | |
364 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
365 | * | data | |
366 | * +-----+-----+-----+-----+ |
367 | * |
368 | * id: the corresponding request identifier |
369 | * type: the type of the corresponding request |
370 | * status: the status of request processing |
371 | * data: any data associated with the response (determined by type and |
372 | * status) |
373 | */ |
374 | |
375 | struct xen_netif_ctrl_response { |
376 | uint16_t id; |
377 | uint16_t type; |
378 | uint32_t status; |
379 | |
380 | #define XEN_NETIF_CTRL_STATUS_SUCCESS 0 |
381 | #define XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED 1 |
382 | #define XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER 2 |
383 | #define XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW 3 |
384 | |
385 | uint32_t data; |
386 | }; |
387 | |
388 | /* |
389 | * Control messages |
390 | * ================ |
391 | * |
392 | * XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM |
393 | * -------------------------------------- |
394 | * |
395 | * This is sent by the frontend to set the desired hash algorithm. |
396 | * |
397 | * Request: |
398 | * |
399 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM |
400 | * data[0] = a XEN_NETIF_CTRL_HASH_ALGORITHM_* value |
401 | * data[1] = 0 |
402 | * data[2] = 0 |
403 | * |
404 | * Response: |
405 | * |
406 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
407 | * supported |
408 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - The algorithm is not |
409 | * supported |
410 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
411 | * |
412 | * NOTE: Setting data[0] to XEN_NETIF_CTRL_HASH_ALGORITHM_NONE disables |
413 | * hashing and the backend is free to choose how it steers packets |
414 | * to queues (which is the default behaviour). |
415 | * |
416 | * XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS |
417 | * ---------------------------------- |
418 | * |
419 | * This is sent by the frontend to query the types of hash supported by |
420 | * the backend. |
421 | * |
422 | * Request: |
423 | * |
424 | * type = XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS |
425 | * data[0] = 0 |
426 | * data[1] = 0 |
427 | * data[2] = 0 |
428 | * |
429 | * Response: |
430 | * |
431 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported |
432 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
433 | * data = supported hash types (if operation was successful) |
434 | * |
435 | * NOTE: A valid hash algorithm must be selected before this operation can |
436 | * succeed. |
437 | * |
438 | * XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS |
439 | * ---------------------------------- |
440 | * |
441 | * This is sent by the frontend to set the types of hash that the backend |
442 | * should calculate. (See above for hash type definitions). |
443 | * Note that the 'maximal' type of hash should always be chosen. For |
444 | * example, if the frontend sets both IPV4 and IPV4_TCP hash types then |
445 | * the latter hash type should be calculated for any TCP packet and the |
446 | * former only calculated for non-TCP packets. |
447 | * |
448 | * Request: |
449 | * |
450 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS |
451 | * data[0] = bitwise OR of XEN_NETIF_CTRL_HASH_TYPE_* values |
452 | * data[1] = 0 |
453 | * data[2] = 0 |
454 | * |
455 | * Response: |
456 | * |
457 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
458 | * supported |
459 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - One or more flag |
460 | * value is invalid or |
461 | * unsupported |
462 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
463 | * data = 0 |
464 | * |
465 | * NOTE: A valid hash algorithm must be selected before this operation can |
466 | * succeed. |
467 | * Also, setting data[0] to zero disables hashing and the backend |
468 | * is free to choose how it steers packets to queues. |
469 | * |
470 | * XEN_NETIF_CTRL_TYPE_SET_HASH_KEY |
471 | * -------------------------------- |
472 | * |
473 | * This is sent by the frontend to set the key of the hash if the algorithm |
474 | * requires it. (See hash algorithms above). |
475 | * |
476 | * Request: |
477 | * |
478 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_KEY |
479 | * data[0] = grant reference of page containing the key (assumed to |
480 | * start at beginning of grant) |
481 | * data[1] = size of key in octets |
482 | * data[2] = 0 |
483 | * |
484 | * Response: |
485 | * |
486 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
487 | * supported |
488 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Key size is invalid |
489 | * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Key size is larger |
490 | * than the backend |
491 | * supports |
492 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
493 | * data = 0 |
494 | * |
495 | * NOTE: Any key octets not specified are assumed to be zero (the key |
496 | * is assumed to be empty by default) and specifying a new key |
497 | * invalidates any previous key, hence specifying a key size of |
498 | * zero will clear the key (which ensures that the calculated hash |
499 | * will always be zero). |
500 | * The maximum size of key is algorithm and backend specific, but |
501 | * is also limited by the single grant reference. |
502 | * The grant reference may be read-only and must remain valid until |
503 | * the response has been processed. |
504 | * |
505 | * XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE |
506 | * ----------------------------------------- |
507 | * |
508 | * This is sent by the frontend to query the maximum size of mapping |
509 | * table supported by the backend. The size is specified in terms of |
510 | * table entries. |
511 | * |
512 | * Request: |
513 | * |
514 | * type = XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE |
515 | * data[0] = 0 |
516 | * data[1] = 0 |
517 | * data[2] = 0 |
518 | * |
519 | * Response: |
520 | * |
521 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported |
522 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
523 | * data = maximum number of entries allowed in the mapping table |
524 | * (if operation was successful) or zero if a mapping table is |
525 | * not supported (i.e. hash mapping is done only by modular |
526 | * arithmetic). |
527 | * |
528 | * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE |
529 | * ------------------------------------- |
530 | * |
531 | * This is sent by the frontend to set the actual size of the mapping |
532 | * table to be used by the backend. The size is specified in terms of |
533 | * table entries. |
534 | * Any previous table is invalidated by this message and any new table |
535 | * is assumed to be zero filled. |
536 | * |
537 | * Request: |
538 | * |
539 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE |
540 | * data[0] = number of entries in mapping table |
541 | * data[1] = 0 |
542 | * data[2] = 0 |
543 | * |
544 | * Response: |
545 | * |
546 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
547 | * supported |
548 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size is invalid |
549 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
550 | * data = 0 |
551 | * |
552 | * NOTE: Setting data[0] to 0 means that hash mapping should be done |
553 | * using modular arithmetic. |
554 | * |
555 | * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING |
556 | * ------------------------------------ |
557 | * |
558 | * This is sent by the frontend to set the content of the table mapping |
559 | * hash value to queue number. The backend should calculate the hash from |
560 | * the packet header, use it as an index into the table (modulo the size |
561 | * of the table) and then steer the packet to the queue number found at |
562 | * that index. |
563 | * |
564 | * Request: |
565 | * |
566 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING |
567 | * data[0] = grant reference of page containing the mapping (sub-)table |
568 | * (assumed to start at beginning of grant) |
569 | * data[1] = size of (sub-)table in entries |
570 | * data[2] = offset, in entries, of sub-table within overall table |
571 | * |
572 | * Response: |
573 | * |
574 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
575 | * supported |
576 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size or content |
577 | * is invalid |
578 | * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Table size is larger |
579 | * than the backend |
580 | * supports |
581 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
582 | * data = 0 |
583 | * |
584 | * NOTE: The overall table has the following format: |
585 | * |
586 | * 0 1 2 3 4 5 6 7 octet |
587 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
588 | * | mapping[0] | mapping[1] | |
589 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
590 | * | . | |
591 | * | . | |
592 | * | . | |
593 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
594 | * | mapping[N-2] | mapping[N-1] | |
595 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
596 | * |
597 | * where N is specified by a XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE |
598 | * message and each mapping must specifies a queue between 0 and |
599 | * "multi-queue-num-queues" (see above). |
600 | * The backend may support a mapping table larger than can be |
601 | * mapped by a single grant reference. Thus sub-tables within a |
602 | * larger table can be individually set by sending multiple messages |
603 | * with differing offset values. Specifying a new sub-table does not |
604 | * invalidate any table data outside that range. |
605 | * The grant reference may be read-only and must remain valid until |
606 | * the response has been processed. |
607 | */ |
608 | |
609 | DEFINE_RING_TYPES(xen_netif_ctrl, |
610 | struct xen_netif_ctrl_request, |
611 | struct xen_netif_ctrl_response); |
612 | |
613 | /* |
614 | * Guest transmit |
615 | * ============== |
616 | * |
617 | * This is the 'wire' format for transmit (frontend -> backend) packets: |
618 | * |
619 | * Fragment 1: xen_netif_tx_request_t - flags = XEN_NETTXF_* |
620 | * size = total packet size |
621 | * [Extra 1: xen_netif_extra_info_t] - (only if fragment 1 flags include |
622 | * XEN_NETTXF_extra_info) |
623 | * ... |
624 | * [Extra N: xen_netif_extra_info_t] - (only if extra N-1 flags include |
625 | * XEN_NETIF_EXTRA_MORE) |
626 | * ... |
627 | * Fragment N: xen_netif_tx_request_t - (only if fragment N-1 flags include |
628 | * XEN_NETTXF_more_data - flags on preceding |
629 | * extras are not relevant here) |
630 | * flags = 0 |
631 | * size = fragment size |
632 | * |
633 | * NOTE: |
634 | * |
635 | * This format slightly is different from that used for receive |
636 | * (backend -> frontend) packets. Specifically, in a multi-fragment |
637 | * packet the actual size of fragment 1 can only be determined by |
638 | * subtracting the sizes of fragments 2..N from the total packet size. |
639 | * |
640 | * Ring slot size is 12 octets, however not all request/response |
641 | * structs use the full size. |
642 | * |
643 | * tx request data (xen_netif_tx_request_t) |
644 | * ------------------------------------ |
645 | * |
646 | * 0 1 2 3 4 5 6 7 octet |
647 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
648 | * | grant ref | offset | flags | |
649 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
650 | * | id | size | |
651 | * +-----+-----+-----+-----+ |
652 | * |
653 | * grant ref: Reference to buffer page. |
654 | * offset: Offset within buffer page. |
655 | * flags: XEN_NETTXF_*. |
656 | * id: request identifier, echoed in response. |
657 | * size: packet size in bytes. |
658 | * |
659 | * tx response (xen_netif_tx_response_t) |
660 | * --------------------------------- |
661 | * |
662 | * 0 1 2 3 4 5 6 7 octet |
663 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
664 | * | id | status | unused | |
665 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
666 | * | unused | |
667 | * +-----+-----+-----+-----+ |
668 | * |
669 | * id: reflects id in transmit request |
670 | * status: XEN_NETIF_RSP_* |
671 | * |
672 | * Guest receive |
673 | * ============= |
674 | * |
675 | * This is the 'wire' format for receive (backend -> frontend) packets: |
676 | * |
677 | * Fragment 1: xen_netif_rx_request_t - flags = XEN_NETRXF_* |
678 | * size = fragment size |
679 | * [Extra 1: xen_netif_extra_info_t] - (only if fragment 1 flags include |
680 | * XEN_NETRXF_extra_info) |
681 | * ... |
682 | * [Extra N: xen_netif_extra_info_t] - (only if extra N-1 flags include |
683 | * XEN_NETIF_EXTRA_MORE) |
684 | * ... |
685 | * Fragment N: xen_netif_rx_request_t - (only if fragment N-1 flags include |
686 | * XEN_NETRXF_more_data - flags on preceding |
687 | * extras are not relevant here) |
688 | * flags = 0 |
689 | * size = fragment size |
690 | * |
691 | * NOTE: |
692 | * |
693 | * This format slightly is different from that used for transmit |
694 | * (frontend -> backend) packets. Specifically, in a multi-fragment |
695 | * packet the size of the packet can only be determined by summing the |
696 | * sizes of fragments 1..N. |
697 | * |
698 | * Ring slot size is 8 octets. |
699 | * |
700 | * rx request (xen_netif_rx_request_t) |
701 | * ------------------------------- |
702 | * |
703 | * 0 1 2 3 4 5 6 7 octet |
704 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
705 | * | id | pad | gref | |
706 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
707 | * |
708 | * id: request identifier, echoed in response. |
709 | * gref: reference to incoming granted frame. |
710 | * |
711 | * rx response (xen_netif_rx_response_t) |
712 | * --------------------------------- |
713 | * |
714 | * 0 1 2 3 4 5 6 7 octet |
715 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
716 | * | id | offset | flags | status | |
717 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
718 | * |
719 | * id: reflects id in receive request |
720 | * offset: offset in page of start of received packet |
721 | * flags: XEN_NETRXF_* |
722 | * status: -ve: XEN_NETIF_RSP_*; +ve: Rx'ed pkt size. |
723 | * |
724 | * NOTE: Historically, to support GSO on the frontend receive side, Linux |
725 | * netfront does not make use of the rx response id (because, as |
726 | * described below, extra info structures overlay the id field). |
727 | * Instead it assumes that responses always appear in the same ring |
728 | * slot as their corresponding request. Thus, to maintain |
729 | * compatibility, backends must make sure this is the case. |
730 | * |
731 | * Extra Info |
732 | * ========== |
733 | * |
734 | * Can be present if initial request or response has NET{T,R}XF_extra_info, |
735 | * or previous extra request has XEN_NETIF_EXTRA_MORE. |
736 | * |
737 | * The struct therefore needs to fit into either a tx or rx slot and |
738 | * is therefore limited to 8 octets. |
739 | * |
740 | * NOTE: Because extra info data overlays the usual request/response |
741 | * structures, there is no id information in the opposite direction. |
742 | * So, if an extra info overlays an rx response the frontend can |
743 | * assume that it is in the same ring slot as the request that was |
744 | * consumed to make the slot available, and the backend must ensure |
745 | * this assumption is true. |
746 | * |
747 | * extra info (xen_netif_extra_info_t) |
748 | * ------------------------------- |
749 | * |
750 | * General format: |
751 | * |
752 | * 0 1 2 3 4 5 6 7 octet |
753 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
754 | * |type |flags| type specific data | |
755 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
756 | * | padding for tx | |
757 | * +-----+-----+-----+-----+ |
758 | * |
759 | * type: XEN_NETIF_EXTRA_TYPE_* |
760 | * flags: XEN_NETIF_EXTRA_FLAG_* |
761 | * padding for tx: present only in the tx case due to 8 octet limit |
762 | * from rx case. Not shown in type specific entries |
763 | * below. |
764 | * |
765 | * XEN_NETIF_EXTRA_TYPE_GSO: |
766 | * |
767 | * 0 1 2 3 4 5 6 7 octet |
768 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
769 | * |type |flags| size |type | pad | features | |
770 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
771 | * |
772 | * type: Must be XEN_NETIF_EXTRA_TYPE_GSO |
773 | * flags: XEN_NETIF_EXTRA_FLAG_* |
774 | * size: Maximum payload size of each segment. For example, |
775 | * for TCP this is just the path MSS. |
776 | * type: XEN_NETIF_GSO_TYPE_*: This determines the protocol of |
777 | * the packet and any extra features required to segment the |
778 | * packet properly. |
779 | * features: EN_XEN_NETIF_GSO_FEAT_*: This specifies any extra GSO |
780 | * features required to process this packet, such as ECN |
781 | * support for TCPv4. |
782 | * |
783 | * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}: |
784 | * |
785 | * 0 1 2 3 4 5 6 7 octet |
786 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
787 | * |type |flags| addr | |
788 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
789 | * |
790 | * type: Must be XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} |
791 | * flags: XEN_NETIF_EXTRA_FLAG_* |
792 | * addr: address to add/remove |
793 | * |
794 | * XEN_NETIF_EXTRA_TYPE_HASH: |
795 | * |
796 | * A backend that supports teoplitz hashing is assumed to accept |
797 | * this type of extra info in transmit packets. |
798 | * A frontend that enables hashing is assumed to accept |
799 | * this type of extra info in receive packets. |
800 | * |
801 | * 0 1 2 3 4 5 6 7 octet |
802 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
803 | * |type |flags|htype| alg |LSB ---- value ---- MSB| |
804 | * +-----+-----+-----+-----+-----+-----+-----+-----+ |
805 | * |
806 | * type: Must be XEN_NETIF_EXTRA_TYPE_HASH |
807 | * flags: XEN_NETIF_EXTRA_FLAG_* |
808 | * htype: Hash type (one of _XEN_NETIF_CTRL_HASH_TYPE_* - see above) |
809 | * alg: The algorithm used to calculate the hash (one of |
810 | * XEN_NETIF_CTRL_HASH_TYPE_ALGORITHM_* - see above) |
811 | * value: Hash value |
812 | */ |
813 | |
814 | /* Protocol checksum field is blank in the packet (hardware offload)? */ |
815 | #define _XEN_NETTXF_csum_blank (0) |
816 | #define XEN_NETTXF_csum_blank (1U<<_XEN_NETTXF_csum_blank) |
817 | |
818 | /* Packet data has been validated against protocol checksum. */ |
819 | #define _XEN_NETTXF_data_validated (1) |
820 | #define XEN_NETTXF_data_validated (1U<<_XEN_NETTXF_data_validated) |
821 | |
822 | /* Packet continues in the next request descriptor. */ |
823 | #define _XEN_NETTXF_more_data (2) |
824 | #define XEN_NETTXF_more_data (1U<<_XEN_NETTXF_more_data) |
825 | |
826 | /* Packet to be followed by extra descriptor(s). */ |
827 | #define (3) |
828 | #define (1U<<_XEN_NETTXF_extra_info) |
829 | |
830 | #define XEN_NETIF_MAX_TX_SIZE 0xFFFF |
831 | struct xen_netif_tx_request { |
832 | grant_ref_t gref; |
833 | uint16_t offset; |
834 | uint16_t flags; |
835 | uint16_t id; |
836 | uint16_t size; |
837 | }; |
838 | |
839 | /* Types of xen_netif_extra_info descriptors. */ |
840 | #define (0) /* Never used - invalid */ |
841 | #define (1) /* u.gso */ |
842 | #define (2) /* u.mcast */ |
843 | #define (3) /* u.mcast */ |
844 | #define (4) /* u.hash */ |
845 | #define (5) /* u.xdp */ |
846 | #define (6) |
847 | |
848 | /* xen_netif_extra_info_t flags. */ |
849 | #define (0) |
850 | #define (1U<<_XEN_NETIF_EXTRA_FLAG_MORE) |
851 | |
852 | /* GSO types */ |
853 | #define XEN_NETIF_GSO_TYPE_NONE (0) |
854 | #define XEN_NETIF_GSO_TYPE_TCPV4 (1) |
855 | #define XEN_NETIF_GSO_TYPE_TCPV6 (2) |
856 | |
857 | /* |
858 | * This structure needs to fit within both xen_netif_tx_request_t and |
859 | * xen_netif_rx_response_t for compatibility. |
860 | */ |
861 | struct { |
862 | uint8_t ; |
863 | uint8_t ; |
864 | union { |
865 | struct { |
866 | uint16_t ; |
867 | uint8_t ; |
868 | uint8_t ; |
869 | uint16_t ; |
870 | } ; |
871 | struct { |
872 | uint8_t [6]; |
873 | } ; |
874 | struct { |
875 | uint8_t ; |
876 | uint8_t ; |
877 | uint8_t [4]; |
878 | } ; |
879 | struct { |
880 | uint16_t ; |
881 | uint16_t [2]; |
882 | } ; |
883 | uint16_t [3]; |
884 | } ; |
885 | }; |
886 | |
887 | struct xen_netif_tx_response { |
888 | uint16_t id; |
889 | int16_t status; |
890 | }; |
891 | |
892 | struct xen_netif_rx_request { |
893 | uint16_t id; /* Echoed in response message. */ |
894 | uint16_t pad; |
895 | grant_ref_t gref; |
896 | }; |
897 | |
898 | /* Packet data has been validated against protocol checksum. */ |
899 | #define _XEN_NETRXF_data_validated (0) |
900 | #define XEN_NETRXF_data_validated (1U<<_XEN_NETRXF_data_validated) |
901 | |
902 | /* Protocol checksum field is blank in the packet (hardware offload)? */ |
903 | #define _XEN_NETRXF_csum_blank (1) |
904 | #define XEN_NETRXF_csum_blank (1U<<_XEN_NETRXF_csum_blank) |
905 | |
906 | /* Packet continues in the next request descriptor. */ |
907 | #define _XEN_NETRXF_more_data (2) |
908 | #define XEN_NETRXF_more_data (1U<<_XEN_NETRXF_more_data) |
909 | |
910 | /* Packet to be followed by extra descriptor(s). */ |
911 | #define (3) |
912 | #define (1U<<_XEN_NETRXF_extra_info) |
913 | |
914 | /* Packet has GSO prefix. Deprecated but included for compatibility */ |
915 | #define _XEN_NETRXF_gso_prefix (4) |
916 | #define XEN_NETRXF_gso_prefix (1U<<_XEN_NETRXF_gso_prefix) |
917 | |
918 | struct xen_netif_rx_response { |
919 | uint16_t id; |
920 | uint16_t offset; |
921 | uint16_t flags; |
922 | int16_t status; |
923 | }; |
924 | |
925 | /* |
926 | * Generate xen_netif ring structures and types. |
927 | */ |
928 | |
929 | DEFINE_RING_TYPES(xen_netif_tx, struct xen_netif_tx_request, |
930 | struct xen_netif_tx_response); |
931 | DEFINE_RING_TYPES(xen_netif_rx, struct xen_netif_rx_request, |
932 | struct xen_netif_rx_response); |
933 | |
934 | #define XEN_NETIF_RSP_DROPPED -2 |
935 | #define XEN_NETIF_RSP_ERROR -1 |
936 | #define XEN_NETIF_RSP_OKAY 0 |
937 | /* No response: used for auxiliary requests (e.g., xen_netif_extra_info_t). */ |
938 | #define XEN_NETIF_RSP_NULL 1 |
939 | |
940 | #endif |
941 | |