1/*-
2 * Copyright (c) 2009-2011 Spectra Logic Corporation
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions, and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * substantially similar to the "NO WARRANTY" disclaimer below
13 * ("Disclaimer") and any redistribution must be conditioned upon
14 * including a substantially similar Disclaimer requirement for further
15 * binary redistribution.
16 *
17 * NO WARRANTY
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGES.
29 *
30 * Authors: Justin T. Gibbs (Spectra Logic Corporation)
31 * Alan Somers (Spectra Logic Corporation)
32 * John Suykerbuyk (Spectra Logic Corporation)
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: head/sys/dev/xen/netback/netback.c 282634 2015-05-08 14:48:40Z royger $");
37
38/**
39 * \file netback.c
40 *
41 * \brief Device driver supporting the vending of network access
42 * from this FreeBSD domain to other domains.
43 */
44#include "opt_inet.h"
45#include "opt_inet6.h"
46
47#include "opt_sctp.h"
48
49#include <sys/param.h>
50#include <sys/kernel.h>
51
52#include <sys/bus.h>
53#include <sys/module.h>
54#include <sys/rman.h>
55#include <sys/socket.h>
56#include <sys/sockio.h>
57#include <sys/sysctl.h>
58
59#include <net/if.h>
60#include <net/if_var.h>
61#include <net/if_arp.h>
62#include <net/ethernet.h>
63#include <net/if_dl.h>
64#include <net/if_media.h>
65#include <net/if_types.h>
66
67#include <netinet/in.h>
68#include <netinet/ip.h>
69#include <netinet/if_ether.h>
70#if __FreeBSD_version >= 700000
71#include <netinet/tcp.h>
72#endif
73#include <netinet/ip_icmp.h>
74#include <netinet/udp.h>
75#include <machine/in_cksum.h>
76
77#include <vm/vm.h>
78#include <vm/pmap.h>
79#include <vm/vm_extern.h>
80#include <vm/vm_kern.h>
81
82#include <machine/_inttypes.h>
83
84#include <xen/xen-os.h>
85#include <xen/hypervisor.h>
86#include <xen/xen_intr.h>
87#include <xen/interface/io/netif.h>
88#include <xen/xenbus/xenbusvar.h>
89
90#include <machine/xen/xenvar.h>
91
92/*--------------------------- Compile-time Tunables --------------------------*/
93
94/*---------------------------------- Macros ----------------------------------*/
95/**
96 * Custom malloc type for all driver allocations.
97 */
98static MALLOC_DEFINE(M_XENNETBACK, "xnb", "Xen Net Back Driver Data");
99
100#define XNB_SG 1 /* netback driver supports feature-sg */
101#define XNB_GSO_TCPV4 0 /* netback driver supports feature-gso-tcpv4 */
102#define XNB_RX_COPY 1 /* netback driver supports feature-rx-copy */
103#define XNB_RX_FLIP 0 /* netback driver does not support feature-rx-flip */
104
105#undef XNB_DEBUG
106#define XNB_DEBUG /* hardcode on during development */
107
108#ifdef XNB_DEBUG
109#define DPRINTF(fmt, args...) \
110 printf("xnb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
111#else
112#define DPRINTF(fmt, args...) do {} while (0)
113#endif
114
115/* Default length for stack-allocated grant tables */
116#define GNTTAB_LEN (64)
117
118/* Features supported by all backends. TSO and LRO can be negotiated */
119#define XNB_CSUM_FEATURES (CSUM_TCP | CSUM_UDP)
120
121#define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)
122#define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)
123
124/**
125 * Two argument version of the standard macro. Second argument is a tentative
126 * value of req_cons
127 */
128#define RING_HAS_UNCONSUMED_REQUESTS_2(_r, cons) ({ \
129 unsigned int req = (_r)->sring->req_prod - cons; \
130 unsigned int rsp = RING_SIZE(_r) - \
131 (cons - (_r)->rsp_prod_pvt); \
132 req < rsp ? req : rsp; \
133})
134
135#define virt_to_mfn(x) (vtomach(x) >> PAGE_SHIFT)
136#define virt_to_offset(x) ((x) & (PAGE_SIZE - 1))
137
138/**
139 * Predefined array type of grant table copy descriptors. Used to pass around
140 * statically allocated memory structures.
141 */
142typedef struct gnttab_copy gnttab_copy_table[GNTTAB_LEN];
143
144/*--------------------------- Forward Declarations ---------------------------*/
145struct xnb_softc;
146struct xnb_pkt;
147
148static void xnb_attach_failed(struct xnb_softc *xnb,
149 int err, const char *fmt, ...)
150 __printflike(3,4);
151static int xnb_shutdown(struct xnb_softc *xnb);
152static int create_netdev(device_t dev);
153static int xnb_detach(device_t dev);
154static int xnb_ifmedia_upd(struct ifnet *ifp);
155static void xnb_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr);
156static void xnb_intr(void *arg);
157static int xnb_send(netif_rx_back_ring_t *rxb, domid_t otherend,
158 const struct mbuf *mbufc, gnttab_copy_table gnttab);
159static int xnb_recv(netif_tx_back_ring_t *txb, domid_t otherend,
160 struct mbuf **mbufc, struct ifnet *ifnet,
161 gnttab_copy_table gnttab);
162static int xnb_ring2pkt(struct xnb_pkt *pkt,
163 const netif_tx_back_ring_t *tx_ring,
164 RING_IDX start);
165static void xnb_txpkt2rsp(const struct xnb_pkt *pkt,
166 netif_tx_back_ring_t *ring, int error);
167static struct mbuf *xnb_pkt2mbufc(const struct xnb_pkt *pkt, struct ifnet *ifp);
168static int xnb_txpkt2gnttab(const struct xnb_pkt *pkt,
169 const struct mbuf *mbufc,
170 gnttab_copy_table gnttab,
171 const netif_tx_back_ring_t *txb,
172 domid_t otherend_id);
173static void xnb_update_mbufc(struct mbuf *mbufc,
174 const gnttab_copy_table gnttab, int n_entries);
175static int xnb_mbufc2pkt(const struct mbuf *mbufc,
176 struct xnb_pkt *pkt,
177 RING_IDX start, int space);
178static int xnb_rxpkt2gnttab(const struct xnb_pkt *pkt,
179 const struct mbuf *mbufc,
180 gnttab_copy_table gnttab,
181 const netif_rx_back_ring_t *rxb,
182 domid_t otherend_id);
183static int xnb_rxpkt2rsp(const struct xnb_pkt *pkt,
184 const gnttab_copy_table gnttab, int n_entries,
185 netif_rx_back_ring_t *ring);
186static void xnb_stop(struct xnb_softc*);
187static int xnb_ioctl(struct ifnet*, u_long, caddr_t);
188static void xnb_start_locked(struct ifnet*);
189static void xnb_start(struct ifnet*);
190static void xnb_ifinit_locked(struct xnb_softc*);
191static void xnb_ifinit(void*);
192#ifdef XNB_DEBUG
193static int xnb_unit_test_main(SYSCTL_HANDLER_ARGS);
194static int xnb_dump_rings(SYSCTL_HANDLER_ARGS);
195#endif
196#if defined(INET) || defined(INET6)
197static void xnb_add_mbuf_cksum(struct mbuf *mbufc);
198#endif
199/*------------------------------ Data Structures -----------------------------*/
200
201
202/**
203 * Representation of a xennet packet. Simplified version of a packet as
204 * stored in the Xen tx ring. Applicable to both RX and TX packets
205 */
206struct xnb_pkt{
207 /**
208 * Array index of the first data-bearing (eg, not extra info) entry
209 * for this packet
210 */
211 RING_IDX car;
212
213 /**
214 * Array index of the second data-bearing entry for this packet.
215 * Invalid if the packet has only one data-bearing entry. If the
216 * packet has more than two data-bearing entries, then the second
217 * through the last will be sequential modulo the ring size
218 */
219 RING_IDX cdr;
220
221 /**
222 * Optional extra info. Only valid if flags contains
223 * NETTXF_extra_info. Note that extra.type will always be
224 * XEN_NETIF_EXTRA_TYPE_GSO. Currently, no known netfront or netback
225 * driver will ever set XEN_NETIF_EXTRA_TYPE_MCAST_*
226 */
227 netif_extra_info_t extra;
228
229 /** Size of entire packet in bytes. */
230 uint16_t size;
231
232 /** The size of the first entry's data in bytes */
233 uint16_t car_size;
234
235 /**
236 * Either NETTXF_ or NETRXF_ flags. Note that the flag values are
237 * not the same for TX and RX packets
238 */
239 uint16_t flags;
240
241 /**
242 * The number of valid data-bearing entries (either netif_tx_request's
243 * or netif_rx_response's) in the packet. If this is 0, it means the
244 * entire packet is invalid.
245 */
246 uint16_t list_len;
247
248 /** There was an error processing the packet */
249 uint8_t error;
250};
251
252/** xnb_pkt method: initialize it */
253static inline void
254xnb_pkt_initialize(struct xnb_pkt *pxnb)
255{
256 bzero(pxnb, sizeof(*pxnb));
257}
258
259/** xnb_pkt method: mark the packet as valid */
260static inline void
261xnb_pkt_validate(struct xnb_pkt *pxnb)
262{
263 pxnb->error = 0;
264};
265
266/** xnb_pkt method: mark the packet as invalid */
267static inline void
268xnb_pkt_invalidate(struct xnb_pkt *pxnb)
269{
270 pxnb->error = 1;
271};
272
273/** xnb_pkt method: Check whether the packet is valid */
274static inline int
275xnb_pkt_is_valid(const struct xnb_pkt *pxnb)
276{
277 return (! pxnb->error);
278}
279
280#ifdef XNB_DEBUG
281/** xnb_pkt method: print the packet's contents in human-readable format*/
282static void __unused
283xnb_dump_pkt(const struct xnb_pkt *pkt) {
284 if (pkt == NULL) {
285 DPRINTF("Was passed a null pointer.\n");
286 return;
287 }
288 DPRINTF("pkt address= %p\n", pkt);
289 DPRINTF("pkt->size=%d\n", pkt->size);
290 DPRINTF("pkt->car_size=%d\n", pkt->car_size);
291 DPRINTF("pkt->flags=0x%04x\n", pkt->flags);
292 DPRINTF("pkt->list_len=%d\n", pkt->list_len);
293 /* DPRINTF("pkt->extra"); TODO */
294 DPRINTF("pkt->car=%d\n", pkt->car);
295 DPRINTF("pkt->cdr=%d\n", pkt->cdr);
296 DPRINTF("pkt->error=%d\n", pkt->error);
297}
298#endif /* XNB_DEBUG */
299
300static void
301xnb_dump_txreq(RING_IDX idx, const struct netif_tx_request *txreq)
302{
303 if (txreq != NULL) {
304 DPRINTF("netif_tx_request index =%u\n", idx);
305 DPRINTF("netif_tx_request.gref =%u\n", txreq->gref);
306 DPRINTF("netif_tx_request.offset=%hu\n", txreq->offset);
307 DPRINTF("netif_tx_request.flags =%hu\n", txreq->flags);
308 DPRINTF("netif_tx_request.id =%hu\n", txreq->id);
309 DPRINTF("netif_tx_request.size =%hu\n", txreq->size);
310 }
311}
312
313
314/**
315 * \brief Configuration data for a shared memory request ring
316 * used to communicate with the front-end client of this
317 * this driver.
318 */
319struct xnb_ring_config {
320 /**
321 * Runtime structures for ring access. Unfortunately, TX and RX rings
322 * use different data structures, and that cannot be changed since it
323 * is part of the interdomain protocol.
324 */
325 union{
326 netif_rx_back_ring_t rx_ring;
327 netif_tx_back_ring_t tx_ring;
328 } back_ring;
329
330 /**
331 * The device bus address returned by the hypervisor when
332 * mapping the ring and required to unmap it when a connection
333 * is torn down.
334 */
335 uint64_t bus_addr;
336
337 /** The pseudo-physical address where ring memory is mapped.*/
338 uint64_t gnt_addr;
339
340 /** KVA address where ring memory is mapped. */
341 vm_offset_t va;
342
343 /**
344 * Grant table handles, one per-ring page, returned by the
345 * hyperpervisor upon mapping of the ring and required to
346 * unmap it when a connection is torn down.
347 */
348 grant_handle_t handle;
349
350 /** The number of ring pages mapped for the current connection. */
351 unsigned ring_pages;
352
353 /**
354 * The grant references, one per-ring page, supplied by the
355 * front-end, allowing us to reference the ring pages in the
356 * front-end's domain and to map these pages into our own domain.
357 */
358 grant_ref_t ring_ref;
359};
360
361/**
362 * Per-instance connection state flags.
363 */
364typedef enum
365{
366 /** Communication with the front-end has been established. */
367 XNBF_RING_CONNECTED = 0x01,
368
369 /**
370 * Front-end requests exist in the ring and are waiting for
371 * xnb_xen_req objects to free up.
372 */
373 XNBF_RESOURCE_SHORTAGE = 0x02,
374
375 /** Connection teardown has started. */
376 XNBF_SHUTDOWN = 0x04,
377
378 /** A thread is already performing shutdown processing. */
379 XNBF_IN_SHUTDOWN = 0x08
380} xnb_flag_t;
381
382/**
383 * Types of rings. Used for array indices and to identify a ring's control
384 * data structure type
385 */
386typedef enum{
387 XNB_RING_TYPE_TX = 0, /* ID of TX rings, used for array indices */
388 XNB_RING_TYPE_RX = 1, /* ID of RX rings, used for array indices */
389 XNB_NUM_RING_TYPES
390} xnb_ring_type_t;
391
392/**
393 * Per-instance configuration data.
394 */
395struct xnb_softc {
396 /** NewBus device corresponding to this instance. */
397 device_t dev;
398
399 /* Media related fields */
400
401 /** Generic network media state */
402 struct ifmedia sc_media;
403
404 /** Media carrier info */
405 struct ifnet *xnb_ifp;
406
407 /** Our own private carrier state */
408 unsigned carrier;
409
410 /** Device MAC Address */
411 uint8_t mac[ETHER_ADDR_LEN];
412
413 /* Xen related fields */
414
415 /**
416 * \brief The netif protocol abi in effect.
417 *
418 * There are situations where the back and front ends can
419 * have a different, native abi (e.g. intel x86_64 and
420 * 32bit x86 domains on the same machine). The back-end
421 * always accomodates the front-end's native abi. That
422 * value is pulled from the XenStore and recorded here.
423 */
424 int abi;
425
426 /**
427 * Name of the bridge to which this VIF is connected, if any
428 * This field is dynamically allocated by xenbus and must be free()ed
429 * when no longer needed
430 */
431 char *bridge;
432
433 /** The interrupt driven even channel used to signal ring events. */
434 evtchn_port_t evtchn;
435
436 /** Xen device handle.*/
437 long handle;
438
439 /** Handle to the communication ring event channel. */
440 xen_intr_handle_t xen_intr_handle;
441
442 /**
443 * \brief Cached value of the front-end's domain id.
444 *
445 * This value is used at once for each mapped page in
446 * a transaction. We cache it to avoid incuring the
447 * cost of an ivar access every time this is needed.
448 */
449 domid_t otherend_id;
450
451 /**
452 * Undocumented frontend feature. Has something to do with
453 * scatter/gather IO
454 */
455 uint8_t can_sg;
456 /** Undocumented frontend feature */
457 uint8_t gso;
458 /** Undocumented frontend feature */
459 uint8_t gso_prefix;
460 /** Can checksum TCP/UDP over IPv4 */
461 uint8_t ip_csum;
462
463 /* Implementation related fields */
464 /**
465 * Preallocated grant table copy descriptor for RX operations.
466 * Access must be protected by rx_lock
467 */
468 gnttab_copy_table rx_gnttab;
469
470 /**
471 * Preallocated grant table copy descriptor for TX operations.
472 * Access must be protected by tx_lock
473 */
474 gnttab_copy_table tx_gnttab;
475
476 /**
477 * Resource representing allocated physical address space
478 * associated with our per-instance kva region.
479 */
480 struct resource *pseudo_phys_res;
481
482 /** Resource id for allocated physical address space. */
483 int pseudo_phys_res_id;
484
485 /** Ring mapping and interrupt configuration data. */
486 struct xnb_ring_config ring_configs[XNB_NUM_RING_TYPES];
487
488 /**
489 * Global pool of kva used for mapping remote domain ring
490 * and I/O transaction data.
491 */
492 vm_offset_t kva;
493
494 /** Psuedo-physical address corresponding to kva. */
495 uint64_t gnt_base_addr;
496
497 /** Various configuration and state bit flags. */
498 xnb_flag_t flags;
499
500 /** Mutex protecting per-instance data in the receive path. */
501 struct mtx rx_lock;
502
503 /** Mutex protecting per-instance data in the softc structure. */
504 struct mtx sc_lock;
505
506 /** Mutex protecting per-instance data in the transmit path. */
507 struct mtx tx_lock;
508
509 /** The size of the global kva pool. */
510 int kva_size;
511
512 /** Name of the interface */
513 char if_name[IFNAMSIZ];
514};
515
516/*---------------------------- Debugging functions ---------------------------*/
517#ifdef XNB_DEBUG
518static void __unused
519xnb_dump_gnttab_copy(const struct gnttab_copy *entry)
520{
521 if (entry == NULL) {
522 printf("NULL grant table pointer\n");
523 return;
524 }
525
526 if (entry->flags & GNTCOPY_dest_gref)
527 printf("gnttab dest ref=\t%u\n", entry->dest.u.ref);
528 else
529 printf("gnttab dest gmfn=\t%lu\n", entry->dest.u.gmfn);
530 printf("gnttab dest offset=\t%hu\n", entry->dest.offset);
531 printf("gnttab dest domid=\t%hu\n", entry->dest.domid);
532 if (entry->flags & GNTCOPY_source_gref)
533 printf("gnttab source ref=\t%u\n", entry->source.u.ref);
534 else
535 printf("gnttab source gmfn=\t%lu\n", entry->source.u.gmfn);
536 printf("gnttab source offset=\t%hu\n", entry->source.offset);
537 printf("gnttab source domid=\t%hu\n", entry->source.domid);
538 printf("gnttab len=\t%hu\n", entry->len);
539 printf("gnttab flags=\t%hu\n", entry->flags);
540 printf("gnttab status=\t%hd\n", entry->status);
541}
542
543static int
544xnb_dump_rings(SYSCTL_HANDLER_ARGS)
545{
546 static char results[720];
547 struct xnb_softc const* xnb = (struct xnb_softc*)arg1;
548 netif_rx_back_ring_t const* rxb =
549 &xnb->ring_configs[XNB_RING_TYPE_RX].back_ring.rx_ring;
550 netif_tx_back_ring_t const* txb =
551 &xnb->ring_configs[XNB_RING_TYPE_TX].back_ring.tx_ring;
552
553 /* empty the result strings */
554 results[0] = 0;
555
556 if ( !txb || !txb->sring || !rxb || !rxb->sring )
557 return (SYSCTL_OUT(req, results, strnlen(results, 720)));
558
559 snprintf(results, 720,
560 "\n\t%35s %18s\n" /* TX, RX */
561 "\t%16s %18d %18d\n" /* req_cons */
562 "\t%16s %18d %18d\n" /* nr_ents */
563 "\t%16s %18d %18d\n" /* rsp_prod_pvt */
564 "\t%16s %18p %18p\n" /* sring */
565 "\t%16s %18d %18d\n" /* req_prod */
566 "\t%16s %18d %18d\n" /* req_event */
567 "\t%16s %18d %18d\n" /* rsp_prod */
568 "\t%16s %18d %18d\n", /* rsp_event */
569 "TX", "RX",
570 "req_cons", txb->req_cons, rxb->req_cons,
571 "nr_ents", txb->nr_ents, rxb->nr_ents,
572 "rsp_prod_pvt", txb->rsp_prod_pvt, rxb->rsp_prod_pvt,
573 "sring", txb->sring, rxb->sring,
574 "sring->req_prod", txb->sring->req_prod, rxb->sring->req_prod,
575 "sring->req_event", txb->sring->req_event, rxb->sring->req_event,
576 "sring->rsp_prod", txb->sring->rsp_prod, rxb->sring->rsp_prod,
577 "sring->rsp_event", txb->sring->rsp_event, rxb->sring->rsp_event);
578
579 return (SYSCTL_OUT(req, results, strnlen(results, 720)));
580}
581
582static void __unused
583xnb_dump_mbuf(const struct mbuf *m)
584{
585 int len;
586 uint8_t *d;
587 if (m == NULL)
588 return;
589
590 printf("xnb_dump_mbuf:\n");
591 if (m->m_flags & M_PKTHDR) {
592 printf(" flowid=%10d, csum_flags=%#8x, csum_data=%#8x, "
593 "tso_segsz=%5hd\n",
594 m->m_pkthdr.flowid, (int)m->m_pkthdr.csum_flags,
595 m->m_pkthdr.csum_data, m->m_pkthdr.tso_segsz);
596 printf(" rcvif=%16p, len=%19d\n",
597 m->m_pkthdr.rcvif, m->m_pkthdr.len);
598 }
599 printf(" m_next=%16p, m_nextpk=%16p, m_data=%16p\n",
600 m->m_next, m->m_nextpkt, m->m_data);
601 printf(" m_len=%17d, m_flags=%#15x, m_type=%18u\n",
602 m->m_len, m->m_flags, m->m_type);
603
604 len = m->m_len;
605 d = mtod(m, uint8_t*);
606 while (len > 0) {
607 int i;
608 printf(" ");
609 for (i = 0; (i < 16) && (len > 0); i++, len--) {
610 printf("%02hhx ", *(d++));
611 }
612 printf("\n");
613 }
614}
615#endif /* XNB_DEBUG */
616
617/*------------------------ Inter-Domain Communication ------------------------*/
618/**
619 * Free dynamically allocated KVA or pseudo-physical address allocations.
620 *
621 * \param xnb Per-instance xnb configuration structure.
622 */
623static void
624xnb_free_communication_mem(struct xnb_softc *xnb)
625{
626 if (xnb->kva != 0) {
627 if (xnb->pseudo_phys_res != NULL) {
628 xenmem_free(xnb->dev, xnb->pseudo_phys_res_id,
629 xnb->pseudo_phys_res);
630 xnb->pseudo_phys_res = NULL;
631 }
632 }
633 xnb->kva = 0;
634 xnb->gnt_base_addr = 0;
635}
636
637/**
638 * Cleanup all inter-domain communication mechanisms.
639 *
640 * \param xnb Per-instance xnb configuration structure.
641 */
642static int
643xnb_disconnect(struct xnb_softc *xnb)
644{
645 struct gnttab_unmap_grant_ref gnts[XNB_NUM_RING_TYPES];
646 int error;
647 int i;
648
649 if (xnb->xen_intr_handle != NULL)
650 xen_intr_unbind(&xnb->xen_intr_handle);
651
652 /*
653 * We may still have another thread currently processing requests. We
654 * must acquire the rx and tx locks to make sure those threads are done,
655 * but we can release those locks as soon as we acquire them, because no
656 * more interrupts will be arriving.
657 */
658 mtx_lock(&xnb->tx_lock);
659 mtx_unlock(&xnb->tx_lock);
660 mtx_lock(&xnb->rx_lock);
661 mtx_unlock(&xnb->rx_lock);
662
663 /* Free malloc'd softc member variables */
664 if (xnb->bridge != NULL) {
665 free(xnb->bridge, M_XENSTORE);
666 xnb->bridge = NULL;
667 }
668
669 /* All request processing has stopped, so unmap the rings */
670 for (i=0; i < XNB_NUM_RING_TYPES; i++) {
671 gnts[i].host_addr = xnb->ring_configs[i].gnt_addr;
672 gnts[i].dev_bus_addr = xnb->ring_configs[i].bus_addr;
673 gnts[i].handle = xnb->ring_configs[i].handle;
674 }
675 error = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, gnts,
676 XNB_NUM_RING_TYPES);
677 KASSERT(error == 0, ("Grant table unmap op failed (%d)", error));
678
679 xnb_free_communication_mem(xnb);
680 /*
681 * Zero the ring config structs because the pointers, handles, and
682 * grant refs contained therein are no longer valid.
683 */
684 bzero(&xnb->ring_configs[XNB_RING_TYPE_TX],
685 sizeof(struct xnb_ring_config));
686 bzero(&xnb->ring_configs[XNB_RING_TYPE_RX],
687 sizeof(struct xnb_ring_config));
688
689 xnb->flags &= ~XNBF_RING_CONNECTED;
690 return (0);
691}
692
693/**
694 * Map a single shared memory ring into domain local address space and
695 * initialize its control structure
696 *
697 * \param xnb Per-instance xnb configuration structure
698 * \param ring_type Array index of this ring in the xnb's array of rings
699 * \return An errno
700 */
701static int
702xnb_connect_ring(struct xnb_softc *xnb, xnb_ring_type_t ring_type)
703{
704 struct gnttab_map_grant_ref gnt;
705 struct xnb_ring_config *ring = &xnb->ring_configs[ring_type];
706 int error;
707
708 /* TX ring type = 0, RX =1 */
709 ring->va = xnb->kva + ring_type * PAGE_SIZE;
710 ring->gnt_addr = xnb->gnt_base_addr + ring_type * PAGE_SIZE;
711
712 gnt.host_addr = ring->gnt_addr;
713 gnt.flags = GNTMAP_host_map;
714 gnt.ref = ring->ring_ref;
715 gnt.dom = xnb->otherend_id;
716
717 error = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &gnt, 1);
718 if (error != 0)
719 panic("netback: Ring page grant table op failed (%d)", error);
720
721 if (gnt.status != 0) {
722 ring->va = 0;
723 error = EACCES;
724 xenbus_dev_fatal(xnb->dev, error,
725 "Ring shared page mapping failed. "
726 "Status %d.", gnt.status);
727 } else {
728 ring->handle = gnt.handle;
729 ring->bus_addr = gnt.dev_bus_addr;
730
731 if (ring_type == XNB_RING_TYPE_TX) {
732 BACK_RING_INIT(&ring->back_ring.tx_ring,
733 (netif_tx_sring_t*)ring->va,
734 ring->ring_pages * PAGE_SIZE);
735 } else if (ring_type == XNB_RING_TYPE_RX) {
736 BACK_RING_INIT(&ring->back_ring.rx_ring,
737 (netif_rx_sring_t*)ring->va,
738 ring->ring_pages * PAGE_SIZE);
739 } else {
740 xenbus_dev_fatal(xnb->dev, error,
741 "Unknown ring type %d", ring_type);
742 }
743 }
744
745 return error;
746}
747
748/**
749 * Setup the shared memory rings and bind an interrupt to the event channel
750 * used to notify us of ring changes.
751 *
752 * \param xnb Per-instance xnb configuration structure.
753 */
754static int
755xnb_connect_comms(struct xnb_softc *xnb)
756{
757 int error;
758 xnb_ring_type_t i;
759
760 if ((xnb->flags & XNBF_RING_CONNECTED) != 0)
761 return (0);
762
763 /*
764 * Kva for our rings are at the tail of the region of kva allocated
765 * by xnb_alloc_communication_mem().
766 */
767 for (i=0; i < XNB_NUM_RING_TYPES; i++) {
768 error = xnb_connect_ring(xnb, i);
769 if (error != 0)
770 return error;
771 }
772
773 xnb->flags |= XNBF_RING_CONNECTED;
774
775 error = xen_intr_bind_remote_port(xnb->dev,
776 xnb->otherend_id,
777 xnb->evtchn,
778 /*filter*/NULL,
779 xnb_intr, /*arg*/xnb,
780 INTR_TYPE_BIO | INTR_MPSAFE,
781 &xnb->xen_intr_handle);
782 if (error != 0) {
783 (void)xnb_disconnect(xnb);
784 xenbus_dev_fatal(xnb->dev, error, "binding event channel");
785 return (error);
786 }
787
788 DPRINTF("rings connected!\n");
789
790 return (0);
791}
792
793/**
794 * Size KVA and pseudo-physical address allocations based on negotiated
795 * values for the size and number of I/O requests, and the size of our
796 * communication ring.
797 *
798 * \param xnb Per-instance xnb configuration structure.
799 *
800 * These address spaces are used to dynamically map pages in the
801 * front-end's domain into our own.
802 */
803static int
804xnb_alloc_communication_mem(struct xnb_softc *xnb)
805{
806 xnb_ring_type_t i;
807
808 xnb->kva_size = 0;
809 for (i=0; i < XNB_NUM_RING_TYPES; i++) {
810 xnb->kva_size += xnb->ring_configs[i].ring_pages * PAGE_SIZE;
811 }
812
813 /*
814 * Reserve a range of pseudo physical memory that we can map
815 * into kva. These pages will only be backed by machine
816 * pages ("real memory") during the lifetime of front-end requests
817 * via grant table operations. We will map the netif tx and rx rings
818 * into this space.
819 */
820 xnb->pseudo_phys_res_id = 0;
821 xnb->pseudo_phys_res = xenmem_alloc(xnb->dev, &xnb->pseudo_phys_res_id,
822 xnb->kva_size);
823 if (xnb->pseudo_phys_res == NULL) {
824 xnb->kva = 0;
825 return (ENOMEM);
826 }
827 xnb->kva = (vm_offset_t)rman_get_virtual(xnb->pseudo_phys_res);
828 xnb->gnt_base_addr = rman_get_start(xnb->pseudo_phys_res);
829 return (0);
830}
831
832/**
833 * Collect information from the XenStore related to our device and its frontend
834 *
835 * \param xnb Per-instance xnb configuration structure.
836 */
837static int
838xnb_collect_xenstore_info(struct xnb_softc *xnb)
839{
840 /**
841 * \todo Linux collects the following info. We should collect most
842 * of this, too:
843 * "feature-rx-notify"
844 */
845 const char *otherend_path;
846 const char *our_path;
847 int err;
848 unsigned int rx_copy, bridge_len;
849 uint8_t no_csum_offload;
850
851 otherend_path = xenbus_get_otherend_path(xnb->dev);
852 our_path = xenbus_get_node(xnb->dev);
853
854 /* Collect the critical communication parameters */
855 err = xs_gather(XST_NIL, otherend_path,
856 "tx-ring-ref", "%l" PRIu32,
857 &xnb->ring_configs[XNB_RING_TYPE_TX].ring_ref,
858 "rx-ring-ref", "%l" PRIu32,
859 &xnb->ring_configs[XNB_RING_TYPE_RX].ring_ref,
860 "event-channel", "%" PRIu32, &xnb->evtchn,
861 NULL);
862 if (err != 0) {
863 xenbus_dev_fatal(xnb->dev, err,
864 "Unable to retrieve ring information from "
865 "frontend %s. Unable to connect.",
866 otherend_path);
867 return (err);
868 }
869
870 /* Collect the handle from xenstore */
871 err = xs_scanf(XST_NIL, our_path, "handle", NULL, "%li", &xnb->handle);
872 if (err != 0) {
873 xenbus_dev_fatal(xnb->dev, err,
874 "Error reading handle from frontend %s. "
875 "Unable to connect.", otherend_path);
876 }
877
878 /*
879 * Collect the bridgename, if any. We do not need bridge_len; we just
880 * throw it away
881 */
882 err = xs_read(XST_NIL, our_path, "bridge", &bridge_len,
883 (void**)&xnb->bridge);
884 if (err != 0)
885 xnb->bridge = NULL;
886
887 /*
888 * Does the frontend request that we use rx copy? If not, return an
889 * error because this driver only supports rx copy.
890 */
891 err = xs_scanf(XST_NIL, otherend_path, "request-rx-copy", NULL,
892 "%" PRIu32, &rx_copy);
893 if (err == ENOENT) {
894 err = 0;
895 rx_copy = 0;
896 }
897 if (err < 0) {
898 xenbus_dev_fatal(xnb->dev, err, "reading %s/request-rx-copy",
899 otherend_path);
900 return err;
901 }
902 /**
903 * \todo: figure out the exact meaning of this feature, and when
904 * the frontend will set it to true. It should be set to true
905 * at some point
906 */
907/* if (!rx_copy)*/
908/* return EOPNOTSUPP;*/
909
910 /** \todo Collect the rx notify feature */
911
912 /* Collect the feature-sg. */
913 if (xs_scanf(XST_NIL, otherend_path, "feature-sg", NULL,
914 "%hhu", &xnb->can_sg) < 0)
915 xnb->can_sg = 0;
916
917 /* Collect remaining frontend features */
918 if (xs_scanf(XST_NIL, otherend_path, "feature-gso-tcpv4", NULL,
919 "%hhu", &xnb->gso) < 0)
920 xnb->gso = 0;
921
922 if (xs_scanf(XST_NIL, otherend_path, "feature-gso-tcpv4-prefix", NULL,
923 "%hhu", &xnb->gso_prefix) < 0)
924 xnb->gso_prefix = 0;
925
926 if (xs_scanf(XST_NIL, otherend_path, "feature-no-csum-offload", NULL,
927 "%hhu", &no_csum_offload) < 0)
928 no_csum_offload = 0;
929 xnb->ip_csum = (no_csum_offload == 0);
930
931 return (0);
932}
933
934/**
935 * Supply information about the physical device to the frontend
936 * via XenBus.
937 *
938 * \param xnb Per-instance xnb configuration structure.
939 */
940static int
941xnb_publish_backend_info(struct xnb_softc *xnb)
942{
943 struct xs_transaction xst;
944 const char *our_path;
945 int error;
946
947 our_path = xenbus_get_node(xnb->dev);
948
949 do {
950 error = xs_transaction_start(&xst);
951 if (error != 0) {
952 xenbus_dev_fatal(xnb->dev, error,
953 "Error publishing backend info "
954 "(start transaction)");
955 break;
956 }
957
958 error = xs_printf(xst, our_path, "feature-sg",
959 "%d", XNB_SG);
960 if (error != 0)
961 break;
962
963 error = xs_printf(xst, our_path, "feature-gso-tcpv4",
964 "%d", XNB_GSO_TCPV4);
965 if (error != 0)
966 break;
967
968 error = xs_printf(xst, our_path, "feature-rx-copy",
969 "%d", XNB_RX_COPY);
970 if (error != 0)
971 break;
972
973 error = xs_printf(xst, our_path, "feature-rx-flip",
974 "%d", XNB_RX_FLIP);
975 if (error != 0)
976 break;
977
978 error = xs_transaction_end(xst, 0);
979 if (error != 0 && error != EAGAIN) {
980 xenbus_dev_fatal(xnb->dev, error, "ending transaction");
981 break;
982 }
983
984 } while (error == EAGAIN);
985
986 return (error);
987}
988
989/**
990 * Connect to our netfront peer now that it has completed publishing
991 * its configuration into the XenStore.
992 *
993 * \param xnb Per-instance xnb configuration structure.
994 */
995static void
996xnb_connect(struct xnb_softc *xnb)
997{
998 int error;
999
1000 if (xenbus_get_state(xnb->dev) == XenbusStateConnected)
1001 return;
1002
1003 if (xnb_collect_xenstore_info(xnb) != 0)
1004 return;
1005
1006 xnb->flags &= ~XNBF_SHUTDOWN;
1007
1008 /* Read front end configuration. */
1009
1010 /* Allocate resources whose size depends on front-end configuration. */
1011 error = xnb_alloc_communication_mem(xnb);
1012 if (error != 0) {
1013 xenbus_dev_fatal(xnb->dev, error,
1014 "Unable to allocate communication memory");
1015 return;
1016 }
1017
1018 /*
1019 * Connect communication channel.
1020 */
1021 error = xnb_connect_comms(xnb);
1022 if (error != 0) {
1023 /* Specific errors are reported by xnb_connect_comms(). */
1024 return;
1025 }
1026 xnb->carrier = 1;
1027
1028 /* Ready for I/O. */
1029 xenbus_set_state(xnb->dev, XenbusStateConnected);
1030}
1031
1032/*-------------------------- Device Teardown Support -------------------------*/
1033/**
1034 * Perform device shutdown functions.
1035 *
1036 * \param xnb Per-instance xnb configuration structure.
1037 *
1038 * Mark this instance as shutting down, wait for any active requests
1039 * to drain, disconnect from the front-end, and notify any waiters (e.g.
1040 * a thread invoking our detach method) that detach can now proceed.
1041 */
1042static int
1043xnb_shutdown(struct xnb_softc *xnb)
1044{
1045 /*
1046 * Due to the need to drop our mutex during some
1047 * xenbus operations, it is possible for two threads
1048 * to attempt to close out shutdown processing at
1049 * the same time. Tell the caller that hits this
1050 * race to try back later.
1051 */
1052 if ((xnb->flags & XNBF_IN_SHUTDOWN) != 0)
1053 return (EAGAIN);
1054
1055 xnb->flags |= XNBF_SHUTDOWN;
1056
1057 xnb->flags |= XNBF_IN_SHUTDOWN;
1058
1059 mtx_unlock(&xnb->sc_lock);
1060 /* Free the network interface */
1061 xnb->carrier = 0;
1062 if (xnb->xnb_ifp != NULL) {
1063 ether_ifdetach(xnb->xnb_ifp);
1064 if_free(xnb->xnb_ifp);
1065 xnb->xnb_ifp = NULL;
1066 }
1067 mtx_lock(&xnb->sc_lock);
1068
1069 xnb_disconnect(xnb);
1070
1071 mtx_unlock(&xnb->sc_lock);
1072 if (xenbus_get_state(xnb->dev) < XenbusStateClosing)
1073 xenbus_set_state(xnb->dev, XenbusStateClosing);
1074 mtx_lock(&xnb->sc_lock);
1075
1076 xnb->flags &= ~XNBF_IN_SHUTDOWN;
1077
1078
1079 /* Indicate to xnb_detach() that is it safe to proceed. */
1080 wakeup(xnb);
1081
1082 return (0);
1083}
1084
1085/**
1086 * Report an attach time error to the console and Xen, and cleanup
1087 * this instance by forcing immediate detach processing.
1088 *
1089 * \param xnb Per-instance xnb configuration structure.
1090 * \param err Errno describing the error.
1091 * \param fmt Printf style format and arguments
1092 */
1093static void
1094xnb_attach_failed(struct xnb_softc *xnb, int err, const char *fmt, ...)
1095{
1096 va_list ap;
1097 va_list ap_hotplug;
1098
1099 va_start(ap, fmt);
1100 va_copy(ap_hotplug, ap);
1101 xs_vprintf(XST_NIL, xenbus_get_node(xnb->dev),
1102 "hotplug-error", fmt, ap_hotplug);
1103 va_end(ap_hotplug);
1104 xs_printf(XST_NIL, xenbus_get_node(xnb->dev),
1105 "hotplug-status", "error");
1106
1107 xenbus_dev_vfatal(xnb->dev, err, fmt, ap);
1108 va_end(ap);
1109
1110 xs_printf(XST_NIL, xenbus_get_node(xnb->dev),
1111 "online", "0");
1112 xnb_detach(xnb->dev);
1113}
1114
1115/*---------------------------- NewBus Entrypoints ----------------------------*/
1116/**
1117 * Inspect a XenBus device and claim it if is of the appropriate type.
1118 *
1119 * \param dev NewBus device object representing a candidate XenBus device.
1120 *
1121 * \return 0 for success, errno codes for failure.
1122 */
1123static int
1124xnb_probe(device_t dev)
1125{
1126 if (!strcmp(xenbus_get_type(dev), "vif")) {
1127 DPRINTF("Claiming device %d, %s\n", device_get_unit(dev),
1128 devclass_get_name(device_get_devclass(dev)));
1129 device_set_desc(dev, "Backend Virtual Network Device");
1130 device_quiet(dev);
1131 return (0);
1132 }
1133 return (ENXIO);
1134}
1135
1136/**
1137 * Setup sysctl variables to control various Network Back parameters.
1138 *
1139 * \param xnb Xen Net Back softc.
1140 *
1141 */
1142static void
1143xnb_setup_sysctl(struct xnb_softc *xnb)
1144{
1145 struct sysctl_ctx_list *sysctl_ctx = NULL;
1146 struct sysctl_oid *sysctl_tree = NULL;
1147
1148 sysctl_ctx = device_get_sysctl_ctx(xnb->dev);
1149 if (sysctl_ctx == NULL)
1150 return;
1151
1152 sysctl_tree = device_get_sysctl_tree(xnb->dev);
1153 if (sysctl_tree == NULL)
1154 return;
1155
1156#ifdef XNB_DEBUG
1157 SYSCTL_ADD_PROC(sysctl_ctx,
1158 SYSCTL_CHILDREN(sysctl_tree),
1159 OID_AUTO,
1160 "unit_test_results",
1161 CTLTYPE_STRING | CTLFLAG_RD,
1162 xnb,
1163 0,
1164 xnb_unit_test_main,
1165 "A",
1166 "Results of builtin unit tests");
1167
1168 SYSCTL_ADD_PROC(sysctl_ctx,
1169 SYSCTL_CHILDREN(sysctl_tree),
1170 OID_AUTO,
1171 "dump_rings",
1172 CTLTYPE_STRING | CTLFLAG_RD,
1173 xnb,
1174 0,
1175 xnb_dump_rings,
1176 "A",
1177 "Xennet Back Rings");
1178#endif /* XNB_DEBUG */
1179}
1180
1181/**
1182 * Create a network device.
1183 * @param handle device handle
1184 */
1185int
1186create_netdev(device_t dev)
1187{
1188 struct ifnet *ifp;
1189 struct xnb_softc *xnb;
1190 int err = 0;
1191 uint32_t handle;
1192
1193 xnb = device_get_softc(dev);
1194 mtx_init(&xnb->sc_lock, "xnb_softc", "xen netback softc lock", MTX_DEF);
1195 mtx_init(&xnb->tx_lock, "xnb_tx", "xen netback tx lock", MTX_DEF);
1196 mtx_init(&xnb->rx_lock, "xnb_rx", "xen netback rx lock", MTX_DEF);
1197
1198 xnb->dev = dev;
1199
1200 ifmedia_init(&xnb->sc_media, 0, xnb_ifmedia_upd, xnb_ifmedia_sts);
1201 ifmedia_add(&xnb->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
1202 ifmedia_set(&xnb->sc_media, IFM_ETHER|IFM_MANUAL);
1203
1204 /*
1205 * Set the MAC address to a dummy value (00:00:00:00:00),
1206 * if the MAC address of the host-facing interface is set
1207 * to the same as the guest-facing one (the value found in
1208 * xenstore), the bridge would stop delivering packets to
1209 * us because it would see that the destination address of
1210 * the packet is the same as the interface, and so the bridge
1211 * would expect the packet has already been delivered locally
1212 * (and just drop it).
1213 */
1214 bzero(&xnb->mac[0], sizeof(xnb->mac));
1215
1216 /* The interface will be named using the following nomenclature:
1217 *
1218 * xnb<domid>.<handle>
1219 *
1220 * Where handle is the oder of the interface referred to the guest.
1221 */
1222 err = xs_scanf(XST_NIL, xenbus_get_node(xnb->dev), "handle", NULL,
1223 "%" PRIu32, &handle);
1224 if (err != 0)
1225 return (err);
1226 snprintf(xnb->if_name, IFNAMSIZ, "xnb%" PRIu16 ".%" PRIu32,
1227 xenbus_get_otherend_id(dev), handle);
1228
1229 if (err == 0) {
1230 /* Set up ifnet structure */
1231 ifp = xnb->xnb_ifp = if_alloc(IFT_ETHER);
1232 ifp->if_softc = xnb;
1233 if_initname(ifp, xnb->if_name, IF_DUNIT_NONE);
1234 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
1235 ifp->if_ioctl = xnb_ioctl;
1236 ifp->if_output = ether_output;
1237 ifp->if_start = xnb_start;
1238#ifdef notyet
1239 ifp->if_watchdog = xnb_watchdog;
1240#endif
1241 ifp->if_init = xnb_ifinit;
1242 ifp->if_mtu = ETHERMTU;
1243 ifp->if_snd.ifq_maxlen = NET_RX_RING_SIZE - 1;
1244
1245 ifp->if_hwassist = XNB_CSUM_FEATURES;
1246 ifp->if_capabilities = IFCAP_HWCSUM;
1247 ifp->if_capenable = IFCAP_HWCSUM;
1248
1249 ether_ifattach(ifp, xnb->mac);
1250 xnb->carrier = 0;
1251 }
1252
1253 return err;
1254}
1255
1256/**
1257 * Attach to a XenBus device that has been claimed by our probe routine.
1258 *
1259 * \param dev NewBus device object representing this Xen Net Back instance.
1260 *
1261 * \return 0 for success, errno codes for failure.
1262 */
1263static int
1264xnb_attach(device_t dev)
1265{
1266 struct xnb_softc *xnb;
1267 int error;
1268 xnb_ring_type_t i;
1269
1270 error = create_netdev(dev);
1271 if (error != 0) {
1272 xenbus_dev_fatal(dev, error, "creating netdev");
1273 return (error);
1274 }
1275
1276 DPRINTF("Attaching to %s\n", xenbus_get_node(dev));
1277
1278 /*
1279 * Basic initialization.
1280 * After this block it is safe to call xnb_detach()
1281 * to clean up any allocated data for this instance.
1282 */
1283 xnb = device_get_softc(dev);
1284 xnb->otherend_id = xenbus_get_otherend_id(dev);
1285 for (i=0; i < XNB_NUM_RING_TYPES; i++) {
1286 xnb->ring_configs[i].ring_pages = 1;
1287 }
1288
1289 /*
1290 * Setup sysctl variables.
1291 */
1292 xnb_setup_sysctl(xnb);
1293
1294 /* Update hot-plug status to satisfy xend. */
1295 error = xs_printf(XST_NIL, xenbus_get_node(xnb->dev),
1296 "hotplug-status", "connected");
1297 if (error != 0) {
1298 xnb_attach_failed(xnb, error, "writing %s/hotplug-status",
1299 xenbus_get_node(xnb->dev));
1300 return (error);
1301 }
1302
1303 if ((error = xnb_publish_backend_info(xnb)) != 0) {
1304 /*
1305 * If we can't publish our data, we cannot participate
1306 * in this connection, and waiting for a front-end state
1307 * change will not help the situation.
1308 */
1309 xnb_attach_failed(xnb, error,
1310 "Publishing backend status for %s",
1311 xenbus_get_node(xnb->dev));
1312 return error;
1313 }
1314
1315 /* Tell the front end that we are ready to connect. */
1316 xenbus_set_state(dev, XenbusStateInitWait);
1317
1318 return (0);
1319}
1320
1321/**
1322 * Detach from a net back device instance.
1323 *
1324 * \param dev NewBus device object representing this Xen Net Back instance.
1325 *
1326 * \return 0 for success, errno codes for failure.
1327 *
1328 * \note A net back device may be detached at any time in its life-cycle,
1329 * including part way through the attach process. For this reason,
1330 * initialization order and the intialization state checks in this
1331 * routine must be carefully coupled so that attach time failures
1332 * are gracefully handled.
1333 */
1334static int
1335xnb_detach(device_t dev)
1336{
1337 struct xnb_softc *xnb;
1338
1339 DPRINTF("\n");
1340
1341 xnb = device_get_softc(dev);
1342 mtx_lock(&xnb->sc_lock);
1343 while (xnb_shutdown(xnb) == EAGAIN) {
1344 msleep(xnb, &xnb->sc_lock, /*wakeup prio unchanged*/0,
1345 "xnb_shutdown", 0);
1346 }
1347 mtx_unlock(&xnb->sc_lock);
1348 DPRINTF("\n");
1349
1350 mtx_destroy(&xnb->tx_lock);
1351 mtx_destroy(&xnb->rx_lock);
1352 mtx_destroy(&xnb->sc_lock);
1353 return (0);
1354}
1355
1356/**
1357 * Prepare this net back device for suspension of this VM.
1358 *
1359 * \param dev NewBus device object representing this Xen net Back instance.
1360 *
1361 * \return 0 for success, errno codes for failure.
1362 */
1363static int
1364xnb_suspend(device_t dev)
1365{
1366 return (0);
1367}
1368
1369/**
1370 * Perform any processing required to recover from a suspended state.
1371 *
1372 * \param dev NewBus device object representing this Xen Net Back instance.
1373 *
1374 * \return 0 for success, errno codes for failure.
1375 */
1376static int
1377xnb_resume(device_t dev)
1378{
1379 return (0);
1380}
1381
1382/**
1383 * Handle state changes expressed via the XenStore by our front-end peer.
1384 *
1385 * \param dev NewBus device object representing this Xen
1386 * Net Back instance.
1387 * \param frontend_state The new state of the front-end.
1388 *
1389 * \return 0 for success, errno codes for failure.
1390 */
1391static void
1392xnb_frontend_changed(device_t dev, XenbusState frontend_state)
1393{
1394 struct xnb_softc *xnb;
1395
1396 xnb = device_get_softc(dev);
1397
1398 DPRINTF("frontend_state=%s, xnb_state=%s\n",
1399 xenbus_strstate(frontend_state),
1400 xenbus_strstate(xenbus_get_state(xnb->dev)));
1401
1402 switch (frontend_state) {
1403 case XenbusStateInitialising:
1404 break;
1405 case XenbusStateInitialised:
1406 case XenbusStateConnected:
1407 xnb_connect(xnb);
1408 break;
1409 case XenbusStateClosing:
1410 case XenbusStateClosed:
1411 mtx_lock(&xnb->sc_lock);
1412 xnb_shutdown(xnb);
1413 mtx_unlock(&xnb->sc_lock);
1414 if (frontend_state == XenbusStateClosed)
1415 xenbus_set_state(xnb->dev, XenbusStateClosed);
1416 break;
1417 default:
1418 xenbus_dev_fatal(xnb->dev, EINVAL, "saw state %d at frontend",
1419 frontend_state);
1420 break;
1421 }
1422}
1423
1424
1425/*---------------------------- Request Processing ----------------------------*/
1426/**
1427 * Interrupt handler bound to the shared ring's event channel.
1428 * Entry point for the xennet transmit path in netback
1429 * Transfers packets from the Xen ring to the host's generic networking stack
1430 *
1431 * \param arg Callback argument registerd during event channel
1432 * binding - the xnb_softc for this instance.
1433 */
1434static void
1435xnb_intr(void *arg)
1436{
1437 struct xnb_softc *xnb;
1438 struct ifnet *ifp;
1439 netif_tx_back_ring_t *txb;
1440 RING_IDX req_prod_local;
1441
1442 xnb = (struct xnb_softc *)arg;
1443 ifp = xnb->xnb_ifp;
1444 txb = &xnb->ring_configs[XNB_RING_TYPE_TX].back_ring.tx_ring;
1445
1446 mtx_lock(&xnb->tx_lock);
1447 do {
1448 int notify;
1449 req_prod_local = txb->sring->req_prod;
1450 xen_rmb();
1451
1452 for (;;) {
1453 struct mbuf *mbufc;
1454 int err;
1455
1456 err = xnb_recv(txb, xnb->otherend_id, &mbufc, ifp,
1457 xnb->tx_gnttab);
1458 if (err || (mbufc == NULL))
1459 break;
1460
1461 /* Send the packet to the generic network stack */
1462 (*xnb->xnb_ifp->if_input)(xnb->xnb_ifp, mbufc);
1463 }
1464
1465 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(txb, notify);
1466 if (notify != 0)
1467 xen_intr_signal(xnb->xen_intr_handle);
1468
1469 txb->sring->req_event = txb->req_cons + 1;
1470 xen_mb();
1471 } while (txb->sring->req_prod != req_prod_local) ;
1472 mtx_unlock(&xnb->tx_lock);
1473
1474 xnb_start(ifp);
1475}
1476
1477
1478/**
1479 * Build a struct xnb_pkt based on netif_tx_request's from a netif tx ring.
1480 * Will read exactly 0 or 1 packets from the ring; never a partial packet.
1481 * \param[out] pkt The returned packet. If there is an error building
1482 * the packet, pkt.list_len will be set to 0.
1483 * \param[in] tx_ring Pointer to the Ring that is the input to this function
1484 * \param[in] start The ring index of the first potential request
1485 * \return The number of requests consumed to build this packet
1486 */
1487static int
1488xnb_ring2pkt(struct xnb_pkt *pkt, const netif_tx_back_ring_t *tx_ring,
1489 RING_IDX start)
1490{
1491 /*
1492 * Outline:
1493 * 1) Initialize pkt
1494 * 2) Read the first request of the packet
1495 * 3) Read the extras
1496 * 4) Set cdr
1497 * 5) Loop on the remainder of the packet
1498 * 6) Finalize pkt (stuff like car_size and list_len)
1499 */
1500 int idx = start;
1501 int discard = 0; /* whether to discard the packet */
1502 int more_data = 0; /* there are more request past the last one */
1503 uint16_t cdr_size = 0; /* accumulated size of requests 2 through n */
1504
1505 xnb_pkt_initialize(pkt);
1506
1507 /* Read the first request */
1508 if (RING_HAS_UNCONSUMED_REQUESTS_2(tx_ring, idx)) {
1509 netif_tx_request_t *tx = RING_GET_REQUEST(tx_ring, idx);
1510 pkt->size = tx->size;
1511 pkt->flags = tx->flags & ~NETTXF_more_data;
1512 more_data = tx->flags & NETTXF_more_data;
1513 pkt->list_len++;
1514 pkt->car = idx;
1515 idx++;
1516 }
1517
1518 /* Read the extra info */
1519 if ((pkt->flags & NETTXF_extra_info) &&
1520 RING_HAS_UNCONSUMED_REQUESTS_2(tx_ring, idx)) {
1521 netif_extra_info_t *ext =
1522 (netif_extra_info_t*) RING_GET_REQUEST(tx_ring, idx);
1523 pkt->extra.type = ext->type;
1524 switch (pkt->extra.type) {
1525 case XEN_NETIF_EXTRA_TYPE_GSO:
1526 pkt->extra.u.gso = ext->u.gso;
1527 break;
1528 default:
1529 /*
1530 * The reference Linux netfront driver will
1531 * never set any other extra.type. So we don't
1532 * know what to do with it. Let's print an
1533 * error, then consume and discard the packet
1534 */
1535 printf("xnb(%s:%d): Unknown extra info type %d."
1536 " Discarding packet\n",
1537 __func__, __LINE__, pkt->extra.type);
1538 xnb_dump_txreq(start, RING_GET_REQUEST(tx_ring,
1539 start));
1540 xnb_dump_txreq(idx, RING_GET_REQUEST(tx_ring,
1541 idx));
1542 discard = 1;
1543 break;
1544 }
1545
1546 pkt->extra.flags = ext->flags;
1547 if (ext->flags & XEN_NETIF_EXTRA_FLAG_MORE) {
1548 /*
1549 * The reference linux netfront driver never sets this
1550 * flag (nor does any other known netfront). So we
1551 * will discard the packet.
1552 */
1553 printf("xnb(%s:%d): Request sets "
1554 "XEN_NETIF_EXTRA_FLAG_MORE, but we can't handle "
1555 "that\n", __func__, __LINE__);
1556 xnb_dump_txreq(start, RING_GET_REQUEST(tx_ring, start));
1557 xnb_dump_txreq(idx, RING_GET_REQUEST(tx_ring, idx));
1558 discard = 1;
1559 }
1560
1561 idx++;
1562 }
1563
1564 /* Set cdr. If there is not more data, cdr is invalid */
1565 pkt->cdr = idx;
1566
1567 /* Loop on remainder of packet */
1568 while (more_data && RING_HAS_UNCONSUMED_REQUESTS_2(tx_ring, idx)) {
1569 netif_tx_request_t *tx = RING_GET_REQUEST(tx_ring, idx);
1570 pkt->list_len++;
1571 cdr_size += tx->size;
1572 if (tx->flags & ~NETTXF_more_data) {
1573 /* There should be no other flags set at this point */
1574 printf("xnb(%s:%d): Request sets unknown flags %d "
1575 "after the 1st request in the packet.\n",
1576 __func__, __LINE__, tx->flags);
1577 xnb_dump_txreq(start, RING_GET_REQUEST(tx_ring, start));
1578 xnb_dump_txreq(idx, RING_GET_REQUEST(tx_ring, idx));
1579 }
1580
1581 more_data = tx->flags & NETTXF_more_data;
1582 idx++;
1583 }
1584
1585 /* Finalize packet */
1586 if (more_data != 0) {
1587 /* The ring ran out of requests before finishing the packet */
1588 xnb_pkt_invalidate(pkt);
1589 idx = start; /* tell caller that we consumed no requests */
1590 } else {
1591 /* Calculate car_size */
1592 pkt->car_size = pkt->size - cdr_size;
1593 }
1594 if (discard != 0) {
1595 xnb_pkt_invalidate(pkt);
1596 }
1597
1598 return idx - start;
1599}
1600
1601
1602/**
1603 * Respond to all the requests that constituted pkt. Builds the responses and
1604 * writes them to the ring, but doesn't push them to the shared ring.
1605 * \param[in] pkt the packet that needs a response
1606 * \param[in] error true if there was an error handling the packet, such
1607 * as in the hypervisor copy op or mbuf allocation
1608 * \param[out] ring Responses go here
1609 */
1610static void
1611xnb_txpkt2rsp(const struct xnb_pkt *pkt, netif_tx_back_ring_t *ring,
1612 int error)
1613{
1614 /*
1615 * Outline:
1616 * 1) Respond to the first request
1617 * 2) Respond to the extra info reques
1618 * Loop through every remaining request in the packet, generating
1619 * responses that copy those requests' ids and sets the status
1620 * appropriately.
1621 */
1622 netif_tx_request_t *tx;
1623 netif_tx_response_t *rsp;
1624 int i;
1625 uint16_t status;
1626
1627 status = (xnb_pkt_is_valid(pkt) == 0) || error ?
1628 NETIF_RSP_ERROR : NETIF_RSP_OKAY;
1629 KASSERT((pkt->list_len == 0) || (ring->rsp_prod_pvt == pkt->car),
1630 ("Cannot respond to ring requests out of order"));
1631
1632 if (pkt->list_len >= 1) {
1633 uint16_t id;
1634 tx = RING_GET_REQUEST(ring, ring->rsp_prod_pvt);
1635 id = tx->id;
1636 rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
1637 rsp->id = id;
1638 rsp->status = status;
1639 ring->rsp_prod_pvt++;
1640
1641 if (pkt->flags & NETRXF_extra_info) {
1642 rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
1643 rsp->status = NETIF_RSP_NULL;
1644 ring->rsp_prod_pvt++;
1645 }
1646 }
1647
1648 for (i=0; i < pkt->list_len - 1; i++) {
1649 uint16_t id;
1650 tx = RING_GET_REQUEST(ring, ring->rsp_prod_pvt);
1651 id = tx->id;
1652 rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
1653 rsp->id = id;
1654 rsp->status = status;
1655 ring->rsp_prod_pvt++;
1656 }
1657}
1658
1659/**
1660 * Create an mbuf chain to represent a packet. Initializes all of the headers
1661 * in the mbuf chain, but does not copy the data. The returned chain must be
1662 * free()'d when no longer needed
1663 * \param[in] pkt A packet to model the mbuf chain after
1664 * \return A newly allocated mbuf chain, possibly with clusters attached.
1665 * NULL on failure
1666 */
1667static struct mbuf*
1668xnb_pkt2mbufc(const struct xnb_pkt *pkt, struct ifnet *ifp)
1669{
1670 /**
1671 * \todo consider using a memory pool for mbufs instead of
1672 * reallocating them for every packet
1673 */
1674 /** \todo handle extra data */
1675 struct mbuf *m;
1676
1677 m = m_getm(NULL, pkt->size, M_NOWAIT, MT_DATA);
1678
1679 if (m != NULL) {
1680 m->m_pkthdr.rcvif = ifp;
1681 if (pkt->flags & NETTXF_data_validated) {
1682 /*
1683 * We lie to the host OS and always tell it that the
1684 * checksums are ok, because the packet is unlikely to
1685 * get corrupted going across domains.
1686 */
1687 m->m_pkthdr.csum_flags = (
1688 CSUM_IP_CHECKED |
1689 CSUM_IP_VALID |
1690 CSUM_DATA_VALID |
1691 CSUM_PSEUDO_HDR
1692 );
1693 m->m_pkthdr.csum_data = 0xffff;
1694 }
1695 }
1696 return m;
1697}
1698
1699/**
1700 * Build a gnttab_copy table that can be used to copy data from a pkt
1701 * to an mbufc. Does not actually perform the copy. Always uses gref's on
1702 * the packet side.
1703 * \param[in] pkt pkt's associated requests form the src for
1704 * the copy operation
1705 * \param[in] mbufc mbufc's storage forms the dest for the copy operation
1706 * \param[out] gnttab Storage for the returned grant table
1707 * \param[in] txb Pointer to the backend ring structure
1708 * \param[in] otherend_id The domain ID of the other end of the copy
1709 * \return The number of gnttab entries filled
1710 */
1711static int
1712xnb_txpkt2gnttab(const struct xnb_pkt *pkt, const struct mbuf *mbufc,
1713 gnttab_copy_table gnttab, const netif_tx_back_ring_t *txb,
1714 domid_t otherend_id)
1715{
1716
1717 const struct mbuf *mbuf = mbufc;/* current mbuf within the chain */
1718 int gnt_idx = 0; /* index into grant table */
1719 RING_IDX r_idx = pkt->car; /* index into tx ring buffer */
1720 int r_ofs = 0; /* offset of next data within tx request's data area */
1721 int m_ofs = 0; /* offset of next data within mbuf's data area */
1722 /* size in bytes that still needs to be represented in the table */
1723 uint16_t size_remaining = pkt->size;
1724
1725 while (size_remaining > 0) {
1726 const netif_tx_request_t *txq = RING_GET_REQUEST(txb, r_idx);
1727 const size_t mbuf_space = M_TRAILINGSPACE(mbuf) - m_ofs;
1728 const size_t req_size =
1729 r_idx == pkt->car ? pkt->car_size : txq->size;
1730 const size_t pkt_space = req_size - r_ofs;
1731 /*
1732 * space is the largest amount of data that can be copied in the
1733 * grant table's next entry
1734 */
1735 const size_t space = MIN(pkt_space, mbuf_space);
1736
1737 /* TODO: handle this error condition without panicking */
1738 KASSERT(gnt_idx < GNTTAB_LEN, ("Grant table is too short"));
1739
1740 gnttab[gnt_idx].source.u.ref = txq->gref;
1741 gnttab[gnt_idx].source.domid = otherend_id;
1742 gnttab[gnt_idx].source.offset = txq->offset + r_ofs;
1743 gnttab[gnt_idx].dest.u.gmfn = virt_to_mfn(
1744 mtod(mbuf, vm_offset_t) + m_ofs);
1745 gnttab[gnt_idx].dest.offset = virt_to_offset(
1746 mtod(mbuf, vm_offset_t) + m_ofs);
1747 gnttab[gnt_idx].dest.domid = DOMID_SELF;
1748 gnttab[gnt_idx].len = space;
1749 gnttab[gnt_idx].flags = GNTCOPY_source_gref;
1750
1751 gnt_idx++;
1752 r_ofs += space;
1753 m_ofs += space;
1754 size_remaining -= space;
1755 if (req_size - r_ofs <= 0) {
1756 /* Must move to the next tx request */
1757 r_ofs = 0;
1758 r_idx = (r_idx == pkt->car) ? pkt->cdr : r_idx + 1;
1759 }
1760 if (M_TRAILINGSPACE(mbuf) - m_ofs <= 0) {
1761 /* Must move to the next mbuf */
1762 m_ofs = 0;
1763 mbuf = mbuf->m_next;
1764 }
1765 }
1766
1767 return gnt_idx;
1768}
1769
1770/**
1771 * Check the status of the grant copy operations, and update mbufs various
1772 * non-data fields to reflect the data present.
1773 * \param[in,out] mbufc mbuf chain to update. The chain must be valid and of
1774 * the correct length, and data should already be present
1775 * \param[in] gnttab A grant table for a just completed copy op
1776 * \param[in] n_entries The number of valid entries in the grant table
1777 */
1778static void
1779xnb_update_mbufc(struct mbuf *mbufc, const gnttab_copy_table gnttab,
1780 int n_entries)
1781{
1782 struct mbuf *mbuf = mbufc;
1783 int i;
1784 size_t total_size = 0;
1785
1786 for (i = 0; i < n_entries; i++) {
1787 KASSERT(gnttab[i].status == GNTST_okay,
1788 ("Some gnttab_copy entry had error status %hd\n",
1789 gnttab[i].status));
1790
1791 mbuf->m_len += gnttab[i].len;
1792 total_size += gnttab[i].len;
1793 if (M_TRAILINGSPACE(mbuf) <= 0) {
1794 mbuf = mbuf->m_next;
1795 }
1796 }
1797 mbufc->m_pkthdr.len = total_size;
1798
1799#if defined(INET) || defined(INET6)
1800 xnb_add_mbuf_cksum(mbufc);
1801#endif
1802}
1803
1804/**
1805 * Dequeue at most one packet from the shared ring
1806 * \param[in,out] txb Netif tx ring. A packet will be removed from it, and
1807 * its private indices will be updated. But the indices
1808 * will not be pushed to the shared ring.
1809 * \param[in] ifnet Interface to which the packet will be sent
1810 * \param[in] otherend Domain ID of the other end of the ring
1811 * \param[out] mbufc The assembled mbuf chain, ready to send to the generic
1812 * networking stack
1813 * \param[in,out] gnttab Pointer to enough memory for a grant table. We make
1814 * this a function parameter so that we will take less
1815 * stack space.
1816 * \return An error code
1817 */
1818static int
1819xnb_recv(netif_tx_back_ring_t *txb, domid_t otherend, struct mbuf **mbufc,
1820 struct ifnet *ifnet, gnttab_copy_table gnttab)
1821{
1822 struct xnb_pkt pkt;
1823 /* number of tx requests consumed to build the last packet */
1824 int num_consumed;
1825 int nr_ents;
1826
1827 *mbufc = NULL;
1828 num_consumed = xnb_ring2pkt(&pkt, txb, txb->req_cons);
1829 if (num_consumed == 0)
1830 return 0; /* Nothing to receive */
1831
1832 /* update statistics independent of errors */
1833 if_inc_counter(ifnet, IFCOUNTER_IPACKETS, 1);
1834
1835 /*
1836 * if we got here, then 1 or more requests was consumed, but the packet
1837 * is not necessarily valid.
1838 */
1839 if (xnb_pkt_is_valid(&pkt) == 0) {
1840 /* got a garbage packet, respond and drop it */
1841 xnb_txpkt2rsp(&pkt, txb, 1);
1842 txb->req_cons += num_consumed;
1843 DPRINTF("xnb_intr: garbage packet, num_consumed=%d\n",
1844 num_consumed);
1845 if_inc_counter(ifnet, IFCOUNTER_IERRORS, 1);
1846 return EINVAL;
1847 }
1848
1849 *mbufc = xnb_pkt2mbufc(&pkt, ifnet);
1850
1851 if (*mbufc == NULL) {
1852 /*
1853 * Couldn't allocate mbufs. Respond and drop the packet. Do
1854 * not consume the requests
1855 */
1856 xnb_txpkt2rsp(&pkt, txb, 1);
1857 DPRINTF("xnb_intr: Couldn't allocate mbufs, num_consumed=%d\n",
1858 num_consumed);
1859 if_inc_counter(ifnet, IFCOUNTER_IQDROPS, 1);
1860 return ENOMEM;
1861 }
1862
1863 nr_ents = xnb_txpkt2gnttab(&pkt, *mbufc, gnttab, txb, otherend);
1864
1865 if (nr_ents > 0) {
1866 int __unused hv_ret = HYPERVISOR_grant_table_op(GNTTABOP_copy,
1867 gnttab, nr_ents);
1868 KASSERT(hv_ret == 0,
1869 ("HYPERVISOR_grant_table_op returned %d\n", hv_ret));
1870 xnb_update_mbufc(*mbufc, gnttab, nr_ents);
1871 }
1872
1873 xnb_txpkt2rsp(&pkt, txb, 0);
1874 txb->req_cons += num_consumed;
1875 return 0;
1876}
1877
1878/**
1879 * Create an xnb_pkt based on the contents of an mbuf chain.
1880 * \param[in] mbufc mbuf chain to transform into a packet
1881 * \param[out] pkt Storage for the newly generated xnb_pkt
1882 * \param[in] start The ring index of the first available slot in the rx
1883 * ring
1884 * \param[in] space The number of free slots in the rx ring
1885 * \retval 0 Success
1886 * \retval EINVAL mbufc was corrupt or not convertible into a pkt
1887 * \retval EAGAIN There was not enough space in the ring to queue the
1888 * packet
1889 */
1890static int
1891xnb_mbufc2pkt(const struct mbuf *mbufc, struct xnb_pkt *pkt,
1892 RING_IDX start, int space)
1893{
1894
1895 int retval = 0;
1896
1897 if ((mbufc == NULL) ||
1898 ( (mbufc->m_flags & M_PKTHDR) == 0) ||
1899 (mbufc->m_pkthdr.len == 0)) {
1900 xnb_pkt_invalidate(pkt);
1901 retval = EINVAL;
1902 } else {
1903 int slots_required;
1904
1905 xnb_pkt_validate(pkt);
1906 pkt->flags = 0;
1907 pkt->size = mbufc->m_pkthdr.len;
1908 pkt->car = start;
1909 pkt->car_size = mbufc->m_len;
1910
1911 if (mbufc->m_pkthdr.csum_flags & CSUM_TSO) {
1912 pkt->flags |= NETRXF_extra_info;
1913 pkt->extra.u.gso.size = mbufc->m_pkthdr.tso_segsz;
1914 pkt->extra.u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
1915 pkt->extra.u.gso.pad = 0;
1916 pkt->extra.u.gso.features = 0;
1917 pkt->extra.type = XEN_NETIF_EXTRA_TYPE_GSO;
1918 pkt->extra.flags = 0;
1919 pkt->cdr = start + 2;
1920 } else {
1921 pkt->cdr = start + 1;
1922 }
1923 if (mbufc->m_pkthdr.csum_flags & (CSUM_TSO | CSUM_DELAY_DATA)) {
1924 pkt->flags |=
1925 (NETRXF_csum_blank | NETRXF_data_validated);
1926 }
1927
1928 /*
1929 * Each ring response can have up to PAGE_SIZE of data.
1930 * Assume that we can defragment the mbuf chain efficiently
1931 * into responses so that each response but the last uses all
1932 * PAGE_SIZE bytes.
1933 */
1934 pkt->list_len = (pkt->size + PAGE_SIZE - 1) / PAGE_SIZE;
1935
1936 if (pkt->list_len > 1) {
1937 pkt->flags |= NETRXF_more_data;
1938 }
1939
1940 slots_required = pkt->list_len +
1941 (pkt->flags & NETRXF_extra_info ? 1 : 0);
1942 if (slots_required > space) {
1943 xnb_pkt_invalidate(pkt);
1944 retval = EAGAIN;
1945 }
1946 }
1947
1948 return retval;
1949}
1950
1951/**
1952 * Build a gnttab_copy table that can be used to copy data from an mbuf chain
1953 * to the frontend's shared buffers. Does not actually perform the copy.
1954 * Always uses gref's on the other end's side.
1955 * \param[in] pkt pkt's associated responses form the dest for the copy
1956 * operatoin
1957 * \param[in] mbufc The source for the copy operation
1958 * \param[out] gnttab Storage for the returned grant table
1959 * \param[in] rxb Pointer to the backend ring structure
1960 * \param[in] otherend_id The domain ID of the other end of the copy
1961 * \return The number of gnttab entries filled
1962 */
1963static int
1964xnb_rxpkt2gnttab(const struct xnb_pkt *pkt, const struct mbuf *mbufc,
1965 gnttab_copy_table gnttab, const netif_rx_back_ring_t *rxb,
1966 domid_t otherend_id)
1967{
1968
1969 const struct mbuf *mbuf = mbufc;/* current mbuf within the chain */
1970 int gnt_idx = 0; /* index into grant table */
1971 RING_IDX r_idx = pkt->car; /* index into rx ring buffer */
1972 int r_ofs = 0; /* offset of next data within rx request's data area */
1973 int m_ofs = 0; /* offset of next data within mbuf's data area */
1974 /* size in bytes that still needs to be represented in the table */
1975 uint16_t size_remaining;
1976
1977 size_remaining = (xnb_pkt_is_valid(pkt) != 0) ? pkt->size : 0;
1978
1979 while (size_remaining > 0) {
1980 const netif_rx_request_t *rxq = RING_GET_REQUEST(rxb, r_idx);
1981 const size_t mbuf_space = mbuf->m_len - m_ofs;
1982 /* Xen shared pages have an implied size of PAGE_SIZE */
1983 const size_t req_size = PAGE_SIZE;
1984 const size_t pkt_space = req_size - r_ofs;
1985 /*
1986 * space is the largest amount of data that can be copied in the
1987 * grant table's next entry
1988 */
1989 const size_t space = MIN(pkt_space, mbuf_space);
1990
1991 /* TODO: handle this error condition without panicing */
1992 KASSERT(gnt_idx < GNTTAB_LEN, ("Grant table is too short"));
1993
1994 gnttab[gnt_idx].dest.u.ref = rxq->gref;
1995 gnttab[gnt_idx].dest.domid = otherend_id;
1996 gnttab[gnt_idx].dest.offset = r_ofs;
1997 gnttab[gnt_idx].source.u.gmfn = virt_to_mfn(
1998 mtod(mbuf, vm_offset_t) + m_ofs);
1999 gnttab[gnt_idx].source.offset = virt_to_offset(
2000 mtod(mbuf, vm_offset_t) + m_ofs);
2001 gnttab[gnt_idx].source.domid = DOMID_SELF;
2002 gnttab[gnt_idx].len = space;
2003 gnttab[gnt_idx].flags = GNTCOPY_dest_gref;
2004
2005 gnt_idx++;
2006
2007 r_ofs += space;
2008 m_ofs += space;
2009 size_remaining -= space;
2010 if (req_size - r_ofs <= 0) {
2011 /* Must move to the next rx request */
2012 r_ofs = 0;
2013 r_idx = (r_idx == pkt->car) ? pkt->cdr : r_idx + 1;
2014 }
2015 if (mbuf->m_len - m_ofs <= 0) {
2016 /* Must move to the next mbuf */
2017 m_ofs = 0;
2018 mbuf = mbuf->m_next;
2019 }
2020 }
2021
2022 return gnt_idx;
2023}
2024
2025/**
2026 * Generates responses for all the requests that constituted pkt. Builds
2027 * responses and writes them to the ring, but doesn't push the shared ring
2028 * indices.
2029 * \param[in] pkt the packet that needs a response
2030 * \param[in] gnttab The grant copy table corresponding to this packet.
2031 * Used to determine how many rsp->netif_rx_response_t's to
2032 * generate.
2033 * \param[in] n_entries Number of relevant entries in the grant table
2034 * \param[out] ring Responses go here
2035 * \return The number of RX requests that were consumed to generate
2036 * the responses
2037 */
2038static int
2039xnb_rxpkt2rsp(const struct xnb_pkt *pkt, const gnttab_copy_table gnttab,
2040 int n_entries, netif_rx_back_ring_t *ring)
2041{
2042 /*
2043 * This code makes the following assumptions:
2044 * * All entries in gnttab set GNTCOPY_dest_gref
2045 * * The entries in gnttab are grouped by their grefs: any two
2046 * entries with the same gref must be adjacent
2047 */
2048 int error = 0;
2049 int gnt_idx, i;
2050 int n_responses = 0;
2051 grant_ref_t last_gref = GRANT_REF_INVALID;
2052 RING_IDX r_idx;
2053
2054 KASSERT(gnttab != NULL, ("Received a null granttable copy"));
2055
2056 /*
2057 * In the event of an error, we only need to send one response to the
2058 * netfront. In that case, we musn't write any data to the responses
2059 * after the one we send. So we must loop all the way through gnttab
2060 * looking for errors before we generate any responses
2061 *
2062 * Since we're looping through the grant table anyway, we'll count the
2063 * number of different gref's in it, which will tell us how many
2064 * responses to generate
2065 */
2066 for (gnt_idx = 0; gnt_idx < n_entries; gnt_idx++) {
2067 int16_t status = gnttab[gnt_idx].status;
2068 if (status != GNTST_okay) {
2069 DPRINTF(
2070 "Got error %d for hypervisor gnttab_copy status\n",
2071 status);
2072 error = 1;
2073 break;
2074 }
2075 if (gnttab[gnt_idx].dest.u.ref != last_gref) {
2076 n_responses++;
2077 last_gref = gnttab[gnt_idx].dest.u.ref;
2078 }
2079 }
2080
2081 if (error != 0) {
2082 uint16_t id;
2083 netif_rx_response_t *rsp;
2084
2085 id = RING_GET_REQUEST(ring, ring->rsp_prod_pvt)->id;
2086 rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
2087 rsp->id = id;
2088 rsp->status = NETIF_RSP_ERROR;
2089 n_responses = 1;
2090 } else {
2091 gnt_idx = 0;
2092 const int has_extra = pkt->flags & NETRXF_extra_info;
2093 if (has_extra != 0)
2094 n_responses++;
2095
2096 for (i = 0; i < n_responses; i++) {
2097 netif_rx_request_t rxq;
2098 netif_rx_response_t *rsp;
2099
2100 r_idx = ring->rsp_prod_pvt + i;
2101 /*
2102 * We copy the structure of rxq instead of making a
2103 * pointer because it shares the same memory as rsp.
2104 */
2105 rxq = *(RING_GET_REQUEST(ring, r_idx));
2106 rsp = RING_GET_RESPONSE(ring, r_idx);
2107 if (has_extra && (i == 1)) {
2108 netif_extra_info_t *ext =
2109 (netif_extra_info_t*)rsp;
2110 ext->type = XEN_NETIF_EXTRA_TYPE_GSO;
2111 ext->flags = 0;
2112 ext->u.gso.size = pkt->extra.u.gso.size;
2113 ext->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
2114 ext->u.gso.pad = 0;
2115 ext->u.gso.features = 0;
2116 } else {
2117 rsp->id = rxq.id;
2118 rsp->status = GNTST_okay;
2119 rsp->offset = 0;
2120 rsp->flags = 0;
2121 if (i < pkt->list_len - 1)
2122 rsp->flags |= NETRXF_more_data;
2123 if ((i == 0) && has_extra)
2124 rsp->flags |= NETRXF_extra_info;
2125 if ((i == 0) &&
2126 (pkt->flags & NETRXF_data_validated)) {
2127 rsp->flags |= NETRXF_data_validated;
2128 rsp->flags |= NETRXF_csum_blank;
2129 }
2130 rsp->status = 0;
2131 for (; gnttab[gnt_idx].dest.u.ref == rxq.gref;
2132 gnt_idx++) {
2133 rsp->status += gnttab[gnt_idx].len;
2134 }
2135 }
2136 }
2137 }
2138
2139 ring->req_cons += n_responses;
2140 ring->rsp_prod_pvt += n_responses;
2141 return n_responses;
2142}
2143
2144#if defined(INET) || defined(INET6)
2145/**
2146 * Add IP, TCP, and/or UDP checksums to every mbuf in a chain. The first mbuf
2147 * in the chain must start with a struct ether_header.
2148 *
2149 * XXX This function will perform incorrectly on UDP packets that are split up
2150 * into multiple ethernet frames.
2151 */
2152static void
2153xnb_add_mbuf_cksum(struct mbuf *mbufc)
2154{
2155 struct ether_header *eh;
2156 struct ip *iph;
2157 uint16_t ether_type;
2158
2159 eh = mtod(mbufc, struct ether_header*);
2160 ether_type = ntohs(eh->ether_type);
2161 if (ether_type != ETHERTYPE_IP) {
2162 /* Nothing to calculate */
2163 return;
2164 }
2165
2166 iph = (struct ip*)(eh + 1);
2167 if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) {
2168 iph->ip_sum = 0;
2169 iph->ip_sum = in_cksum_hdr(iph);
2170 }
2171
2172 switch (iph->ip_p) {
2173 case IPPROTO_TCP:
2174 if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) {
2175 size_t tcplen = ntohs(iph->ip_len) - sizeof(struct ip);
2176 struct tcphdr *th = (struct tcphdr*)(iph + 1);
2177 th->th_sum = in_pseudo(iph->ip_src.s_addr,
2178 iph->ip_dst.s_addr, htons(IPPROTO_TCP + tcplen));
2179 th->th_sum = in_cksum_skip(mbufc,
2180 sizeof(struct ether_header) + ntohs(iph->ip_len),
2181 sizeof(struct ether_header) + (iph->ip_hl << 2));
2182 }
2183 break;
2184 case IPPROTO_UDP:
2185 if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) {
2186 size_t udplen = ntohs(iph->ip_len) - sizeof(struct ip);
2187 struct udphdr *uh = (struct udphdr*)(iph + 1);
2188 uh->uh_sum = in_pseudo(iph->ip_src.s_addr,
2189 iph->ip_dst.s_addr, htons(IPPROTO_UDP + udplen));
2190 uh->uh_sum = in_cksum_skip(mbufc,
2191 sizeof(struct ether_header) + ntohs(iph->ip_len),
2192 sizeof(struct ether_header) + (iph->ip_hl << 2));
2193 }
2194 break;
2195 default:
2196 break;
2197 }
2198}
2199#endif /* INET || INET6 */
2200
2201static void
2202xnb_stop(struct xnb_softc *xnb)
2203{
2204 struct ifnet *ifp;
2205
2206 mtx_assert(&xnb->sc_lock, MA_OWNED);
2207 ifp = xnb->xnb_ifp;
2208 ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
2209 if_link_state_change(ifp, LINK_STATE_DOWN);
2210}
2211
2212static int
2213xnb_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
2214{
2215 struct xnb_softc *xnb = ifp->if_softc;
2216 struct ifreq *ifr = (struct ifreq*) data;
2217#ifdef INET
2218 struct ifaddr *ifa = (struct ifaddr*)data;
2219#endif
2220 int error = 0;
2221
2222 switch (cmd) {
2223 case SIOCSIFFLAGS:
2224 mtx_lock(&xnb->sc_lock);
2225 if (ifp->if_flags & IFF_UP) {
2226 xnb_ifinit_locked(xnb);
2227 } else {
2228 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
2229 xnb_stop(xnb);
2230 }
2231 }
2232 /*
2233 * Note: netfront sets a variable named xn_if_flags
2234 * here, but that variable is never read
2235 */
2236 mtx_unlock(&xnb->sc_lock);
2237 break;
2238 case SIOCSIFADDR:
2239#ifdef INET
2240 mtx_lock(&xnb->sc_lock);
2241 if (ifa->ifa_addr->sa_family == AF_INET) {
2242 ifp->if_flags |= IFF_UP;
2243 if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
2244 ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
2245 IFF_DRV_OACTIVE);
2246 if_link_state_change(ifp,
2247 LINK_STATE_DOWN);
2248 ifp->if_drv_flags |= IFF_DRV_RUNNING;
2249 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
2250 if_link_state_change(ifp,
2251 LINK_STATE_UP);
2252 }
2253 arp_ifinit(ifp, ifa);
2254 mtx_unlock(&xnb->sc_lock);
2255 } else {
2256 mtx_unlock(&xnb->sc_lock);
2257#endif
2258 error = ether_ioctl(ifp, cmd, data);
2259#ifdef INET
2260 }
2261#endif
2262 break;
2263 case SIOCSIFCAP:
2264 mtx_lock(&xnb->sc_lock);
2265 if (ifr->ifr_reqcap & IFCAP_TXCSUM) {
2266 ifp->if_capenable |= IFCAP_TXCSUM;
2267 ifp->if_hwassist |= XNB_CSUM_FEATURES;
2268 } else {
2269 ifp->if_capenable &= ~(IFCAP_TXCSUM);
2270 ifp->if_hwassist &= ~(XNB_CSUM_FEATURES);
2271 }
2272 if ((ifr->ifr_reqcap & IFCAP_RXCSUM)) {
2273 ifp->if_capenable |= IFCAP_RXCSUM;
2274 } else {
2275 ifp->if_capenable &= ~(IFCAP_RXCSUM);
2276 }
2277 /*
2278 * TODO enable TSO4 and LRO once we no longer need
2279 * to calculate checksums in software
2280 */
2281#if 0
2282 if (ifr->if_reqcap |= IFCAP_TSO4) {
2283 if (IFCAP_TXCSUM & ifp->if_capenable) {
2284 printf("xnb: Xen netif requires that "
2285 "TXCSUM be enabled in order "
2286 "to use TSO4\n");
2287 error = EINVAL;
2288 } else {
2289 ifp->if_capenable |= IFCAP_TSO4;
2290 ifp->if_hwassist |= CSUM_TSO;
2291 }
2292 } else {
2293 ifp->if_capenable &= ~(IFCAP_TSO4);
2294 ifp->if_hwassist &= ~(CSUM_TSO);
2295 }
2296 if (ifr->ifreqcap |= IFCAP_LRO) {
2297 ifp->if_capenable |= IFCAP_LRO;
2298 } else {
2299 ifp->if_capenable &= ~(IFCAP_LRO);
2300 }
2301#endif
2302 mtx_unlock(&xnb->sc_lock);
2303 break;
2304 case SIOCSIFMTU:
2305 ifp->if_mtu = ifr->ifr_mtu;
2306 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
2307 xnb_ifinit(xnb);
2308 break;
2309 case SIOCADDMULTI:
2310 case SIOCDELMULTI:
2311 case SIOCSIFMEDIA:
2312 case SIOCGIFMEDIA:
2313 error = ifmedia_ioctl(ifp, ifr, &xnb->sc_media, cmd);
2314 break;
2315 default:
2316 error = ether_ioctl(ifp, cmd, data);
2317 break;
2318 }
2319 return (error);
2320}
2321
2322static void
2323xnb_start_locked(struct ifnet *ifp)
2324{
2325 netif_rx_back_ring_t *rxb;
2326 struct xnb_softc *xnb;
2327 struct mbuf *mbufc;
2328 RING_IDX req_prod_local;
2329
2330 xnb = ifp->if_softc;
2331 rxb = &xnb->ring_configs[XNB_RING_TYPE_RX].back_ring.rx_ring;
2332
2333 if (!xnb->carrier)
2334 return;
2335
2336 do {
2337 int out_of_space = 0;
2338 int notify;
2339 req_prod_local = rxb->sring->req_prod;
2340 xen_rmb();
2341 for (;;) {
2342 int error;
2343
2344 IF_DEQUEUE(&ifp->if_snd, mbufc);
2345 if (mbufc == NULL)
2346 break;
2347 error = xnb_send(rxb, xnb->otherend_id, mbufc,
2348 xnb->rx_gnttab);
2349 switch (error) {
2350 case EAGAIN:
2351 /*
2352 * Insufficient space in the ring.
2353 * Requeue pkt and send when space is
2354 * available.
2355 */
2356 IF_PREPEND(&ifp->if_snd, mbufc);
2357 /*
2358 * Perhaps the frontend missed an IRQ
2359 * and went to sleep. Notify it to wake
2360 * it up.
2361 */
2362 out_of_space = 1;
2363 break;
2364
2365 case EINVAL:
2366 /* OS gave a corrupt packet. Drop it.*/
2367 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
2368 /* FALLTHROUGH */
2369 default:
2370 /* Send succeeded, or packet had error.
2371 * Free the packet */
2372 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
2373 if (mbufc)
2374 m_freem(mbufc);
2375 break;
2376 }
2377 if (out_of_space != 0)
2378 break;
2379 }
2380
2381 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(rxb, notify);
2382 if ((notify != 0) || (out_of_space != 0))
2383 xen_intr_signal(xnb->xen_intr_handle);
2384 rxb->sring->req_event = req_prod_local + 1;
2385 xen_mb();
2386 } while (rxb->sring->req_prod != req_prod_local) ;
2387}
2388
2389/**
2390 * Sends one packet to the ring. Blocks until the packet is on the ring
2391 * \param[in] mbufc Contains one packet to send. Caller must free
2392 * \param[in,out] rxb The packet will be pushed onto this ring, but the
2393 * otherend will not be notified.
2394 * \param[in] otherend The domain ID of the other end of the connection
2395 * \retval EAGAIN The ring did not have enough space for the packet.
2396 * The ring has not been modified
2397 * \param[in,out] gnttab Pointer to enough memory for a grant table. We make
2398 * this a function parameter so that we will take less
2399 * stack space.
2400 * \retval EINVAL mbufc was corrupt or not convertible into a pkt
2401 */
2402static int
2403xnb_send(netif_rx_back_ring_t *ring, domid_t otherend, const struct mbuf *mbufc,
2404 gnttab_copy_table gnttab)
2405{
2406 struct xnb_pkt pkt;
2407 int error, n_entries, n_reqs;
2408 RING_IDX space;
2409
2410 space = ring->sring->req_prod - ring->req_cons;
2411 error = xnb_mbufc2pkt(mbufc, &pkt, ring->rsp_prod_pvt, space);
2412 if (error != 0)
2413 return error;
2414 n_entries = xnb_rxpkt2gnttab(&pkt, mbufc, gnttab, ring, otherend);
2415 if (n_entries != 0) {
2416 int __unused hv_ret = HYPERVISOR_grant_table_op(GNTTABOP_copy,
2417 gnttab, n_entries);
2418 KASSERT(hv_ret == 0, ("HYPERVISOR_grant_table_op returned %d\n",
2419 hv_ret));
2420 }
2421
2422 n_reqs = xnb_rxpkt2rsp(&pkt, gnttab, n_entries, ring);
2423
2424 return 0;
2425}
2426
2427static void
2428xnb_start(struct ifnet *ifp)
2429{
2430 struct xnb_softc *xnb;
2431
2432 xnb = ifp->if_softc;
2433 mtx_lock(&xnb->rx_lock);
2434 xnb_start_locked(ifp);
2435 mtx_unlock(&xnb->rx_lock);
2436}
2437
2438/* equivalent of network_open() in Linux */
2439static void
2440xnb_ifinit_locked(struct xnb_softc *xnb)
2441{
2442 struct ifnet *ifp;
2443
2444 ifp = xnb->xnb_ifp;
2445
2446 mtx_assert(&xnb->sc_lock, MA_OWNED);
2447
2448 if (ifp->if_drv_flags & IFF_DRV_RUNNING)
2449 return;
2450
2451 xnb_stop(xnb);
2452
2453 ifp->if_drv_flags |= IFF_DRV_RUNNING;
2454 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
2455 if_link_state_change(ifp, LINK_STATE_UP);
2456}
2457
2458
2459static void
2460xnb_ifinit(void *xsc)
2461{
2462 struct xnb_softc *xnb = xsc;
2463
2464 mtx_lock(&xnb->sc_lock);
2465 xnb_ifinit_locked(xnb);
2466 mtx_unlock(&xnb->sc_lock);
2467}
2468
2469/**
2470 * Callback used by the generic networking code to tell us when our carrier
2471 * state has changed. Since we don't have a physical carrier, we don't care
2472 */
2473static int
2474xnb_ifmedia_upd(struct ifnet *ifp)
2475{
2476 return (0);
2477}
2478
2479/**
2480 * Callback used by the generic networking code to ask us what our carrier
2481 * state is. Since we don't have a physical carrier, this is very simple
2482 */
2483static void
2484xnb_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
2485{
2486 ifmr->ifm_status = IFM_AVALID|IFM_ACTIVE;
2487 ifmr->ifm_active = IFM_ETHER|IFM_MANUAL;
2488}
2489
2490
2491/*---------------------------- NewBus Registration ---------------------------*/
2492static device_method_t xnb_methods[] = {
2493 /* Device interface */
2494 DEVMETHOD(device_probe, xnb_probe),
2495 DEVMETHOD(device_attach, xnb_attach),
2496 DEVMETHOD(device_detach, xnb_detach),
2497 DEVMETHOD(device_shutdown, bus_generic_shutdown),
2498 DEVMETHOD(device_suspend, xnb_suspend),
2499 DEVMETHOD(device_resume, xnb_resume),
2500
2501 /* Xenbus interface */
2502 DEVMETHOD(xenbus_otherend_changed, xnb_frontend_changed),
2503
2504 { 0, 0 }
2505};
2506
2507static driver_t xnb_driver = {
2508 "xnb",
2509 xnb_methods,
2510 sizeof(struct xnb_softc),
2511};
2512devclass_t xnb_devclass;
2513
2514DRIVER_MODULE(xnb, xenbusb_back, xnb_driver, xnb_devclass, 0, 0);
2515
2516
2517/*-------------------------- Unit Tests -------------------------------------*/
2518#ifdef XNB_DEBUG
2519#include "netback_unit_tests.c"
2520#endif