xref: /freebsd/sys/dev/xen/netback/netback.c (revision 3157ba21)
1 /*
2  * Copyright (c) 2006, Cisco Systems, Inc.
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  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of Cisco Systems, Inc. nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 #include "opt_sctp.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/sockio.h>
38 #include <sys/mbuf.h>
39 #include <sys/malloc.h>
40 #include <sys/kernel.h>
41 #include <sys/socket.h>
42 #include <sys/queue.h>
43 #include <sys/taskqueue.h>
44 
45 #include <sys/module.h>
46 #include <sys/bus.h>
47 #include <sys/sysctl.h>
48 
49 #include <net/if.h>
50 #include <net/if_arp.h>
51 #include <net/if_types.h>
52 #include <net/ethernet.h>
53 #include <net/if_bridgevar.h>
54 
55 #include <netinet/in_systm.h>
56 #include <netinet/in.h>
57 #include <netinet/in_var.h>
58 #include <netinet/ip.h>
59 #include <netinet/tcp.h>
60 #include <netinet/udp.h>
61 #ifdef SCTP
62 #include <netinet/sctp.h>
63 #include <netinet/sctp_crc32.h>
64 #endif
65 
66 #include <vm/vm_extern.h>
67 #include <vm/vm_kern.h>
68 
69 #include <machine/in_cksum.h>
70 #include <machine/xen-os.h>
71 #include <machine/hypervisor.h>
72 #include <machine/hypervisor-ifs.h>
73 #include <machine/xen_intr.h>
74 #include <machine/evtchn.h>
75 #include <machine/xenbus.h>
76 #include <machine/gnttab.h>
77 #include <machine/xen-public/memory.h>
78 #include <dev/xen/xenbus/xenbus_comms.h>
79 
80 
81 #ifdef XEN_NETBACK_DEBUG
82 #define DPRINTF(fmt, args...) \
83     printf("netback (%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
84 #else
85 #define DPRINTF(fmt, args...) ((void)0)
86 #endif
87 
88 #ifdef XEN_NETBACK_DEBUG_LOTS
89 #define DDPRINTF(fmt, args...) \
90     printf("netback (%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
91 #define DPRINTF_MBUF(_m) print_mbuf(_m, 0)
92 #define DPRINTF_MBUF_LEN(_m, _len) print_mbuf(_m, _len)
93 #else
94 #define DDPRINTF(fmt, args...) ((void)0)
95 #define DPRINTF_MBUF(_m) ((void)0)
96 #define DPRINTF_MBUF_LEN(_m, _len) ((void)0)
97 #endif
98 
99 #define WPRINTF(fmt, args...) \
100     printf("netback (%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
101 
102 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
103 #define BUG_ON PANIC_IF
104 
105 #define IFNAME(_np) (_np)->ifp->if_xname
106 
107 #define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)
108 #define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)
109 
110 struct ring_ref {
111 	vm_offset_t va;
112 	grant_handle_t handle;
113 	uint64_t bus_addr;
114 };
115 
116 typedef struct netback_info {
117 
118 	/* Schedule lists */
119 	STAILQ_ENTRY(netback_info) next_tx;
120 	STAILQ_ENTRY(netback_info) next_rx;
121 	int on_tx_sched_list;
122 	int on_rx_sched_list;
123 
124 	struct xenbus_device *xdev;
125 	XenbusState frontend_state;
126 
127 	domid_t domid;
128 	int handle;
129 	char *bridge;
130 
131 	int rings_connected;
132 	struct ring_ref tx_ring_ref;
133 	struct ring_ref rx_ring_ref;
134 	netif_tx_back_ring_t tx;
135 	netif_rx_back_ring_t rx;
136 	evtchn_port_t evtchn;
137 	int irq;
138 	void *irq_cookie;
139 
140 	struct ifnet *ifp;
141 	int ref_cnt;
142 
143 	device_t ndev;
144 	int attached;
145 } netif_t;
146 
147 
148 #define MAX_PENDING_REQS 256
149 #define PKT_PROT_LEN 64
150 
151 static struct {
152 	netif_tx_request_t req;
153 	netif_t *netif;
154 } pending_tx_info[MAX_PENDING_REQS];
155 static uint16_t pending_ring[MAX_PENDING_REQS];
156 typedef unsigned int PEND_RING_IDX;
157 #define MASK_PEND_IDX(_i) ((_i)&(MAX_PENDING_REQS-1))
158 static PEND_RING_IDX pending_prod, pending_cons;
159 #define NR_PENDING_REQS (MAX_PENDING_REQS - pending_prod + pending_cons)
160 
161 static unsigned long mmap_vstart;
162 #define MMAP_VADDR(_req) (mmap_vstart + ((_req) * PAGE_SIZE))
163 
164 /* Freed TX mbufs get batched on this ring before return to pending_ring. */
165 static uint16_t dealloc_ring[MAX_PENDING_REQS];
166 static PEND_RING_IDX dealloc_prod, dealloc_cons;
167 
168 static multicall_entry_t rx_mcl[NET_RX_RING_SIZE+1];
169 static mmu_update_t rx_mmu[NET_RX_RING_SIZE];
170 static gnttab_transfer_t grant_rx_op[NET_RX_RING_SIZE];
171 
172 static grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
173 static gnttab_unmap_grant_ref_t tx_unmap_ops[MAX_PENDING_REQS];
174 static gnttab_map_grant_ref_t tx_map_ops[MAX_PENDING_REQS];
175 
176 static struct task net_tx_task, net_rx_task;
177 static struct callout rx_task_callout;
178 
179 static STAILQ_HEAD(netback_tx_sched_list, netback_info) tx_sched_list =
180 	STAILQ_HEAD_INITIALIZER(tx_sched_list);
181 static STAILQ_HEAD(netback_rx_sched_list, netback_info) rx_sched_list =
182 	STAILQ_HEAD_INITIALIZER(rx_sched_list);
183 static struct mtx tx_sched_list_lock;
184 static struct mtx rx_sched_list_lock;
185 
186 static int vif_unit_maker = 0;
187 
188 /* Protos */
189 static void netback_start(struct ifnet *ifp);
190 static int netback_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
191 static int vif_add_dev(struct xenbus_device *xdev);
192 static void disconnect_rings(netif_t *netif);
193 
194 #ifdef XEN_NETBACK_DEBUG_LOTS
195 /* Debug code to display the contents of an mbuf */
196 static void
197 print_mbuf(struct mbuf *m, int max)
198 {
199 	int i, j=0;
200 	printf("mbuf %08x len = %d", (unsigned int)m, m->m_pkthdr.len);
201 	for (; m; m = m->m_next) {
202 		unsigned char *d = m->m_data;
203 		for (i=0; i < m->m_len; i++) {
204 			if (max && j == max)
205 				break;
206 			if ((j++ % 16) == 0)
207 				printf("\n%04x:", j);
208 			printf(" %02x", d[i]);
209 		}
210 	}
211 	printf("\n");
212 }
213 #endif
214 
215 
216 #define MAX_MFN_ALLOC 64
217 static unsigned long mfn_list[MAX_MFN_ALLOC];
218 static unsigned int alloc_index = 0;
219 
220 static unsigned long
221 alloc_mfn(void)
222 {
223 	unsigned long mfn = 0;
224 	struct xen_memory_reservation reservation = {
225 		.extent_start = mfn_list,
226 		.nr_extents   = MAX_MFN_ALLOC,
227 		.extent_order = 0,
228 		.domid        = DOMID_SELF
229 	};
230 	if ( unlikely(alloc_index == 0) )
231 		alloc_index = HYPERVISOR_memory_op(
232 			XENMEM_increase_reservation, &reservation);
233 	if ( alloc_index != 0 )
234 		mfn = mfn_list[--alloc_index];
235 	return mfn;
236 }
237 
238 static unsigned long
239 alloc_empty_page_range(unsigned long nr_pages)
240 {
241 	void *pages;
242 	int i = 0, j = 0;
243 	multicall_entry_t mcl[17];
244 	unsigned long mfn_list[16];
245 	struct xen_memory_reservation reservation = {
246 		.extent_start = mfn_list,
247 		.nr_extents   = 0,
248 		.address_bits = 0,
249 		.extent_order = 0,
250 		.domid        = DOMID_SELF
251 	};
252 
253 	pages = malloc(nr_pages*PAGE_SIZE, M_DEVBUF, M_NOWAIT);
254 	if (pages == NULL)
255 		return 0;
256 
257 	memset(mcl, 0, sizeof(mcl));
258 
259 	while (i < nr_pages) {
260 		unsigned long va = (unsigned long)pages + (i++ * PAGE_SIZE);
261 
262 		mcl[j].op = __HYPERVISOR_update_va_mapping;
263 		mcl[j].args[0] = va;
264 
265 		mfn_list[j++] = vtomach(va) >> PAGE_SHIFT;
266 
267 		xen_phys_machine[(vtophys(va) >> PAGE_SHIFT)] = INVALID_P2M_ENTRY;
268 
269 		if (j == 16 || i == nr_pages) {
270 			mcl[j-1].args[MULTI_UVMFLAGS_INDEX] = UVMF_TLB_FLUSH|UVMF_LOCAL;
271 
272 			reservation.nr_extents = j;
273 
274 			mcl[j].op = __HYPERVISOR_memory_op;
275 			mcl[j].args[0] = XENMEM_decrease_reservation;
276 			mcl[j].args[1] =  (unsigned long)&reservation;
277 
278 			(void)HYPERVISOR_multicall(mcl, j+1);
279 
280 			mcl[j-1].args[MULTI_UVMFLAGS_INDEX] = 0;
281 			j = 0;
282 		}
283 	}
284 
285 	return (unsigned long)pages;
286 }
287 
288 #ifdef XEN_NETBACK_FIXUP_CSUM
289 static void
290 fixup_checksum(struct mbuf *m)
291 {
292 	struct ether_header *eh = mtod(m, struct ether_header *);
293 	struct ip *ip = (struct ip *)(eh + 1);
294 	int iphlen = ip->ip_hl << 2;
295 	int iplen = ntohs(ip->ip_len);
296 
297 	if ((m->m_pkthdr.csum_flags & CSUM_TCP)) {
298 		struct tcphdr *th = (struct tcphdr *)((caddr_t)ip + iphlen);
299 		th->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
300 			htons(IPPROTO_TCP + (iplen - iphlen)));
301 		th->th_sum = in_cksum_skip(m, iplen + sizeof(*eh), sizeof(*eh) + iphlen);
302 		m->m_pkthdr.csum_flags &= ~CSUM_TCP;
303 #ifdef SCTP
304 	} else if (sw_csum & CSUM_SCTP) {
305 		sctp_delayed_cksum(m, iphlen);
306 		sw_csum &= ~CSUM_SCTP;
307 #endif
308 	} else {
309 		u_short csum;
310 		struct udphdr *uh = (struct udphdr *)((caddr_t)ip + iphlen);
311 		uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
312 			htons(IPPROTO_UDP + (iplen - iphlen)));
313 		if ((csum = in_cksum_skip(m, iplen + sizeof(*eh), sizeof(*eh) + iphlen)) == 0)
314 			csum = 0xffff;
315 		uh->uh_sum = csum;
316 		m->m_pkthdr.csum_flags &= ~CSUM_UDP;
317 	}
318 }
319 #endif
320 
321 /* Add the interface to the specified bridge */
322 static int
323 add_to_bridge(struct ifnet *ifp, char *bridge)
324 {
325 	struct ifdrv ifd;
326 	struct ifbreq ifb;
327 	struct ifnet *ifp_bridge = ifunit(bridge);
328 
329 	if (!ifp_bridge)
330 		return ENOENT;
331 
332 	bzero(&ifd, sizeof(ifd));
333 	bzero(&ifb, sizeof(ifb));
334 
335 	strcpy(ifb.ifbr_ifsname, ifp->if_xname);
336 	strcpy(ifd.ifd_name, ifp->if_xname);
337 	ifd.ifd_cmd = BRDGADD;
338 	ifd.ifd_len = sizeof(ifb);
339 	ifd.ifd_data = &ifb;
340 
341 	return bridge_ioctl_kern(ifp_bridge, SIOCSDRVSPEC, &ifd);
342 
343 }
344 
345 static int
346 netif_create(int handle, struct xenbus_device *xdev, char *bridge)
347 {
348 	netif_t *netif;
349 	struct ifnet *ifp;
350 
351 	netif = (netif_t *)malloc(sizeof(*netif), M_DEVBUF, M_NOWAIT | M_ZERO);
352 	if (!netif)
353 		return ENOMEM;
354 
355 	netif->ref_cnt = 1;
356 	netif->handle = handle;
357 	netif->domid = xdev->otherend_id;
358 	netif->xdev = xdev;
359 	netif->bridge = bridge;
360 	xdev->data = netif;
361 
362 	/* Set up ifnet structure */
363 	ifp = netif->ifp = if_alloc(IFT_ETHER);
364 	if (!ifp) {
365 		if (bridge)
366 			free(bridge, M_DEVBUF);
367 		free(netif, M_DEVBUF);
368 		return ENOMEM;
369 	}
370 
371 	ifp->if_softc = netif;
372 	if_initname(ifp, "vif",
373 		atomic_fetchadd_int(&vif_unit_maker, 1) /* ifno */ );
374 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX;
375 	ifp->if_output = ether_output;
376 	ifp->if_start = netback_start;
377 	ifp->if_ioctl = netback_ioctl;
378 	ifp->if_mtu = ETHERMTU;
379 	ifp->if_snd.ifq_maxlen = NET_TX_RING_SIZE - 1;
380 
381 	DPRINTF("Created %s for domid=%d handle=%d\n", IFNAME(netif), netif->domid, netif->handle);
382 
383 	return 0;
384 }
385 
386 static void
387 netif_get(netif_t *netif)
388 {
389 	atomic_add_int(&netif->ref_cnt, 1);
390 }
391 
392 static void
393 netif_put(netif_t *netif)
394 {
395 	if (atomic_fetchadd_int(&netif->ref_cnt, -1) == 1) {
396 		DPRINTF("%s\n", IFNAME(netif));
397 		disconnect_rings(netif);
398 		if (netif->ifp) {
399 			if_free(netif->ifp);
400 			netif->ifp = NULL;
401 		}
402 		if (netif->bridge)
403 			free(netif->bridge, M_DEVBUF);
404 		free(netif, M_DEVBUF);
405 	}
406 }
407 
408 static int
409 netback_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
410 {
411 	switch (cmd) {
412 	case SIOCSIFFLAGS:
413 	DDPRINTF("%s cmd=SIOCSIFFLAGS flags=%x\n",
414 			IFNAME((struct netback_info *)ifp->if_softc), ((struct ifreq *)data)->ifr_flags);
415 		return 0;
416 	}
417 
418 	DDPRINTF("%s cmd=%lx\n", IFNAME((struct netback_info *)ifp->if_softc), cmd);
419 
420 	return ether_ioctl(ifp, cmd, data);
421 }
422 
423 static inline void
424 maybe_schedule_tx_action(void)
425 {
426 	smp_mb();
427 	if ((NR_PENDING_REQS < (MAX_PENDING_REQS/2)) && !STAILQ_EMPTY(&tx_sched_list))
428 		taskqueue_enqueue(taskqueue_swi, &net_tx_task);
429 }
430 
431 /* Removes netif from front of list and does not call netif_put() (caller must) */
432 static netif_t *
433 remove_from_tx_schedule_list(void)
434 {
435 	netif_t *netif;
436 
437 	mtx_lock(&tx_sched_list_lock);
438 
439 	if ((netif = STAILQ_FIRST(&tx_sched_list))) {
440 		STAILQ_REMOVE(&tx_sched_list, netif, netback_info, next_tx);
441 		STAILQ_NEXT(netif, next_tx) = NULL;
442 		netif->on_tx_sched_list = 0;
443 	}
444 
445 	mtx_unlock(&tx_sched_list_lock);
446 
447 	return netif;
448 }
449 
450 /* Adds netif to end of list and calls netif_get() */
451 static void
452 add_to_tx_schedule_list_tail(netif_t *netif)
453 {
454 	if (netif->on_tx_sched_list)
455 		return;
456 
457 	mtx_lock(&tx_sched_list_lock);
458 	if (!netif->on_tx_sched_list && (netif->ifp->if_drv_flags & IFF_DRV_RUNNING)) {
459 		netif_get(netif);
460 		STAILQ_INSERT_TAIL(&tx_sched_list, netif, next_tx);
461 		netif->on_tx_sched_list = 1;
462 	}
463 	mtx_unlock(&tx_sched_list_lock);
464 }
465 
466 /*
467  * Note on CONFIG_XEN_NETDEV_PIPELINED_TRANSMITTER:
468  * If this driver is pipelining transmit requests then we can be very
469  * aggressive in avoiding new-packet notifications -- frontend only needs to
470  * send a notification if there are no outstanding unreceived responses.
471  * If we may be buffer transmit buffers for any reason then we must be rather
472  * more conservative and treat this as the final check for pending work.
473  */
474 static void
475 netif_schedule_tx_work(netif_t *netif)
476 {
477 	int more_to_do;
478 
479 #ifdef CONFIG_XEN_NETDEV_PIPELINED_TRANSMITTER
480 	more_to_do = RING_HAS_UNCONSUMED_REQUESTS(&netif->tx);
481 #else
482 	RING_FINAL_CHECK_FOR_REQUESTS(&netif->tx, more_to_do);
483 #endif
484 
485 	if (more_to_do) {
486 		DDPRINTF("Adding %s to tx sched list\n", IFNAME(netif));
487 		add_to_tx_schedule_list_tail(netif);
488 		maybe_schedule_tx_action();
489 	}
490 }
491 
492 static struct mtx dealloc_lock;
493 MTX_SYSINIT(netback_dealloc, &dealloc_lock, "DEALLOC LOCK", MTX_SPIN | MTX_NOWITNESS);
494 
495 static void
496 netif_idx_release(uint16_t pending_idx)
497 {
498 	mtx_lock_spin(&dealloc_lock);
499 	dealloc_ring[MASK_PEND_IDX(dealloc_prod++)] = pending_idx;
500 	mtx_unlock_spin(&dealloc_lock);
501 
502 	taskqueue_enqueue(taskqueue_swi, &net_tx_task);
503 }
504 
505 static void
506 make_tx_response(netif_t *netif,
507 				 uint16_t    id,
508 				 int8_t      st)
509 {
510 	RING_IDX i = netif->tx.rsp_prod_pvt;
511 	netif_tx_response_t *resp;
512 	int notify;
513 
514 	resp = RING_GET_RESPONSE(&netif->tx, i);
515 	resp->id     = id;
516 	resp->status = st;
517 
518 	netif->tx.rsp_prod_pvt = ++i;
519 	RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netif->tx, notify);
520 	if (notify)
521 		notify_remote_via_irq(netif->irq);
522 
523 #ifdef CONFIG_XEN_NETDEV_PIPELINED_TRANSMITTER
524 	if (i == netif->tx.req_cons) {
525 		int more_to_do;
526 		RING_FINAL_CHECK_FOR_REQUESTS(&netif->tx, more_to_do);
527 		if (more_to_do)
528 			add_to_tx_schedule_list_tail(netif);
529 	}
530 #endif
531 }
532 
533 inline static void
534 net_tx_action_dealloc(void)
535 {
536 	gnttab_unmap_grant_ref_t *gop;
537 	uint16_t pending_idx;
538 	PEND_RING_IDX dc, dp;
539 	netif_t *netif;
540 	int ret;
541 
542 	dc = dealloc_cons;
543 	dp = dealloc_prod;
544 
545 	/*
546 	 * Free up any grants we have finished using
547 	 */
548 	gop = tx_unmap_ops;
549 	while (dc != dp) {
550 		pending_idx = dealloc_ring[MASK_PEND_IDX(dc++)];
551 		gop->host_addr    = MMAP_VADDR(pending_idx);
552 		gop->dev_bus_addr = 0;
553 		gop->handle       = grant_tx_handle[pending_idx];
554 		gop++;
555 	}
556 	ret = HYPERVISOR_grant_table_op(
557 		GNTTABOP_unmap_grant_ref, tx_unmap_ops, gop - tx_unmap_ops);
558 	BUG_ON(ret);
559 
560 	while (dealloc_cons != dp) {
561 		pending_idx = dealloc_ring[MASK_PEND_IDX(dealloc_cons++)];
562 
563 		netif = pending_tx_info[pending_idx].netif;
564 
565 		make_tx_response(netif, pending_tx_info[pending_idx].req.id,
566 				 NETIF_RSP_OKAY);
567 
568 		pending_ring[MASK_PEND_IDX(pending_prod++)] = pending_idx;
569 
570 		netif_put(netif);
571 	}
572 }
573 
574 static void
575 netif_page_release(void *buf, void *args)
576 {
577 	uint16_t pending_idx = (unsigned int)args;
578 
579 	DDPRINTF("pending_idx=%u\n", pending_idx);
580 
581 	KASSERT(pending_idx < MAX_PENDING_REQS, ("%s: bad index %u", __func__, pending_idx));
582 
583 	netif_idx_release(pending_idx);
584 }
585 
586 static void
587 net_tx_action(void *context, int pending)
588 {
589 	struct mbuf *m;
590 	netif_t *netif;
591 	netif_tx_request_t txreq;
592 	uint16_t pending_idx;
593 	RING_IDX i;
594 	gnttab_map_grant_ref_t *mop;
595 	int ret, work_to_do;
596 	struct mbuf *txq = NULL, *txq_last = NULL;
597 
598 	if (dealloc_cons != dealloc_prod)
599 		net_tx_action_dealloc();
600 
601 	mop = tx_map_ops;
602 	while ((NR_PENDING_REQS < MAX_PENDING_REQS) && !STAILQ_EMPTY(&tx_sched_list)) {
603 
604 		/* Get a netif from the list with work to do. */
605 		netif = remove_from_tx_schedule_list();
606 
607 		DDPRINTF("Processing %s (prod=%u, cons=%u)\n",
608 				IFNAME(netif), netif->tx.sring->req_prod, netif->tx.req_cons);
609 
610 		RING_FINAL_CHECK_FOR_REQUESTS(&netif->tx, work_to_do);
611 		if (!work_to_do) {
612 			netif_put(netif);
613 			continue;
614 		}
615 
616 		i = netif->tx.req_cons;
617 		rmb(); /* Ensure that we see the request before we copy it. */
618 		memcpy(&txreq, RING_GET_REQUEST(&netif->tx, i), sizeof(txreq));
619 
620 		/* If we want credit-based scheduling, coud add it here - WORK */
621 
622 		netif->tx.req_cons++;
623 
624 		netif_schedule_tx_work(netif);
625 
626 		if (unlikely(txreq.size < ETHER_HDR_LEN) ||
627 		    unlikely(txreq.size > (ETHER_MAX_LEN-ETHER_CRC_LEN))) {
628 			WPRINTF("Bad packet size: %d\n", txreq.size);
629 			make_tx_response(netif, txreq.id, NETIF_RSP_ERROR);
630 			netif_put(netif);
631 			continue;
632 		}
633 
634 		/* No crossing a page as the payload mustn't fragment. */
635 		if (unlikely((txreq.offset + txreq.size) >= PAGE_SIZE)) {
636 			WPRINTF("txreq.offset: %x, size: %u, end: %u\n",
637 				txreq.offset, txreq.size,
638 				(txreq.offset & PAGE_MASK) + txreq.size);
639 			make_tx_response(netif, txreq.id, NETIF_RSP_ERROR);
640 			netif_put(netif);
641 			continue;
642 		}
643 
644 		pending_idx = pending_ring[MASK_PEND_IDX(pending_cons)];
645 
646 		MGETHDR(m, M_DONTWAIT, MT_DATA);
647 		if (!m) {
648 			WPRINTF("Failed to allocate mbuf\n");
649 			make_tx_response(netif, txreq.id, NETIF_RSP_ERROR);
650 			netif_put(netif);
651 			break;
652 		}
653 		m->m_pkthdr.rcvif = netif->ifp;
654 
655 		if ((m->m_pkthdr.len = txreq.size) > PKT_PROT_LEN) {
656 			struct mbuf *n;
657 			MGET(n, M_DONTWAIT, MT_DATA);
658 			if (!(m->m_next = n)) {
659 				m_freem(m);
660 				WPRINTF("Failed to allocate second mbuf\n");
661 				make_tx_response(netif, txreq.id, NETIF_RSP_ERROR);
662 				netif_put(netif);
663 				break;
664 			}
665 			n->m_len = txreq.size - PKT_PROT_LEN;
666 			m->m_len = PKT_PROT_LEN;
667 		} else
668 			m->m_len = txreq.size;
669 
670 		mop->host_addr = MMAP_VADDR(pending_idx);
671 		mop->dom       = netif->domid;
672 		mop->ref       = txreq.gref;
673 		mop->flags     = GNTMAP_host_map | GNTMAP_readonly;
674 		mop++;
675 
676 		memcpy(&pending_tx_info[pending_idx].req,
677 		       &txreq, sizeof(txreq));
678 		pending_tx_info[pending_idx].netif = netif;
679 		*((uint16_t *)m->m_data) = pending_idx;
680 
681 		if (txq_last)
682 			txq_last->m_nextpkt = m;
683 		else
684 			txq = m;
685 		txq_last = m;
686 
687 		pending_cons++;
688 
689 		if ((mop - tx_map_ops) >= ARRAY_SIZE(tx_map_ops))
690 			break;
691 	}
692 
693 	if (!txq)
694 		return;
695 
696 	ret = HYPERVISOR_grant_table_op(
697 		GNTTABOP_map_grant_ref, tx_map_ops, mop - tx_map_ops);
698 	BUG_ON(ret);
699 
700 	mop = tx_map_ops;
701 	while ((m = txq) != NULL) {
702 		caddr_t data;
703 
704 		txq = m->m_nextpkt;
705 		m->m_nextpkt = NULL;
706 
707 		pending_idx = *((uint16_t *)m->m_data);
708 		netif       = pending_tx_info[pending_idx].netif;
709 		memcpy(&txreq, &pending_tx_info[pending_idx].req, sizeof(txreq));
710 
711 		/* Check the remap error code. */
712 		if (unlikely(mop->status)) {
713 			WPRINTF("#### netback grant fails\n");
714 			make_tx_response(netif, txreq.id, NETIF_RSP_ERROR);
715 			netif_put(netif);
716 			m_freem(m);
717 			mop++;
718 			pending_ring[MASK_PEND_IDX(pending_prod++)] = pending_idx;
719 			continue;
720 		}
721 
722 #if 0
723 		/* Can't do this in FreeBSD since vtophys() returns the pfn */
724 		/* of the remote domain who loaned us the machine page - DPT */
725 		xen_phys_machine[(vtophys(MMAP_VADDR(pending_idx)) >> PAGE_SHIFT)] =
726 			mop->dev_bus_addr >> PAGE_SHIFT;
727 #endif
728 		grant_tx_handle[pending_idx] = mop->handle;
729 
730 		/* Setup data in mbuf (lengths are already set) */
731 		data = (caddr_t)(MMAP_VADDR(pending_idx)|txreq.offset);
732 		bcopy(data, m->m_data, m->m_len);
733 		if (m->m_next) {
734 			struct mbuf *n = m->m_next;
735 			MEXTADD(n, MMAP_VADDR(pending_idx), PAGE_SIZE, netif_page_release,
736 				(void *)(unsigned int)pending_idx, M_RDONLY, EXT_NET_DRV);
737 			n->m_data = &data[PKT_PROT_LEN];
738 		} else {
739 			/* Schedule a response immediately. */
740 			netif_idx_release(pending_idx);
741 		}
742 
743 		if ((txreq.flags & NETTXF_data_validated)) {
744 			/* Tell the stack the checksums are okay */
745 			m->m_pkthdr.csum_flags |=
746 				(CSUM_IP_CHECKED | CSUM_IP_VALID | CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
747 			m->m_pkthdr.csum_data = 0xffff;
748 		}
749 
750 		/* If necessary, inform stack to compute the checksums if it forwards the packet */
751 		if ((txreq.flags & NETTXF_csum_blank)) {
752 			struct ether_header *eh = mtod(m, struct ether_header *);
753 			if (ntohs(eh->ether_type) == ETHERTYPE_IP) {
754 				struct ip *ip = (struct ip *)&m->m_data[14];
755 				if (ip->ip_p == IPPROTO_TCP)
756 					m->m_pkthdr.csum_flags |= CSUM_TCP;
757 				else if (ip->ip_p == IPPROTO_UDP)
758 					m->m_pkthdr.csum_flags |= CSUM_UDP;
759 			}
760 		}
761 
762 		netif->ifp->if_ibytes += m->m_pkthdr.len;
763 		netif->ifp->if_ipackets++;
764 
765 		DDPRINTF("RECV %d bytes from %s (cflags=%x)\n",
766 			m->m_pkthdr.len, IFNAME(netif), m->m_pkthdr.csum_flags);
767 		DPRINTF_MBUF_LEN(m, 128);
768 
769 		(*netif->ifp->if_input)(netif->ifp, m);
770 
771 		mop++;
772 	}
773 }
774 
775 /* Handle interrupt from a frontend */
776 static void
777 netback_intr(void *arg)
778 {
779 	netif_t *netif = arg;
780 	DDPRINTF("%s\n", IFNAME(netif));
781 	add_to_tx_schedule_list_tail(netif);
782 	maybe_schedule_tx_action();
783 }
784 
785 /* Removes netif from front of list and does not call netif_put() (caller must) */
786 static netif_t *
787 remove_from_rx_schedule_list(void)
788 {
789 	netif_t *netif;
790 
791 	mtx_lock(&rx_sched_list_lock);
792 
793 	if ((netif = STAILQ_FIRST(&rx_sched_list))) {
794 		STAILQ_REMOVE(&rx_sched_list, netif, netback_info, next_rx);
795 		STAILQ_NEXT(netif, next_rx) = NULL;
796 		netif->on_rx_sched_list = 0;
797 	}
798 
799 	mtx_unlock(&rx_sched_list_lock);
800 
801 	return netif;
802 }
803 
804 /* Adds netif to end of list and calls netif_get() */
805 static void
806 add_to_rx_schedule_list_tail(netif_t *netif)
807 {
808 	if (netif->on_rx_sched_list)
809 		return;
810 
811 	mtx_lock(&rx_sched_list_lock);
812 	if (!netif->on_rx_sched_list && (netif->ifp->if_drv_flags & IFF_DRV_RUNNING)) {
813 		netif_get(netif);
814 		STAILQ_INSERT_TAIL(&rx_sched_list, netif, next_rx);
815 		netif->on_rx_sched_list = 1;
816 	}
817 	mtx_unlock(&rx_sched_list_lock);
818 }
819 
820 static int
821 make_rx_response(netif_t *netif, uint16_t id, int8_t st,
822 				 uint16_t offset, uint16_t size, uint16_t flags)
823 {
824 	RING_IDX i = netif->rx.rsp_prod_pvt;
825 	netif_rx_response_t *resp;
826 	int notify;
827 
828 	resp = RING_GET_RESPONSE(&netif->rx, i);
829 	resp->offset     = offset;
830 	resp->flags      = flags;
831 	resp->id         = id;
832 	resp->status     = (int16_t)size;
833 	if (st < 0)
834 		resp->status = (int16_t)st;
835 
836 	DDPRINTF("rx resp(%d): off=%x fl=%x id=%x stat=%d\n",
837 		i, resp->offset, resp->flags, resp->id, resp->status);
838 
839 	netif->rx.rsp_prod_pvt = ++i;
840 	RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netif->rx, notify);
841 
842 	return notify;
843 }
844 
845 static int
846 netif_rx(netif_t *netif)
847 {
848 	struct ifnet *ifp = netif->ifp;
849 	struct mbuf *m;
850 	multicall_entry_t *mcl;
851 	mmu_update_t *mmu;
852 	gnttab_transfer_t *gop;
853 	unsigned long vdata, old_mfn, new_mfn;
854 	struct mbuf *rxq = NULL, *rxq_last = NULL;
855 	int ret, notify = 0, pkts_dequeued = 0;
856 
857 	DDPRINTF("%s\n", IFNAME(netif));
858 
859 	mcl = rx_mcl;
860 	mmu = rx_mmu;
861 	gop = grant_rx_op;
862 
863 	while (!IFQ_DRV_IS_EMPTY(&ifp->if_snd)) {
864 
865 		/* Quit if the target domain has no receive buffers */
866 		if (netif->rx.req_cons == netif->rx.sring->req_prod)
867 			break;
868 
869 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
870 		if (m == NULL)
871 			break;
872 
873 		pkts_dequeued++;
874 
875 		/* Check if we need to copy the data */
876 		if (((m->m_flags & (M_RDONLY|M_EXT)) != M_EXT) ||
877 			(*m->m_ext.ref_cnt > 1) || m->m_next != NULL) {
878 			struct mbuf *n;
879 
880 			DDPRINTF("copying mbuf (fl=%x ext=%x rc=%d n=%x)\n",
881 				m->m_flags,
882 				(m->m_flags & M_EXT) ? m->m_ext.ext_type : 0,
883 				(m->m_flags & M_EXT) ? *m->m_ext.ref_cnt : 0,
884 				(unsigned int)m->m_next);
885 
886 			/* Make copy */
887 			MGETHDR(n, M_DONTWAIT, MT_DATA);
888 			if (!n)
889 				goto drop;
890 
891 			MCLGET(n, M_DONTWAIT);
892 			if (!(n->m_flags & M_EXT)) {
893 				m_freem(n);
894 				goto drop;
895 			}
896 
897 			/* Leave space at front and keep current alignment */
898 			n->m_data += 16 + ((unsigned int)m->m_data & 0x3);
899 
900 			if (m->m_pkthdr.len > M_TRAILINGSPACE(n)) {
901 				WPRINTF("pkt to big %d\n", m->m_pkthdr.len);
902 				m_freem(n);
903 				goto drop;
904 			}
905 			m_copydata(m, 0, m->m_pkthdr.len, n->m_data);
906 			n->m_pkthdr.len = n->m_len = m->m_pkthdr.len;
907 			n->m_pkthdr.csum_flags = (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA);
908 			m_freem(m);
909 			m = n;
910 		}
911 
912 		vdata = (unsigned long)m->m_data;
913 		old_mfn = vtomach(vdata) >> PAGE_SHIFT;
914 
915 		if ((new_mfn = alloc_mfn()) == 0)
916 			goto drop;
917 
918 #ifdef XEN_NETBACK_FIXUP_CSUM
919 		/* Check if we need to compute a checksum.  This happens */
920 		/* when bridging from one domain to another. */
921 		if ((m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) ||
922 			(m->m_pkthdr.csum_flags & CSUM_SCTP))
923 			fixup_checksum(m);
924 #endif
925 
926 		xen_phys_machine[(vtophys(vdata) >> PAGE_SHIFT)] = new_mfn;
927 
928 		mcl->op = __HYPERVISOR_update_va_mapping;
929 		mcl->args[0] = vdata;
930 		mcl->args[1] = (new_mfn << PAGE_SHIFT) | PG_V | PG_RW | PG_M | PG_A;
931 		mcl->args[2] = 0;
932 		mcl->args[3] = 0;
933 		mcl++;
934 
935 		gop->mfn = old_mfn;
936 		gop->domid = netif->domid;
937 		gop->ref = RING_GET_REQUEST(&netif->rx, netif->rx.req_cons)->gref;
938 		netif->rx.req_cons++;
939 		gop++;
940 
941 		mmu->ptr = (new_mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
942 		mmu->val = vtophys(vdata) >> PAGE_SHIFT;
943 		mmu++;
944 
945 		if (rxq_last)
946 			rxq_last->m_nextpkt = m;
947 		else
948 			rxq = m;
949 		rxq_last = m;
950 
951 		DDPRINTF("XMIT %d bytes to %s\n", m->m_pkthdr.len, IFNAME(netif));
952 		DPRINTF_MBUF_LEN(m, 128);
953 
954 		/* Filled the batch queue? */
955 		if ((gop - grant_rx_op) == ARRAY_SIZE(grant_rx_op))
956 			break;
957 
958 		continue;
959 	drop:
960 		DDPRINTF("dropping pkt\n");
961 		ifp->if_oerrors++;
962 		m_freem(m);
963 	}
964 
965 	if (mcl == rx_mcl)
966 		return pkts_dequeued;
967 
968 	mcl->op = __HYPERVISOR_mmu_update;
969 	mcl->args[0] = (unsigned long)rx_mmu;
970 	mcl->args[1] = mmu - rx_mmu;
971 	mcl->args[2] = 0;
972 	mcl->args[3] = DOMID_SELF;
973 	mcl++;
974 
975 	mcl[-2].args[MULTI_UVMFLAGS_INDEX] = UVMF_TLB_FLUSH|UVMF_ALL;
976 	ret = HYPERVISOR_multicall(rx_mcl, mcl - rx_mcl);
977 	BUG_ON(ret != 0);
978 
979 	ret = HYPERVISOR_grant_table_op(GNTTABOP_transfer, grant_rx_op, gop - grant_rx_op);
980 	BUG_ON(ret != 0);
981 
982 	mcl = rx_mcl;
983 	gop = grant_rx_op;
984 
985 	while ((m = rxq) != NULL) {
986 		int8_t status;
987 		uint16_t id, flags = 0;
988 
989 		rxq = m->m_nextpkt;
990 		m->m_nextpkt = NULL;
991 
992 		/* Rederive the machine addresses. */
993 		new_mfn = mcl->args[1] >> PAGE_SHIFT;
994 		old_mfn = gop->mfn;
995 
996 		ifp->if_obytes += m->m_pkthdr.len;
997 		ifp->if_opackets++;
998 
999 		/* The update_va_mapping() must not fail. */
1000 		BUG_ON(mcl->result != 0);
1001 
1002 		/* Setup flags */
1003 		if ((m->m_pkthdr.csum_flags & CSUM_DELAY_DATA))
1004 			flags |= NETRXF_csum_blank | NETRXF_data_validated;
1005 		else if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID))
1006 			flags |= NETRXF_data_validated;
1007 
1008 		/* Check the reassignment error code. */
1009 		status = NETIF_RSP_OKAY;
1010 		if (gop->status != 0) {
1011 			DPRINTF("Bad status %d from grant transfer to DOM%u\n",
1012 				gop->status, netif->domid);
1013 			/*
1014 			 * Page no longer belongs to us unless GNTST_bad_page,
1015 			 * but that should be a fatal error anyway.
1016 			 */
1017 			BUG_ON(gop->status == GNTST_bad_page);
1018 			status = NETIF_RSP_ERROR;
1019 		}
1020 		id = RING_GET_REQUEST(&netif->rx, netif->rx.rsp_prod_pvt)->id;
1021 		notify |= make_rx_response(netif, id, status,
1022 					(unsigned long)m->m_data & PAGE_MASK,
1023 					m->m_pkthdr.len, flags);
1024 
1025 		m_freem(m);
1026 		mcl++;
1027 		gop++;
1028 	}
1029 
1030 	if (notify)
1031 		notify_remote_via_irq(netif->irq);
1032 
1033 	return pkts_dequeued;
1034 }
1035 
1036 static void
1037 rx_task_timer(void *arg)
1038 {
1039 	DDPRINTF("\n");
1040 	taskqueue_enqueue(taskqueue_swi, &net_rx_task);
1041 }
1042 
1043 static void
1044 net_rx_action(void *context, int pending)
1045 {
1046 	netif_t *netif, *last_zero_work = NULL;
1047 
1048 	DDPRINTF("\n");
1049 
1050 	while ((netif = remove_from_rx_schedule_list())) {
1051 		struct ifnet *ifp = netif->ifp;
1052 
1053 		if (netif == last_zero_work) {
1054 			if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
1055 				add_to_rx_schedule_list_tail(netif);
1056 			netif_put(netif);
1057 			if (!STAILQ_EMPTY(&rx_sched_list))
1058 				callout_reset(&rx_task_callout, 1, rx_task_timer, NULL);
1059 			break;
1060 		}
1061 
1062 		if ((ifp->if_drv_flags & IFF_DRV_RUNNING)) {
1063 			if (netif_rx(netif))
1064 				last_zero_work = NULL;
1065 			else if (!last_zero_work)
1066 				last_zero_work = netif;
1067 			if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
1068 				add_to_rx_schedule_list_tail(netif);
1069 		}
1070 
1071 		netif_put(netif);
1072 	}
1073 }
1074 
1075 static void
1076 netback_start(struct ifnet *ifp)
1077 {
1078 	netif_t *netif = (netif_t *)ifp->if_softc;
1079 
1080 	DDPRINTF("%s\n", IFNAME(netif));
1081 
1082 	add_to_rx_schedule_list_tail(netif);
1083 	taskqueue_enqueue(taskqueue_swi, &net_rx_task);
1084 }
1085 
1086 /* Map a grant ref to a ring */
1087 static int
1088 map_ring(grant_ref_t ref, domid_t dom, struct ring_ref *ring)
1089 {
1090 	struct gnttab_map_grant_ref op;
1091 
1092 	ring->va = kmem_alloc_nofault(kernel_map, PAGE_SIZE);
1093 	if (ring->va == 0)
1094 		return ENOMEM;
1095 
1096 	op.host_addr = ring->va;
1097 	op.flags = GNTMAP_host_map;
1098 	op.ref = ref;
1099 	op.dom = dom;
1100 	HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1);
1101 	if (op.status) {
1102 		WPRINTF("grant table op err=%d\n", op.status);
1103 		kmem_free(kernel_map, ring->va, PAGE_SIZE);
1104 		ring->va = 0;
1105 		return EACCES;
1106 	}
1107 
1108 	ring->handle = op.handle;
1109 	ring->bus_addr = op.dev_bus_addr;
1110 
1111 	return 0;
1112 }
1113 
1114 /* Unmap grant ref for a ring */
1115 static void
1116 unmap_ring(struct ring_ref *ring)
1117 {
1118 	struct gnttab_unmap_grant_ref op;
1119 
1120 	op.host_addr = ring->va;
1121 	op.dev_bus_addr = ring->bus_addr;
1122 	op.handle = ring->handle;
1123 	HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1);
1124 	if (op.status)
1125 		WPRINTF("grant table op err=%d\n", op.status);
1126 
1127 	kmem_free(kernel_map, ring->va, PAGE_SIZE);
1128 	ring->va = 0;
1129 }
1130 
1131 static int
1132 connect_rings(netif_t *netif)
1133 {
1134 	struct xenbus_device *xdev = netif->xdev;
1135 	netif_tx_sring_t *txs;
1136 	netif_rx_sring_t *rxs;
1137 	unsigned long tx_ring_ref, rx_ring_ref;
1138 	evtchn_port_t evtchn;
1139 	evtchn_op_t op = { .cmd = EVTCHNOP_bind_interdomain };
1140 	int err;
1141 
1142 	// Grab FE data and map his memory
1143 	err = xenbus_gather(NULL, xdev->otherend,
1144 			"tx-ring-ref", "%lu", &tx_ring_ref,
1145 		    "rx-ring-ref", "%lu", &rx_ring_ref,
1146 		    "event-channel", "%u", &evtchn, NULL);
1147 	if (err) {
1148 		xenbus_dev_fatal(xdev, err,
1149 			"reading %s/ring-ref and event-channel",
1150 			xdev->otherend);
1151 		return err;
1152 	}
1153 
1154 	err = map_ring(tx_ring_ref, netif->domid, &netif->tx_ring_ref);
1155 	if (err) {
1156 		xenbus_dev_fatal(xdev, err, "mapping tx ring");
1157 		return err;
1158 	}
1159 	txs = (netif_tx_sring_t *)netif->tx_ring_ref.va;
1160 	BACK_RING_INIT(&netif->tx, txs, PAGE_SIZE);
1161 
1162 	err = map_ring(rx_ring_ref, netif->domid, &netif->rx_ring_ref);
1163 	if (err) {
1164 		unmap_ring(&netif->tx_ring_ref);
1165 		xenbus_dev_fatal(xdev, err, "mapping rx ring");
1166 		return err;
1167 	}
1168 	rxs = (netif_rx_sring_t *)netif->rx_ring_ref.va;
1169 	BACK_RING_INIT(&netif->rx, rxs, PAGE_SIZE);
1170 
1171 	op.u.bind_interdomain.remote_dom = netif->domid;
1172 	op.u.bind_interdomain.remote_port = evtchn;
1173 	err = HYPERVISOR_event_channel_op(&op);
1174 	if (err) {
1175 		unmap_ring(&netif->tx_ring_ref);
1176 		unmap_ring(&netif->rx_ring_ref);
1177 		xenbus_dev_fatal(xdev, err, "binding event channel");
1178 		return err;
1179 	}
1180 	netif->evtchn = op.u.bind_interdomain.local_port;
1181 
1182 	/* bind evtchn to irq handler */
1183 	netif->irq =
1184 		bind_evtchn_to_irqhandler(netif->evtchn, "netback",
1185 			netback_intr, netif, INTR_TYPE_NET|INTR_MPSAFE, &netif->irq_cookie);
1186 
1187 	netif->rings_connected = 1;
1188 
1189 	DPRINTF("%s connected! evtchn=%d irq=%d\n",
1190 		IFNAME(netif), netif->evtchn, netif->irq);
1191 
1192 	return 0;
1193 }
1194 
1195 static void
1196 disconnect_rings(netif_t *netif)
1197 {
1198 	DPRINTF("\n");
1199 
1200 	if (netif->rings_connected) {
1201 		unbind_from_irqhandler(netif->irq, netif->irq_cookie);
1202 		netif->irq = 0;
1203 		unmap_ring(&netif->tx_ring_ref);
1204 		unmap_ring(&netif->rx_ring_ref);
1205 		netif->rings_connected = 0;
1206 	}
1207 }
1208 
1209 static void
1210 connect(netif_t *netif)
1211 {
1212 	if (!netif->xdev ||
1213 		!netif->attached ||
1214 		netif->frontend_state != XenbusStateConnected) {
1215 		return;
1216 	}
1217 
1218 	if (!connect_rings(netif)) {
1219 		xenbus_switch_state(netif->xdev, NULL, XenbusStateConnected);
1220 
1221 		/* Turn on interface */
1222 		netif->ifp->if_drv_flags |= IFF_DRV_RUNNING;
1223 		netif->ifp->if_flags |= IFF_UP;
1224 	}
1225 }
1226 
1227 static int
1228 netback_remove(struct xenbus_device *xdev)
1229 {
1230 	netif_t *netif = xdev->data;
1231 	device_t ndev;
1232 
1233 	DPRINTF("remove %s\n", xdev->nodename);
1234 
1235 	if ((ndev = netif->ndev)) {
1236 		netif->ndev = NULL;
1237 		mtx_lock(&Giant);
1238 		device_detach(ndev);
1239 		mtx_unlock(&Giant);
1240 	}
1241 
1242 	xdev->data = NULL;
1243 	netif->xdev = NULL;
1244 	netif_put(netif);
1245 
1246 	return 0;
1247 }
1248 
1249 /**
1250  * Entry point to this code when a new device is created.  Allocate the basic
1251  * structures and the ring buffers for communication with the frontend.
1252  * Switch to Connected state.
1253  */
1254 static int
1255 netback_probe(struct xenbus_device *xdev, const struct xenbus_device_id *id)
1256 {
1257 	int err;
1258 	long handle;
1259 	char *bridge;
1260 
1261 	DPRINTF("node=%s\n", xdev->nodename);
1262 
1263 	/* Grab the handle */
1264 	err = xenbus_scanf(NULL, xdev->nodename, "handle", "%li", &handle);
1265 	if (err != 1) {
1266 		xenbus_dev_fatal(xdev, err, "reading handle");
1267 		return err;
1268 	}
1269 
1270 	/* Check for bridge */
1271 	bridge = xenbus_read(NULL, xdev->nodename, "bridge", NULL);
1272 	if (IS_ERR(bridge))
1273 		bridge = NULL;
1274 
1275 	err = xenbus_switch_state(xdev, NULL, XenbusStateInitWait);
1276 	if (err) {
1277 		xenbus_dev_fatal(xdev, err, "writing switch state");
1278 		return err;
1279 	}
1280 
1281 	err = netif_create(handle, xdev, bridge);
1282 	if (err) {
1283 		xenbus_dev_fatal(xdev, err, "creating netif");
1284 		return err;
1285 	}
1286 
1287 	err = vif_add_dev(xdev);
1288 	if (err) {
1289 		netif_put((netif_t *)xdev->data);
1290 		xenbus_dev_fatal(xdev, err, "adding vif device");
1291 		return err;
1292 	}
1293 
1294 	return 0;
1295 }
1296 
1297 /**
1298  * We are reconnecting to the backend, due to a suspend/resume, or a backend
1299  * driver restart.  We tear down our netif structure and recreate it, but
1300  * leave the device-layer structures intact so that this is transparent to the
1301  * rest of the kernel.
1302  */
1303 static int netback_resume(struct xenbus_device *xdev)
1304 {
1305 	DPRINTF("node=%s\n", xdev->nodename);
1306 	return 0;
1307 }
1308 
1309 
1310 /**
1311  * Callback received when the frontend's state changes.
1312  */
1313 static void frontend_changed(struct xenbus_device *xdev,
1314 							 XenbusState frontend_state)
1315 {
1316 	netif_t *netif = xdev->data;
1317 
1318 	DPRINTF("state=%d\n", frontend_state);
1319 
1320 	netif->frontend_state = frontend_state;
1321 
1322 	switch (frontend_state) {
1323 	case XenbusStateInitialising:
1324 	case XenbusStateInitialised:
1325 		break;
1326 	case XenbusStateConnected:
1327 		connect(netif);
1328 		break;
1329 	case XenbusStateClosing:
1330 		xenbus_switch_state(xdev, NULL, XenbusStateClosing);
1331 		break;
1332 	case XenbusStateClosed:
1333 		xenbus_remove_device(xdev);
1334 		break;
1335 	case XenbusStateUnknown:
1336 	case XenbusStateInitWait:
1337 		xenbus_dev_fatal(xdev, EINVAL, "saw state %d at frontend",
1338 						 frontend_state);
1339 		break;
1340 	}
1341 }
1342 
1343 /* ** Driver registration ** */
1344 
1345 static struct xenbus_device_id netback_ids[] = {
1346 	{ "vif" },
1347 	{ "" }
1348 };
1349 
1350 static struct xenbus_driver netback = {
1351 	.name = "netback",
1352 	.ids = netback_ids,
1353 	.probe = netback_probe,
1354 	.remove = netback_remove,
1355 	.resume= netback_resume,
1356 	.otherend_changed = frontend_changed,
1357 };
1358 
1359 static void
1360 netback_init(void *unused)
1361 {
1362 	callout_init(&rx_task_callout, CALLOUT_MPSAFE);
1363 
1364 	mmap_vstart = alloc_empty_page_range(MAX_PENDING_REQS);
1365 	BUG_ON(!mmap_vstart);
1366 
1367 	pending_cons = 0;
1368 	for (pending_prod = 0; pending_prod < MAX_PENDING_REQS; pending_prod++)
1369 		pending_ring[pending_prod] = pending_prod;
1370 
1371 	TASK_INIT(&net_tx_task, 0, net_tx_action, NULL);
1372 	TASK_INIT(&net_rx_task, 0, net_rx_action, NULL);
1373 	mtx_init(&tx_sched_list_lock, "nb_tx_sched_lock", "netback tx sched lock", MTX_DEF);
1374 	mtx_init(&rx_sched_list_lock, "nb_rx_sched_lock", "netback rx sched lock", MTX_DEF);
1375 
1376 	DPRINTF("registering %s\n", netback.name);
1377 
1378 	xenbus_register_backend(&netback);
1379 }
1380 
1381 SYSINIT(xnbedev, SI_SUB_PSEUDO, SI_ORDER_ANY, netback_init, NULL)
1382 
1383 static int
1384 vif_add_dev(struct xenbus_device *xdev)
1385 {
1386 	netif_t *netif = xdev->data;
1387 	device_t nexus, ndev;
1388 	devclass_t dc;
1389 	int err = 0;
1390 
1391 	mtx_lock(&Giant);
1392 
1393 	/* We will add a vif device as a child of nexus0 (for now) */
1394 	if (!(dc = devclass_find("nexus")) ||
1395 		!(nexus = devclass_get_device(dc, 0))) {
1396 		WPRINTF("could not find nexus0!\n");
1397 		err = ENOENT;
1398 		goto done;
1399 	}
1400 
1401 
1402 	/* Create a newbus device representing the vif */
1403 	ndev = BUS_ADD_CHILD(nexus, 0, "vif", netif->ifp->if_dunit);
1404 	if (!ndev) {
1405 		WPRINTF("could not create newbus device %s!\n", IFNAME(netif));
1406 		err = EFAULT;
1407 		goto done;
1408 	}
1409 
1410 	netif_get(netif);
1411 	device_set_ivars(ndev, netif);
1412 	netif->ndev = ndev;
1413 
1414 	device_probe_and_attach(ndev);
1415 
1416  done:
1417 
1418 	mtx_unlock(&Giant);
1419 
1420 	return err;
1421 }
1422 
1423 enum {
1424 	VIF_SYSCTL_DOMID,
1425 	VIF_SYSCTL_HANDLE,
1426 	VIF_SYSCTL_TXRING,
1427 	VIF_SYSCTL_RXRING,
1428 };
1429 
1430 static char *
1431 vif_sysctl_ring_info(netif_t *netif, int cmd)
1432 {
1433 	char *buf = malloc(256, M_DEVBUF, M_WAITOK);
1434 	if (buf) {
1435 		if (!netif->rings_connected)
1436 			sprintf(buf, "rings not connected\n");
1437 		else if (cmd == VIF_SYSCTL_TXRING) {
1438 			netif_tx_back_ring_t *tx = &netif->tx;
1439 			sprintf(buf, "nr_ents=%x req_cons=%x"
1440 					" req_prod=%x req_event=%x"
1441 					" rsp_prod=%x rsp_event=%x",
1442 					tx->nr_ents, tx->req_cons,
1443 					tx->sring->req_prod, tx->sring->req_event,
1444 					tx->sring->rsp_prod, tx->sring->rsp_event);
1445 		} else {
1446 			netif_rx_back_ring_t *rx = &netif->rx;
1447 			sprintf(buf, "nr_ents=%x req_cons=%x"
1448 					" req_prod=%x req_event=%x"
1449 					" rsp_prod=%x rsp_event=%x",
1450 					rx->nr_ents, rx->req_cons,
1451 					rx->sring->req_prod, rx->sring->req_event,
1452 					rx->sring->rsp_prod, rx->sring->rsp_event);
1453 		}
1454 	}
1455 	return buf;
1456 }
1457 
1458 static int
1459 vif_sysctl_handler(SYSCTL_HANDLER_ARGS)
1460 {
1461 	device_t dev = (device_t)arg1;
1462 	netif_t *netif = (netif_t *)device_get_ivars(dev);
1463 	const char *value;
1464 	char *buf = NULL;
1465 	int err;
1466 
1467 	switch (arg2) {
1468 	case VIF_SYSCTL_DOMID:
1469 		return sysctl_handle_int(oidp, NULL, netif->domid, req);
1470 	case VIF_SYSCTL_HANDLE:
1471 		return sysctl_handle_int(oidp, NULL, netif->handle, req);
1472 	case VIF_SYSCTL_TXRING:
1473 	case VIF_SYSCTL_RXRING:
1474 		value = buf = vif_sysctl_ring_info(netif, arg2);
1475 		break;
1476 	default:
1477 		return (EINVAL);
1478 	}
1479 
1480 	err = SYSCTL_OUT(req, value, strlen(value));
1481 	if (buf != NULL)
1482 		free(buf, M_DEVBUF);
1483 
1484 	return err;
1485 }
1486 
1487 /* Newbus vif device driver probe */
1488 static int
1489 vif_probe(device_t dev)
1490 {
1491 	DDPRINTF("vif%d\n", device_get_unit(dev));
1492 	return 0;
1493 }
1494 
1495 /* Newbus vif device driver attach */
1496 static int
1497 vif_attach(device_t dev)
1498 {
1499 	netif_t *netif = (netif_t *)device_get_ivars(dev);
1500 	uint8_t mac[ETHER_ADDR_LEN];
1501 
1502 	DDPRINTF("%s\n", IFNAME(netif));
1503 
1504 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1505 	    OID_AUTO, "domid", CTLTYPE_INT|CTLFLAG_RD,
1506 	    dev, VIF_SYSCTL_DOMID, vif_sysctl_handler, "I",
1507 	    "domid of frontend");
1508 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1509 	    OID_AUTO, "handle", CTLTYPE_INT|CTLFLAG_RD,
1510 	    dev, VIF_SYSCTL_HANDLE, vif_sysctl_handler, "I",
1511 	    "handle of frontend");
1512 #ifdef XEN_NETBACK_DEBUG
1513 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1514 	    OID_AUTO, "txring", CTLFLAG_RD,
1515 	    dev, VIF_SYSCTL_TXRING, vif_sysctl_handler, "A",
1516 	    "tx ring info");
1517 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1518 	    OID_AUTO, "rxring", CTLFLAG_RD,
1519 	    dev, VIF_SYSCTL_RXRING, vif_sysctl_handler, "A",
1520 	    "rx ring info");
1521 #endif
1522 
1523 	memset(mac, 0xff, sizeof(mac));
1524 	mac[0] &= ~0x01;
1525 
1526 	ether_ifattach(netif->ifp, mac);
1527 	netif->attached = 1;
1528 
1529 	connect(netif);
1530 
1531 	if (netif->bridge) {
1532 		DPRINTF("Adding %s to bridge %s\n", IFNAME(netif), netif->bridge);
1533 		int err = add_to_bridge(netif->ifp, netif->bridge);
1534 		if (err) {
1535 			WPRINTF("Error adding %s to %s; err=%d\n",
1536 				IFNAME(netif), netif->bridge, err);
1537 		}
1538 	}
1539 
1540 	return bus_generic_attach(dev);
1541 }
1542 
1543 /* Newbus vif device driver detach */
1544 static int
1545 vif_detach(device_t dev)
1546 {
1547 	netif_t *netif = (netif_t *)device_get_ivars(dev);
1548 	struct ifnet *ifp = netif->ifp;
1549 
1550 	DDPRINTF("%s\n", IFNAME(netif));
1551 
1552 	/* Tell the stack that the interface is no longer active */
1553 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
1554 
1555 	ether_ifdetach(ifp);
1556 
1557 	bus_generic_detach(dev);
1558 
1559 	netif->attached = 0;
1560 
1561 	netif_put(netif);
1562 
1563 	return 0;
1564 }
1565 
1566 static device_method_t vif_methods[] = {
1567 	/* Device interface */
1568 	DEVMETHOD(device_probe,		vif_probe),
1569 	DEVMETHOD(device_attach, 	vif_attach),
1570 	DEVMETHOD(device_detach,	vif_detach),
1571 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
1572 	DEVMETHOD(device_suspend,	bus_generic_suspend),
1573 	DEVMETHOD(device_resume,	bus_generic_resume),
1574 	{0, 0}
1575 };
1576 
1577 static devclass_t vif_devclass;
1578 
1579 static driver_t vif_driver = {
1580 	"vif",
1581 	vif_methods,
1582 	0,
1583 };
1584 
1585 DRIVER_MODULE(vif, nexus, vif_driver, vif_devclass, 0, 0);
1586 
1587 
1588 /*
1589  * Local variables:
1590  * mode: C
1591  * c-set-style: "BSD"
1592  * c-basic-offset: 4
1593  * tab-width: 4
1594  * indent-tabs-mode: t
1595  * End:
1596  */
1597