| 1 | /* |
| 2 | * Back-end of the driver for virtual network devices. This portion of the |
| 3 | * driver exports a 'unified' network-device interface that can be accessed |
| 4 | * by any operating system that implements a compatible front end. A |
| 5 | * reference front-end implementation can be found in: |
| 6 | * drivers/net/xen-netfront.c |
| 7 | * |
| 8 | * Copyright (c) 2002-2005, K A Fraser |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License version 2 |
| 12 | * as published by the Free Software Foundation; or, when distributed |
| 13 | * separately from the Linux kernel or incorporated into other |
| 14 | * software packages, subject to the following license: |
| 15 | * |
| 16 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 17 | * of this source file (the "Software"), to deal in the Software without |
| 18 | * restriction, including without limitation the rights to use, copy, modify, |
| 19 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| 20 | * and to permit persons to whom the Software is furnished to do so, subject to |
| 21 | * the following conditions: |
| 22 | * |
| 23 | * The above copyright notice and this permission notice shall be included in |
| 24 | * all copies or substantial portions of the Software. |
| 25 | * |
| 26 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 27 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 28 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 29 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 30 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 31 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 32 | * IN THE SOFTWARE. |
| 33 | */ |
| 34 | |
| 35 | #include "common.h" |
| 36 | |
| 37 | #include <linux/kthread.h> |
| 38 | #include <linux/if_vlan.h> |
| 39 | #include <linux/udp.h> |
| 40 | |
| 41 | #include <net/tcp.h> |
| 42 | #include <net/ip6_checksum.h> |
| 43 | |
| 44 | #include <xen/xen.h> |
| 45 | #include <xen/events.h> |
| 46 | #include <xen/interface/memory.h> |
| 47 | |
| 48 | #include <asm/xen/hypercall.h> |
| 49 | #include <asm/xen/page.h> |
| 50 | |
| 51 | /* Provide an option to disable split event channels at load time as |
| 52 | * event channels are limited resource. Split event channels are |
| 53 | * enabled by default. |
| 54 | */ |
| 55 | bool separate_tx_rx_irq = 1; |
| 56 | module_param(separate_tx_rx_irq, bool, 0644); |
| 57 | |
| 58 | /* |
| 59 | * This is the maximum slots a skb can have. If a guest sends a skb |
| 60 | * which exceeds this limit it is considered malicious. |
| 61 | */ |
| 62 | #define FATAL_SKB_SLOTS_DEFAULT 20 |
| 63 | static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT; |
| 64 | module_param(fatal_skb_slots, uint, 0444); |
| 65 | |
| 66 | /* |
| 67 | * To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating |
| 68 | * the maximum slots a valid packet can use. Now this value is defined |
| 69 | * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by |
| 70 | * all backend. |
| 71 | */ |
| 72 | #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN |
| 73 | |
| 74 | /* |
| 75 | * If head != INVALID_PENDING_RING_IDX, it means this tx request is head of |
| 76 | * one or more merged tx requests, otherwise it is the continuation of |
| 77 | * previous tx request. |
| 78 | */ |
| 79 | static inline int pending_tx_is_head(struct xenvif *vif, RING_IDX idx) |
| 80 | { |
| 81 | return vif->pending_tx_info[idx].head != INVALID_PENDING_RING_IDX; |
| 82 | } |
| 83 | |
| 84 | static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx, |
| 85 | u8 status); |
| 86 | |
| 87 | static void make_tx_response(struct xenvif *vif, |
| 88 | struct xen_netif_tx_request *txp, |
| 89 | s8 st); |
| 90 | |
| 91 | static inline int tx_work_todo(struct xenvif *vif); |
| 92 | static inline int rx_work_todo(struct xenvif *vif); |
| 93 | |
| 94 | static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, |
| 95 | u16 id, |
| 96 | s8 st, |
| 97 | u16 offset, |
| 98 | u16 size, |
| 99 | u16 flags); |
| 100 | |
| 101 | static inline unsigned long idx_to_pfn(struct xenvif *vif, |
| 102 | u16 idx) |
| 103 | { |
| 104 | return page_to_pfn(vif->mmap_pages[idx]); |
| 105 | } |
| 106 | |
| 107 | static inline unsigned long idx_to_kaddr(struct xenvif *vif, |
| 108 | u16 idx) |
| 109 | { |
| 110 | return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx)); |
| 111 | } |
| 112 | |
| 113 | /* This is a miniumum size for the linear area to avoid lots of |
| 114 | * calls to __pskb_pull_tail() as we set up checksum offsets. The |
| 115 | * value 128 was chosen as it covers all IPv4 and most likely |
| 116 | * IPv6 headers. |
| 117 | */ |
| 118 | #define PKT_PROT_LEN 128 |
| 119 | |
| 120 | static u16 frag_get_pending_idx(skb_frag_t *frag) |
| 121 | { |
| 122 | return (u16)frag->page_offset; |
| 123 | } |
| 124 | |
| 125 | static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx) |
| 126 | { |
| 127 | frag->page_offset = pending_idx; |
| 128 | } |
| 129 | |
| 130 | static inline pending_ring_idx_t pending_index(unsigned i) |
| 131 | { |
| 132 | return i & (MAX_PENDING_REQS-1); |
| 133 | } |
| 134 | |
| 135 | static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif) |
| 136 | { |
| 137 | return MAX_PENDING_REQS - |
| 138 | vif->pending_prod + vif->pending_cons; |
| 139 | } |
| 140 | |
| 141 | bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed) |
| 142 | { |
| 143 | RING_IDX prod, cons; |
| 144 | |
| 145 | do { |
| 146 | prod = vif->rx.sring->req_prod; |
| 147 | cons = vif->rx.req_cons; |
| 148 | |
| 149 | if (prod - cons >= needed) |
| 150 | return true; |
| 151 | |
| 152 | vif->rx.sring->req_event = prod + 1; |
| 153 | |
| 154 | /* Make sure event is visible before we check prod |
| 155 | * again. |
| 156 | */ |
| 157 | mb(); |
| 158 | } while (vif->rx.sring->req_prod != prod); |
| 159 | |
| 160 | return false; |
| 161 | } |
| 162 | |
| 163 | /* |
| 164 | * Returns true if we should start a new receive buffer instead of |
| 165 | * adding 'size' bytes to a buffer which currently contains 'offset' |
| 166 | * bytes. |
| 167 | */ |
| 168 | static bool start_new_rx_buffer(int offset, unsigned long size, int head) |
| 169 | { |
| 170 | /* simple case: we have completely filled the current buffer. */ |
| 171 | if (offset == MAX_BUFFER_OFFSET) |
| 172 | return true; |
| 173 | |
| 174 | /* |
| 175 | * complex case: start a fresh buffer if the current frag |
| 176 | * would overflow the current buffer but only if: |
| 177 | * (i) this frag would fit completely in the next buffer |
| 178 | * and (ii) there is already some data in the current buffer |
| 179 | * and (iii) this is not the head buffer. |
| 180 | * |
| 181 | * Where: |
| 182 | * - (i) stops us splitting a frag into two copies |
| 183 | * unless the frag is too large for a single buffer. |
| 184 | * - (ii) stops us from leaving a buffer pointlessly empty. |
| 185 | * - (iii) stops us leaving the first buffer |
| 186 | * empty. Strictly speaking this is already covered |
| 187 | * by (ii) but is explicitly checked because |
| 188 | * netfront relies on the first buffer being |
| 189 | * non-empty and can crash otherwise. |
| 190 | * |
| 191 | * This means we will effectively linearise small |
| 192 | * frags but do not needlessly split large buffers |
| 193 | * into multiple copies tend to give large frags their |
| 194 | * own buffers as before. |
| 195 | */ |
| 196 | if ((offset + size > MAX_BUFFER_OFFSET) && |
| 197 | (size <= MAX_BUFFER_OFFSET) && offset && !head) |
| 198 | return true; |
| 199 | |
| 200 | return false; |
| 201 | } |
| 202 | |
| 203 | struct netrx_pending_operations { |
| 204 | unsigned copy_prod, copy_cons; |
| 205 | unsigned meta_prod, meta_cons; |
| 206 | struct gnttab_copy *copy; |
| 207 | struct xenvif_rx_meta *meta; |
| 208 | int copy_off; |
| 209 | grant_ref_t copy_gref; |
| 210 | }; |
| 211 | |
| 212 | static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif, |
| 213 | struct netrx_pending_operations *npo) |
| 214 | { |
| 215 | struct xenvif_rx_meta *meta; |
| 216 | struct xen_netif_rx_request *req; |
| 217 | |
| 218 | req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); |
| 219 | |
| 220 | meta = npo->meta + npo->meta_prod++; |
| 221 | meta->gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| 222 | meta->gso_size = 0; |
| 223 | meta->size = 0; |
| 224 | meta->id = req->id; |
| 225 | |
| 226 | npo->copy_off = 0; |
| 227 | npo->copy_gref = req->gref; |
| 228 | |
| 229 | return meta; |
| 230 | } |
| 231 | |
| 232 | /* |
| 233 | * Set up the grant operations for this fragment. If it's a flipping |
| 234 | * interface, we also set up the unmap request from here. |
| 235 | */ |
| 236 | static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb, |
| 237 | struct netrx_pending_operations *npo, |
| 238 | struct page *page, unsigned long size, |
| 239 | unsigned long offset, int *head) |
| 240 | { |
| 241 | struct gnttab_copy *copy_gop; |
| 242 | struct xenvif_rx_meta *meta; |
| 243 | unsigned long bytes; |
| 244 | int gso_type; |
| 245 | |
| 246 | /* Data must not cross a page boundary. */ |
| 247 | BUG_ON(size + offset > PAGE_SIZE<<compound_order(page)); |
| 248 | |
| 249 | meta = npo->meta + npo->meta_prod - 1; |
| 250 | |
| 251 | /* Skip unused frames from start of page */ |
| 252 | page += offset >> PAGE_SHIFT; |
| 253 | offset &= ~PAGE_MASK; |
| 254 | |
| 255 | while (size > 0) { |
| 256 | BUG_ON(offset >= PAGE_SIZE); |
| 257 | BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET); |
| 258 | |
| 259 | bytes = PAGE_SIZE - offset; |
| 260 | |
| 261 | if (bytes > size) |
| 262 | bytes = size; |
| 263 | |
| 264 | if (start_new_rx_buffer(npo->copy_off, bytes, *head)) { |
| 265 | /* |
| 266 | * Netfront requires there to be some data in the head |
| 267 | * buffer. |
| 268 | */ |
| 269 | BUG_ON(*head); |
| 270 | |
| 271 | meta = get_next_rx_buffer(vif, npo); |
| 272 | } |
| 273 | |
| 274 | if (npo->copy_off + bytes > MAX_BUFFER_OFFSET) |
| 275 | bytes = MAX_BUFFER_OFFSET - npo->copy_off; |
| 276 | |
| 277 | copy_gop = npo->copy + npo->copy_prod++; |
| 278 | copy_gop->flags = GNTCOPY_dest_gref; |
| 279 | copy_gop->len = bytes; |
| 280 | |
| 281 | copy_gop->source.domid = DOMID_SELF; |
| 282 | copy_gop->source.u.gmfn = virt_to_mfn(page_address(page)); |
| 283 | copy_gop->source.offset = offset; |
| 284 | |
| 285 | copy_gop->dest.domid = vif->domid; |
| 286 | copy_gop->dest.offset = npo->copy_off; |
| 287 | copy_gop->dest.u.ref = npo->copy_gref; |
| 288 | |
| 289 | npo->copy_off += bytes; |
| 290 | meta->size += bytes; |
| 291 | |
| 292 | offset += bytes; |
| 293 | size -= bytes; |
| 294 | |
| 295 | /* Next frame */ |
| 296 | if (offset == PAGE_SIZE && size) { |
| 297 | BUG_ON(!PageCompound(page)); |
| 298 | page++; |
| 299 | offset = 0; |
| 300 | } |
| 301 | |
| 302 | /* Leave a gap for the GSO descriptor. */ |
| 303 | if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) |
| 304 | gso_type = XEN_NETIF_GSO_TYPE_TCPV4; |
| 305 | else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) |
| 306 | gso_type = XEN_NETIF_GSO_TYPE_TCPV6; |
| 307 | else |
| 308 | gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| 309 | |
| 310 | if (*head && ((1 << gso_type) & vif->gso_mask)) |
| 311 | vif->rx.req_cons++; |
| 312 | |
| 313 | *head = 0; /* There must be something in this buffer now. */ |
| 314 | |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | /* |
| 319 | * Prepare an SKB to be transmitted to the frontend. |
| 320 | * |
| 321 | * This function is responsible for allocating grant operations, meta |
| 322 | * structures, etc. |
| 323 | * |
| 324 | * It returns the number of meta structures consumed. The number of |
| 325 | * ring slots used is always equal to the number of meta slots used |
| 326 | * plus the number of GSO descriptors used. Currently, we use either |
| 327 | * zero GSO descriptors (for non-GSO packets) or one descriptor (for |
| 328 | * frontend-side LRO). |
| 329 | */ |
| 330 | static int xenvif_gop_skb(struct sk_buff *skb, |
| 331 | struct netrx_pending_operations *npo) |
| 332 | { |
| 333 | struct xenvif *vif = netdev_priv(skb->dev); |
| 334 | int nr_frags = skb_shinfo(skb)->nr_frags; |
| 335 | int i; |
| 336 | struct xen_netif_rx_request *req; |
| 337 | struct xenvif_rx_meta *meta; |
| 338 | unsigned char *data; |
| 339 | int head = 1; |
| 340 | int old_meta_prod; |
| 341 | int gso_type; |
| 342 | int gso_size; |
| 343 | |
| 344 | old_meta_prod = npo->meta_prod; |
| 345 | |
| 346 | if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) { |
| 347 | gso_type = XEN_NETIF_GSO_TYPE_TCPV4; |
| 348 | gso_size = skb_shinfo(skb)->gso_size; |
| 349 | } else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) { |
| 350 | gso_type = XEN_NETIF_GSO_TYPE_TCPV6; |
| 351 | gso_size = skb_shinfo(skb)->gso_size; |
| 352 | } else { |
| 353 | gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| 354 | gso_size = 0; |
| 355 | } |
| 356 | |
| 357 | /* Set up a GSO prefix descriptor, if necessary */ |
| 358 | if ((1 << gso_type) & vif->gso_prefix_mask) { |
| 359 | req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); |
| 360 | meta = npo->meta + npo->meta_prod++; |
| 361 | meta->gso_type = gso_type; |
| 362 | meta->gso_size = gso_size; |
| 363 | meta->size = 0; |
| 364 | meta->id = req->id; |
| 365 | } |
| 366 | |
| 367 | req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); |
| 368 | meta = npo->meta + npo->meta_prod++; |
| 369 | |
| 370 | if ((1 << gso_type) & vif->gso_mask) { |
| 371 | meta->gso_type = gso_type; |
| 372 | meta->gso_size = gso_size; |
| 373 | } else { |
| 374 | meta->gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| 375 | meta->gso_size = 0; |
| 376 | } |
| 377 | |
| 378 | meta->size = 0; |
| 379 | meta->id = req->id; |
| 380 | npo->copy_off = 0; |
| 381 | npo->copy_gref = req->gref; |
| 382 | |
| 383 | data = skb->data; |
| 384 | while (data < skb_tail_pointer(skb)) { |
| 385 | unsigned int offset = offset_in_page(data); |
| 386 | unsigned int len = PAGE_SIZE - offset; |
| 387 | |
| 388 | if (data + len > skb_tail_pointer(skb)) |
| 389 | len = skb_tail_pointer(skb) - data; |
| 390 | |
| 391 | xenvif_gop_frag_copy(vif, skb, npo, |
| 392 | virt_to_page(data), len, offset, &head); |
| 393 | data += len; |
| 394 | } |
| 395 | |
| 396 | for (i = 0; i < nr_frags; i++) { |
| 397 | xenvif_gop_frag_copy(vif, skb, npo, |
| 398 | skb_frag_page(&skb_shinfo(skb)->frags[i]), |
| 399 | skb_frag_size(&skb_shinfo(skb)->frags[i]), |
| 400 | skb_shinfo(skb)->frags[i].page_offset, |
| 401 | &head); |
| 402 | } |
| 403 | |
| 404 | return npo->meta_prod - old_meta_prod; |
| 405 | } |
| 406 | |
| 407 | /* |
| 408 | * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was |
| 409 | * used to set up the operations on the top of |
| 410 | * netrx_pending_operations, which have since been done. Check that |
| 411 | * they didn't give any errors and advance over them. |
| 412 | */ |
| 413 | static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots, |
| 414 | struct netrx_pending_operations *npo) |
| 415 | { |
| 416 | struct gnttab_copy *copy_op; |
| 417 | int status = XEN_NETIF_RSP_OKAY; |
| 418 | int i; |
| 419 | |
| 420 | for (i = 0; i < nr_meta_slots; i++) { |
| 421 | copy_op = npo->copy + npo->copy_cons++; |
| 422 | if (copy_op->status != GNTST_okay) { |
| 423 | netdev_dbg(vif->dev, |
| 424 | "Bad status %d from copy to DOM%d.\n", |
| 425 | copy_op->status, vif->domid); |
| 426 | status = XEN_NETIF_RSP_ERROR; |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | return status; |
| 431 | } |
| 432 | |
| 433 | static void xenvif_add_frag_responses(struct xenvif *vif, int status, |
| 434 | struct xenvif_rx_meta *meta, |
| 435 | int nr_meta_slots) |
| 436 | { |
| 437 | int i; |
| 438 | unsigned long offset; |
| 439 | |
| 440 | /* No fragments used */ |
| 441 | if (nr_meta_slots <= 1) |
| 442 | return; |
| 443 | |
| 444 | nr_meta_slots--; |
| 445 | |
| 446 | for (i = 0; i < nr_meta_slots; i++) { |
| 447 | int flags; |
| 448 | if (i == nr_meta_slots - 1) |
| 449 | flags = 0; |
| 450 | else |
| 451 | flags = XEN_NETRXF_more_data; |
| 452 | |
| 453 | offset = 0; |
| 454 | make_rx_response(vif, meta[i].id, status, offset, |
| 455 | meta[i].size, flags); |
| 456 | } |
| 457 | } |
| 458 | |
| 459 | struct skb_cb_overlay { |
| 460 | int meta_slots_used; |
| 461 | }; |
| 462 | |
| 463 | void xenvif_kick_thread(struct xenvif *vif) |
| 464 | { |
| 465 | wake_up(&vif->wq); |
| 466 | } |
| 467 | |
| 468 | static void xenvif_rx_action(struct xenvif *vif) |
| 469 | { |
| 470 | s8 status; |
| 471 | u16 flags; |
| 472 | struct xen_netif_rx_response *resp; |
| 473 | struct sk_buff_head rxq; |
| 474 | struct sk_buff *skb; |
| 475 | LIST_HEAD(notify); |
| 476 | int ret; |
| 477 | unsigned long offset; |
| 478 | struct skb_cb_overlay *sco; |
| 479 | bool need_to_notify = false; |
| 480 | bool ring_full = false; |
| 481 | |
| 482 | struct netrx_pending_operations npo = { |
| 483 | .copy = vif->grant_copy_op, |
| 484 | .meta = vif->meta, |
| 485 | }; |
| 486 | |
| 487 | skb_queue_head_init(&rxq); |
| 488 | |
| 489 | while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) { |
| 490 | int max_slots_needed; |
| 491 | int i; |
| 492 | |
| 493 | /* We need a cheap worse case estimate for the number of |
| 494 | * slots we'll use. |
| 495 | */ |
| 496 | |
| 497 | max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) + |
| 498 | skb_headlen(skb), |
| 499 | PAGE_SIZE); |
| 500 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 501 | unsigned int size; |
| 502 | size = skb_frag_size(&skb_shinfo(skb)->frags[i]); |
| 503 | max_slots_needed += DIV_ROUND_UP(size, PAGE_SIZE); |
| 504 | } |
| 505 | if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 || |
| 506 | skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) |
| 507 | max_slots_needed++; |
| 508 | |
| 509 | /* If the skb may not fit then bail out now */ |
| 510 | if (!xenvif_rx_ring_slots_available(vif, max_slots_needed)) { |
| 511 | skb_queue_head(&vif->rx_queue, skb); |
| 512 | need_to_notify = true; |
| 513 | ring_full = true; |
| 514 | break; |
| 515 | } |
| 516 | |
| 517 | sco = (struct skb_cb_overlay *)skb->cb; |
| 518 | sco->meta_slots_used = xenvif_gop_skb(skb, &npo); |
| 519 | BUG_ON(sco->meta_slots_used > max_slots_needed); |
| 520 | |
| 521 | __skb_queue_tail(&rxq, skb); |
| 522 | } |
| 523 | |
| 524 | BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta)); |
| 525 | |
| 526 | vif->rx_queue_stopped = !npo.copy_prod && ring_full; |
| 527 | |
| 528 | if (!npo.copy_prod) |
| 529 | goto done; |
| 530 | |
| 531 | BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS); |
| 532 | gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod); |
| 533 | |
| 534 | while ((skb = __skb_dequeue(&rxq)) != NULL) { |
| 535 | sco = (struct skb_cb_overlay *)skb->cb; |
| 536 | |
| 537 | if ((1 << vif->meta[npo.meta_cons].gso_type) & |
| 538 | vif->gso_prefix_mask) { |
| 539 | resp = RING_GET_RESPONSE(&vif->rx, |
| 540 | vif->rx.rsp_prod_pvt++); |
| 541 | |
| 542 | resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data; |
| 543 | |
| 544 | resp->offset = vif->meta[npo.meta_cons].gso_size; |
| 545 | resp->id = vif->meta[npo.meta_cons].id; |
| 546 | resp->status = sco->meta_slots_used; |
| 547 | |
| 548 | npo.meta_cons++; |
| 549 | sco->meta_slots_used--; |
| 550 | } |
| 551 | |
| 552 | |
| 553 | vif->dev->stats.tx_bytes += skb->len; |
| 554 | vif->dev->stats.tx_packets++; |
| 555 | |
| 556 | status = xenvif_check_gop(vif, sco->meta_slots_used, &npo); |
| 557 | |
| 558 | if (sco->meta_slots_used == 1) |
| 559 | flags = 0; |
| 560 | else |
| 561 | flags = XEN_NETRXF_more_data; |
| 562 | |
| 563 | if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */ |
| 564 | flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated; |
| 565 | else if (skb->ip_summed == CHECKSUM_UNNECESSARY) |
| 566 | /* remote but checksummed. */ |
| 567 | flags |= XEN_NETRXF_data_validated; |
| 568 | |
| 569 | offset = 0; |
| 570 | resp = make_rx_response(vif, vif->meta[npo.meta_cons].id, |
| 571 | status, offset, |
| 572 | vif->meta[npo.meta_cons].size, |
| 573 | flags); |
| 574 | |
| 575 | if ((1 << vif->meta[npo.meta_cons].gso_type) & |
| 576 | vif->gso_mask) { |
| 577 | struct xen_netif_extra_info *gso = |
| 578 | (struct xen_netif_extra_info *) |
| 579 | RING_GET_RESPONSE(&vif->rx, |
| 580 | vif->rx.rsp_prod_pvt++); |
| 581 | |
| 582 | resp->flags |= XEN_NETRXF_extra_info; |
| 583 | |
| 584 | gso->u.gso.type = vif->meta[npo.meta_cons].gso_type; |
| 585 | gso->u.gso.size = vif->meta[npo.meta_cons].gso_size; |
| 586 | gso->u.gso.pad = 0; |
| 587 | gso->u.gso.features = 0; |
| 588 | |
| 589 | gso->type = XEN_NETIF_EXTRA_TYPE_GSO; |
| 590 | gso->flags = 0; |
| 591 | } |
| 592 | |
| 593 | xenvif_add_frag_responses(vif, status, |
| 594 | vif->meta + npo.meta_cons + 1, |
| 595 | sco->meta_slots_used); |
| 596 | |
| 597 | RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret); |
| 598 | |
| 599 | need_to_notify |= !!ret; |
| 600 | |
| 601 | npo.meta_cons += sco->meta_slots_used; |
| 602 | dev_kfree_skb(skb); |
| 603 | } |
| 604 | |
| 605 | done: |
| 606 | if (need_to_notify) |
| 607 | notify_remote_via_irq(vif->rx_irq); |
| 608 | } |
| 609 | |
| 610 | void xenvif_check_rx_xenvif(struct xenvif *vif) |
| 611 | { |
| 612 | int more_to_do; |
| 613 | |
| 614 | RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do); |
| 615 | |
| 616 | if (more_to_do) |
| 617 | napi_schedule(&vif->napi); |
| 618 | } |
| 619 | |
| 620 | static void tx_add_credit(struct xenvif *vif) |
| 621 | { |
| 622 | unsigned long max_burst, max_credit; |
| 623 | |
| 624 | /* |
| 625 | * Allow a burst big enough to transmit a jumbo packet of up to 128kB. |
| 626 | * Otherwise the interface can seize up due to insufficient credit. |
| 627 | */ |
| 628 | max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size; |
| 629 | max_burst = min(max_burst, 131072UL); |
| 630 | max_burst = max(max_burst, vif->credit_bytes); |
| 631 | |
| 632 | /* Take care that adding a new chunk of credit doesn't wrap to zero. */ |
| 633 | max_credit = vif->remaining_credit + vif->credit_bytes; |
| 634 | if (max_credit < vif->remaining_credit) |
| 635 | max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */ |
| 636 | |
| 637 | vif->remaining_credit = min(max_credit, max_burst); |
| 638 | } |
| 639 | |
| 640 | static void tx_credit_callback(unsigned long data) |
| 641 | { |
| 642 | struct xenvif *vif = (struct xenvif *)data; |
| 643 | tx_add_credit(vif); |
| 644 | xenvif_check_rx_xenvif(vif); |
| 645 | } |
| 646 | |
| 647 | static void xenvif_tx_err(struct xenvif *vif, |
| 648 | struct xen_netif_tx_request *txp, RING_IDX end) |
| 649 | { |
| 650 | RING_IDX cons = vif->tx.req_cons; |
| 651 | |
| 652 | do { |
| 653 | make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR); |
| 654 | if (cons == end) |
| 655 | break; |
| 656 | txp = RING_GET_REQUEST(&vif->tx, cons++); |
| 657 | } while (1); |
| 658 | vif->tx.req_cons = cons; |
| 659 | } |
| 660 | |
| 661 | static void xenvif_fatal_tx_err(struct xenvif *vif) |
| 662 | { |
| 663 | netdev_err(vif->dev, "fatal error; disabling device\n"); |
| 664 | xenvif_carrier_off(vif); |
| 665 | } |
| 666 | |
| 667 | static int xenvif_count_requests(struct xenvif *vif, |
| 668 | struct xen_netif_tx_request *first, |
| 669 | struct xen_netif_tx_request *txp, |
| 670 | int work_to_do) |
| 671 | { |
| 672 | RING_IDX cons = vif->tx.req_cons; |
| 673 | int slots = 0; |
| 674 | int drop_err = 0; |
| 675 | int more_data; |
| 676 | |
| 677 | if (!(first->flags & XEN_NETTXF_more_data)) |
| 678 | return 0; |
| 679 | |
| 680 | do { |
| 681 | struct xen_netif_tx_request dropped_tx = { 0 }; |
| 682 | |
| 683 | if (slots >= work_to_do) { |
| 684 | netdev_err(vif->dev, |
| 685 | "Asked for %d slots but exceeds this limit\n", |
| 686 | work_to_do); |
| 687 | xenvif_fatal_tx_err(vif); |
| 688 | return -ENODATA; |
| 689 | } |
| 690 | |
| 691 | /* This guest is really using too many slots and |
| 692 | * considered malicious. |
| 693 | */ |
| 694 | if (unlikely(slots >= fatal_skb_slots)) { |
| 695 | netdev_err(vif->dev, |
| 696 | "Malicious frontend using %d slots, threshold %u\n", |
| 697 | slots, fatal_skb_slots); |
| 698 | xenvif_fatal_tx_err(vif); |
| 699 | return -E2BIG; |
| 700 | } |
| 701 | |
| 702 | /* Xen network protocol had implicit dependency on |
| 703 | * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to |
| 704 | * the historical MAX_SKB_FRAGS value 18 to honor the |
| 705 | * same behavior as before. Any packet using more than |
| 706 | * 18 slots but less than fatal_skb_slots slots is |
| 707 | * dropped |
| 708 | */ |
| 709 | if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) { |
| 710 | if (net_ratelimit()) |
| 711 | netdev_dbg(vif->dev, |
| 712 | "Too many slots (%d) exceeding limit (%d), dropping packet\n", |
| 713 | slots, XEN_NETBK_LEGACY_SLOTS_MAX); |
| 714 | drop_err = -E2BIG; |
| 715 | } |
| 716 | |
| 717 | if (drop_err) |
| 718 | txp = &dropped_tx; |
| 719 | |
| 720 | memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots), |
| 721 | sizeof(*txp)); |
| 722 | |
| 723 | /* If the guest submitted a frame >= 64 KiB then |
| 724 | * first->size overflowed and following slots will |
| 725 | * appear to be larger than the frame. |
| 726 | * |
| 727 | * This cannot be fatal error as there are buggy |
| 728 | * frontends that do this. |
| 729 | * |
| 730 | * Consume all slots and drop the packet. |
| 731 | */ |
| 732 | if (!drop_err && txp->size > first->size) { |
| 733 | if (net_ratelimit()) |
| 734 | netdev_dbg(vif->dev, |
| 735 | "Invalid tx request, slot size %u > remaining size %u\n", |
| 736 | txp->size, first->size); |
| 737 | drop_err = -EIO; |
| 738 | } |
| 739 | |
| 740 | first->size -= txp->size; |
| 741 | slots++; |
| 742 | |
| 743 | if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) { |
| 744 | netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n", |
| 745 | txp->offset, txp->size); |
| 746 | xenvif_fatal_tx_err(vif); |
| 747 | return -EINVAL; |
| 748 | } |
| 749 | |
| 750 | more_data = txp->flags & XEN_NETTXF_more_data; |
| 751 | |
| 752 | if (!drop_err) |
| 753 | txp++; |
| 754 | |
| 755 | } while (more_data); |
| 756 | |
| 757 | if (drop_err) { |
| 758 | xenvif_tx_err(vif, first, cons + slots); |
| 759 | return drop_err; |
| 760 | } |
| 761 | |
| 762 | return slots; |
| 763 | } |
| 764 | |
| 765 | static struct page *xenvif_alloc_page(struct xenvif *vif, |
| 766 | u16 pending_idx) |
| 767 | { |
| 768 | struct page *page; |
| 769 | |
| 770 | page = alloc_page(GFP_ATOMIC|__GFP_COLD); |
| 771 | if (!page) |
| 772 | return NULL; |
| 773 | vif->mmap_pages[pending_idx] = page; |
| 774 | |
| 775 | return page; |
| 776 | } |
| 777 | |
| 778 | static struct gnttab_copy *xenvif_get_requests(struct xenvif *vif, |
| 779 | struct sk_buff *skb, |
| 780 | struct xen_netif_tx_request *txp, |
| 781 | struct gnttab_copy *gop) |
| 782 | { |
| 783 | struct skb_shared_info *shinfo = skb_shinfo(skb); |
| 784 | skb_frag_t *frags = shinfo->frags; |
| 785 | u16 pending_idx = *((u16 *)skb->data); |
| 786 | u16 head_idx = 0; |
| 787 | int slot, start; |
| 788 | struct page *page; |
| 789 | pending_ring_idx_t index, start_idx = 0; |
| 790 | uint16_t dst_offset; |
| 791 | unsigned int nr_slots; |
| 792 | struct pending_tx_info *first = NULL; |
| 793 | |
| 794 | /* At this point shinfo->nr_frags is in fact the number of |
| 795 | * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX. |
| 796 | */ |
| 797 | nr_slots = shinfo->nr_frags; |
| 798 | |
| 799 | /* Skip first skb fragment if it is on same page as header fragment. */ |
| 800 | start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); |
| 801 | |
| 802 | /* Coalesce tx requests, at this point the packet passed in |
| 803 | * should be <= 64K. Any packets larger than 64K have been |
| 804 | * handled in xenvif_count_requests(). |
| 805 | */ |
| 806 | for (shinfo->nr_frags = slot = start; slot < nr_slots; |
| 807 | shinfo->nr_frags++) { |
| 808 | struct pending_tx_info *pending_tx_info = |
| 809 | vif->pending_tx_info; |
| 810 | |
| 811 | page = alloc_page(GFP_ATOMIC|__GFP_COLD); |
| 812 | if (!page) |
| 813 | goto err; |
| 814 | |
| 815 | dst_offset = 0; |
| 816 | first = NULL; |
| 817 | while (dst_offset < PAGE_SIZE && slot < nr_slots) { |
| 818 | gop->flags = GNTCOPY_source_gref; |
| 819 | |
| 820 | gop->source.u.ref = txp->gref; |
| 821 | gop->source.domid = vif->domid; |
| 822 | gop->source.offset = txp->offset; |
| 823 | |
| 824 | gop->dest.domid = DOMID_SELF; |
| 825 | |
| 826 | gop->dest.offset = dst_offset; |
| 827 | gop->dest.u.gmfn = virt_to_mfn(page_address(page)); |
| 828 | |
| 829 | if (dst_offset + txp->size > PAGE_SIZE) { |
| 830 | /* This page can only merge a portion |
| 831 | * of tx request. Do not increment any |
| 832 | * pointer / counter here. The txp |
| 833 | * will be dealt with in future |
| 834 | * rounds, eventually hitting the |
| 835 | * `else` branch. |
| 836 | */ |
| 837 | gop->len = PAGE_SIZE - dst_offset; |
| 838 | txp->offset += gop->len; |
| 839 | txp->size -= gop->len; |
| 840 | dst_offset += gop->len; /* quit loop */ |
| 841 | } else { |
| 842 | /* This tx request can be merged in the page */ |
| 843 | gop->len = txp->size; |
| 844 | dst_offset += gop->len; |
| 845 | |
| 846 | index = pending_index(vif->pending_cons++); |
| 847 | |
| 848 | pending_idx = vif->pending_ring[index]; |
| 849 | |
| 850 | memcpy(&pending_tx_info[pending_idx].req, txp, |
| 851 | sizeof(*txp)); |
| 852 | |
| 853 | /* Poison these fields, corresponding |
| 854 | * fields for head tx req will be set |
| 855 | * to correct values after the loop. |
| 856 | */ |
| 857 | vif->mmap_pages[pending_idx] = (void *)(~0UL); |
| 858 | pending_tx_info[pending_idx].head = |
| 859 | INVALID_PENDING_RING_IDX; |
| 860 | |
| 861 | if (!first) { |
| 862 | first = &pending_tx_info[pending_idx]; |
| 863 | start_idx = index; |
| 864 | head_idx = pending_idx; |
| 865 | } |
| 866 | |
| 867 | txp++; |
| 868 | slot++; |
| 869 | } |
| 870 | |
| 871 | gop++; |
| 872 | } |
| 873 | |
| 874 | first->req.offset = 0; |
| 875 | first->req.size = dst_offset; |
| 876 | first->head = start_idx; |
| 877 | vif->mmap_pages[head_idx] = page; |
| 878 | frag_set_pending_idx(&frags[shinfo->nr_frags], head_idx); |
| 879 | } |
| 880 | |
| 881 | BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS); |
| 882 | |
| 883 | return gop; |
| 884 | err: |
| 885 | /* Unwind, freeing all pages and sending error responses. */ |
| 886 | while (shinfo->nr_frags-- > start) { |
| 887 | xenvif_idx_release(vif, |
| 888 | frag_get_pending_idx(&frags[shinfo->nr_frags]), |
| 889 | XEN_NETIF_RSP_ERROR); |
| 890 | } |
| 891 | /* The head too, if necessary. */ |
| 892 | if (start) |
| 893 | xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); |
| 894 | |
| 895 | return NULL; |
| 896 | } |
| 897 | |
| 898 | static int xenvif_tx_check_gop(struct xenvif *vif, |
| 899 | struct sk_buff *skb, |
| 900 | struct gnttab_copy **gopp) |
| 901 | { |
| 902 | struct gnttab_copy *gop = *gopp; |
| 903 | u16 pending_idx = *((u16 *)skb->data); |
| 904 | struct skb_shared_info *shinfo = skb_shinfo(skb); |
| 905 | struct pending_tx_info *tx_info; |
| 906 | int nr_frags = shinfo->nr_frags; |
| 907 | int i, err, start; |
| 908 | u16 peek; /* peek into next tx request */ |
| 909 | |
| 910 | /* Check status of header. */ |
| 911 | err = gop->status; |
| 912 | if (unlikely(err)) |
| 913 | xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); |
| 914 | |
| 915 | /* Skip first skb fragment if it is on same page as header fragment. */ |
| 916 | start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); |
| 917 | |
| 918 | for (i = start; i < nr_frags; i++) { |
| 919 | int j, newerr; |
| 920 | pending_ring_idx_t head; |
| 921 | |
| 922 | pending_idx = frag_get_pending_idx(&shinfo->frags[i]); |
| 923 | tx_info = &vif->pending_tx_info[pending_idx]; |
| 924 | head = tx_info->head; |
| 925 | |
| 926 | /* Check error status: if okay then remember grant handle. */ |
| 927 | do { |
| 928 | newerr = (++gop)->status; |
| 929 | if (newerr) |
| 930 | break; |
| 931 | peek = vif->pending_ring[pending_index(++head)]; |
| 932 | } while (!pending_tx_is_head(vif, peek)); |
| 933 | |
| 934 | if (likely(!newerr)) { |
| 935 | /* Had a previous error? Invalidate this fragment. */ |
| 936 | if (unlikely(err)) |
| 937 | xenvif_idx_release(vif, pending_idx, |
| 938 | XEN_NETIF_RSP_OKAY); |
| 939 | continue; |
| 940 | } |
| 941 | |
| 942 | /* Error on this fragment: respond to client with an error. */ |
| 943 | xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); |
| 944 | |
| 945 | /* Not the first error? Preceding frags already invalidated. */ |
| 946 | if (err) |
| 947 | continue; |
| 948 | |
| 949 | /* First error: invalidate header and preceding fragments. */ |
| 950 | pending_idx = *((u16 *)skb->data); |
| 951 | xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY); |
| 952 | for (j = start; j < i; j++) { |
| 953 | pending_idx = frag_get_pending_idx(&shinfo->frags[j]); |
| 954 | xenvif_idx_release(vif, pending_idx, |
| 955 | XEN_NETIF_RSP_OKAY); |
| 956 | } |
| 957 | |
| 958 | /* Remember the error: invalidate all subsequent fragments. */ |
| 959 | err = newerr; |
| 960 | } |
| 961 | |
| 962 | *gopp = gop + 1; |
| 963 | return err; |
| 964 | } |
| 965 | |
| 966 | static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb) |
| 967 | { |
| 968 | struct skb_shared_info *shinfo = skb_shinfo(skb); |
| 969 | int nr_frags = shinfo->nr_frags; |
| 970 | int i; |
| 971 | |
| 972 | for (i = 0; i < nr_frags; i++) { |
| 973 | skb_frag_t *frag = shinfo->frags + i; |
| 974 | struct xen_netif_tx_request *txp; |
| 975 | struct page *page; |
| 976 | u16 pending_idx; |
| 977 | |
| 978 | pending_idx = frag_get_pending_idx(frag); |
| 979 | |
| 980 | txp = &vif->pending_tx_info[pending_idx].req; |
| 981 | page = virt_to_page(idx_to_kaddr(vif, pending_idx)); |
| 982 | __skb_fill_page_desc(skb, i, page, txp->offset, txp->size); |
| 983 | skb->len += txp->size; |
| 984 | skb->data_len += txp->size; |
| 985 | skb->truesize += txp->size; |
| 986 | |
| 987 | /* Take an extra reference to offset xenvif_idx_release */ |
| 988 | get_page(vif->mmap_pages[pending_idx]); |
| 989 | xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY); |
| 990 | } |
| 991 | } |
| 992 | |
| 993 | static int xenvif_get_extras(struct xenvif *vif, |
| 994 | struct xen_netif_extra_info *extras, |
| 995 | int work_to_do) |
| 996 | { |
| 997 | struct xen_netif_extra_info extra; |
| 998 | RING_IDX cons = vif->tx.req_cons; |
| 999 | |
| 1000 | do { |
| 1001 | if (unlikely(work_to_do-- <= 0)) { |
| 1002 | netdev_err(vif->dev, "Missing extra info\n"); |
| 1003 | xenvif_fatal_tx_err(vif); |
| 1004 | return -EBADR; |
| 1005 | } |
| 1006 | |
| 1007 | memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons), |
| 1008 | sizeof(extra)); |
| 1009 | if (unlikely(!extra.type || |
| 1010 | extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) { |
| 1011 | vif->tx.req_cons = ++cons; |
| 1012 | netdev_err(vif->dev, |
| 1013 | "Invalid extra type: %d\n", extra.type); |
| 1014 | xenvif_fatal_tx_err(vif); |
| 1015 | return -EINVAL; |
| 1016 | } |
| 1017 | |
| 1018 | memcpy(&extras[extra.type - 1], &extra, sizeof(extra)); |
| 1019 | vif->tx.req_cons = ++cons; |
| 1020 | } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE); |
| 1021 | |
| 1022 | return work_to_do; |
| 1023 | } |
| 1024 | |
| 1025 | static int xenvif_set_skb_gso(struct xenvif *vif, |
| 1026 | struct sk_buff *skb, |
| 1027 | struct xen_netif_extra_info *gso) |
| 1028 | { |
| 1029 | if (!gso->u.gso.size) { |
| 1030 | netdev_err(vif->dev, "GSO size must not be zero.\n"); |
| 1031 | xenvif_fatal_tx_err(vif); |
| 1032 | return -EINVAL; |
| 1033 | } |
| 1034 | |
| 1035 | switch (gso->u.gso.type) { |
| 1036 | case XEN_NETIF_GSO_TYPE_TCPV4: |
| 1037 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; |
| 1038 | break; |
| 1039 | case XEN_NETIF_GSO_TYPE_TCPV6: |
| 1040 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; |
| 1041 | break; |
| 1042 | default: |
| 1043 | netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type); |
| 1044 | xenvif_fatal_tx_err(vif); |
| 1045 | return -EINVAL; |
| 1046 | } |
| 1047 | |
| 1048 | skb_shinfo(skb)->gso_size = gso->u.gso.size; |
| 1049 | /* gso_segs will be calculated later */ |
| 1050 | |
| 1051 | return 0; |
| 1052 | } |
| 1053 | |
| 1054 | static inline int maybe_pull_tail(struct sk_buff *skb, unsigned int len, |
| 1055 | unsigned int max) |
| 1056 | { |
| 1057 | if (skb_headlen(skb) >= len) |
| 1058 | return 0; |
| 1059 | |
| 1060 | /* If we need to pullup then pullup to the max, so we |
| 1061 | * won't need to do it again. |
| 1062 | */ |
| 1063 | if (max > skb->len) |
| 1064 | max = skb->len; |
| 1065 | |
| 1066 | if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL) |
| 1067 | return -ENOMEM; |
| 1068 | |
| 1069 | if (skb_headlen(skb) < len) |
| 1070 | return -EPROTO; |
| 1071 | |
| 1072 | return 0; |
| 1073 | } |
| 1074 | |
| 1075 | /* This value should be large enough to cover a tagged ethernet header plus |
| 1076 | * maximally sized IP and TCP or UDP headers. |
| 1077 | */ |
| 1078 | #define MAX_IP_HDR_LEN 128 |
| 1079 | |
| 1080 | static int checksum_setup_ip(struct xenvif *vif, struct sk_buff *skb, |
| 1081 | int recalculate_partial_csum) |
| 1082 | { |
| 1083 | unsigned int off; |
| 1084 | bool fragment; |
| 1085 | int err; |
| 1086 | |
| 1087 | fragment = false; |
| 1088 | |
| 1089 | err = maybe_pull_tail(skb, |
| 1090 | sizeof(struct iphdr), |
| 1091 | MAX_IP_HDR_LEN); |
| 1092 | if (err < 0) |
| 1093 | goto out; |
| 1094 | |
| 1095 | if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF)) |
| 1096 | fragment = true; |
| 1097 | |
| 1098 | off = ip_hdrlen(skb); |
| 1099 | |
| 1100 | err = -EPROTO; |
| 1101 | |
| 1102 | if (fragment) |
| 1103 | goto out; |
| 1104 | |
| 1105 | switch (ip_hdr(skb)->protocol) { |
| 1106 | case IPPROTO_TCP: |
| 1107 | err = maybe_pull_tail(skb, |
| 1108 | off + sizeof(struct tcphdr), |
| 1109 | MAX_IP_HDR_LEN); |
| 1110 | if (err < 0) |
| 1111 | goto out; |
| 1112 | |
| 1113 | if (!skb_partial_csum_set(skb, off, |
| 1114 | offsetof(struct tcphdr, check))) { |
| 1115 | err = -EPROTO; |
| 1116 | goto out; |
| 1117 | } |
| 1118 | |
| 1119 | if (recalculate_partial_csum) |
| 1120 | tcp_hdr(skb)->check = |
| 1121 | ~csum_tcpudp_magic(ip_hdr(skb)->saddr, |
| 1122 | ip_hdr(skb)->daddr, |
| 1123 | skb->len - off, |
| 1124 | IPPROTO_TCP, 0); |
| 1125 | break; |
| 1126 | case IPPROTO_UDP: |
| 1127 | err = maybe_pull_tail(skb, |
| 1128 | off + sizeof(struct udphdr), |
| 1129 | MAX_IP_HDR_LEN); |
| 1130 | if (err < 0) |
| 1131 | goto out; |
| 1132 | |
| 1133 | if (!skb_partial_csum_set(skb, off, |
| 1134 | offsetof(struct udphdr, check))) { |
| 1135 | err = -EPROTO; |
| 1136 | goto out; |
| 1137 | } |
| 1138 | |
| 1139 | if (recalculate_partial_csum) |
| 1140 | udp_hdr(skb)->check = |
| 1141 | ~csum_tcpudp_magic(ip_hdr(skb)->saddr, |
| 1142 | ip_hdr(skb)->daddr, |
| 1143 | skb->len - off, |
| 1144 | IPPROTO_UDP, 0); |
| 1145 | break; |
| 1146 | default: |
| 1147 | goto out; |
| 1148 | } |
| 1149 | |
| 1150 | err = 0; |
| 1151 | |
| 1152 | out: |
| 1153 | return err; |
| 1154 | } |
| 1155 | |
| 1156 | /* This value should be large enough to cover a tagged ethernet header plus |
| 1157 | * an IPv6 header, all options, and a maximal TCP or UDP header. |
| 1158 | */ |
| 1159 | #define MAX_IPV6_HDR_LEN 256 |
| 1160 | |
| 1161 | #define OPT_HDR(type, skb, off) \ |
| 1162 | (type *)(skb_network_header(skb) + (off)) |
| 1163 | |
| 1164 | static int checksum_setup_ipv6(struct xenvif *vif, struct sk_buff *skb, |
| 1165 | int recalculate_partial_csum) |
| 1166 | { |
| 1167 | int err; |
| 1168 | u8 nexthdr; |
| 1169 | unsigned int off; |
| 1170 | unsigned int len; |
| 1171 | bool fragment; |
| 1172 | bool done; |
| 1173 | |
| 1174 | fragment = false; |
| 1175 | done = false; |
| 1176 | |
| 1177 | off = sizeof(struct ipv6hdr); |
| 1178 | |
| 1179 | err = maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN); |
| 1180 | if (err < 0) |
| 1181 | goto out; |
| 1182 | |
| 1183 | nexthdr = ipv6_hdr(skb)->nexthdr; |
| 1184 | |
| 1185 | len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len); |
| 1186 | while (off <= len && !done) { |
| 1187 | switch (nexthdr) { |
| 1188 | case IPPROTO_DSTOPTS: |
| 1189 | case IPPROTO_HOPOPTS: |
| 1190 | case IPPROTO_ROUTING: { |
| 1191 | struct ipv6_opt_hdr *hp; |
| 1192 | |
| 1193 | err = maybe_pull_tail(skb, |
| 1194 | off + |
| 1195 | sizeof(struct ipv6_opt_hdr), |
| 1196 | MAX_IPV6_HDR_LEN); |
| 1197 | if (err < 0) |
| 1198 | goto out; |
| 1199 | |
| 1200 | hp = OPT_HDR(struct ipv6_opt_hdr, skb, off); |
| 1201 | nexthdr = hp->nexthdr; |
| 1202 | off += ipv6_optlen(hp); |
| 1203 | break; |
| 1204 | } |
| 1205 | case IPPROTO_AH: { |
| 1206 | struct ip_auth_hdr *hp; |
| 1207 | |
| 1208 | err = maybe_pull_tail(skb, |
| 1209 | off + |
| 1210 | sizeof(struct ip_auth_hdr), |
| 1211 | MAX_IPV6_HDR_LEN); |
| 1212 | if (err < 0) |
| 1213 | goto out; |
| 1214 | |
| 1215 | hp = OPT_HDR(struct ip_auth_hdr, skb, off); |
| 1216 | nexthdr = hp->nexthdr; |
| 1217 | off += ipv6_authlen(hp); |
| 1218 | break; |
| 1219 | } |
| 1220 | case IPPROTO_FRAGMENT: { |
| 1221 | struct frag_hdr *hp; |
| 1222 | |
| 1223 | err = maybe_pull_tail(skb, |
| 1224 | off + |
| 1225 | sizeof(struct frag_hdr), |
| 1226 | MAX_IPV6_HDR_LEN); |
| 1227 | if (err < 0) |
| 1228 | goto out; |
| 1229 | |
| 1230 | hp = OPT_HDR(struct frag_hdr, skb, off); |
| 1231 | |
| 1232 | if (hp->frag_off & htons(IP6_OFFSET | IP6_MF)) |
| 1233 | fragment = true; |
| 1234 | |
| 1235 | nexthdr = hp->nexthdr; |
| 1236 | off += sizeof(struct frag_hdr); |
| 1237 | break; |
| 1238 | } |
| 1239 | default: |
| 1240 | done = true; |
| 1241 | break; |
| 1242 | } |
| 1243 | } |
| 1244 | |
| 1245 | err = -EPROTO; |
| 1246 | |
| 1247 | if (!done || fragment) |
| 1248 | goto out; |
| 1249 | |
| 1250 | switch (nexthdr) { |
| 1251 | case IPPROTO_TCP: |
| 1252 | err = maybe_pull_tail(skb, |
| 1253 | off + sizeof(struct tcphdr), |
| 1254 | MAX_IPV6_HDR_LEN); |
| 1255 | if (err < 0) |
| 1256 | goto out; |
| 1257 | |
| 1258 | if (!skb_partial_csum_set(skb, off, |
| 1259 | offsetof(struct tcphdr, check))) { |
| 1260 | err = -EPROTO; |
| 1261 | goto out; |
| 1262 | } |
| 1263 | |
| 1264 | if (recalculate_partial_csum) |
| 1265 | tcp_hdr(skb)->check = |
| 1266 | ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| 1267 | &ipv6_hdr(skb)->daddr, |
| 1268 | skb->len - off, |
| 1269 | IPPROTO_TCP, 0); |
| 1270 | break; |
| 1271 | case IPPROTO_UDP: |
| 1272 | err = maybe_pull_tail(skb, |
| 1273 | off + sizeof(struct udphdr), |
| 1274 | MAX_IPV6_HDR_LEN); |
| 1275 | if (err < 0) |
| 1276 | goto out; |
| 1277 | |
| 1278 | if (!skb_partial_csum_set(skb, off, |
| 1279 | offsetof(struct udphdr, check))) { |
| 1280 | err = -EPROTO; |
| 1281 | goto out; |
| 1282 | } |
| 1283 | |
| 1284 | if (recalculate_partial_csum) |
| 1285 | udp_hdr(skb)->check = |
| 1286 | ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| 1287 | &ipv6_hdr(skb)->daddr, |
| 1288 | skb->len - off, |
| 1289 | IPPROTO_UDP, 0); |
| 1290 | break; |
| 1291 | default: |
| 1292 | goto out; |
| 1293 | } |
| 1294 | |
| 1295 | err = 0; |
| 1296 | |
| 1297 | out: |
| 1298 | return err; |
| 1299 | } |
| 1300 | |
| 1301 | static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) |
| 1302 | { |
| 1303 | int err = -EPROTO; |
| 1304 | int recalculate_partial_csum = 0; |
| 1305 | |
| 1306 | /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy |
| 1307 | * peers can fail to set NETRXF_csum_blank when sending a GSO |
| 1308 | * frame. In this case force the SKB to CHECKSUM_PARTIAL and |
| 1309 | * recalculate the partial checksum. |
| 1310 | */ |
| 1311 | if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { |
| 1312 | vif->rx_gso_checksum_fixup++; |
| 1313 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1314 | recalculate_partial_csum = 1; |
| 1315 | } |
| 1316 | |
| 1317 | /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ |
| 1318 | if (skb->ip_summed != CHECKSUM_PARTIAL) |
| 1319 | return 0; |
| 1320 | |
| 1321 | if (skb->protocol == htons(ETH_P_IP)) |
| 1322 | err = checksum_setup_ip(vif, skb, recalculate_partial_csum); |
| 1323 | else if (skb->protocol == htons(ETH_P_IPV6)) |
| 1324 | err = checksum_setup_ipv6(vif, skb, recalculate_partial_csum); |
| 1325 | |
| 1326 | return err; |
| 1327 | } |
| 1328 | |
| 1329 | static bool tx_credit_exceeded(struct xenvif *vif, unsigned size) |
| 1330 | { |
| 1331 | u64 now = get_jiffies_64(); |
| 1332 | u64 next_credit = vif->credit_window_start + |
| 1333 | msecs_to_jiffies(vif->credit_usec / 1000); |
| 1334 | |
| 1335 | /* Timer could already be pending in rare cases. */ |
| 1336 | if (timer_pending(&vif->credit_timeout)) |
| 1337 | return true; |
| 1338 | |
| 1339 | /* Passed the point where we can replenish credit? */ |
| 1340 | if (time_after_eq64(now, next_credit)) { |
| 1341 | vif->credit_window_start = now; |
| 1342 | tx_add_credit(vif); |
| 1343 | } |
| 1344 | |
| 1345 | /* Still too big to send right now? Set a callback. */ |
| 1346 | if (size > vif->remaining_credit) { |
| 1347 | vif->credit_timeout.data = |
| 1348 | (unsigned long)vif; |
| 1349 | vif->credit_timeout.function = |
| 1350 | tx_credit_callback; |
| 1351 | mod_timer(&vif->credit_timeout, |
| 1352 | next_credit); |
| 1353 | vif->credit_window_start = next_credit; |
| 1354 | |
| 1355 | return true; |
| 1356 | } |
| 1357 | |
| 1358 | return false; |
| 1359 | } |
| 1360 | |
| 1361 | static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget) |
| 1362 | { |
| 1363 | struct gnttab_copy *gop = vif->tx_copy_ops, *request_gop; |
| 1364 | struct sk_buff *skb; |
| 1365 | int ret; |
| 1366 | |
| 1367 | while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX |
| 1368 | < MAX_PENDING_REQS) && |
| 1369 | (skb_queue_len(&vif->tx_queue) < budget)) { |
| 1370 | struct xen_netif_tx_request txreq; |
| 1371 | struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX]; |
| 1372 | struct page *page; |
| 1373 | struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1]; |
| 1374 | u16 pending_idx; |
| 1375 | RING_IDX idx; |
| 1376 | int work_to_do; |
| 1377 | unsigned int data_len; |
| 1378 | pending_ring_idx_t index; |
| 1379 | |
| 1380 | if (vif->tx.sring->req_prod - vif->tx.req_cons > |
| 1381 | XEN_NETIF_TX_RING_SIZE) { |
| 1382 | netdev_err(vif->dev, |
| 1383 | "Impossible number of requests. " |
| 1384 | "req_prod %d, req_cons %d, size %ld\n", |
| 1385 | vif->tx.sring->req_prod, vif->tx.req_cons, |
| 1386 | XEN_NETIF_TX_RING_SIZE); |
| 1387 | xenvif_fatal_tx_err(vif); |
| 1388 | continue; |
| 1389 | } |
| 1390 | |
| 1391 | work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&vif->tx); |
| 1392 | if (!work_to_do) |
| 1393 | break; |
| 1394 | |
| 1395 | idx = vif->tx.req_cons; |
| 1396 | rmb(); /* Ensure that we see the request before we copy it. */ |
| 1397 | memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq)); |
| 1398 | |
| 1399 | /* Credit-based scheduling. */ |
| 1400 | if (txreq.size > vif->remaining_credit && |
| 1401 | tx_credit_exceeded(vif, txreq.size)) |
| 1402 | break; |
| 1403 | |
| 1404 | vif->remaining_credit -= txreq.size; |
| 1405 | |
| 1406 | work_to_do--; |
| 1407 | vif->tx.req_cons = ++idx; |
| 1408 | |
| 1409 | memset(extras, 0, sizeof(extras)); |
| 1410 | if (txreq.flags & XEN_NETTXF_extra_info) { |
| 1411 | work_to_do = xenvif_get_extras(vif, extras, |
| 1412 | work_to_do); |
| 1413 | idx = vif->tx.req_cons; |
| 1414 | if (unlikely(work_to_do < 0)) |
| 1415 | break; |
| 1416 | } |
| 1417 | |
| 1418 | ret = xenvif_count_requests(vif, &txreq, txfrags, work_to_do); |
| 1419 | if (unlikely(ret < 0)) |
| 1420 | break; |
| 1421 | |
| 1422 | idx += ret; |
| 1423 | |
| 1424 | if (unlikely(txreq.size < ETH_HLEN)) { |
| 1425 | netdev_dbg(vif->dev, |
| 1426 | "Bad packet size: %d\n", txreq.size); |
| 1427 | xenvif_tx_err(vif, &txreq, idx); |
| 1428 | break; |
| 1429 | } |
| 1430 | |
| 1431 | /* No crossing a page as the payload mustn't fragment. */ |
| 1432 | if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) { |
| 1433 | netdev_err(vif->dev, |
| 1434 | "txreq.offset: %x, size: %u, end: %lu\n", |
| 1435 | txreq.offset, txreq.size, |
| 1436 | (txreq.offset&~PAGE_MASK) + txreq.size); |
| 1437 | xenvif_fatal_tx_err(vif); |
| 1438 | break; |
| 1439 | } |
| 1440 | |
| 1441 | index = pending_index(vif->pending_cons); |
| 1442 | pending_idx = vif->pending_ring[index]; |
| 1443 | |
| 1444 | data_len = (txreq.size > PKT_PROT_LEN && |
| 1445 | ret < XEN_NETBK_LEGACY_SLOTS_MAX) ? |
| 1446 | PKT_PROT_LEN : txreq.size; |
| 1447 | |
| 1448 | skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN, |
| 1449 | GFP_ATOMIC | __GFP_NOWARN); |
| 1450 | if (unlikely(skb == NULL)) { |
| 1451 | netdev_dbg(vif->dev, |
| 1452 | "Can't allocate a skb in start_xmit.\n"); |
| 1453 | xenvif_tx_err(vif, &txreq, idx); |
| 1454 | break; |
| 1455 | } |
| 1456 | |
| 1457 | /* Packets passed to netif_rx() must have some headroom. */ |
| 1458 | skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); |
| 1459 | |
| 1460 | if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { |
| 1461 | struct xen_netif_extra_info *gso; |
| 1462 | gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; |
| 1463 | |
| 1464 | if (xenvif_set_skb_gso(vif, skb, gso)) { |
| 1465 | /* Failure in xenvif_set_skb_gso is fatal. */ |
| 1466 | kfree_skb(skb); |
| 1467 | break; |
| 1468 | } |
| 1469 | } |
| 1470 | |
| 1471 | /* XXX could copy straight to head */ |
| 1472 | page = xenvif_alloc_page(vif, pending_idx); |
| 1473 | if (!page) { |
| 1474 | kfree_skb(skb); |
| 1475 | xenvif_tx_err(vif, &txreq, idx); |
| 1476 | break; |
| 1477 | } |
| 1478 | |
| 1479 | gop->source.u.ref = txreq.gref; |
| 1480 | gop->source.domid = vif->domid; |
| 1481 | gop->source.offset = txreq.offset; |
| 1482 | |
| 1483 | gop->dest.u.gmfn = virt_to_mfn(page_address(page)); |
| 1484 | gop->dest.domid = DOMID_SELF; |
| 1485 | gop->dest.offset = txreq.offset; |
| 1486 | |
| 1487 | gop->len = txreq.size; |
| 1488 | gop->flags = GNTCOPY_source_gref; |
| 1489 | |
| 1490 | gop++; |
| 1491 | |
| 1492 | memcpy(&vif->pending_tx_info[pending_idx].req, |
| 1493 | &txreq, sizeof(txreq)); |
| 1494 | vif->pending_tx_info[pending_idx].head = index; |
| 1495 | *((u16 *)skb->data) = pending_idx; |
| 1496 | |
| 1497 | __skb_put(skb, data_len); |
| 1498 | |
| 1499 | skb_shinfo(skb)->nr_frags = ret; |
| 1500 | if (data_len < txreq.size) { |
| 1501 | skb_shinfo(skb)->nr_frags++; |
| 1502 | frag_set_pending_idx(&skb_shinfo(skb)->frags[0], |
| 1503 | pending_idx); |
| 1504 | } else { |
| 1505 | frag_set_pending_idx(&skb_shinfo(skb)->frags[0], |
| 1506 | INVALID_PENDING_IDX); |
| 1507 | } |
| 1508 | |
| 1509 | vif->pending_cons++; |
| 1510 | |
| 1511 | request_gop = xenvif_get_requests(vif, skb, txfrags, gop); |
| 1512 | if (request_gop == NULL) { |
| 1513 | kfree_skb(skb); |
| 1514 | xenvif_tx_err(vif, &txreq, idx); |
| 1515 | break; |
| 1516 | } |
| 1517 | gop = request_gop; |
| 1518 | |
| 1519 | __skb_queue_tail(&vif->tx_queue, skb); |
| 1520 | |
| 1521 | vif->tx.req_cons = idx; |
| 1522 | |
| 1523 | if ((gop-vif->tx_copy_ops) >= ARRAY_SIZE(vif->tx_copy_ops)) |
| 1524 | break; |
| 1525 | } |
| 1526 | |
| 1527 | return gop - vif->tx_copy_ops; |
| 1528 | } |
| 1529 | |
| 1530 | |
| 1531 | static int xenvif_tx_submit(struct xenvif *vif) |
| 1532 | { |
| 1533 | struct gnttab_copy *gop = vif->tx_copy_ops; |
| 1534 | struct sk_buff *skb; |
| 1535 | int work_done = 0; |
| 1536 | |
| 1537 | while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) { |
| 1538 | struct xen_netif_tx_request *txp; |
| 1539 | u16 pending_idx; |
| 1540 | unsigned data_len; |
| 1541 | |
| 1542 | pending_idx = *((u16 *)skb->data); |
| 1543 | txp = &vif->pending_tx_info[pending_idx].req; |
| 1544 | |
| 1545 | /* Check the remap error code. */ |
| 1546 | if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) { |
| 1547 | netdev_dbg(vif->dev, "netback grant failed.\n"); |
| 1548 | skb_shinfo(skb)->nr_frags = 0; |
| 1549 | kfree_skb(skb); |
| 1550 | continue; |
| 1551 | } |
| 1552 | |
| 1553 | data_len = skb->len; |
| 1554 | memcpy(skb->data, |
| 1555 | (void *)(idx_to_kaddr(vif, pending_idx)|txp->offset), |
| 1556 | data_len); |
| 1557 | if (data_len < txp->size) { |
| 1558 | /* Append the packet payload as a fragment. */ |
| 1559 | txp->offset += data_len; |
| 1560 | txp->size -= data_len; |
| 1561 | } else { |
| 1562 | /* Schedule a response immediately. */ |
| 1563 | xenvif_idx_release(vif, pending_idx, |
| 1564 | XEN_NETIF_RSP_OKAY); |
| 1565 | } |
| 1566 | |
| 1567 | if (txp->flags & XEN_NETTXF_csum_blank) |
| 1568 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1569 | else if (txp->flags & XEN_NETTXF_data_validated) |
| 1570 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 1571 | |
| 1572 | xenvif_fill_frags(vif, skb); |
| 1573 | |
| 1574 | if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) { |
| 1575 | int target = min_t(int, skb->len, PKT_PROT_LEN); |
| 1576 | __pskb_pull_tail(skb, target - skb_headlen(skb)); |
| 1577 | } |
| 1578 | |
| 1579 | skb->dev = vif->dev; |
| 1580 | skb->protocol = eth_type_trans(skb, skb->dev); |
| 1581 | skb_reset_network_header(skb); |
| 1582 | |
| 1583 | if (checksum_setup(vif, skb)) { |
| 1584 | netdev_dbg(vif->dev, |
| 1585 | "Can't setup checksum in net_tx_action\n"); |
| 1586 | kfree_skb(skb); |
| 1587 | continue; |
| 1588 | } |
| 1589 | |
| 1590 | skb_probe_transport_header(skb, 0); |
| 1591 | |
| 1592 | /* If the packet is GSO then we will have just set up the |
| 1593 | * transport header offset in checksum_setup so it's now |
| 1594 | * straightforward to calculate gso_segs. |
| 1595 | */ |
| 1596 | if (skb_is_gso(skb)) { |
| 1597 | int mss = skb_shinfo(skb)->gso_size; |
| 1598 | int hdrlen = skb_transport_header(skb) - |
| 1599 | skb_mac_header(skb) + |
| 1600 | tcp_hdrlen(skb); |
| 1601 | |
| 1602 | skb_shinfo(skb)->gso_segs = |
| 1603 | DIV_ROUND_UP(skb->len - hdrlen, mss); |
| 1604 | } |
| 1605 | |
| 1606 | vif->dev->stats.rx_bytes += skb->len; |
| 1607 | vif->dev->stats.rx_packets++; |
| 1608 | |
| 1609 | work_done++; |
| 1610 | |
| 1611 | netif_receive_skb(skb); |
| 1612 | } |
| 1613 | |
| 1614 | return work_done; |
| 1615 | } |
| 1616 | |
| 1617 | /* Called after netfront has transmitted */ |
| 1618 | int xenvif_tx_action(struct xenvif *vif, int budget) |
| 1619 | { |
| 1620 | unsigned nr_gops; |
| 1621 | int work_done; |
| 1622 | |
| 1623 | if (unlikely(!tx_work_todo(vif))) |
| 1624 | return 0; |
| 1625 | |
| 1626 | nr_gops = xenvif_tx_build_gops(vif, budget); |
| 1627 | |
| 1628 | if (nr_gops == 0) |
| 1629 | return 0; |
| 1630 | |
| 1631 | gnttab_batch_copy(vif->tx_copy_ops, nr_gops); |
| 1632 | |
| 1633 | work_done = xenvif_tx_submit(vif); |
| 1634 | |
| 1635 | return work_done; |
| 1636 | } |
| 1637 | |
| 1638 | static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx, |
| 1639 | u8 status) |
| 1640 | { |
| 1641 | struct pending_tx_info *pending_tx_info; |
| 1642 | pending_ring_idx_t head; |
| 1643 | u16 peek; /* peek into next tx request */ |
| 1644 | |
| 1645 | BUG_ON(vif->mmap_pages[pending_idx] == (void *)(~0UL)); |
| 1646 | |
| 1647 | /* Already complete? */ |
| 1648 | if (vif->mmap_pages[pending_idx] == NULL) |
| 1649 | return; |
| 1650 | |
| 1651 | pending_tx_info = &vif->pending_tx_info[pending_idx]; |
| 1652 | |
| 1653 | head = pending_tx_info->head; |
| 1654 | |
| 1655 | BUG_ON(!pending_tx_is_head(vif, head)); |
| 1656 | BUG_ON(vif->pending_ring[pending_index(head)] != pending_idx); |
| 1657 | |
| 1658 | do { |
| 1659 | pending_ring_idx_t index; |
| 1660 | pending_ring_idx_t idx = pending_index(head); |
| 1661 | u16 info_idx = vif->pending_ring[idx]; |
| 1662 | |
| 1663 | pending_tx_info = &vif->pending_tx_info[info_idx]; |
| 1664 | make_tx_response(vif, &pending_tx_info->req, status); |
| 1665 | |
| 1666 | /* Setting any number other than |
| 1667 | * INVALID_PENDING_RING_IDX indicates this slot is |
| 1668 | * starting a new packet / ending a previous packet. |
| 1669 | */ |
| 1670 | pending_tx_info->head = 0; |
| 1671 | |
| 1672 | index = pending_index(vif->pending_prod++); |
| 1673 | vif->pending_ring[index] = vif->pending_ring[info_idx]; |
| 1674 | |
| 1675 | peek = vif->pending_ring[pending_index(++head)]; |
| 1676 | |
| 1677 | } while (!pending_tx_is_head(vif, peek)); |
| 1678 | |
| 1679 | put_page(vif->mmap_pages[pending_idx]); |
| 1680 | vif->mmap_pages[pending_idx] = NULL; |
| 1681 | } |
| 1682 | |
| 1683 | |
| 1684 | static void make_tx_response(struct xenvif *vif, |
| 1685 | struct xen_netif_tx_request *txp, |
| 1686 | s8 st) |
| 1687 | { |
| 1688 | RING_IDX i = vif->tx.rsp_prod_pvt; |
| 1689 | struct xen_netif_tx_response *resp; |
| 1690 | int notify; |
| 1691 | |
| 1692 | resp = RING_GET_RESPONSE(&vif->tx, i); |
| 1693 | resp->id = txp->id; |
| 1694 | resp->status = st; |
| 1695 | |
| 1696 | if (txp->flags & XEN_NETTXF_extra_info) |
| 1697 | RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL; |
| 1698 | |
| 1699 | vif->tx.rsp_prod_pvt = ++i; |
| 1700 | RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify); |
| 1701 | if (notify) |
| 1702 | notify_remote_via_irq(vif->tx_irq); |
| 1703 | } |
| 1704 | |
| 1705 | static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, |
| 1706 | u16 id, |
| 1707 | s8 st, |
| 1708 | u16 offset, |
| 1709 | u16 size, |
| 1710 | u16 flags) |
| 1711 | { |
| 1712 | RING_IDX i = vif->rx.rsp_prod_pvt; |
| 1713 | struct xen_netif_rx_response *resp; |
| 1714 | |
| 1715 | resp = RING_GET_RESPONSE(&vif->rx, i); |
| 1716 | resp->offset = offset; |
| 1717 | resp->flags = flags; |
| 1718 | resp->id = id; |
| 1719 | resp->status = (s16)size; |
| 1720 | if (st < 0) |
| 1721 | resp->status = (s16)st; |
| 1722 | |
| 1723 | vif->rx.rsp_prod_pvt = ++i; |
| 1724 | |
| 1725 | return resp; |
| 1726 | } |
| 1727 | |
| 1728 | static inline int rx_work_todo(struct xenvif *vif) |
| 1729 | { |
| 1730 | return (!skb_queue_empty(&vif->rx_queue) && !vif->rx_queue_stopped) || |
| 1731 | vif->rx_event; |
| 1732 | } |
| 1733 | |
| 1734 | static inline int tx_work_todo(struct xenvif *vif) |
| 1735 | { |
| 1736 | |
| 1737 | if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)) && |
| 1738 | (nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX |
| 1739 | < MAX_PENDING_REQS)) |
| 1740 | return 1; |
| 1741 | |
| 1742 | return 0; |
| 1743 | } |
| 1744 | |
| 1745 | void xenvif_unmap_frontend_rings(struct xenvif *vif) |
| 1746 | { |
| 1747 | if (vif->tx.sring) |
| 1748 | xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), |
| 1749 | vif->tx.sring); |
| 1750 | if (vif->rx.sring) |
| 1751 | xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), |
| 1752 | vif->rx.sring); |
| 1753 | } |
| 1754 | |
| 1755 | int xenvif_map_frontend_rings(struct xenvif *vif, |
| 1756 | grant_ref_t tx_ring_ref, |
| 1757 | grant_ref_t rx_ring_ref) |
| 1758 | { |
| 1759 | void *addr; |
| 1760 | struct xen_netif_tx_sring *txs; |
| 1761 | struct xen_netif_rx_sring *rxs; |
| 1762 | |
| 1763 | int err = -ENOMEM; |
| 1764 | |
| 1765 | err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), |
| 1766 | tx_ring_ref, &addr); |
| 1767 | if (err) |
| 1768 | goto err; |
| 1769 | |
| 1770 | txs = (struct xen_netif_tx_sring *)addr; |
| 1771 | BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE); |
| 1772 | |
| 1773 | err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), |
| 1774 | rx_ring_ref, &addr); |
| 1775 | if (err) |
| 1776 | goto err; |
| 1777 | |
| 1778 | rxs = (struct xen_netif_rx_sring *)addr; |
| 1779 | BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE); |
| 1780 | |
| 1781 | return 0; |
| 1782 | |
| 1783 | err: |
| 1784 | xenvif_unmap_frontend_rings(vif); |
| 1785 | return err; |
| 1786 | } |
| 1787 | |
| 1788 | void xenvif_stop_queue(struct xenvif *vif) |
| 1789 | { |
| 1790 | if (!vif->can_queue) |
| 1791 | return; |
| 1792 | |
| 1793 | netif_stop_queue(vif->dev); |
| 1794 | } |
| 1795 | |
| 1796 | static void xenvif_start_queue(struct xenvif *vif) |
| 1797 | { |
| 1798 | if (xenvif_schedulable(vif)) |
| 1799 | netif_wake_queue(vif->dev); |
| 1800 | } |
| 1801 | |
| 1802 | int xenvif_kthread(void *data) |
| 1803 | { |
| 1804 | struct xenvif *vif = data; |
| 1805 | struct sk_buff *skb; |
| 1806 | |
| 1807 | while (!kthread_should_stop()) { |
| 1808 | wait_event_interruptible(vif->wq, |
| 1809 | rx_work_todo(vif) || |
| 1810 | kthread_should_stop()); |
| 1811 | if (kthread_should_stop()) |
| 1812 | break; |
| 1813 | |
| 1814 | if (!skb_queue_empty(&vif->rx_queue)) |
| 1815 | xenvif_rx_action(vif); |
| 1816 | |
| 1817 | vif->rx_event = false; |
| 1818 | |
| 1819 | if (skb_queue_empty(&vif->rx_queue) && |
| 1820 | netif_queue_stopped(vif->dev)) |
| 1821 | xenvif_start_queue(vif); |
| 1822 | |
| 1823 | cond_resched(); |
| 1824 | } |
| 1825 | |
| 1826 | /* Bin any remaining skbs */ |
| 1827 | while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) |
| 1828 | dev_kfree_skb(skb); |
| 1829 | |
| 1830 | return 0; |
| 1831 | } |
| 1832 | |
| 1833 | static int __init netback_init(void) |
| 1834 | { |
| 1835 | int rc = 0; |
| 1836 | |
| 1837 | if (!xen_domain()) |
| 1838 | return -ENODEV; |
| 1839 | |
| 1840 | if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) { |
| 1841 | pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n", |
| 1842 | fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX); |
| 1843 | fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX; |
| 1844 | } |
| 1845 | |
| 1846 | rc = xenvif_xenbus_init(); |
| 1847 | if (rc) |
| 1848 | goto failed_init; |
| 1849 | |
| 1850 | return 0; |
| 1851 | |
| 1852 | failed_init: |
| 1853 | return rc; |
| 1854 | } |
| 1855 | |
| 1856 | module_init(netback_init); |
| 1857 | |
| 1858 | static void __exit netback_fini(void) |
| 1859 | { |
| 1860 | xenvif_xenbus_fini(); |
| 1861 | } |
| 1862 | module_exit(netback_fini); |
| 1863 | |
| 1864 | MODULE_LICENSE("Dual BSD/GPL"); |
| 1865 | MODULE_ALIAS("xen-backend:vif"); |