| 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 | #include <linux/highmem.h> |
| 41 | |
| 42 | #include <net/tcp.h> |
| 43 | |
| 44 | #include <xen/xen.h> |
| 45 | #include <xen/events.h> |
| 46 | #include <xen/interface/memory.h> |
| 47 | #include <xen/page.h> |
| 48 | |
| 49 | #include <asm/xen/hypercall.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 = true; |
| 56 | module_param(separate_tx_rx_irq, bool, 0644); |
| 57 | |
| 58 | /* The time that packets can stay on the guest Rx internal queue |
| 59 | * before they are dropped. |
| 60 | */ |
| 61 | unsigned int rx_drain_timeout_msecs = 10000; |
| 62 | module_param(rx_drain_timeout_msecs, uint, 0444); |
| 63 | |
| 64 | /* The length of time before the frontend is considered unresponsive |
| 65 | * because it isn't providing Rx slots. |
| 66 | */ |
| 67 | unsigned int rx_stall_timeout_msecs = 60000; |
| 68 | module_param(rx_stall_timeout_msecs, uint, 0444); |
| 69 | |
| 70 | unsigned int xenvif_max_queues; |
| 71 | module_param_named(max_queues, xenvif_max_queues, uint, 0644); |
| 72 | MODULE_PARM_DESC(max_queues, |
| 73 | "Maximum number of queues per virtual interface"); |
| 74 | |
| 75 | /* |
| 76 | * This is the maximum slots a skb can have. If a guest sends a skb |
| 77 | * which exceeds this limit it is considered malicious. |
| 78 | */ |
| 79 | #define FATAL_SKB_SLOTS_DEFAULT 20 |
| 80 | static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT; |
| 81 | module_param(fatal_skb_slots, uint, 0444); |
| 82 | |
| 83 | /* The amount to copy out of the first guest Tx slot into the skb's |
| 84 | * linear area. If the first slot has more data, it will be mapped |
| 85 | * and put into the first frag. |
| 86 | * |
| 87 | * This is sized to avoid pulling headers from the frags for most |
| 88 | * TCP/IP packets. |
| 89 | */ |
| 90 | #define XEN_NETBACK_TX_COPY_LEN 128 |
| 91 | |
| 92 | |
| 93 | static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx, |
| 94 | u8 status); |
| 95 | |
| 96 | static void make_tx_response(struct xenvif_queue *queue, |
| 97 | struct xen_netif_tx_request *txp, |
| 98 | unsigned int extra_count, |
| 99 | s8 st); |
| 100 | static void push_tx_responses(struct xenvif_queue *queue); |
| 101 | |
| 102 | static inline int tx_work_todo(struct xenvif_queue *queue); |
| 103 | |
| 104 | static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue, |
| 105 | u16 id, |
| 106 | s8 st, |
| 107 | u16 offset, |
| 108 | u16 size, |
| 109 | u16 flags); |
| 110 | |
| 111 | static inline unsigned long idx_to_pfn(struct xenvif_queue *queue, |
| 112 | u16 idx) |
| 113 | { |
| 114 | return page_to_pfn(queue->mmap_pages[idx]); |
| 115 | } |
| 116 | |
| 117 | static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue, |
| 118 | u16 idx) |
| 119 | { |
| 120 | return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx)); |
| 121 | } |
| 122 | |
| 123 | #define callback_param(vif, pending_idx) \ |
| 124 | (vif->pending_tx_info[pending_idx].callback_struct) |
| 125 | |
| 126 | /* Find the containing VIF's structure from a pointer in pending_tx_info array |
| 127 | */ |
| 128 | static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info *ubuf) |
| 129 | { |
| 130 | u16 pending_idx = ubuf->desc; |
| 131 | struct pending_tx_info *temp = |
| 132 | container_of(ubuf, struct pending_tx_info, callback_struct); |
| 133 | return container_of(temp - pending_idx, |
| 134 | struct xenvif_queue, |
| 135 | pending_tx_info[0]); |
| 136 | } |
| 137 | |
| 138 | static u16 frag_get_pending_idx(skb_frag_t *frag) |
| 139 | { |
| 140 | return (u16)frag->page_offset; |
| 141 | } |
| 142 | |
| 143 | static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx) |
| 144 | { |
| 145 | frag->page_offset = pending_idx; |
| 146 | } |
| 147 | |
| 148 | static inline pending_ring_idx_t pending_index(unsigned i) |
| 149 | { |
| 150 | return i & (MAX_PENDING_REQS-1); |
| 151 | } |
| 152 | |
| 153 | static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue) |
| 154 | { |
| 155 | RING_IDX prod, cons; |
| 156 | struct sk_buff *skb; |
| 157 | int needed; |
| 158 | |
| 159 | skb = skb_peek(&queue->rx_queue); |
| 160 | if (!skb) |
| 161 | return false; |
| 162 | |
| 163 | needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE); |
| 164 | if (skb_is_gso(skb)) |
| 165 | needed++; |
| 166 | |
| 167 | do { |
| 168 | prod = queue->rx.sring->req_prod; |
| 169 | cons = queue->rx.req_cons; |
| 170 | |
| 171 | if (prod - cons >= needed) |
| 172 | return true; |
| 173 | |
| 174 | queue->rx.sring->req_event = prod + 1; |
| 175 | |
| 176 | /* Make sure event is visible before we check prod |
| 177 | * again. |
| 178 | */ |
| 179 | mb(); |
| 180 | } while (queue->rx.sring->req_prod != prod); |
| 181 | |
| 182 | return false; |
| 183 | } |
| 184 | |
| 185 | void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb) |
| 186 | { |
| 187 | unsigned long flags; |
| 188 | |
| 189 | spin_lock_irqsave(&queue->rx_queue.lock, flags); |
| 190 | |
| 191 | __skb_queue_tail(&queue->rx_queue, skb); |
| 192 | |
| 193 | queue->rx_queue_len += skb->len; |
| 194 | if (queue->rx_queue_len > queue->rx_queue_max) |
| 195 | netif_tx_stop_queue(netdev_get_tx_queue(queue->vif->dev, queue->id)); |
| 196 | |
| 197 | spin_unlock_irqrestore(&queue->rx_queue.lock, flags); |
| 198 | } |
| 199 | |
| 200 | static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue) |
| 201 | { |
| 202 | struct sk_buff *skb; |
| 203 | |
| 204 | spin_lock_irq(&queue->rx_queue.lock); |
| 205 | |
| 206 | skb = __skb_dequeue(&queue->rx_queue); |
| 207 | if (skb) |
| 208 | queue->rx_queue_len -= skb->len; |
| 209 | |
| 210 | spin_unlock_irq(&queue->rx_queue.lock); |
| 211 | |
| 212 | return skb; |
| 213 | } |
| 214 | |
| 215 | static void xenvif_rx_queue_maybe_wake(struct xenvif_queue *queue) |
| 216 | { |
| 217 | spin_lock_irq(&queue->rx_queue.lock); |
| 218 | |
| 219 | if (queue->rx_queue_len < queue->rx_queue_max) |
| 220 | netif_tx_wake_queue(netdev_get_tx_queue(queue->vif->dev, queue->id)); |
| 221 | |
| 222 | spin_unlock_irq(&queue->rx_queue.lock); |
| 223 | } |
| 224 | |
| 225 | |
| 226 | static void xenvif_rx_queue_purge(struct xenvif_queue *queue) |
| 227 | { |
| 228 | struct sk_buff *skb; |
| 229 | while ((skb = xenvif_rx_dequeue(queue)) != NULL) |
| 230 | kfree_skb(skb); |
| 231 | } |
| 232 | |
| 233 | static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue) |
| 234 | { |
| 235 | struct sk_buff *skb; |
| 236 | |
| 237 | for(;;) { |
| 238 | skb = skb_peek(&queue->rx_queue); |
| 239 | if (!skb) |
| 240 | break; |
| 241 | if (time_before(jiffies, XENVIF_RX_CB(skb)->expires)) |
| 242 | break; |
| 243 | xenvif_rx_dequeue(queue); |
| 244 | kfree_skb(skb); |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | struct netrx_pending_operations { |
| 249 | unsigned copy_prod, copy_cons; |
| 250 | unsigned meta_prod, meta_cons; |
| 251 | struct gnttab_copy *copy; |
| 252 | struct xenvif_rx_meta *meta; |
| 253 | int copy_off; |
| 254 | grant_ref_t copy_gref; |
| 255 | }; |
| 256 | |
| 257 | static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue, |
| 258 | struct netrx_pending_operations *npo) |
| 259 | { |
| 260 | struct xenvif_rx_meta *meta; |
| 261 | struct xen_netif_rx_request req; |
| 262 | |
| 263 | RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req); |
| 264 | |
| 265 | meta = npo->meta + npo->meta_prod++; |
| 266 | meta->gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| 267 | meta->gso_size = 0; |
| 268 | meta->size = 0; |
| 269 | meta->id = req.id; |
| 270 | |
| 271 | npo->copy_off = 0; |
| 272 | npo->copy_gref = req.gref; |
| 273 | |
| 274 | return meta; |
| 275 | } |
| 276 | |
| 277 | struct gop_frag_copy { |
| 278 | struct xenvif_queue *queue; |
| 279 | struct netrx_pending_operations *npo; |
| 280 | struct xenvif_rx_meta *meta; |
| 281 | int head; |
| 282 | int gso_type; |
| 283 | |
| 284 | struct page *page; |
| 285 | }; |
| 286 | |
| 287 | static void xenvif_setup_copy_gop(unsigned long gfn, |
| 288 | unsigned int offset, |
| 289 | unsigned int *len, |
| 290 | struct gop_frag_copy *info) |
| 291 | { |
| 292 | struct gnttab_copy *copy_gop; |
| 293 | struct xen_page_foreign *foreign; |
| 294 | /* Convenient aliases */ |
| 295 | struct xenvif_queue *queue = info->queue; |
| 296 | struct netrx_pending_operations *npo = info->npo; |
| 297 | struct page *page = info->page; |
| 298 | |
| 299 | BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET); |
| 300 | |
| 301 | if (npo->copy_off == MAX_BUFFER_OFFSET) |
| 302 | info->meta = get_next_rx_buffer(queue, npo); |
| 303 | |
| 304 | if (npo->copy_off + *len > MAX_BUFFER_OFFSET) |
| 305 | *len = MAX_BUFFER_OFFSET - npo->copy_off; |
| 306 | |
| 307 | copy_gop = npo->copy + npo->copy_prod++; |
| 308 | copy_gop->flags = GNTCOPY_dest_gref; |
| 309 | copy_gop->len = *len; |
| 310 | |
| 311 | foreign = xen_page_foreign(page); |
| 312 | if (foreign) { |
| 313 | copy_gop->source.domid = foreign->domid; |
| 314 | copy_gop->source.u.ref = foreign->gref; |
| 315 | copy_gop->flags |= GNTCOPY_source_gref; |
| 316 | } else { |
| 317 | copy_gop->source.domid = DOMID_SELF; |
| 318 | copy_gop->source.u.gmfn = gfn; |
| 319 | } |
| 320 | copy_gop->source.offset = offset; |
| 321 | |
| 322 | copy_gop->dest.domid = queue->vif->domid; |
| 323 | copy_gop->dest.offset = npo->copy_off; |
| 324 | copy_gop->dest.u.ref = npo->copy_gref; |
| 325 | |
| 326 | npo->copy_off += *len; |
| 327 | info->meta->size += *len; |
| 328 | |
| 329 | /* Leave a gap for the GSO descriptor. */ |
| 330 | if (info->head && ((1 << info->gso_type) & queue->vif->gso_mask)) |
| 331 | queue->rx.req_cons++; |
| 332 | |
| 333 | info->head = 0; /* There must be something in this buffer now */ |
| 334 | } |
| 335 | |
| 336 | static void xenvif_gop_frag_copy_grant(unsigned long gfn, |
| 337 | unsigned offset, |
| 338 | unsigned int len, |
| 339 | void *data) |
| 340 | { |
| 341 | unsigned int bytes; |
| 342 | |
| 343 | while (len) { |
| 344 | bytes = len; |
| 345 | xenvif_setup_copy_gop(gfn, offset, &bytes, data); |
| 346 | offset += bytes; |
| 347 | len -= bytes; |
| 348 | } |
| 349 | } |
| 350 | |
| 351 | /* |
| 352 | * Set up the grant operations for this fragment. If it's a flipping |
| 353 | * interface, we also set up the unmap request from here. |
| 354 | */ |
| 355 | static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb, |
| 356 | struct netrx_pending_operations *npo, |
| 357 | struct page *page, unsigned long size, |
| 358 | unsigned long offset, int *head) |
| 359 | { |
| 360 | struct gop_frag_copy info = { |
| 361 | .queue = queue, |
| 362 | .npo = npo, |
| 363 | .head = *head, |
| 364 | .gso_type = XEN_NETIF_GSO_TYPE_NONE, |
| 365 | }; |
| 366 | unsigned long bytes; |
| 367 | |
| 368 | if (skb_is_gso(skb)) { |
| 369 | if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) |
| 370 | info.gso_type = XEN_NETIF_GSO_TYPE_TCPV4; |
| 371 | else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) |
| 372 | info.gso_type = XEN_NETIF_GSO_TYPE_TCPV6; |
| 373 | } |
| 374 | |
| 375 | /* Data must not cross a page boundary. */ |
| 376 | BUG_ON(size + offset > PAGE_SIZE<<compound_order(page)); |
| 377 | |
| 378 | info.meta = npo->meta + npo->meta_prod - 1; |
| 379 | |
| 380 | /* Skip unused frames from start of page */ |
| 381 | page += offset >> PAGE_SHIFT; |
| 382 | offset &= ~PAGE_MASK; |
| 383 | |
| 384 | while (size > 0) { |
| 385 | BUG_ON(offset >= PAGE_SIZE); |
| 386 | |
| 387 | bytes = PAGE_SIZE - offset; |
| 388 | if (bytes > size) |
| 389 | bytes = size; |
| 390 | |
| 391 | info.page = page; |
| 392 | gnttab_foreach_grant_in_range(page, offset, bytes, |
| 393 | xenvif_gop_frag_copy_grant, |
| 394 | &info); |
| 395 | size -= bytes; |
| 396 | offset = 0; |
| 397 | |
| 398 | /* Next page */ |
| 399 | if (size) { |
| 400 | BUG_ON(!PageCompound(page)); |
| 401 | page++; |
| 402 | } |
| 403 | } |
| 404 | |
| 405 | *head = info.head; |
| 406 | } |
| 407 | |
| 408 | /* |
| 409 | * Prepare an SKB to be transmitted to the frontend. |
| 410 | * |
| 411 | * This function is responsible for allocating grant operations, meta |
| 412 | * structures, etc. |
| 413 | * |
| 414 | * It returns the number of meta structures consumed. The number of |
| 415 | * ring slots used is always equal to the number of meta slots used |
| 416 | * plus the number of GSO descriptors used. Currently, we use either |
| 417 | * zero GSO descriptors (for non-GSO packets) or one descriptor (for |
| 418 | * frontend-side LRO). |
| 419 | */ |
| 420 | static int xenvif_gop_skb(struct sk_buff *skb, |
| 421 | struct netrx_pending_operations *npo, |
| 422 | struct xenvif_queue *queue) |
| 423 | { |
| 424 | struct xenvif *vif = netdev_priv(skb->dev); |
| 425 | int nr_frags = skb_shinfo(skb)->nr_frags; |
| 426 | int i; |
| 427 | struct xen_netif_rx_request req; |
| 428 | struct xenvif_rx_meta *meta; |
| 429 | unsigned char *data; |
| 430 | int head = 1; |
| 431 | int old_meta_prod; |
| 432 | int gso_type; |
| 433 | |
| 434 | old_meta_prod = npo->meta_prod; |
| 435 | |
| 436 | gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| 437 | if (skb_is_gso(skb)) { |
| 438 | if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) |
| 439 | gso_type = XEN_NETIF_GSO_TYPE_TCPV4; |
| 440 | else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) |
| 441 | gso_type = XEN_NETIF_GSO_TYPE_TCPV6; |
| 442 | } |
| 443 | |
| 444 | /* Set up a GSO prefix descriptor, if necessary */ |
| 445 | if ((1 << gso_type) & vif->gso_prefix_mask) { |
| 446 | RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req); |
| 447 | meta = npo->meta + npo->meta_prod++; |
| 448 | meta->gso_type = gso_type; |
| 449 | meta->gso_size = skb_shinfo(skb)->gso_size; |
| 450 | meta->size = 0; |
| 451 | meta->id = req.id; |
| 452 | } |
| 453 | |
| 454 | RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req); |
| 455 | meta = npo->meta + npo->meta_prod++; |
| 456 | |
| 457 | if ((1 << gso_type) & vif->gso_mask) { |
| 458 | meta->gso_type = gso_type; |
| 459 | meta->gso_size = skb_shinfo(skb)->gso_size; |
| 460 | } else { |
| 461 | meta->gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| 462 | meta->gso_size = 0; |
| 463 | } |
| 464 | |
| 465 | meta->size = 0; |
| 466 | meta->id = req.id; |
| 467 | npo->copy_off = 0; |
| 468 | npo->copy_gref = req.gref; |
| 469 | |
| 470 | data = skb->data; |
| 471 | while (data < skb_tail_pointer(skb)) { |
| 472 | unsigned int offset = offset_in_page(data); |
| 473 | unsigned int len = PAGE_SIZE - offset; |
| 474 | |
| 475 | if (data + len > skb_tail_pointer(skb)) |
| 476 | len = skb_tail_pointer(skb) - data; |
| 477 | |
| 478 | xenvif_gop_frag_copy(queue, skb, npo, |
| 479 | virt_to_page(data), len, offset, &head); |
| 480 | data += len; |
| 481 | } |
| 482 | |
| 483 | for (i = 0; i < nr_frags; i++) { |
| 484 | xenvif_gop_frag_copy(queue, skb, npo, |
| 485 | skb_frag_page(&skb_shinfo(skb)->frags[i]), |
| 486 | skb_frag_size(&skb_shinfo(skb)->frags[i]), |
| 487 | skb_shinfo(skb)->frags[i].page_offset, |
| 488 | &head); |
| 489 | } |
| 490 | |
| 491 | return npo->meta_prod - old_meta_prod; |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was |
| 496 | * used to set up the operations on the top of |
| 497 | * netrx_pending_operations, which have since been done. Check that |
| 498 | * they didn't give any errors and advance over them. |
| 499 | */ |
| 500 | static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots, |
| 501 | struct netrx_pending_operations *npo) |
| 502 | { |
| 503 | struct gnttab_copy *copy_op; |
| 504 | int status = XEN_NETIF_RSP_OKAY; |
| 505 | int i; |
| 506 | |
| 507 | for (i = 0; i < nr_meta_slots; i++) { |
| 508 | copy_op = npo->copy + npo->copy_cons++; |
| 509 | if (copy_op->status != GNTST_okay) { |
| 510 | netdev_dbg(vif->dev, |
| 511 | "Bad status %d from copy to DOM%d.\n", |
| 512 | copy_op->status, vif->domid); |
| 513 | status = XEN_NETIF_RSP_ERROR; |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | return status; |
| 518 | } |
| 519 | |
| 520 | static void xenvif_add_frag_responses(struct xenvif_queue *queue, int status, |
| 521 | struct xenvif_rx_meta *meta, |
| 522 | int nr_meta_slots) |
| 523 | { |
| 524 | int i; |
| 525 | unsigned long offset; |
| 526 | |
| 527 | /* No fragments used */ |
| 528 | if (nr_meta_slots <= 1) |
| 529 | return; |
| 530 | |
| 531 | nr_meta_slots--; |
| 532 | |
| 533 | for (i = 0; i < nr_meta_slots; i++) { |
| 534 | int flags; |
| 535 | if (i == nr_meta_slots - 1) |
| 536 | flags = 0; |
| 537 | else |
| 538 | flags = XEN_NETRXF_more_data; |
| 539 | |
| 540 | offset = 0; |
| 541 | make_rx_response(queue, meta[i].id, status, offset, |
| 542 | meta[i].size, flags); |
| 543 | } |
| 544 | } |
| 545 | |
| 546 | void xenvif_kick_thread(struct xenvif_queue *queue) |
| 547 | { |
| 548 | wake_up(&queue->wq); |
| 549 | } |
| 550 | |
| 551 | static void xenvif_rx_action(struct xenvif_queue *queue) |
| 552 | { |
| 553 | s8 status; |
| 554 | u16 flags; |
| 555 | struct xen_netif_rx_response *resp; |
| 556 | struct sk_buff_head rxq; |
| 557 | struct sk_buff *skb; |
| 558 | LIST_HEAD(notify); |
| 559 | int ret; |
| 560 | unsigned long offset; |
| 561 | bool need_to_notify = false; |
| 562 | |
| 563 | struct netrx_pending_operations npo = { |
| 564 | .copy = queue->grant_copy_op, |
| 565 | .meta = queue->meta, |
| 566 | }; |
| 567 | |
| 568 | skb_queue_head_init(&rxq); |
| 569 | |
| 570 | while (xenvif_rx_ring_slots_available(queue) |
| 571 | && (skb = xenvif_rx_dequeue(queue)) != NULL) { |
| 572 | queue->last_rx_time = jiffies; |
| 573 | |
| 574 | XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo, queue); |
| 575 | |
| 576 | __skb_queue_tail(&rxq, skb); |
| 577 | } |
| 578 | |
| 579 | BUG_ON(npo.meta_prod > ARRAY_SIZE(queue->meta)); |
| 580 | |
| 581 | if (!npo.copy_prod) |
| 582 | goto done; |
| 583 | |
| 584 | BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS); |
| 585 | gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod); |
| 586 | |
| 587 | while ((skb = __skb_dequeue(&rxq)) != NULL) { |
| 588 | |
| 589 | if ((1 << queue->meta[npo.meta_cons].gso_type) & |
| 590 | queue->vif->gso_prefix_mask) { |
| 591 | resp = RING_GET_RESPONSE(&queue->rx, |
| 592 | queue->rx.rsp_prod_pvt++); |
| 593 | |
| 594 | resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data; |
| 595 | |
| 596 | resp->offset = queue->meta[npo.meta_cons].gso_size; |
| 597 | resp->id = queue->meta[npo.meta_cons].id; |
| 598 | resp->status = XENVIF_RX_CB(skb)->meta_slots_used; |
| 599 | |
| 600 | npo.meta_cons++; |
| 601 | XENVIF_RX_CB(skb)->meta_slots_used--; |
| 602 | } |
| 603 | |
| 604 | |
| 605 | queue->stats.tx_bytes += skb->len; |
| 606 | queue->stats.tx_packets++; |
| 607 | |
| 608 | status = xenvif_check_gop(queue->vif, |
| 609 | XENVIF_RX_CB(skb)->meta_slots_used, |
| 610 | &npo); |
| 611 | |
| 612 | if (XENVIF_RX_CB(skb)->meta_slots_used == 1) |
| 613 | flags = 0; |
| 614 | else |
| 615 | flags = XEN_NETRXF_more_data; |
| 616 | |
| 617 | if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */ |
| 618 | flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated; |
| 619 | else if (skb->ip_summed == CHECKSUM_UNNECESSARY) |
| 620 | /* remote but checksummed. */ |
| 621 | flags |= XEN_NETRXF_data_validated; |
| 622 | |
| 623 | offset = 0; |
| 624 | resp = make_rx_response(queue, queue->meta[npo.meta_cons].id, |
| 625 | status, offset, |
| 626 | queue->meta[npo.meta_cons].size, |
| 627 | flags); |
| 628 | |
| 629 | if ((1 << queue->meta[npo.meta_cons].gso_type) & |
| 630 | queue->vif->gso_mask) { |
| 631 | struct xen_netif_extra_info *gso = |
| 632 | (struct xen_netif_extra_info *) |
| 633 | RING_GET_RESPONSE(&queue->rx, |
| 634 | queue->rx.rsp_prod_pvt++); |
| 635 | |
| 636 | resp->flags |= XEN_NETRXF_extra_info; |
| 637 | |
| 638 | gso->u.gso.type = queue->meta[npo.meta_cons].gso_type; |
| 639 | gso->u.gso.size = queue->meta[npo.meta_cons].gso_size; |
| 640 | gso->u.gso.pad = 0; |
| 641 | gso->u.gso.features = 0; |
| 642 | |
| 643 | gso->type = XEN_NETIF_EXTRA_TYPE_GSO; |
| 644 | gso->flags = 0; |
| 645 | } |
| 646 | |
| 647 | xenvif_add_frag_responses(queue, status, |
| 648 | queue->meta + npo.meta_cons + 1, |
| 649 | XENVIF_RX_CB(skb)->meta_slots_used); |
| 650 | |
| 651 | RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->rx, ret); |
| 652 | |
| 653 | need_to_notify |= !!ret; |
| 654 | |
| 655 | npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used; |
| 656 | dev_kfree_skb(skb); |
| 657 | } |
| 658 | |
| 659 | done: |
| 660 | if (need_to_notify) |
| 661 | notify_remote_via_irq(queue->rx_irq); |
| 662 | } |
| 663 | |
| 664 | void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue) |
| 665 | { |
| 666 | int more_to_do; |
| 667 | |
| 668 | RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do); |
| 669 | |
| 670 | if (more_to_do) |
| 671 | napi_schedule(&queue->napi); |
| 672 | } |
| 673 | |
| 674 | static void tx_add_credit(struct xenvif_queue *queue) |
| 675 | { |
| 676 | unsigned long max_burst, max_credit; |
| 677 | |
| 678 | /* |
| 679 | * Allow a burst big enough to transmit a jumbo packet of up to 128kB. |
| 680 | * Otherwise the interface can seize up due to insufficient credit. |
| 681 | */ |
| 682 | max_burst = max(131072UL, queue->credit_bytes); |
| 683 | |
| 684 | /* Take care that adding a new chunk of credit doesn't wrap to zero. */ |
| 685 | max_credit = queue->remaining_credit + queue->credit_bytes; |
| 686 | if (max_credit < queue->remaining_credit) |
| 687 | max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */ |
| 688 | |
| 689 | queue->remaining_credit = min(max_credit, max_burst); |
| 690 | } |
| 691 | |
| 692 | void xenvif_tx_credit_callback(unsigned long data) |
| 693 | { |
| 694 | struct xenvif_queue *queue = (struct xenvif_queue *)data; |
| 695 | tx_add_credit(queue); |
| 696 | xenvif_napi_schedule_or_enable_events(queue); |
| 697 | } |
| 698 | |
| 699 | static void xenvif_tx_err(struct xenvif_queue *queue, |
| 700 | struct xen_netif_tx_request *txp, |
| 701 | unsigned int extra_count, RING_IDX end) |
| 702 | { |
| 703 | RING_IDX cons = queue->tx.req_cons; |
| 704 | unsigned long flags; |
| 705 | |
| 706 | do { |
| 707 | spin_lock_irqsave(&queue->response_lock, flags); |
| 708 | make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR); |
| 709 | push_tx_responses(queue); |
| 710 | spin_unlock_irqrestore(&queue->response_lock, flags); |
| 711 | if (cons == end) |
| 712 | break; |
| 713 | RING_COPY_REQUEST(&queue->tx, cons++, txp); |
| 714 | extra_count = 0; /* only the first frag can have extras */ |
| 715 | } while (1); |
| 716 | queue->tx.req_cons = cons; |
| 717 | } |
| 718 | |
| 719 | static void xenvif_fatal_tx_err(struct xenvif *vif) |
| 720 | { |
| 721 | netdev_err(vif->dev, "fatal error; disabling device\n"); |
| 722 | vif->disabled = true; |
| 723 | /* Disable the vif from queue 0's kthread */ |
| 724 | if (vif->queues) |
| 725 | xenvif_kick_thread(&vif->queues[0]); |
| 726 | } |
| 727 | |
| 728 | static int xenvif_count_requests(struct xenvif_queue *queue, |
| 729 | struct xen_netif_tx_request *first, |
| 730 | unsigned int extra_count, |
| 731 | struct xen_netif_tx_request *txp, |
| 732 | int work_to_do) |
| 733 | { |
| 734 | RING_IDX cons = queue->tx.req_cons; |
| 735 | int slots = 0; |
| 736 | int drop_err = 0; |
| 737 | int more_data; |
| 738 | |
| 739 | if (!(first->flags & XEN_NETTXF_more_data)) |
| 740 | return 0; |
| 741 | |
| 742 | do { |
| 743 | struct xen_netif_tx_request dropped_tx = { 0 }; |
| 744 | |
| 745 | if (slots >= work_to_do) { |
| 746 | netdev_err(queue->vif->dev, |
| 747 | "Asked for %d slots but exceeds this limit\n", |
| 748 | work_to_do); |
| 749 | xenvif_fatal_tx_err(queue->vif); |
| 750 | return -ENODATA; |
| 751 | } |
| 752 | |
| 753 | /* This guest is really using too many slots and |
| 754 | * considered malicious. |
| 755 | */ |
| 756 | if (unlikely(slots >= fatal_skb_slots)) { |
| 757 | netdev_err(queue->vif->dev, |
| 758 | "Malicious frontend using %d slots, threshold %u\n", |
| 759 | slots, fatal_skb_slots); |
| 760 | xenvif_fatal_tx_err(queue->vif); |
| 761 | return -E2BIG; |
| 762 | } |
| 763 | |
| 764 | /* Xen network protocol had implicit dependency on |
| 765 | * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to |
| 766 | * the historical MAX_SKB_FRAGS value 18 to honor the |
| 767 | * same behavior as before. Any packet using more than |
| 768 | * 18 slots but less than fatal_skb_slots slots is |
| 769 | * dropped |
| 770 | */ |
| 771 | if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) { |
| 772 | if (net_ratelimit()) |
| 773 | netdev_dbg(queue->vif->dev, |
| 774 | "Too many slots (%d) exceeding limit (%d), dropping packet\n", |
| 775 | slots, XEN_NETBK_LEGACY_SLOTS_MAX); |
| 776 | drop_err = -E2BIG; |
| 777 | } |
| 778 | |
| 779 | if (drop_err) |
| 780 | txp = &dropped_tx; |
| 781 | |
| 782 | RING_COPY_REQUEST(&queue->tx, cons + slots, txp); |
| 783 | |
| 784 | /* If the guest submitted a frame >= 64 KiB then |
| 785 | * first->size overflowed and following slots will |
| 786 | * appear to be larger than the frame. |
| 787 | * |
| 788 | * This cannot be fatal error as there are buggy |
| 789 | * frontends that do this. |
| 790 | * |
| 791 | * Consume all slots and drop the packet. |
| 792 | */ |
| 793 | if (!drop_err && txp->size > first->size) { |
| 794 | if (net_ratelimit()) |
| 795 | netdev_dbg(queue->vif->dev, |
| 796 | "Invalid tx request, slot size %u > remaining size %u\n", |
| 797 | txp->size, first->size); |
| 798 | drop_err = -EIO; |
| 799 | } |
| 800 | |
| 801 | first->size -= txp->size; |
| 802 | slots++; |
| 803 | |
| 804 | if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) { |
| 805 | netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n", |
| 806 | txp->offset, txp->size); |
| 807 | xenvif_fatal_tx_err(queue->vif); |
| 808 | return -EINVAL; |
| 809 | } |
| 810 | |
| 811 | more_data = txp->flags & XEN_NETTXF_more_data; |
| 812 | |
| 813 | if (!drop_err) |
| 814 | txp++; |
| 815 | |
| 816 | } while (more_data); |
| 817 | |
| 818 | if (drop_err) { |
| 819 | xenvif_tx_err(queue, first, extra_count, cons + slots); |
| 820 | return drop_err; |
| 821 | } |
| 822 | |
| 823 | return slots; |
| 824 | } |
| 825 | |
| 826 | |
| 827 | struct xenvif_tx_cb { |
| 828 | u16 pending_idx; |
| 829 | }; |
| 830 | |
| 831 | #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb) |
| 832 | |
| 833 | static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue, |
| 834 | u16 pending_idx, |
| 835 | struct xen_netif_tx_request *txp, |
| 836 | unsigned int extra_count, |
| 837 | struct gnttab_map_grant_ref *mop) |
| 838 | { |
| 839 | queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx]; |
| 840 | gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx), |
| 841 | GNTMAP_host_map | GNTMAP_readonly, |
| 842 | txp->gref, queue->vif->domid); |
| 843 | |
| 844 | memcpy(&queue->pending_tx_info[pending_idx].req, txp, |
| 845 | sizeof(*txp)); |
| 846 | queue->pending_tx_info[pending_idx].extra_count = extra_count; |
| 847 | } |
| 848 | |
| 849 | static inline struct sk_buff *xenvif_alloc_skb(unsigned int size) |
| 850 | { |
| 851 | struct sk_buff *skb = |
| 852 | alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN, |
| 853 | GFP_ATOMIC | __GFP_NOWARN); |
| 854 | if (unlikely(skb == NULL)) |
| 855 | return NULL; |
| 856 | |
| 857 | /* Packets passed to netif_rx() must have some headroom. */ |
| 858 | skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); |
| 859 | |
| 860 | /* Initialize it here to avoid later surprises */ |
| 861 | skb_shinfo(skb)->destructor_arg = NULL; |
| 862 | |
| 863 | return skb; |
| 864 | } |
| 865 | |
| 866 | static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *queue, |
| 867 | struct sk_buff *skb, |
| 868 | struct xen_netif_tx_request *txp, |
| 869 | struct gnttab_map_grant_ref *gop, |
| 870 | unsigned int frag_overflow, |
| 871 | struct sk_buff *nskb) |
| 872 | { |
| 873 | struct skb_shared_info *shinfo = skb_shinfo(skb); |
| 874 | skb_frag_t *frags = shinfo->frags; |
| 875 | u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx; |
| 876 | int start; |
| 877 | pending_ring_idx_t index; |
| 878 | unsigned int nr_slots; |
| 879 | |
| 880 | nr_slots = shinfo->nr_frags; |
| 881 | |
| 882 | /* Skip first skb fragment if it is on same page as header fragment. */ |
| 883 | start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); |
| 884 | |
| 885 | for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots; |
| 886 | shinfo->nr_frags++, txp++, gop++) { |
| 887 | index = pending_index(queue->pending_cons++); |
| 888 | pending_idx = queue->pending_ring[index]; |
| 889 | xenvif_tx_create_map_op(queue, pending_idx, txp, 0, gop); |
| 890 | frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx); |
| 891 | } |
| 892 | |
| 893 | if (frag_overflow) { |
| 894 | |
| 895 | shinfo = skb_shinfo(nskb); |
| 896 | frags = shinfo->frags; |
| 897 | |
| 898 | for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow; |
| 899 | shinfo->nr_frags++, txp++, gop++) { |
| 900 | index = pending_index(queue->pending_cons++); |
| 901 | pending_idx = queue->pending_ring[index]; |
| 902 | xenvif_tx_create_map_op(queue, pending_idx, txp, 0, |
| 903 | gop); |
| 904 | frag_set_pending_idx(&frags[shinfo->nr_frags], |
| 905 | pending_idx); |
| 906 | } |
| 907 | |
| 908 | skb_shinfo(skb)->frag_list = nskb; |
| 909 | } |
| 910 | |
| 911 | return gop; |
| 912 | } |
| 913 | |
| 914 | static inline void xenvif_grant_handle_set(struct xenvif_queue *queue, |
| 915 | u16 pending_idx, |
| 916 | grant_handle_t handle) |
| 917 | { |
| 918 | if (unlikely(queue->grant_tx_handle[pending_idx] != |
| 919 | NETBACK_INVALID_HANDLE)) { |
| 920 | netdev_err(queue->vif->dev, |
| 921 | "Trying to overwrite active handle! pending_idx: 0x%x\n", |
| 922 | pending_idx); |
| 923 | BUG(); |
| 924 | } |
| 925 | queue->grant_tx_handle[pending_idx] = handle; |
| 926 | } |
| 927 | |
| 928 | static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue, |
| 929 | u16 pending_idx) |
| 930 | { |
| 931 | if (unlikely(queue->grant_tx_handle[pending_idx] == |
| 932 | NETBACK_INVALID_HANDLE)) { |
| 933 | netdev_err(queue->vif->dev, |
| 934 | "Trying to unmap invalid handle! pending_idx: 0x%x\n", |
| 935 | pending_idx); |
| 936 | BUG(); |
| 937 | } |
| 938 | queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE; |
| 939 | } |
| 940 | |
| 941 | static int xenvif_tx_check_gop(struct xenvif_queue *queue, |
| 942 | struct sk_buff *skb, |
| 943 | struct gnttab_map_grant_ref **gopp_map, |
| 944 | struct gnttab_copy **gopp_copy) |
| 945 | { |
| 946 | struct gnttab_map_grant_ref *gop_map = *gopp_map; |
| 947 | u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx; |
| 948 | /* This always points to the shinfo of the skb being checked, which |
| 949 | * could be either the first or the one on the frag_list |
| 950 | */ |
| 951 | struct skb_shared_info *shinfo = skb_shinfo(skb); |
| 952 | /* If this is non-NULL, we are currently checking the frag_list skb, and |
| 953 | * this points to the shinfo of the first one |
| 954 | */ |
| 955 | struct skb_shared_info *first_shinfo = NULL; |
| 956 | int nr_frags = shinfo->nr_frags; |
| 957 | const bool sharedslot = nr_frags && |
| 958 | frag_get_pending_idx(&shinfo->frags[0]) == pending_idx; |
| 959 | int i, err; |
| 960 | |
| 961 | /* Check status of header. */ |
| 962 | err = (*gopp_copy)->status; |
| 963 | if (unlikely(err)) { |
| 964 | if (net_ratelimit()) |
| 965 | netdev_dbg(queue->vif->dev, |
| 966 | "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n", |
| 967 | (*gopp_copy)->status, |
| 968 | pending_idx, |
| 969 | (*gopp_copy)->source.u.ref); |
| 970 | /* The first frag might still have this slot mapped */ |
| 971 | if (!sharedslot) |
| 972 | xenvif_idx_release(queue, pending_idx, |
| 973 | XEN_NETIF_RSP_ERROR); |
| 974 | } |
| 975 | (*gopp_copy)++; |
| 976 | |
| 977 | check_frags: |
| 978 | for (i = 0; i < nr_frags; i++, gop_map++) { |
| 979 | int j, newerr; |
| 980 | |
| 981 | pending_idx = frag_get_pending_idx(&shinfo->frags[i]); |
| 982 | |
| 983 | /* Check error status: if okay then remember grant handle. */ |
| 984 | newerr = gop_map->status; |
| 985 | |
| 986 | if (likely(!newerr)) { |
| 987 | xenvif_grant_handle_set(queue, |
| 988 | pending_idx, |
| 989 | gop_map->handle); |
| 990 | /* Had a previous error? Invalidate this fragment. */ |
| 991 | if (unlikely(err)) { |
| 992 | xenvif_idx_unmap(queue, pending_idx); |
| 993 | /* If the mapping of the first frag was OK, but |
| 994 | * the header's copy failed, and they are |
| 995 | * sharing a slot, send an error |
| 996 | */ |
| 997 | if (i == 0 && sharedslot) |
| 998 | xenvif_idx_release(queue, pending_idx, |
| 999 | XEN_NETIF_RSP_ERROR); |
| 1000 | else |
| 1001 | xenvif_idx_release(queue, pending_idx, |
| 1002 | XEN_NETIF_RSP_OKAY); |
| 1003 | } |
| 1004 | continue; |
| 1005 | } |
| 1006 | |
| 1007 | /* Error on this fragment: respond to client with an error. */ |
| 1008 | if (net_ratelimit()) |
| 1009 | netdev_dbg(queue->vif->dev, |
| 1010 | "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n", |
| 1011 | i, |
| 1012 | gop_map->status, |
| 1013 | pending_idx, |
| 1014 | gop_map->ref); |
| 1015 | |
| 1016 | xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR); |
| 1017 | |
| 1018 | /* Not the first error? Preceding frags already invalidated. */ |
| 1019 | if (err) |
| 1020 | continue; |
| 1021 | |
| 1022 | /* First error: if the header haven't shared a slot with the |
| 1023 | * first frag, release it as well. |
| 1024 | */ |
| 1025 | if (!sharedslot) |
| 1026 | xenvif_idx_release(queue, |
| 1027 | XENVIF_TX_CB(skb)->pending_idx, |
| 1028 | XEN_NETIF_RSP_OKAY); |
| 1029 | |
| 1030 | /* Invalidate preceding fragments of this skb. */ |
| 1031 | for (j = 0; j < i; j++) { |
| 1032 | pending_idx = frag_get_pending_idx(&shinfo->frags[j]); |
| 1033 | xenvif_idx_unmap(queue, pending_idx); |
| 1034 | xenvif_idx_release(queue, pending_idx, |
| 1035 | XEN_NETIF_RSP_OKAY); |
| 1036 | } |
| 1037 | |
| 1038 | /* And if we found the error while checking the frag_list, unmap |
| 1039 | * the first skb's frags |
| 1040 | */ |
| 1041 | if (first_shinfo) { |
| 1042 | for (j = 0; j < first_shinfo->nr_frags; j++) { |
| 1043 | pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]); |
| 1044 | xenvif_idx_unmap(queue, pending_idx); |
| 1045 | xenvif_idx_release(queue, pending_idx, |
| 1046 | XEN_NETIF_RSP_OKAY); |
| 1047 | } |
| 1048 | } |
| 1049 | |
| 1050 | /* Remember the error: invalidate all subsequent fragments. */ |
| 1051 | err = newerr; |
| 1052 | } |
| 1053 | |
| 1054 | if (skb_has_frag_list(skb) && !first_shinfo) { |
| 1055 | first_shinfo = skb_shinfo(skb); |
| 1056 | shinfo = skb_shinfo(skb_shinfo(skb)->frag_list); |
| 1057 | nr_frags = shinfo->nr_frags; |
| 1058 | |
| 1059 | goto check_frags; |
| 1060 | } |
| 1061 | |
| 1062 | *gopp_map = gop_map; |
| 1063 | return err; |
| 1064 | } |
| 1065 | |
| 1066 | static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb) |
| 1067 | { |
| 1068 | struct skb_shared_info *shinfo = skb_shinfo(skb); |
| 1069 | int nr_frags = shinfo->nr_frags; |
| 1070 | int i; |
| 1071 | u16 prev_pending_idx = INVALID_PENDING_IDX; |
| 1072 | |
| 1073 | for (i = 0; i < nr_frags; i++) { |
| 1074 | skb_frag_t *frag = shinfo->frags + i; |
| 1075 | struct xen_netif_tx_request *txp; |
| 1076 | struct page *page; |
| 1077 | u16 pending_idx; |
| 1078 | |
| 1079 | pending_idx = frag_get_pending_idx(frag); |
| 1080 | |
| 1081 | /* If this is not the first frag, chain it to the previous*/ |
| 1082 | if (prev_pending_idx == INVALID_PENDING_IDX) |
| 1083 | skb_shinfo(skb)->destructor_arg = |
| 1084 | &callback_param(queue, pending_idx); |
| 1085 | else |
| 1086 | callback_param(queue, prev_pending_idx).ctx = |
| 1087 | &callback_param(queue, pending_idx); |
| 1088 | |
| 1089 | callback_param(queue, pending_idx).ctx = NULL; |
| 1090 | prev_pending_idx = pending_idx; |
| 1091 | |
| 1092 | txp = &queue->pending_tx_info[pending_idx].req; |
| 1093 | page = virt_to_page(idx_to_kaddr(queue, pending_idx)); |
| 1094 | __skb_fill_page_desc(skb, i, page, txp->offset, txp->size); |
| 1095 | skb->len += txp->size; |
| 1096 | skb->data_len += txp->size; |
| 1097 | skb->truesize += txp->size; |
| 1098 | |
| 1099 | /* Take an extra reference to offset network stack's put_page */ |
| 1100 | get_page(queue->mmap_pages[pending_idx]); |
| 1101 | } |
| 1102 | } |
| 1103 | |
| 1104 | static int xenvif_get_extras(struct xenvif_queue *queue, |
| 1105 | struct xen_netif_extra_info *extras, |
| 1106 | unsigned int *extra_count, |
| 1107 | int work_to_do) |
| 1108 | { |
| 1109 | struct xen_netif_extra_info extra; |
| 1110 | RING_IDX cons = queue->tx.req_cons; |
| 1111 | |
| 1112 | do { |
| 1113 | if (unlikely(work_to_do-- <= 0)) { |
| 1114 | netdev_err(queue->vif->dev, "Missing extra info\n"); |
| 1115 | xenvif_fatal_tx_err(queue->vif); |
| 1116 | return -EBADR; |
| 1117 | } |
| 1118 | |
| 1119 | RING_COPY_REQUEST(&queue->tx, cons, &extra); |
| 1120 | |
| 1121 | queue->tx.req_cons = ++cons; |
| 1122 | (*extra_count)++; |
| 1123 | |
| 1124 | if (unlikely(!extra.type || |
| 1125 | extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) { |
| 1126 | netdev_err(queue->vif->dev, |
| 1127 | "Invalid extra type: %d\n", extra.type); |
| 1128 | xenvif_fatal_tx_err(queue->vif); |
| 1129 | return -EINVAL; |
| 1130 | } |
| 1131 | |
| 1132 | memcpy(&extras[extra.type - 1], &extra, sizeof(extra)); |
| 1133 | } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE); |
| 1134 | |
| 1135 | return work_to_do; |
| 1136 | } |
| 1137 | |
| 1138 | static int xenvif_set_skb_gso(struct xenvif *vif, |
| 1139 | struct sk_buff *skb, |
| 1140 | struct xen_netif_extra_info *gso) |
| 1141 | { |
| 1142 | if (!gso->u.gso.size) { |
| 1143 | netdev_err(vif->dev, "GSO size must not be zero.\n"); |
| 1144 | xenvif_fatal_tx_err(vif); |
| 1145 | return -EINVAL; |
| 1146 | } |
| 1147 | |
| 1148 | switch (gso->u.gso.type) { |
| 1149 | case XEN_NETIF_GSO_TYPE_TCPV4: |
| 1150 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; |
| 1151 | break; |
| 1152 | case XEN_NETIF_GSO_TYPE_TCPV6: |
| 1153 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; |
| 1154 | break; |
| 1155 | default: |
| 1156 | netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type); |
| 1157 | xenvif_fatal_tx_err(vif); |
| 1158 | return -EINVAL; |
| 1159 | } |
| 1160 | |
| 1161 | skb_shinfo(skb)->gso_size = gso->u.gso.size; |
| 1162 | /* gso_segs will be calculated later */ |
| 1163 | |
| 1164 | return 0; |
| 1165 | } |
| 1166 | |
| 1167 | static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb) |
| 1168 | { |
| 1169 | bool recalculate_partial_csum = false; |
| 1170 | |
| 1171 | /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy |
| 1172 | * peers can fail to set NETRXF_csum_blank when sending a GSO |
| 1173 | * frame. In this case force the SKB to CHECKSUM_PARTIAL and |
| 1174 | * recalculate the partial checksum. |
| 1175 | */ |
| 1176 | if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { |
| 1177 | queue->stats.rx_gso_checksum_fixup++; |
| 1178 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1179 | recalculate_partial_csum = true; |
| 1180 | } |
| 1181 | |
| 1182 | /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ |
| 1183 | if (skb->ip_summed != CHECKSUM_PARTIAL) |
| 1184 | return 0; |
| 1185 | |
| 1186 | return skb_checksum_setup(skb, recalculate_partial_csum); |
| 1187 | } |
| 1188 | |
| 1189 | static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size) |
| 1190 | { |
| 1191 | u64 now = get_jiffies_64(); |
| 1192 | u64 next_credit = queue->credit_window_start + |
| 1193 | msecs_to_jiffies(queue->credit_usec / 1000); |
| 1194 | |
| 1195 | /* Timer could already be pending in rare cases. */ |
| 1196 | if (timer_pending(&queue->credit_timeout)) |
| 1197 | return true; |
| 1198 | |
| 1199 | /* Passed the point where we can replenish credit? */ |
| 1200 | if (time_after_eq64(now, next_credit)) { |
| 1201 | queue->credit_window_start = now; |
| 1202 | tx_add_credit(queue); |
| 1203 | } |
| 1204 | |
| 1205 | /* Still too big to send right now? Set a callback. */ |
| 1206 | if (size > queue->remaining_credit) { |
| 1207 | queue->credit_timeout.data = |
| 1208 | (unsigned long)queue; |
| 1209 | mod_timer(&queue->credit_timeout, |
| 1210 | next_credit); |
| 1211 | queue->credit_window_start = next_credit; |
| 1212 | |
| 1213 | return true; |
| 1214 | } |
| 1215 | |
| 1216 | return false; |
| 1217 | } |
| 1218 | |
| 1219 | /* No locking is required in xenvif_mcast_add/del() as they are |
| 1220 | * only ever invoked from NAPI poll. An RCU list is used because |
| 1221 | * xenvif_mcast_match() is called asynchronously, during start_xmit. |
| 1222 | */ |
| 1223 | |
| 1224 | static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr) |
| 1225 | { |
| 1226 | struct xenvif_mcast_addr *mcast; |
| 1227 | |
| 1228 | if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) { |
| 1229 | if (net_ratelimit()) |
| 1230 | netdev_err(vif->dev, |
| 1231 | "Too many multicast addresses\n"); |
| 1232 | return -ENOSPC; |
| 1233 | } |
| 1234 | |
| 1235 | mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC); |
| 1236 | if (!mcast) |
| 1237 | return -ENOMEM; |
| 1238 | |
| 1239 | ether_addr_copy(mcast->addr, addr); |
| 1240 | list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr); |
| 1241 | vif->fe_mcast_count++; |
| 1242 | |
| 1243 | return 0; |
| 1244 | } |
| 1245 | |
| 1246 | static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr) |
| 1247 | { |
| 1248 | struct xenvif_mcast_addr *mcast; |
| 1249 | |
| 1250 | list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) { |
| 1251 | if (ether_addr_equal(addr, mcast->addr)) { |
| 1252 | --vif->fe_mcast_count; |
| 1253 | list_del_rcu(&mcast->entry); |
| 1254 | kfree_rcu(mcast, rcu); |
| 1255 | break; |
| 1256 | } |
| 1257 | } |
| 1258 | } |
| 1259 | |
| 1260 | bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr) |
| 1261 | { |
| 1262 | struct xenvif_mcast_addr *mcast; |
| 1263 | |
| 1264 | rcu_read_lock(); |
| 1265 | list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) { |
| 1266 | if (ether_addr_equal(addr, mcast->addr)) { |
| 1267 | rcu_read_unlock(); |
| 1268 | return true; |
| 1269 | } |
| 1270 | } |
| 1271 | rcu_read_unlock(); |
| 1272 | |
| 1273 | return false; |
| 1274 | } |
| 1275 | |
| 1276 | void xenvif_mcast_addr_list_free(struct xenvif *vif) |
| 1277 | { |
| 1278 | /* No need for locking or RCU here. NAPI poll and TX queue |
| 1279 | * are stopped. |
| 1280 | */ |
| 1281 | while (!list_empty(&vif->fe_mcast_addr)) { |
| 1282 | struct xenvif_mcast_addr *mcast; |
| 1283 | |
| 1284 | mcast = list_first_entry(&vif->fe_mcast_addr, |
| 1285 | struct xenvif_mcast_addr, |
| 1286 | entry); |
| 1287 | --vif->fe_mcast_count; |
| 1288 | list_del(&mcast->entry); |
| 1289 | kfree(mcast); |
| 1290 | } |
| 1291 | } |
| 1292 | |
| 1293 | static void xenvif_tx_build_gops(struct xenvif_queue *queue, |
| 1294 | int budget, |
| 1295 | unsigned *copy_ops, |
| 1296 | unsigned *map_ops) |
| 1297 | { |
| 1298 | struct gnttab_map_grant_ref *gop = queue->tx_map_ops; |
| 1299 | struct sk_buff *skb, *nskb; |
| 1300 | int ret; |
| 1301 | unsigned int frag_overflow; |
| 1302 | |
| 1303 | while (skb_queue_len(&queue->tx_queue) < budget) { |
| 1304 | struct xen_netif_tx_request txreq; |
| 1305 | struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX]; |
| 1306 | struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1]; |
| 1307 | unsigned int extra_count; |
| 1308 | u16 pending_idx; |
| 1309 | RING_IDX idx; |
| 1310 | int work_to_do; |
| 1311 | unsigned int data_len; |
| 1312 | pending_ring_idx_t index; |
| 1313 | |
| 1314 | if (queue->tx.sring->req_prod - queue->tx.req_cons > |
| 1315 | XEN_NETIF_TX_RING_SIZE) { |
| 1316 | netdev_err(queue->vif->dev, |
| 1317 | "Impossible number of requests. " |
| 1318 | "req_prod %d, req_cons %d, size %ld\n", |
| 1319 | queue->tx.sring->req_prod, queue->tx.req_cons, |
| 1320 | XEN_NETIF_TX_RING_SIZE); |
| 1321 | xenvif_fatal_tx_err(queue->vif); |
| 1322 | break; |
| 1323 | } |
| 1324 | |
| 1325 | work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx); |
| 1326 | if (!work_to_do) |
| 1327 | break; |
| 1328 | |
| 1329 | idx = queue->tx.req_cons; |
| 1330 | rmb(); /* Ensure that we see the request before we copy it. */ |
| 1331 | RING_COPY_REQUEST(&queue->tx, idx, &txreq); |
| 1332 | |
| 1333 | /* Credit-based scheduling. */ |
| 1334 | if (txreq.size > queue->remaining_credit && |
| 1335 | tx_credit_exceeded(queue, txreq.size)) |
| 1336 | break; |
| 1337 | |
| 1338 | queue->remaining_credit -= txreq.size; |
| 1339 | |
| 1340 | work_to_do--; |
| 1341 | queue->tx.req_cons = ++idx; |
| 1342 | |
| 1343 | memset(extras, 0, sizeof(extras)); |
| 1344 | extra_count = 0; |
| 1345 | if (txreq.flags & XEN_NETTXF_extra_info) { |
| 1346 | work_to_do = xenvif_get_extras(queue, extras, |
| 1347 | &extra_count, |
| 1348 | work_to_do); |
| 1349 | idx = queue->tx.req_cons; |
| 1350 | if (unlikely(work_to_do < 0)) |
| 1351 | break; |
| 1352 | } |
| 1353 | |
| 1354 | if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) { |
| 1355 | struct xen_netif_extra_info *extra; |
| 1356 | |
| 1357 | extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1]; |
| 1358 | ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr); |
| 1359 | |
| 1360 | make_tx_response(queue, &txreq, extra_count, |
| 1361 | (ret == 0) ? |
| 1362 | XEN_NETIF_RSP_OKAY : |
| 1363 | XEN_NETIF_RSP_ERROR); |
| 1364 | push_tx_responses(queue); |
| 1365 | continue; |
| 1366 | } |
| 1367 | |
| 1368 | if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) { |
| 1369 | struct xen_netif_extra_info *extra; |
| 1370 | |
| 1371 | extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1]; |
| 1372 | xenvif_mcast_del(queue->vif, extra->u.mcast.addr); |
| 1373 | |
| 1374 | make_tx_response(queue, &txreq, extra_count, |
| 1375 | XEN_NETIF_RSP_OKAY); |
| 1376 | push_tx_responses(queue); |
| 1377 | continue; |
| 1378 | } |
| 1379 | |
| 1380 | ret = xenvif_count_requests(queue, &txreq, extra_count, |
| 1381 | txfrags, work_to_do); |
| 1382 | if (unlikely(ret < 0)) |
| 1383 | break; |
| 1384 | |
| 1385 | idx += ret; |
| 1386 | |
| 1387 | if (unlikely(txreq.size < ETH_HLEN)) { |
| 1388 | netdev_dbg(queue->vif->dev, |
| 1389 | "Bad packet size: %d\n", txreq.size); |
| 1390 | xenvif_tx_err(queue, &txreq, extra_count, idx); |
| 1391 | break; |
| 1392 | } |
| 1393 | |
| 1394 | /* No crossing a page as the payload mustn't fragment. */ |
| 1395 | if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) { |
| 1396 | netdev_err(queue->vif->dev, |
| 1397 | "txreq.offset: %u, size: %u, end: %lu\n", |
| 1398 | txreq.offset, txreq.size, |
| 1399 | (unsigned long)(txreq.offset&~XEN_PAGE_MASK) + txreq.size); |
| 1400 | xenvif_fatal_tx_err(queue->vif); |
| 1401 | break; |
| 1402 | } |
| 1403 | |
| 1404 | index = pending_index(queue->pending_cons); |
| 1405 | pending_idx = queue->pending_ring[index]; |
| 1406 | |
| 1407 | data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN && |
| 1408 | ret < XEN_NETBK_LEGACY_SLOTS_MAX) ? |
| 1409 | XEN_NETBACK_TX_COPY_LEN : txreq.size; |
| 1410 | |
| 1411 | skb = xenvif_alloc_skb(data_len); |
| 1412 | if (unlikely(skb == NULL)) { |
| 1413 | netdev_dbg(queue->vif->dev, |
| 1414 | "Can't allocate a skb in start_xmit.\n"); |
| 1415 | xenvif_tx_err(queue, &txreq, extra_count, idx); |
| 1416 | break; |
| 1417 | } |
| 1418 | |
| 1419 | skb_shinfo(skb)->nr_frags = ret; |
| 1420 | if (data_len < txreq.size) |
| 1421 | skb_shinfo(skb)->nr_frags++; |
| 1422 | /* At this point shinfo->nr_frags is in fact the number of |
| 1423 | * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX. |
| 1424 | */ |
| 1425 | frag_overflow = 0; |
| 1426 | nskb = NULL; |
| 1427 | if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) { |
| 1428 | frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS; |
| 1429 | BUG_ON(frag_overflow > MAX_SKB_FRAGS); |
| 1430 | skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS; |
| 1431 | nskb = xenvif_alloc_skb(0); |
| 1432 | if (unlikely(nskb == NULL)) { |
| 1433 | kfree_skb(skb); |
| 1434 | xenvif_tx_err(queue, &txreq, extra_count, idx); |
| 1435 | if (net_ratelimit()) |
| 1436 | netdev_err(queue->vif->dev, |
| 1437 | "Can't allocate the frag_list skb.\n"); |
| 1438 | break; |
| 1439 | } |
| 1440 | } |
| 1441 | |
| 1442 | if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { |
| 1443 | struct xen_netif_extra_info *gso; |
| 1444 | gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; |
| 1445 | |
| 1446 | if (xenvif_set_skb_gso(queue->vif, skb, gso)) { |
| 1447 | /* Failure in xenvif_set_skb_gso is fatal. */ |
| 1448 | kfree_skb(skb); |
| 1449 | kfree_skb(nskb); |
| 1450 | break; |
| 1451 | } |
| 1452 | } |
| 1453 | |
| 1454 | XENVIF_TX_CB(skb)->pending_idx = pending_idx; |
| 1455 | |
| 1456 | __skb_put(skb, data_len); |
| 1457 | queue->tx_copy_ops[*copy_ops].source.u.ref = txreq.gref; |
| 1458 | queue->tx_copy_ops[*copy_ops].source.domid = queue->vif->domid; |
| 1459 | queue->tx_copy_ops[*copy_ops].source.offset = txreq.offset; |
| 1460 | |
| 1461 | queue->tx_copy_ops[*copy_ops].dest.u.gmfn = |
| 1462 | virt_to_gfn(skb->data); |
| 1463 | queue->tx_copy_ops[*copy_ops].dest.domid = DOMID_SELF; |
| 1464 | queue->tx_copy_ops[*copy_ops].dest.offset = |
| 1465 | offset_in_page(skb->data) & ~XEN_PAGE_MASK; |
| 1466 | |
| 1467 | queue->tx_copy_ops[*copy_ops].len = data_len; |
| 1468 | queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref; |
| 1469 | |
| 1470 | (*copy_ops)++; |
| 1471 | |
| 1472 | if (data_len < txreq.size) { |
| 1473 | frag_set_pending_idx(&skb_shinfo(skb)->frags[0], |
| 1474 | pending_idx); |
| 1475 | xenvif_tx_create_map_op(queue, pending_idx, &txreq, |
| 1476 | extra_count, gop); |
| 1477 | gop++; |
| 1478 | } else { |
| 1479 | frag_set_pending_idx(&skb_shinfo(skb)->frags[0], |
| 1480 | INVALID_PENDING_IDX); |
| 1481 | memcpy(&queue->pending_tx_info[pending_idx].req, |
| 1482 | &txreq, sizeof(txreq)); |
| 1483 | queue->pending_tx_info[pending_idx].extra_count = |
| 1484 | extra_count; |
| 1485 | } |
| 1486 | |
| 1487 | queue->pending_cons++; |
| 1488 | |
| 1489 | gop = xenvif_get_requests(queue, skb, txfrags, gop, |
| 1490 | frag_overflow, nskb); |
| 1491 | |
| 1492 | __skb_queue_tail(&queue->tx_queue, skb); |
| 1493 | |
| 1494 | queue->tx.req_cons = idx; |
| 1495 | |
| 1496 | if (((gop-queue->tx_map_ops) >= ARRAY_SIZE(queue->tx_map_ops)) || |
| 1497 | (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops))) |
| 1498 | break; |
| 1499 | } |
| 1500 | |
| 1501 | (*map_ops) = gop - queue->tx_map_ops; |
| 1502 | return; |
| 1503 | } |
| 1504 | |
| 1505 | /* Consolidate skb with a frag_list into a brand new one with local pages on |
| 1506 | * frags. Returns 0 or -ENOMEM if can't allocate new pages. |
| 1507 | */ |
| 1508 | static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb) |
| 1509 | { |
| 1510 | unsigned int offset = skb_headlen(skb); |
| 1511 | skb_frag_t frags[MAX_SKB_FRAGS]; |
| 1512 | int i, f; |
| 1513 | struct ubuf_info *uarg; |
| 1514 | struct sk_buff *nskb = skb_shinfo(skb)->frag_list; |
| 1515 | |
| 1516 | queue->stats.tx_zerocopy_sent += 2; |
| 1517 | queue->stats.tx_frag_overflow++; |
| 1518 | |
| 1519 | xenvif_fill_frags(queue, nskb); |
| 1520 | /* Subtract frags size, we will correct it later */ |
| 1521 | skb->truesize -= skb->data_len; |
| 1522 | skb->len += nskb->len; |
| 1523 | skb->data_len += nskb->len; |
| 1524 | |
| 1525 | /* create a brand new frags array and coalesce there */ |
| 1526 | for (i = 0; offset < skb->len; i++) { |
| 1527 | struct page *page; |
| 1528 | unsigned int len; |
| 1529 | |
| 1530 | BUG_ON(i >= MAX_SKB_FRAGS); |
| 1531 | page = alloc_page(GFP_ATOMIC); |
| 1532 | if (!page) { |
| 1533 | int j; |
| 1534 | skb->truesize += skb->data_len; |
| 1535 | for (j = 0; j < i; j++) |
| 1536 | put_page(frags[j].page.p); |
| 1537 | return -ENOMEM; |
| 1538 | } |
| 1539 | |
| 1540 | if (offset + PAGE_SIZE < skb->len) |
| 1541 | len = PAGE_SIZE; |
| 1542 | else |
| 1543 | len = skb->len - offset; |
| 1544 | if (skb_copy_bits(skb, offset, page_address(page), len)) |
| 1545 | BUG(); |
| 1546 | |
| 1547 | offset += len; |
| 1548 | frags[i].page.p = page; |
| 1549 | frags[i].page_offset = 0; |
| 1550 | skb_frag_size_set(&frags[i], len); |
| 1551 | } |
| 1552 | |
| 1553 | /* Copied all the bits from the frag list -- free it. */ |
| 1554 | skb_frag_list_init(skb); |
| 1555 | xenvif_skb_zerocopy_prepare(queue, nskb); |
| 1556 | kfree_skb(nskb); |
| 1557 | |
| 1558 | /* Release all the original (foreign) frags. */ |
| 1559 | for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) |
| 1560 | skb_frag_unref(skb, f); |
| 1561 | uarg = skb_shinfo(skb)->destructor_arg; |
| 1562 | /* increase inflight counter to offset decrement in callback */ |
| 1563 | atomic_inc(&queue->inflight_packets); |
| 1564 | uarg->callback(uarg, true); |
| 1565 | skb_shinfo(skb)->destructor_arg = NULL; |
| 1566 | |
| 1567 | /* Fill the skb with the new (local) frags. */ |
| 1568 | memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t)); |
| 1569 | skb_shinfo(skb)->nr_frags = i; |
| 1570 | skb->truesize += i * PAGE_SIZE; |
| 1571 | |
| 1572 | return 0; |
| 1573 | } |
| 1574 | |
| 1575 | static int xenvif_tx_submit(struct xenvif_queue *queue) |
| 1576 | { |
| 1577 | struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops; |
| 1578 | struct gnttab_copy *gop_copy = queue->tx_copy_ops; |
| 1579 | struct sk_buff *skb; |
| 1580 | int work_done = 0; |
| 1581 | |
| 1582 | while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) { |
| 1583 | struct xen_netif_tx_request *txp; |
| 1584 | u16 pending_idx; |
| 1585 | unsigned data_len; |
| 1586 | |
| 1587 | pending_idx = XENVIF_TX_CB(skb)->pending_idx; |
| 1588 | txp = &queue->pending_tx_info[pending_idx].req; |
| 1589 | |
| 1590 | /* Check the remap error code. */ |
| 1591 | if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) { |
| 1592 | /* If there was an error, xenvif_tx_check_gop is |
| 1593 | * expected to release all the frags which were mapped, |
| 1594 | * so kfree_skb shouldn't do it again |
| 1595 | */ |
| 1596 | skb_shinfo(skb)->nr_frags = 0; |
| 1597 | if (skb_has_frag_list(skb)) { |
| 1598 | struct sk_buff *nskb = |
| 1599 | skb_shinfo(skb)->frag_list; |
| 1600 | skb_shinfo(nskb)->nr_frags = 0; |
| 1601 | } |
| 1602 | kfree_skb(skb); |
| 1603 | continue; |
| 1604 | } |
| 1605 | |
| 1606 | data_len = skb->len; |
| 1607 | callback_param(queue, pending_idx).ctx = NULL; |
| 1608 | if (data_len < txp->size) { |
| 1609 | /* Append the packet payload as a fragment. */ |
| 1610 | txp->offset += data_len; |
| 1611 | txp->size -= data_len; |
| 1612 | } else { |
| 1613 | /* Schedule a response immediately. */ |
| 1614 | xenvif_idx_release(queue, pending_idx, |
| 1615 | XEN_NETIF_RSP_OKAY); |
| 1616 | } |
| 1617 | |
| 1618 | if (txp->flags & XEN_NETTXF_csum_blank) |
| 1619 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1620 | else if (txp->flags & XEN_NETTXF_data_validated) |
| 1621 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 1622 | |
| 1623 | xenvif_fill_frags(queue, skb); |
| 1624 | |
| 1625 | if (unlikely(skb_has_frag_list(skb))) { |
| 1626 | if (xenvif_handle_frag_list(queue, skb)) { |
| 1627 | if (net_ratelimit()) |
| 1628 | netdev_err(queue->vif->dev, |
| 1629 | "Not enough memory to consolidate frag_list!\n"); |
| 1630 | xenvif_skb_zerocopy_prepare(queue, skb); |
| 1631 | kfree_skb(skb); |
| 1632 | continue; |
| 1633 | } |
| 1634 | } |
| 1635 | |
| 1636 | skb->dev = queue->vif->dev; |
| 1637 | skb->protocol = eth_type_trans(skb, skb->dev); |
| 1638 | skb_reset_network_header(skb); |
| 1639 | |
| 1640 | if (checksum_setup(queue, skb)) { |
| 1641 | netdev_dbg(queue->vif->dev, |
| 1642 | "Can't setup checksum in net_tx_action\n"); |
| 1643 | /* We have to set this flag to trigger the callback */ |
| 1644 | if (skb_shinfo(skb)->destructor_arg) |
| 1645 | xenvif_skb_zerocopy_prepare(queue, skb); |
| 1646 | kfree_skb(skb); |
| 1647 | continue; |
| 1648 | } |
| 1649 | |
| 1650 | skb_probe_transport_header(skb, 0); |
| 1651 | |
| 1652 | /* If the packet is GSO then we will have just set up the |
| 1653 | * transport header offset in checksum_setup so it's now |
| 1654 | * straightforward to calculate gso_segs. |
| 1655 | */ |
| 1656 | if (skb_is_gso(skb)) { |
| 1657 | int mss = skb_shinfo(skb)->gso_size; |
| 1658 | int hdrlen = skb_transport_header(skb) - |
| 1659 | skb_mac_header(skb) + |
| 1660 | tcp_hdrlen(skb); |
| 1661 | |
| 1662 | skb_shinfo(skb)->gso_segs = |
| 1663 | DIV_ROUND_UP(skb->len - hdrlen, mss); |
| 1664 | } |
| 1665 | |
| 1666 | queue->stats.rx_bytes += skb->len; |
| 1667 | queue->stats.rx_packets++; |
| 1668 | |
| 1669 | work_done++; |
| 1670 | |
| 1671 | /* Set this flag right before netif_receive_skb, otherwise |
| 1672 | * someone might think this packet already left netback, and |
| 1673 | * do a skb_copy_ubufs while we are still in control of the |
| 1674 | * skb. E.g. the __pskb_pull_tail earlier can do such thing. |
| 1675 | */ |
| 1676 | if (skb_shinfo(skb)->destructor_arg) { |
| 1677 | xenvif_skb_zerocopy_prepare(queue, skb); |
| 1678 | queue->stats.tx_zerocopy_sent++; |
| 1679 | } |
| 1680 | |
| 1681 | netif_receive_skb(skb); |
| 1682 | } |
| 1683 | |
| 1684 | return work_done; |
| 1685 | } |
| 1686 | |
| 1687 | void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success) |
| 1688 | { |
| 1689 | unsigned long flags; |
| 1690 | pending_ring_idx_t index; |
| 1691 | struct xenvif_queue *queue = ubuf_to_queue(ubuf); |
| 1692 | |
| 1693 | /* This is the only place where we grab this lock, to protect callbacks |
| 1694 | * from each other. |
| 1695 | */ |
| 1696 | spin_lock_irqsave(&queue->callback_lock, flags); |
| 1697 | do { |
| 1698 | u16 pending_idx = ubuf->desc; |
| 1699 | ubuf = (struct ubuf_info *) ubuf->ctx; |
| 1700 | BUG_ON(queue->dealloc_prod - queue->dealloc_cons >= |
| 1701 | MAX_PENDING_REQS); |
| 1702 | index = pending_index(queue->dealloc_prod); |
| 1703 | queue->dealloc_ring[index] = pending_idx; |
| 1704 | /* Sync with xenvif_tx_dealloc_action: |
| 1705 | * insert idx then incr producer. |
| 1706 | */ |
| 1707 | smp_wmb(); |
| 1708 | queue->dealloc_prod++; |
| 1709 | } while (ubuf); |
| 1710 | spin_unlock_irqrestore(&queue->callback_lock, flags); |
| 1711 | |
| 1712 | if (likely(zerocopy_success)) |
| 1713 | queue->stats.tx_zerocopy_success++; |
| 1714 | else |
| 1715 | queue->stats.tx_zerocopy_fail++; |
| 1716 | xenvif_skb_zerocopy_complete(queue); |
| 1717 | } |
| 1718 | |
| 1719 | static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue) |
| 1720 | { |
| 1721 | struct gnttab_unmap_grant_ref *gop; |
| 1722 | pending_ring_idx_t dc, dp; |
| 1723 | u16 pending_idx, pending_idx_release[MAX_PENDING_REQS]; |
| 1724 | unsigned int i = 0; |
| 1725 | |
| 1726 | dc = queue->dealloc_cons; |
| 1727 | gop = queue->tx_unmap_ops; |
| 1728 | |
| 1729 | /* Free up any grants we have finished using */ |
| 1730 | do { |
| 1731 | dp = queue->dealloc_prod; |
| 1732 | |
| 1733 | /* Ensure we see all indices enqueued by all |
| 1734 | * xenvif_zerocopy_callback(). |
| 1735 | */ |
| 1736 | smp_rmb(); |
| 1737 | |
| 1738 | while (dc != dp) { |
| 1739 | BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS); |
| 1740 | pending_idx = |
| 1741 | queue->dealloc_ring[pending_index(dc++)]; |
| 1742 | |
| 1743 | pending_idx_release[gop - queue->tx_unmap_ops] = |
| 1744 | pending_idx; |
| 1745 | queue->pages_to_unmap[gop - queue->tx_unmap_ops] = |
| 1746 | queue->mmap_pages[pending_idx]; |
| 1747 | gnttab_set_unmap_op(gop, |
| 1748 | idx_to_kaddr(queue, pending_idx), |
| 1749 | GNTMAP_host_map, |
| 1750 | queue->grant_tx_handle[pending_idx]); |
| 1751 | xenvif_grant_handle_reset(queue, pending_idx); |
| 1752 | ++gop; |
| 1753 | } |
| 1754 | |
| 1755 | } while (dp != queue->dealloc_prod); |
| 1756 | |
| 1757 | queue->dealloc_cons = dc; |
| 1758 | |
| 1759 | if (gop - queue->tx_unmap_ops > 0) { |
| 1760 | int ret; |
| 1761 | ret = gnttab_unmap_refs(queue->tx_unmap_ops, |
| 1762 | NULL, |
| 1763 | queue->pages_to_unmap, |
| 1764 | gop - queue->tx_unmap_ops); |
| 1765 | if (ret) { |
| 1766 | netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tu ret %d\n", |
| 1767 | gop - queue->tx_unmap_ops, ret); |
| 1768 | for (i = 0; i < gop - queue->tx_unmap_ops; ++i) { |
| 1769 | if (gop[i].status != GNTST_okay) |
| 1770 | netdev_err(queue->vif->dev, |
| 1771 | " host_addr: 0x%llx handle: 0x%x status: %d\n", |
| 1772 | gop[i].host_addr, |
| 1773 | gop[i].handle, |
| 1774 | gop[i].status); |
| 1775 | } |
| 1776 | BUG(); |
| 1777 | } |
| 1778 | } |
| 1779 | |
| 1780 | for (i = 0; i < gop - queue->tx_unmap_ops; ++i) |
| 1781 | xenvif_idx_release(queue, pending_idx_release[i], |
| 1782 | XEN_NETIF_RSP_OKAY); |
| 1783 | } |
| 1784 | |
| 1785 | |
| 1786 | /* Called after netfront has transmitted */ |
| 1787 | int xenvif_tx_action(struct xenvif_queue *queue, int budget) |
| 1788 | { |
| 1789 | unsigned nr_mops, nr_cops = 0; |
| 1790 | int work_done, ret; |
| 1791 | |
| 1792 | if (unlikely(!tx_work_todo(queue))) |
| 1793 | return 0; |
| 1794 | |
| 1795 | xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops); |
| 1796 | |
| 1797 | if (nr_cops == 0) |
| 1798 | return 0; |
| 1799 | |
| 1800 | gnttab_batch_copy(queue->tx_copy_ops, nr_cops); |
| 1801 | if (nr_mops != 0) { |
| 1802 | ret = gnttab_map_refs(queue->tx_map_ops, |
| 1803 | NULL, |
| 1804 | queue->pages_to_map, |
| 1805 | nr_mops); |
| 1806 | BUG_ON(ret); |
| 1807 | } |
| 1808 | |
| 1809 | work_done = xenvif_tx_submit(queue); |
| 1810 | |
| 1811 | return work_done; |
| 1812 | } |
| 1813 | |
| 1814 | static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx, |
| 1815 | u8 status) |
| 1816 | { |
| 1817 | struct pending_tx_info *pending_tx_info; |
| 1818 | pending_ring_idx_t index; |
| 1819 | unsigned long flags; |
| 1820 | |
| 1821 | pending_tx_info = &queue->pending_tx_info[pending_idx]; |
| 1822 | |
| 1823 | spin_lock_irqsave(&queue->response_lock, flags); |
| 1824 | |
| 1825 | make_tx_response(queue, &pending_tx_info->req, |
| 1826 | pending_tx_info->extra_count, status); |
| 1827 | |
| 1828 | /* Release the pending index before pusing the Tx response so |
| 1829 | * its available before a new Tx request is pushed by the |
| 1830 | * frontend. |
| 1831 | */ |
| 1832 | index = pending_index(queue->pending_prod++); |
| 1833 | queue->pending_ring[index] = pending_idx; |
| 1834 | |
| 1835 | push_tx_responses(queue); |
| 1836 | |
| 1837 | spin_unlock_irqrestore(&queue->response_lock, flags); |
| 1838 | } |
| 1839 | |
| 1840 | |
| 1841 | static void make_tx_response(struct xenvif_queue *queue, |
| 1842 | struct xen_netif_tx_request *txp, |
| 1843 | unsigned int extra_count, |
| 1844 | s8 st) |
| 1845 | { |
| 1846 | RING_IDX i = queue->tx.rsp_prod_pvt; |
| 1847 | struct xen_netif_tx_response *resp; |
| 1848 | |
| 1849 | resp = RING_GET_RESPONSE(&queue->tx, i); |
| 1850 | resp->id = txp->id; |
| 1851 | resp->status = st; |
| 1852 | |
| 1853 | while (extra_count-- != 0) |
| 1854 | RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL; |
| 1855 | |
| 1856 | queue->tx.rsp_prod_pvt = ++i; |
| 1857 | } |
| 1858 | |
| 1859 | static void push_tx_responses(struct xenvif_queue *queue) |
| 1860 | { |
| 1861 | int notify; |
| 1862 | |
| 1863 | RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify); |
| 1864 | if (notify) |
| 1865 | notify_remote_via_irq(queue->tx_irq); |
| 1866 | } |
| 1867 | |
| 1868 | static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue, |
| 1869 | u16 id, |
| 1870 | s8 st, |
| 1871 | u16 offset, |
| 1872 | u16 size, |
| 1873 | u16 flags) |
| 1874 | { |
| 1875 | RING_IDX i = queue->rx.rsp_prod_pvt; |
| 1876 | struct xen_netif_rx_response *resp; |
| 1877 | |
| 1878 | resp = RING_GET_RESPONSE(&queue->rx, i); |
| 1879 | resp->offset = offset; |
| 1880 | resp->flags = flags; |
| 1881 | resp->id = id; |
| 1882 | resp->status = (s16)size; |
| 1883 | if (st < 0) |
| 1884 | resp->status = (s16)st; |
| 1885 | |
| 1886 | queue->rx.rsp_prod_pvt = ++i; |
| 1887 | |
| 1888 | return resp; |
| 1889 | } |
| 1890 | |
| 1891 | void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx) |
| 1892 | { |
| 1893 | int ret; |
| 1894 | struct gnttab_unmap_grant_ref tx_unmap_op; |
| 1895 | |
| 1896 | gnttab_set_unmap_op(&tx_unmap_op, |
| 1897 | idx_to_kaddr(queue, pending_idx), |
| 1898 | GNTMAP_host_map, |
| 1899 | queue->grant_tx_handle[pending_idx]); |
| 1900 | xenvif_grant_handle_reset(queue, pending_idx); |
| 1901 | |
| 1902 | ret = gnttab_unmap_refs(&tx_unmap_op, NULL, |
| 1903 | &queue->mmap_pages[pending_idx], 1); |
| 1904 | if (ret) { |
| 1905 | netdev_err(queue->vif->dev, |
| 1906 | "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n", |
| 1907 | ret, |
| 1908 | pending_idx, |
| 1909 | tx_unmap_op.host_addr, |
| 1910 | tx_unmap_op.handle, |
| 1911 | tx_unmap_op.status); |
| 1912 | BUG(); |
| 1913 | } |
| 1914 | } |
| 1915 | |
| 1916 | static inline int tx_work_todo(struct xenvif_queue *queue) |
| 1917 | { |
| 1918 | if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))) |
| 1919 | return 1; |
| 1920 | |
| 1921 | return 0; |
| 1922 | } |
| 1923 | |
| 1924 | static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue) |
| 1925 | { |
| 1926 | return queue->dealloc_cons != queue->dealloc_prod; |
| 1927 | } |
| 1928 | |
| 1929 | void xenvif_unmap_frontend_rings(struct xenvif_queue *queue) |
| 1930 | { |
| 1931 | if (queue->tx.sring) |
| 1932 | xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif), |
| 1933 | queue->tx.sring); |
| 1934 | if (queue->rx.sring) |
| 1935 | xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif), |
| 1936 | queue->rx.sring); |
| 1937 | } |
| 1938 | |
| 1939 | int xenvif_map_frontend_rings(struct xenvif_queue *queue, |
| 1940 | grant_ref_t tx_ring_ref, |
| 1941 | grant_ref_t rx_ring_ref) |
| 1942 | { |
| 1943 | void *addr; |
| 1944 | struct xen_netif_tx_sring *txs; |
| 1945 | struct xen_netif_rx_sring *rxs; |
| 1946 | |
| 1947 | int err = -ENOMEM; |
| 1948 | |
| 1949 | err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif), |
| 1950 | &tx_ring_ref, 1, &addr); |
| 1951 | if (err) |
| 1952 | goto err; |
| 1953 | |
| 1954 | txs = (struct xen_netif_tx_sring *)addr; |
| 1955 | BACK_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE); |
| 1956 | |
| 1957 | err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif), |
| 1958 | &rx_ring_ref, 1, &addr); |
| 1959 | if (err) |
| 1960 | goto err; |
| 1961 | |
| 1962 | rxs = (struct xen_netif_rx_sring *)addr; |
| 1963 | BACK_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE); |
| 1964 | |
| 1965 | return 0; |
| 1966 | |
| 1967 | err: |
| 1968 | xenvif_unmap_frontend_rings(queue); |
| 1969 | return err; |
| 1970 | } |
| 1971 | |
| 1972 | static void xenvif_queue_carrier_off(struct xenvif_queue *queue) |
| 1973 | { |
| 1974 | struct xenvif *vif = queue->vif; |
| 1975 | |
| 1976 | queue->stalled = true; |
| 1977 | |
| 1978 | /* At least one queue has stalled? Disable the carrier. */ |
| 1979 | spin_lock(&vif->lock); |
| 1980 | if (vif->stalled_queues++ == 0) { |
| 1981 | netdev_info(vif->dev, "Guest Rx stalled"); |
| 1982 | netif_carrier_off(vif->dev); |
| 1983 | } |
| 1984 | spin_unlock(&vif->lock); |
| 1985 | } |
| 1986 | |
| 1987 | static void xenvif_queue_carrier_on(struct xenvif_queue *queue) |
| 1988 | { |
| 1989 | struct xenvif *vif = queue->vif; |
| 1990 | |
| 1991 | queue->last_rx_time = jiffies; /* Reset Rx stall detection. */ |
| 1992 | queue->stalled = false; |
| 1993 | |
| 1994 | /* All queues are ready? Enable the carrier. */ |
| 1995 | spin_lock(&vif->lock); |
| 1996 | if (--vif->stalled_queues == 0) { |
| 1997 | netdev_info(vif->dev, "Guest Rx ready"); |
| 1998 | netif_carrier_on(vif->dev); |
| 1999 | } |
| 2000 | spin_unlock(&vif->lock); |
| 2001 | } |
| 2002 | |
| 2003 | static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue) |
| 2004 | { |
| 2005 | RING_IDX prod, cons; |
| 2006 | |
| 2007 | prod = queue->rx.sring->req_prod; |
| 2008 | cons = queue->rx.req_cons; |
| 2009 | |
| 2010 | return !queue->stalled && prod - cons < 1 |
| 2011 | && time_after(jiffies, |
| 2012 | queue->last_rx_time + queue->vif->stall_timeout); |
| 2013 | } |
| 2014 | |
| 2015 | static bool xenvif_rx_queue_ready(struct xenvif_queue *queue) |
| 2016 | { |
| 2017 | RING_IDX prod, cons; |
| 2018 | |
| 2019 | prod = queue->rx.sring->req_prod; |
| 2020 | cons = queue->rx.req_cons; |
| 2021 | |
| 2022 | return queue->stalled && prod - cons >= 1; |
| 2023 | } |
| 2024 | |
| 2025 | static bool xenvif_have_rx_work(struct xenvif_queue *queue) |
| 2026 | { |
| 2027 | return xenvif_rx_ring_slots_available(queue) |
| 2028 | || (queue->vif->stall_timeout && |
| 2029 | (xenvif_rx_queue_stalled(queue) |
| 2030 | || xenvif_rx_queue_ready(queue))) |
| 2031 | || kthread_should_stop() |
| 2032 | || queue->vif->disabled; |
| 2033 | } |
| 2034 | |
| 2035 | static long xenvif_rx_queue_timeout(struct xenvif_queue *queue) |
| 2036 | { |
| 2037 | struct sk_buff *skb; |
| 2038 | long timeout; |
| 2039 | |
| 2040 | skb = skb_peek(&queue->rx_queue); |
| 2041 | if (!skb) |
| 2042 | return MAX_SCHEDULE_TIMEOUT; |
| 2043 | |
| 2044 | timeout = XENVIF_RX_CB(skb)->expires - jiffies; |
| 2045 | return timeout < 0 ? 0 : timeout; |
| 2046 | } |
| 2047 | |
| 2048 | /* Wait until the guest Rx thread has work. |
| 2049 | * |
| 2050 | * The timeout needs to be adjusted based on the current head of the |
| 2051 | * queue (and not just the head at the beginning). In particular, if |
| 2052 | * the queue is initially empty an infinite timeout is used and this |
| 2053 | * needs to be reduced when a skb is queued. |
| 2054 | * |
| 2055 | * This cannot be done with wait_event_timeout() because it only |
| 2056 | * calculates the timeout once. |
| 2057 | */ |
| 2058 | static void xenvif_wait_for_rx_work(struct xenvif_queue *queue) |
| 2059 | { |
| 2060 | DEFINE_WAIT(wait); |
| 2061 | |
| 2062 | if (xenvif_have_rx_work(queue)) |
| 2063 | return; |
| 2064 | |
| 2065 | for (;;) { |
| 2066 | long ret; |
| 2067 | |
| 2068 | prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE); |
| 2069 | if (xenvif_have_rx_work(queue)) |
| 2070 | break; |
| 2071 | ret = schedule_timeout(xenvif_rx_queue_timeout(queue)); |
| 2072 | if (!ret) |
| 2073 | break; |
| 2074 | } |
| 2075 | finish_wait(&queue->wq, &wait); |
| 2076 | } |
| 2077 | |
| 2078 | int xenvif_kthread_guest_rx(void *data) |
| 2079 | { |
| 2080 | struct xenvif_queue *queue = data; |
| 2081 | struct xenvif *vif = queue->vif; |
| 2082 | |
| 2083 | if (!vif->stall_timeout) |
| 2084 | xenvif_queue_carrier_on(queue); |
| 2085 | |
| 2086 | for (;;) { |
| 2087 | xenvif_wait_for_rx_work(queue); |
| 2088 | |
| 2089 | if (kthread_should_stop()) |
| 2090 | break; |
| 2091 | |
| 2092 | /* This frontend is found to be rogue, disable it in |
| 2093 | * kthread context. Currently this is only set when |
| 2094 | * netback finds out frontend sends malformed packet, |
| 2095 | * but we cannot disable the interface in softirq |
| 2096 | * context so we defer it here, if this thread is |
| 2097 | * associated with queue 0. |
| 2098 | */ |
| 2099 | if (unlikely(vif->disabled && queue->id == 0)) { |
| 2100 | xenvif_carrier_off(vif); |
| 2101 | break; |
| 2102 | } |
| 2103 | |
| 2104 | if (!skb_queue_empty(&queue->rx_queue)) |
| 2105 | xenvif_rx_action(queue); |
| 2106 | |
| 2107 | /* If the guest hasn't provided any Rx slots for a |
| 2108 | * while it's probably not responsive, drop the |
| 2109 | * carrier so packets are dropped earlier. |
| 2110 | */ |
| 2111 | if (vif->stall_timeout) { |
| 2112 | if (xenvif_rx_queue_stalled(queue)) |
| 2113 | xenvif_queue_carrier_off(queue); |
| 2114 | else if (xenvif_rx_queue_ready(queue)) |
| 2115 | xenvif_queue_carrier_on(queue); |
| 2116 | } |
| 2117 | |
| 2118 | /* Queued packets may have foreign pages from other |
| 2119 | * domains. These cannot be queued indefinitely as |
| 2120 | * this would starve guests of grant refs and transmit |
| 2121 | * slots. |
| 2122 | */ |
| 2123 | xenvif_rx_queue_drop_expired(queue); |
| 2124 | |
| 2125 | xenvif_rx_queue_maybe_wake(queue); |
| 2126 | |
| 2127 | cond_resched(); |
| 2128 | } |
| 2129 | |
| 2130 | /* Bin any remaining skbs */ |
| 2131 | xenvif_rx_queue_purge(queue); |
| 2132 | |
| 2133 | return 0; |
| 2134 | } |
| 2135 | |
| 2136 | static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue) |
| 2137 | { |
| 2138 | /* Dealloc thread must remain running until all inflight |
| 2139 | * packets complete. |
| 2140 | */ |
| 2141 | return kthread_should_stop() && |
| 2142 | !atomic_read(&queue->inflight_packets); |
| 2143 | } |
| 2144 | |
| 2145 | int xenvif_dealloc_kthread(void *data) |
| 2146 | { |
| 2147 | struct xenvif_queue *queue = data; |
| 2148 | |
| 2149 | for (;;) { |
| 2150 | wait_event_interruptible(queue->dealloc_wq, |
| 2151 | tx_dealloc_work_todo(queue) || |
| 2152 | xenvif_dealloc_kthread_should_stop(queue)); |
| 2153 | if (xenvif_dealloc_kthread_should_stop(queue)) |
| 2154 | break; |
| 2155 | |
| 2156 | xenvif_tx_dealloc_action(queue); |
| 2157 | cond_resched(); |
| 2158 | } |
| 2159 | |
| 2160 | /* Unmap anything remaining*/ |
| 2161 | if (tx_dealloc_work_todo(queue)) |
| 2162 | xenvif_tx_dealloc_action(queue); |
| 2163 | |
| 2164 | return 0; |
| 2165 | } |
| 2166 | |
| 2167 | static int __init netback_init(void) |
| 2168 | { |
| 2169 | int rc = 0; |
| 2170 | |
| 2171 | if (!xen_domain()) |
| 2172 | return -ENODEV; |
| 2173 | |
| 2174 | /* Allow as many queues as there are CPUs if user has not |
| 2175 | * specified a value. |
| 2176 | */ |
| 2177 | if (xenvif_max_queues == 0) |
| 2178 | xenvif_max_queues = num_online_cpus(); |
| 2179 | |
| 2180 | if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) { |
| 2181 | pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n", |
| 2182 | fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX); |
| 2183 | fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX; |
| 2184 | } |
| 2185 | |
| 2186 | rc = xenvif_xenbus_init(); |
| 2187 | if (rc) |
| 2188 | goto failed_init; |
| 2189 | |
| 2190 | #ifdef CONFIG_DEBUG_FS |
| 2191 | xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL); |
| 2192 | if (IS_ERR_OR_NULL(xen_netback_dbg_root)) |
| 2193 | pr_warn("Init of debugfs returned %ld!\n", |
| 2194 | PTR_ERR(xen_netback_dbg_root)); |
| 2195 | #endif /* CONFIG_DEBUG_FS */ |
| 2196 | |
| 2197 | return 0; |
| 2198 | |
| 2199 | failed_init: |
| 2200 | return rc; |
| 2201 | } |
| 2202 | |
| 2203 | module_init(netback_init); |
| 2204 | |
| 2205 | static void __exit netback_fini(void) |
| 2206 | { |
| 2207 | #ifdef CONFIG_DEBUG_FS |
| 2208 | if (!IS_ERR_OR_NULL(xen_netback_dbg_root)) |
| 2209 | debugfs_remove_recursive(xen_netback_dbg_root); |
| 2210 | #endif /* CONFIG_DEBUG_FS */ |
| 2211 | xenvif_xenbus_fini(); |
| 2212 | } |
| 2213 | module_exit(netback_fini); |
| 2214 | |
| 2215 | MODULE_LICENSE("Dual BSD/GPL"); |
| 2216 | MODULE_ALIAS("xen-backend:vif"); |