xref: /netbsd-src/sys/arch/xen/xen/if_xennet_xenbus.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /*      $NetBSD: if_xennet_xenbus.c,v 1.51 2011/05/30 13:03:56 joerg Exp $      */
2 
3 /*
4  * Copyright (c) 2006 Manuel Bouyer.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
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  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  */
27 
28 /*
29  * Copyright (c) 2004 Christian Limpach.
30  * All rights reserved.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  *
41  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
42  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
43  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
44  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
45  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
47  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
48  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
49  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
50  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
51  */
52 
53 /*
54  * This file contains the xennet frontend code required for the network
55  * communication between two Xen domains.
56  * It ressembles xbd, but is a little more complex as it must deal with two
57  * rings:
58  * - the TX ring, to transmit packets to backend (inside => outside)
59  * - the RX ring, to receive packets from backend (outside => inside)
60  *
61  * Principles are following.
62  *
63  * For TX:
64  * Purpose is to transmit packets to the outside. The start of day is in
65  * xennet_start() (default output routine of xennet) that schedules a softint,
66  * xennet_softstart(). xennet_softstart() generates the requests associated
67  * to the TX mbufs queued (see altq(9)).
68  * The backend's responses are processed by xennet_tx_complete(), called either
69  * from:
70  * - xennet_start()
71  * - xennet_handler(), during an asynchronous event notification from backend
72  *   (similar to an IRQ).
73  *
74  * for RX:
75  * Purpose is to process the packets received from the outside. RX buffers
76  * are pre-allocated through xennet_alloc_rx_buffer(), during xennet autoconf
77  * attach. During pre-allocation, frontend pushes requests in the I/O ring, in
78  * preparation for incoming packets from backend.
79  * When RX packets need to be processed, backend takes the requests previously
80  * offered by frontend and pushes the associated responses inside the I/O ring.
81  * When done, it notifies frontend through an event notification, which will
82  * asynchronously call xennet_handler() in frontend.
83  * xennet_handler() processes the responses, generates the associated mbuf, and
84  * passes it to the MI layer for further processing.
85  */
86 
87 #include <sys/cdefs.h>
88 __KERNEL_RCSID(0, "$NetBSD: if_xennet_xenbus.c,v 1.51 2011/05/30 13:03:56 joerg Exp $");
89 
90 #include "opt_xen.h"
91 #include "opt_nfs_boot.h"
92 #include "rnd.h"
93 
94 #include <sys/param.h>
95 #include <sys/device.h>
96 #include <sys/conf.h>
97 #include <sys/kernel.h>
98 #include <sys/proc.h>
99 #include <sys/systm.h>
100 #include <sys/intr.h>
101 #if NRND > 0
102 #include <sys/rnd.h>
103 #endif
104 
105 #include <net/if.h>
106 #include <net/if_dl.h>
107 #include <net/if_ether.h>
108 #include <net/bpf.h>
109 #include <net/bpfdesc.h>
110 
111 #if defined(NFS_BOOT_BOOTSTATIC)
112 #include <sys/fstypes.h>
113 #include <sys/mount.h>
114 #include <sys/statvfs.h>
115 #include <netinet/in.h>
116 #include <nfs/rpcv2.h>
117 #include <nfs/nfsproto.h>
118 #include <nfs/nfs.h>
119 #include <nfs/nfsmount.h>
120 #include <nfs/nfsdiskless.h>
121 #include <xen/if_xennetvar.h>
122 #endif /* defined(NFS_BOOT_BOOTSTATIC) */
123 
124 #include <xen/xennet_checksum.h>
125 
126 #include <uvm/uvm.h>
127 
128 #include <xen/hypervisor.h>
129 #include <xen/evtchn.h>
130 #include <xen/granttables.h>
131 #include <xen/xen3-public/io/netif.h>
132 #include <xen/xenpmap.h>
133 
134 #include <xen/xenbus.h>
135 #include "locators.h"
136 
137 #undef XENNET_DEBUG_DUMP
138 #undef XENNET_DEBUG
139 #ifdef XENNET_DEBUG
140 #define XEDB_FOLLOW     0x01
141 #define XEDB_INIT       0x02
142 #define XEDB_EVENT      0x04
143 #define XEDB_MBUF       0x08
144 #define XEDB_MEM        0x10
145 int xennet_debug = 0xff;
146 #define DPRINTF(x) if (xennet_debug) printf x;
147 #define DPRINTFN(n,x) if (xennet_debug & (n)) printf x;
148 #else
149 #define DPRINTF(x)
150 #define DPRINTFN(n,x)
151 #endif
152 
153 #define GRANT_INVALID_REF -1 /* entry is free */
154 #define GRANT_STACK_REF   -2 /* entry owned by the network stack */
155 
156 #define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)
157 #define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)
158 
159 struct xennet_txreq {
160 	SLIST_ENTRY(xennet_txreq) txreq_next;
161 	uint16_t txreq_id; /* ID passed to backend */
162 	grant_ref_t txreq_gntref; /* grant ref of this request */
163 	struct mbuf *txreq_m; /* mbuf being transmitted */
164 };
165 
166 struct xennet_rxreq {
167 	SLIST_ENTRY(xennet_rxreq) rxreq_next;
168 	uint16_t rxreq_id; /* ID passed to backend */
169 	grant_ref_t rxreq_gntref; /* grant ref of this request */
170 /* va/pa for this receive buf. ma will be provided by backend */
171 	paddr_t rxreq_pa;
172 	vaddr_t rxreq_va;
173 	struct xennet_xenbus_softc *rxreq_sc; /* pointer to our interface */
174 };
175 
176 struct xennet_xenbus_softc {
177 	device_t sc_dev;
178 	struct ethercom sc_ethercom;
179 	uint8_t sc_enaddr[6];
180 	struct xenbus_device *sc_xbusd;
181 
182 	netif_tx_front_ring_t sc_tx_ring;
183 	netif_rx_front_ring_t sc_rx_ring;
184 
185 	unsigned int sc_evtchn;
186 	void *sc_softintr;
187 
188 	grant_ref_t sc_tx_ring_gntref;
189 	grant_ref_t sc_rx_ring_gntref;
190 
191 	struct xennet_txreq sc_txreqs[NET_TX_RING_SIZE];
192 	struct xennet_rxreq sc_rxreqs[NET_RX_RING_SIZE];
193 	SLIST_HEAD(,xennet_txreq) sc_txreq_head; /* list of free TX requests */
194 	SLIST_HEAD(,xennet_rxreq) sc_rxreq_head; /* list of free RX requests */
195 	int sc_free_rxreql; /* number of free receive request struct */
196 
197 	int sc_backend_status; /* our status with backend */
198 #define BEST_CLOSED		0
199 #define BEST_DISCONNECTED	1
200 #define BEST_CONNECTED		2
201 #define BEST_SUSPENDED		3
202 	unsigned long sc_rx_feature;
203 #define FEATURE_RX_FLIP		0
204 #define FEATURE_RX_COPY		1
205 #if NRND > 0
206 	rndsource_element_t     sc_rnd_source;
207 #endif
208 };
209 #define SC_NLIVEREQ(sc) ((sc)->sc_rx_ring.req_prod_pvt - \
210 			    (sc)->sc_rx_ring.sring->rsp_prod)
211 
212 /* too big to be on stack */
213 static multicall_entry_t rx_mcl[NET_RX_RING_SIZE+1];
214 static u_long xennet_pages[NET_RX_RING_SIZE];
215 
216 static int  xennet_xenbus_match(device_t, cfdata_t, void *);
217 static void xennet_xenbus_attach(device_t, device_t, void *);
218 static int  xennet_xenbus_detach(device_t, int);
219 static void xennet_backend_changed(void *, XenbusState);
220 
221 static int  xennet_xenbus_resume(void *);
222 static void xennet_alloc_rx_buffer(struct xennet_xenbus_softc *);
223 static void xennet_free_rx_buffer(struct xennet_xenbus_softc *);
224 static void xennet_tx_complete(struct xennet_xenbus_softc *);
225 static void xennet_rx_mbuf_free(struct mbuf *, void *, size_t, void *);
226 static int  xennet_handler(void *);
227 static int  xennet_talk_to_backend(struct xennet_xenbus_softc *);
228 #ifdef XENNET_DEBUG_DUMP
229 static void xennet_hex_dump(const unsigned char *, size_t, const char *, int);
230 #endif
231 
232 static int  xennet_init(struct ifnet *);
233 static void xennet_stop(struct ifnet *, int);
234 static void xennet_reset(struct xennet_xenbus_softc *);
235 static void xennet_softstart(void *);
236 static void xennet_start(struct ifnet *);
237 static int  xennet_ioctl(struct ifnet *, u_long, void *);
238 static void xennet_watchdog(struct ifnet *);
239 
240 CFATTACH_DECL_NEW(xennet, sizeof(struct xennet_xenbus_softc),
241    xennet_xenbus_match, xennet_xenbus_attach, xennet_xenbus_detach, NULL);
242 
243 static int
244 xennet_xenbus_match(device_t parent, cfdata_t match, void *aux)
245 {
246 	struct xenbusdev_attach_args *xa = aux;
247 
248 	if (strcmp(xa->xa_type, "vif") != 0)
249 		return 0;
250 
251 	if (match->cf_loc[XENBUSCF_ID] != XENBUSCF_ID_DEFAULT &&
252 	    match->cf_loc[XENBUSCF_ID] != xa->xa_id)
253 		return 0;
254 
255 	return 1;
256 }
257 
258 static void
259 xennet_xenbus_attach(device_t parent, device_t self, void *aux)
260 {
261 	struct xennet_xenbus_softc *sc = device_private(self);
262 	struct xenbusdev_attach_args *xa = aux;
263 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
264 	int err;
265 	RING_IDX i;
266 	char *val, *e, *p;
267 	int s;
268 	extern int ifqmaxlen; /* XXX */
269 #ifdef XENNET_DEBUG
270 	char **dir;
271 	int dir_n = 0;
272 	char id_str[20];
273 #endif
274 
275 	aprint_normal(": Xen Virtual Network Interface\n");
276 	sc->sc_dev = self;
277 
278 #ifdef XENNET_DEBUG
279 	printf("path: %s\n", xa->xa_xbusd->xbusd_path);
280 	snprintf(id_str, sizeof(id_str), "%d", xa->xa_id);
281 	err = xenbus_directory(NULL, "device/vif", id_str, &dir_n, &dir);
282 	if (err) {
283 		aprint_error_dev(self, "xenbus_directory err %d\n", err);
284 	} else {
285 		printf("%s/\n", xa->xa_xbusd->xbusd_path);
286 		for (i = 0; i < dir_n; i++) {
287 			printf("\t/%s", dir[i]);
288 			err = xenbus_read(NULL, xa->xa_xbusd->xbusd_path,
289 				          dir[i], NULL, &val);
290 			if (err) {
291 				aprint_error_dev(self, "xenbus_read err %d\n",
292 					         err);
293 			} else {
294 				printf(" = %s\n", val);
295 				free(val, M_DEVBUF);
296 			}
297 		}
298 	}
299 #endif /* XENNET_DEBUG */
300 	sc->sc_xbusd = xa->xa_xbusd;
301 	sc->sc_xbusd->xbusd_otherend_changed = xennet_backend_changed;
302 
303 	/* initialize free RX and RX request lists */
304 	SLIST_INIT(&sc->sc_txreq_head);
305 	for (i = 0; i < NET_TX_RING_SIZE; i++) {
306 		sc->sc_txreqs[i].txreq_id = i;
307 		SLIST_INSERT_HEAD(&sc->sc_txreq_head, &sc->sc_txreqs[i],
308 		    txreq_next);
309 	}
310 	SLIST_INIT(&sc->sc_rxreq_head);
311 	s = splvm();
312 	for (i = 0; i < NET_RX_RING_SIZE; i++) {
313 		struct xennet_rxreq *rxreq = &sc->sc_rxreqs[i];
314 		rxreq->rxreq_id = i;
315 		rxreq->rxreq_sc = sc;
316 		rxreq->rxreq_va = uvm_km_alloc(kernel_map,
317 		    PAGE_SIZE, PAGE_SIZE, UVM_KMF_WIRED | UVM_KMF_ZERO);
318 		if (rxreq->rxreq_va == 0)
319 			break;
320 		if (!pmap_extract(pmap_kernel(), rxreq->rxreq_va,
321 		    &rxreq->rxreq_pa))
322 			panic("%s: no pa for mapped va ?", device_xname(self));
323 		rxreq->rxreq_gntref = GRANT_INVALID_REF;
324 		SLIST_INSERT_HEAD(&sc->sc_rxreq_head, rxreq, rxreq_next);
325 	}
326 	splx(s);
327 	sc->sc_free_rxreql = i;
328 	if (sc->sc_free_rxreql == 0) {
329 		aprint_error_dev(self, "failed to allocate rx memory\n");
330 		return;
331 	}
332 
333 	/* read mac address */
334 	err = xenbus_read(NULL, xa->xa_xbusd->xbusd_path, "mac", NULL, &val);
335 	if (err) {
336 		aprint_error_dev(self, "can't read mac address, err %d\n", err);
337 		return;
338 	}
339 	for (i = 0, p = val; i < 6; i++) {
340 		sc->sc_enaddr[i] = strtoul(p, &e, 16);
341 		if ((e[0] == '\0' && i != 5) && e[0] != ':') {
342 			aprint_error_dev(self,
343 			    "%s is not a valid mac address\n", val);
344 			free(val, M_DEVBUF);
345 			return;
346 		}
347 		p = &e[1];
348 	}
349 	free(val, M_DEVBUF);
350 	aprint_normal_dev(self, "MAC address %s\n",
351 	    ether_sprintf(sc->sc_enaddr));
352 	/* Initialize ifnet structure and attach interface */
353 	strlcpy(ifp->if_xname, device_xname(self), IFNAMSIZ);
354 	ifp->if_softc = sc;
355 	ifp->if_start = xennet_start;
356 	ifp->if_ioctl = xennet_ioctl;
357 	ifp->if_watchdog = xennet_watchdog;
358 	ifp->if_init = xennet_init;
359 	ifp->if_stop = xennet_stop;
360 	ifp->if_flags = IFF_BROADCAST|IFF_SIMPLEX|IFF_NOTRAILERS|IFF_MULTICAST;
361 	ifp->if_timer = 0;
362 	ifp->if_snd.ifq_maxlen = max(ifqmaxlen, NET_TX_RING_SIZE * 2);
363 	ifp->if_capabilities = IFCAP_CSUM_TCPv4_Tx | IFCAP_CSUM_UDPv4_Tx;
364 	IFQ_SET_READY(&ifp->if_snd);
365 	if_attach(ifp);
366 	ether_ifattach(ifp, sc->sc_enaddr);
367 	sc->sc_softintr = softint_establish(SOFTINT_NET, xennet_softstart, sc);
368 	if (sc->sc_softintr == NULL)
369 		panic("%s: can't establish soft interrupt",
370 			device_xname(self));
371 
372 #if NRND > 0
373 	rnd_attach_source(&sc->sc_rnd_source, device_xname(sc->sc_dev),
374 	    RND_TYPE_NET, 0);
375 #endif
376 
377 	/* resume shared structures and tell backend that we are ready */
378 	xennet_xenbus_resume(sc);
379 }
380 
381 static int
382 xennet_xenbus_detach(device_t self, int flags)
383 {
384 	struct xennet_xenbus_softc *sc = device_private(self);
385 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
386 	int s0, s1;
387 	RING_IDX i;
388 
389 	DPRINTF(("%s: xennet_xenbus_detach\n", device_xname(self)));
390 	s0 = splnet();
391 	xennet_stop(ifp, 1);
392 	/* wait for pending TX to complete, and collect pending RX packets */
393 	xennet_handler(sc);
394 	while (sc->sc_tx_ring.sring->rsp_prod != sc->sc_tx_ring.rsp_cons) {
395 		tsleep(xennet_xenbus_detach, PRIBIO, "xnet_detach", hz/2);
396 		xennet_handler(sc);
397 	}
398 	xennet_free_rx_buffer(sc);
399 
400 	s1 = splvm();
401 	for (i = 0; i < NET_RX_RING_SIZE; i++) {
402 		struct xennet_rxreq *rxreq = &sc->sc_rxreqs[i];
403 		uvm_km_free(kernel_map, rxreq->rxreq_va, PAGE_SIZE,
404 		    UVM_KMF_WIRED);
405 	}
406 	splx(s1);
407 
408 	ether_ifdetach(ifp);
409 	if_detach(ifp);
410 
411 #if NRND > 0
412 	/* Unhook the entropy source. */
413 	rnd_detach_source(&sc->sc_rnd_source);
414 #endif
415 
416 	while (xengnt_status(sc->sc_tx_ring_gntref)) {
417 		tsleep(xennet_xenbus_detach, PRIBIO, "xnet_txref", hz/2);
418 	}
419 	xengnt_revoke_access(sc->sc_tx_ring_gntref);
420 	uvm_km_free(kernel_map, (vaddr_t)sc->sc_tx_ring.sring, PAGE_SIZE,
421 	    UVM_KMF_WIRED);
422 	while (xengnt_status(sc->sc_rx_ring_gntref)) {
423 		tsleep(xennet_xenbus_detach, PRIBIO, "xnet_rxref", hz/2);
424 	}
425 	xengnt_revoke_access(sc->sc_rx_ring_gntref);
426 	uvm_km_free(kernel_map, (vaddr_t)sc->sc_rx_ring.sring, PAGE_SIZE,
427 	    UVM_KMF_WIRED);
428 	softint_disestablish(sc->sc_softintr);
429 	event_remove_handler(sc->sc_evtchn, &xennet_handler, sc);
430 	splx(s0);
431 	DPRINTF(("%s: xennet_xenbus_detach done\n", device_xname(self)));
432 	return 0;
433 }
434 
435 static int
436 xennet_xenbus_resume(void *p)
437 {
438 	struct xennet_xenbus_softc *sc = p;
439 	int error;
440 	netif_tx_sring_t *tx_ring;
441 	netif_rx_sring_t *rx_ring;
442 	paddr_t ma;
443 
444 	sc->sc_tx_ring_gntref = GRANT_INVALID_REF;
445 	sc->sc_rx_ring_gntref = GRANT_INVALID_REF;
446 
447 	/* setup device: alloc event channel and shared rings */
448 	tx_ring = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
449 	     UVM_KMF_WIRED | UVM_KMF_ZERO);
450 	rx_ring = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
451 	    UVM_KMF_WIRED | UVM_KMF_ZERO);
452 	if (tx_ring == NULL || rx_ring == NULL)
453 		panic("xennet_xenbus_resume: can't alloc rings");
454 
455 	SHARED_RING_INIT(tx_ring);
456 	FRONT_RING_INIT(&sc->sc_tx_ring, tx_ring, PAGE_SIZE);
457 	SHARED_RING_INIT(rx_ring);
458 	FRONT_RING_INIT(&sc->sc_rx_ring, rx_ring, PAGE_SIZE);
459 
460 	(void)pmap_extract_ma(pmap_kernel(), (vaddr_t)tx_ring, &ma);
461 	error = xenbus_grant_ring(sc->sc_xbusd, ma, &sc->sc_tx_ring_gntref);
462 	if (error)
463 		return error;
464 	(void)pmap_extract_ma(pmap_kernel(), (vaddr_t)rx_ring, &ma);
465 	error = xenbus_grant_ring(sc->sc_xbusd, ma, &sc->sc_rx_ring_gntref);
466 	if (error)
467 		return error;
468 	error = xenbus_alloc_evtchn(sc->sc_xbusd, &sc->sc_evtchn);
469 	if (error)
470 		return error;
471 	aprint_verbose_dev(sc->sc_dev, "using event channel %d\n",
472 	    sc->sc_evtchn);
473 	event_set_handler(sc->sc_evtchn, &xennet_handler, sc,
474 	    IPL_NET, device_xname(sc->sc_dev));
475 
476 	return 0;
477 }
478 
479 static int
480 xennet_talk_to_backend(struct xennet_xenbus_softc *sc)
481 {
482 	int error;
483 	unsigned long rx_copy;
484 	struct xenbus_transaction *xbt;
485 	const char *errmsg;
486 
487 	error = xenbus_read_ul(NULL, sc->sc_xbusd->xbusd_otherend,
488 	    "feature-rx-copy", &rx_copy, 10);
489 	if (error)
490 		rx_copy = 0; /* default value if key is absent */
491 
492 	if (rx_copy == 1) {
493 		aprint_normal_dev(sc->sc_dev, "using RX copy mode\n");
494 		sc->sc_rx_feature = FEATURE_RX_COPY;
495 	} else {
496 		aprint_normal_dev(sc->sc_dev, "using RX flip mode\n");
497 		sc->sc_rx_feature = FEATURE_RX_FLIP;
498 	}
499 
500 again:
501 	xbt = xenbus_transaction_start();
502 	if (xbt == NULL)
503 		return ENOMEM;
504 	error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
505 	    "vifname", "%s", device_xname(sc->sc_dev));
506 	if (error) {
507 		errmsg = "vifname";
508 		goto abort_transaction;
509 	}
510 	error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
511 	    "tx-ring-ref","%u", sc->sc_tx_ring_gntref);
512 	if (error) {
513 		errmsg = "writing tx ring-ref";
514 		goto abort_transaction;
515 	}
516 	error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
517 	    "rx-ring-ref","%u", sc->sc_rx_ring_gntref);
518 	if (error) {
519 		errmsg = "writing rx ring-ref";
520 		goto abort_transaction;
521 	}
522 	error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
523 	    "request-rx-copy", "%lu", rx_copy);
524 	if (error) {
525 		errmsg = "writing request-rx-copy";
526 		goto abort_transaction;
527 	}
528 	error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
529 	    "feature-rx-notify", "%u", 1);
530 	if (error) {
531 		errmsg = "writing feature-rx-notify";
532 		goto abort_transaction;
533 	}
534 	error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
535 	    "event-channel", "%u", sc->sc_evtchn);
536 	if (error) {
537 		errmsg = "writing event channel";
538 		goto abort_transaction;
539 	}
540 	error = xenbus_transaction_end(xbt, 0);
541 	if (error == EAGAIN)
542 		goto again;
543 	if (error) {
544 		xenbus_dev_fatal(sc->sc_xbusd, error, "completing transaction");
545 		return -1;
546 	}
547 	xennet_alloc_rx_buffer(sc);
548 	sc->sc_backend_status = BEST_CONNECTED;
549 	return 0;
550 
551 abort_transaction:
552 	xenbus_transaction_end(xbt, 1);
553 	xenbus_dev_fatal(sc->sc_xbusd, error, "%s", errmsg);
554 	return error;
555 }
556 
557 static void xennet_backend_changed(void *arg, XenbusState new_state)
558 {
559 	struct xennet_xenbus_softc *sc = device_private((device_t)arg);
560 	DPRINTF(("%s: new backend state %d\n",
561 	    device_xname(sc->sc_dev), new_state));
562 
563 	switch (new_state) {
564 	case XenbusStateInitialising:
565 	case XenbusStateInitialised:
566 	case XenbusStateConnected:
567 		break;
568 	case XenbusStateClosing:
569 		sc->sc_backend_status = BEST_CLOSED;
570 		xenbus_switch_state(sc->sc_xbusd, NULL, XenbusStateClosed);
571 		break;
572 	case XenbusStateInitWait:
573 		if (sc->sc_backend_status == BEST_CONNECTED)
574 			break;
575 		if (xennet_talk_to_backend(sc) == 0)
576 			xenbus_switch_state(sc->sc_xbusd, NULL,
577 			    XenbusStateConnected);
578 		break;
579 	case XenbusStateUnknown:
580 	default:
581 		panic("bad backend state %d", new_state);
582 	}
583 }
584 
585 /*
586  * Allocate RX buffers and put the associated request structures
587  * in the ring. This allows the backend to use them to communicate with
588  * frontend when some data is destined to frontend
589  */
590 
591 static void
592 xennet_alloc_rx_buffer(struct xennet_xenbus_softc *sc)
593 {
594 	RING_IDX req_prod = sc->sc_rx_ring.req_prod_pvt;
595 	RING_IDX i;
596 	struct xennet_rxreq *req;
597 	struct xen_memory_reservation reservation;
598 	int s1, s2, otherend_id;
599 	paddr_t pfn;
600 
601 	otherend_id = sc->sc_xbusd->xbusd_otherend_id;
602 
603 	s1 = splnet();
604 	for (i = 0; sc->sc_free_rxreql != 0; i++) {
605 		req  = SLIST_FIRST(&sc->sc_rxreq_head);
606 		KASSERT(req != NULL);
607 		KASSERT(req == &sc->sc_rxreqs[req->rxreq_id]);
608 		RING_GET_REQUEST(&sc->sc_rx_ring, req_prod + i)->id =
609 		    req->rxreq_id;
610 
611 		switch (sc->sc_rx_feature) {
612 		case FEATURE_RX_COPY:
613 			if (xengnt_grant_access(otherend_id,
614 			    xpmap_ptom_masked(req->rxreq_pa),
615 			    0, &req->rxreq_gntref) != 0) {
616 				goto out_loop;
617 			}
618 			break;
619 		case FEATURE_RX_FLIP:
620 			if (xengnt_grant_transfer(otherend_id,
621 			    &req->rxreq_gntref) != 0) {
622 				goto out_loop;
623 			}
624 			break;
625 		default:
626 			panic("%s: unsupported RX feature mode: %ld\n",
627 			    __func__, sc->sc_rx_feature);
628 		}
629 
630 		RING_GET_REQUEST(&sc->sc_rx_ring, req_prod + i)->gref =
631 		    req->rxreq_gntref;
632 
633 		SLIST_REMOVE_HEAD(&sc->sc_rxreq_head, rxreq_next);
634 		sc->sc_free_rxreql--;
635 
636 		if (sc->sc_rx_feature == FEATURE_RX_FLIP) {
637 			/* unmap the page */
638 			MULTI_update_va_mapping(&rx_mcl[i],
639 			    req->rxreq_va, 0, 0);
640 			/*
641 			 * Remove this page from pseudo phys map before
642 			 * passing back to Xen.
643 			 */
644 			pfn = (req->rxreq_pa - XPMAP_OFFSET) >> PAGE_SHIFT;
645 			xennet_pages[i] = xpmap_phys_to_machine_mapping[pfn];
646 			xpmap_phys_to_machine_mapping[pfn] = INVALID_P2M_ENTRY;
647 		}
648 	}
649 
650 out_loop:
651 	if (i == 0) {
652 		splx(s1);
653 		return;
654 	}
655 
656 	if (sc->sc_rx_feature == FEATURE_RX_FLIP) {
657 		/* also make sure to flush all TLB entries */
658 		rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] =
659 		    UVMF_TLB_FLUSH | UVMF_ALL;
660 		/*
661 		 * We may have allocated buffers which have entries
662 		 * outstanding in the page update queue -- make sure we flush
663 		 * those first!
664 		 */
665 		s2 = splvm();
666 		xpq_flush_queue();
667 		splx(s2);
668 		/* now decrease reservation */
669 		xenguest_handle(reservation.extent_start) = xennet_pages;
670 		reservation.nr_extents = i;
671 		reservation.extent_order = 0;
672 		reservation.address_bits = 0;
673 		reservation.domid = DOMID_SELF;
674 		rx_mcl[i].op = __HYPERVISOR_memory_op;
675 		rx_mcl[i].args[0] = XENMEM_decrease_reservation;
676 		rx_mcl[i].args[1] = (unsigned long)&reservation;
677 		HYPERVISOR_multicall(rx_mcl, i+1);
678 		if (__predict_false(rx_mcl[i].result != i)) {
679 			panic("xennet_alloc_rx_buffer: "
680 			    "XENMEM_decrease_reservation");
681 		}
682 	}
683 
684 	sc->sc_rx_ring.req_prod_pvt = req_prod + i;
685 	RING_PUSH_REQUESTS(&sc->sc_rx_ring);
686 
687 	splx(s1);
688 	return;
689 }
690 
691 /*
692  * Reclaim all RX buffers used by the I/O ring between frontend and backend
693  */
694 static void
695 xennet_free_rx_buffer(struct xennet_xenbus_softc *sc)
696 {
697 	paddr_t ma, pa;
698 	vaddr_t va;
699 	RING_IDX i;
700 	mmu_update_t mmu[1];
701 	multicall_entry_t mcl[2];
702 
703 	int s = splbio();
704 
705 	DPRINTF(("%s: xennet_free_rx_buffer\n", device_xname(sc->sc_dev)));
706 	/* get back memory from RX ring */
707 	for (i = 0; i < NET_RX_RING_SIZE; i++) {
708 		struct xennet_rxreq *rxreq = &sc->sc_rxreqs[i];
709 
710 		/*
711 		 * if the buffer is in transit in the network stack, wait for
712 		 * the network stack to free it.
713 		 */
714 		while ((volatile grant_ref_t)rxreq->rxreq_gntref ==
715 		    GRANT_STACK_REF)
716 			tsleep(xennet_xenbus_detach, PRIBIO, "xnet_free", hz/2);
717 
718 		if (rxreq->rxreq_gntref != GRANT_INVALID_REF) {
719 			/*
720 			 * this req is still granted. Get back the page or
721 			 * allocate a new one, and remap it.
722 			 */
723 			SLIST_INSERT_HEAD(&sc->sc_rxreq_head, rxreq,
724 			    rxreq_next);
725 			sc->sc_free_rxreql++;
726 
727 			switch (sc->sc_rx_feature) {
728 			case FEATURE_RX_COPY:
729 				xengnt_revoke_access(rxreq->rxreq_gntref);
730 				rxreq->rxreq_gntref = GRANT_INVALID_REF;
731 				break;
732 			case FEATURE_RX_FLIP:
733 				ma = xengnt_revoke_transfer(
734 				    rxreq->rxreq_gntref);
735 				rxreq->rxreq_gntref = GRANT_INVALID_REF;
736 				if (ma == 0) {
737 					u_long pfn;
738 					struct xen_memory_reservation xenres;
739 					/*
740 					 * transfer not complete, we lost the page.
741 					 * Get one from hypervisor
742 					 */
743 					xenguest_handle(xenres.extent_start) = &pfn;
744 					xenres.nr_extents = 1;
745 					xenres.extent_order = 0;
746 					xenres.address_bits = 31;
747 					xenres.domid = DOMID_SELF;
748 					if (HYPERVISOR_memory_op(
749 					    XENMEM_increase_reservation, &xenres) < 0) {
750 						panic("xennet_free_rx_buffer: "
751 						    "can't get memory back");
752 					}
753 					ma = pfn;
754 					KASSERT(ma != 0);
755 				}
756 				pa = rxreq->rxreq_pa;
757 				va = rxreq->rxreq_va;
758 				/* remap the page */
759 				mmu[0].ptr = (ma << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
760 				mmu[0].val = ((pa - XPMAP_OFFSET) >> PAGE_SHIFT);
761 				MULTI_update_va_mapping(&mcl[0], va,
762 				    (ma << PAGE_SHIFT) | PG_V | PG_KW,
763 				    UVMF_TLB_FLUSH|UVMF_ALL);
764 				xpmap_phys_to_machine_mapping[
765 				    (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = ma;
766 				mcl[1].op = __HYPERVISOR_mmu_update;
767 				mcl[1].args[0] = (unsigned long)mmu;
768 				mcl[1].args[1] = 1;
769 				mcl[1].args[2] = 0;
770 				mcl[1].args[3] = DOMID_SELF;
771 				HYPERVISOR_multicall(mcl, 2);
772 				break;
773 			default:
774 				panic("%s: unsupported RX feature mode: %ld\n",
775 				    __func__, sc->sc_rx_feature);
776 			}
777 		}
778 
779 	}
780 	splx(s);
781 	DPRINTF(("%s: xennet_free_rx_buffer done\n", device_xname(sc->sc_dev)));
782 }
783 
784 /*
785  * Clears a used RX request when its associated mbuf has been processed
786  */
787 static void
788 xennet_rx_mbuf_free(struct mbuf *m, void *buf, size_t size, void *arg)
789 {
790 	struct xennet_rxreq *req = arg;
791 	struct xennet_xenbus_softc *sc = req->rxreq_sc;
792 
793 	int s = splnet();
794 
795 	/* puts back the RX request in the list of free RX requests */
796 	SLIST_INSERT_HEAD(&sc->sc_rxreq_head, req, rxreq_next);
797 	sc->sc_free_rxreql++;
798 
799 	/*
800 	 * ring needs more requests to be pushed in, allocate some
801 	 * RX buffers to catch-up with backend's consumption
802 	 */
803 	req->rxreq_gntref = GRANT_INVALID_REF;
804 	if (sc->sc_free_rxreql >= SC_NLIVEREQ(sc) &&
805 	    __predict_true(sc->sc_backend_status == BEST_CONNECTED)) {
806 		xennet_alloc_rx_buffer(sc);
807 	}
808 
809 	if (m)
810 		pool_cache_put(mb_cache, m);
811 	splx(s);
812 }
813 
814 /*
815  * Process responses associated to the TX mbufs sent previously through
816  * xennet_softstart()
817  * Called at splnet.
818  */
819 static void
820 xennet_tx_complete(struct xennet_xenbus_softc *sc)
821 {
822 	struct xennet_txreq *req;
823 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
824 	RING_IDX resp_prod, i;
825 
826 	DPRINTFN(XEDB_EVENT, ("xennet_tx_complete prod %d cons %d\n",
827 	    sc->sc_tx_ring.sring->rsp_prod, sc->sc_tx_ring.rsp_cons));
828 
829 again:
830 	resp_prod = sc->sc_tx_ring.sring->rsp_prod;
831 	xen_rmb();
832 	for (i = sc->sc_tx_ring.rsp_cons; i != resp_prod; i++) {
833 		req = &sc->sc_txreqs[RING_GET_RESPONSE(&sc->sc_tx_ring, i)->id];
834 		KASSERT(req->txreq_id ==
835 		    RING_GET_RESPONSE(&sc->sc_tx_ring, i)->id);
836 		if (__predict_false(xengnt_status(req->txreq_gntref))) {
837 			aprint_verbose_dev(sc->sc_dev,
838 					   "grant still used by backend\n");
839 			sc->sc_tx_ring.rsp_cons = i;
840 			goto end;
841 		}
842 		if (__predict_false(
843 		    RING_GET_RESPONSE(&sc->sc_tx_ring, i)->status !=
844 		    NETIF_RSP_OKAY))
845 			ifp->if_oerrors++;
846 		else
847 			ifp->if_opackets++;
848 		xengnt_revoke_access(req->txreq_gntref);
849 		m_freem(req->txreq_m);
850 		SLIST_INSERT_HEAD(&sc->sc_txreq_head, req, txreq_next);
851 	}
852 	sc->sc_tx_ring.rsp_cons = resp_prod;
853 	/* set new event and check for race with rsp_cons update */
854 	sc->sc_tx_ring.sring->rsp_event =
855 	    resp_prod + ((sc->sc_tx_ring.sring->req_prod - resp_prod) >> 1) + 1;
856 	ifp->if_timer = 0;
857 	xen_wmb();
858 	if (resp_prod != sc->sc_tx_ring.sring->rsp_prod)
859 		goto again;
860 end:
861 	if (ifp->if_flags & IFF_OACTIVE) {
862 		ifp->if_flags &= ~IFF_OACTIVE;
863 		xennet_softstart(sc);
864 	}
865 }
866 
867 /*
868  * Xennet event handler.
869  * Get outstanding responses of TX packets, then collect all responses of
870  * pending RX packets
871  * Called at splnet.
872  */
873 static int
874 xennet_handler(void *arg)
875 {
876 	struct xennet_xenbus_softc *sc = arg;
877 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
878 	RING_IDX resp_prod, i;
879 	struct xennet_rxreq *req;
880 	paddr_t ma, pa;
881 	vaddr_t va;
882 	mmu_update_t mmu[1];
883 	multicall_entry_t mcl[2];
884 	struct mbuf *m;
885 	void *pktp;
886 	int more_to_do;
887 
888 	if (sc->sc_backend_status != BEST_CONNECTED)
889 		return 1;
890 
891 	xennet_tx_complete(sc);
892 
893 #if NRND > 0
894 	rnd_add_uint32(&sc->sc_rnd_source, sc->sc_tx_ring.req_prod_pvt);
895 #endif
896 again:
897 	DPRINTFN(XEDB_EVENT, ("xennet_handler prod %d cons %d\n",
898 	    sc->sc_rx_ring.sring->rsp_prod, sc->sc_rx_ring.rsp_cons));
899 
900 	resp_prod = sc->sc_rx_ring.sring->rsp_prod;
901 	xen_rmb(); /* ensure we see replies up to resp_prod */
902 	for (i = sc->sc_rx_ring.rsp_cons; i != resp_prod; i++) {
903 		netif_rx_response_t *rx = RING_GET_RESPONSE(&sc->sc_rx_ring, i);
904 		req = &sc->sc_rxreqs[rx->id];
905 		KASSERT(req->rxreq_gntref != GRANT_INVALID_REF);
906 		KASSERT(req->rxreq_id == rx->id);
907 
908 		ma = 0;
909 		switch (sc->sc_rx_feature) {
910 		case FEATURE_RX_COPY:
911 			xengnt_revoke_access(req->rxreq_gntref);
912 			break;
913 		case FEATURE_RX_FLIP:
914 			ma = xengnt_revoke_transfer(req->rxreq_gntref);
915 			if (ma == 0) {
916 				DPRINTFN(XEDB_EVENT, ("xennet_handler ma == 0\n"));
917 				/*
918 				 * the remote could't send us a packet.
919 				 * we can't free this rxreq as no page will be mapped
920 				 * here. Instead give it back immediatly to backend.
921 				 */
922 				ifp->if_ierrors++;
923 				RING_GET_REQUEST(&sc->sc_rx_ring,
924 				    sc->sc_rx_ring.req_prod_pvt)->id = req->rxreq_id;
925 				RING_GET_REQUEST(&sc->sc_rx_ring,
926 				    sc->sc_rx_ring.req_prod_pvt)->gref =
927 					req->rxreq_gntref;
928 				sc->sc_rx_ring.req_prod_pvt++;
929 				RING_PUSH_REQUESTS(&sc->sc_rx_ring);
930 				continue;
931 			}
932 			break;
933 		default:
934 			panic("%s: unsupported RX feature mode: %ld\n",
935 			    __func__, sc->sc_rx_feature);
936 		}
937 
938 		req->rxreq_gntref = GRANT_INVALID_REF;
939 
940 		pa = req->rxreq_pa;
941 		va = req->rxreq_va;
942 
943 		if (sc->sc_rx_feature == FEATURE_RX_FLIP) {
944 			/* remap the page */
945 			mmu[0].ptr = (ma << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
946 			mmu[0].val = ((pa - XPMAP_OFFSET) >> PAGE_SHIFT);
947 			MULTI_update_va_mapping(&mcl[0], va,
948 			    (ma << PAGE_SHIFT) | PG_V | PG_KW, UVMF_TLB_FLUSH|UVMF_ALL);
949 			xpmap_phys_to_machine_mapping[
950 			    (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = ma;
951 			mcl[1].op = __HYPERVISOR_mmu_update;
952 			mcl[1].args[0] = (unsigned long)mmu;
953 			mcl[1].args[1] = 1;
954 			mcl[1].args[2] = 0;
955 			mcl[1].args[3] = DOMID_SELF;
956 			HYPERVISOR_multicall(mcl, 2);
957 		}
958 
959 		pktp = (void *)(va + rx->offset);
960 #ifdef XENNET_DEBUG_DUMP
961 		xennet_hex_dump(pktp, rx->status, "r", rx->id);
962 #endif
963 		if ((ifp->if_flags & IFF_PROMISC) == 0) {
964 			struct ether_header *eh = pktp;
965 			if (ETHER_IS_MULTICAST(eh->ether_dhost) == 0 &&
966 			    memcmp(CLLADDR(ifp->if_sadl), eh->ether_dhost,
967 			    ETHER_ADDR_LEN) != 0) {
968 				DPRINTFN(XEDB_EVENT,
969 				    ("xennet_handler bad dest\n"));
970 				/* packet not for us */
971 				xennet_rx_mbuf_free(NULL, (void *)va, PAGE_SIZE,
972 				    req);
973 				continue;
974 			}
975 		}
976 		MGETHDR(m, M_DONTWAIT, MT_DATA);
977 		if (__predict_false(m == NULL)) {
978 			printf("%s: rx no mbuf\n", ifp->if_xname);
979 			ifp->if_ierrors++;
980 			xennet_rx_mbuf_free(NULL, (void *)va, PAGE_SIZE, req);
981 			continue;
982 		}
983 		MCLAIM(m, &sc->sc_ethercom.ec_rx_mowner);
984 
985 		m->m_pkthdr.rcvif = ifp;
986 		if (__predict_true(sc->sc_rx_ring.req_prod_pvt !=
987 		    sc->sc_rx_ring.sring->rsp_prod)) {
988 			m->m_len = m->m_pkthdr.len = rx->status;
989 			MEXTADD(m, pktp, rx->status,
990 			    M_DEVBUF, xennet_rx_mbuf_free, req);
991 			m->m_flags |= M_EXT_RW; /* we own the buffer */
992 			req->rxreq_gntref = GRANT_STACK_REF;
993 		} else {
994 			/*
995 			 * This was our last receive buffer, allocate
996 			 * memory, copy data and push the receive
997 			 * buffer back to the hypervisor.
998 			 */
999 			m->m_len = min(MHLEN, rx->status);
1000 			m->m_pkthdr.len = 0;
1001 			m_copyback(m, 0, rx->status, pktp);
1002 			xennet_rx_mbuf_free(NULL, (void *)va, PAGE_SIZE, req);
1003 			if (m->m_pkthdr.len < rx->status) {
1004 				/* out of memory, just drop packets */
1005 				ifp->if_ierrors++;
1006 				m_freem(m);
1007 				continue;
1008 			}
1009 		}
1010 		if ((rx->flags & NETRXF_csum_blank) != 0) {
1011 			xennet_checksum_fill(&m);
1012 			if (m == NULL) {
1013 				ifp->if_ierrors++;
1014 				continue;
1015 			}
1016 		}
1017 		/*
1018 		 * Pass packet to bpf if there is a listener.
1019 		 */
1020 		bpf_mtap(ifp, m);
1021 
1022 		ifp->if_ipackets++;
1023 
1024 		/* Pass the packet up. */
1025 		(*ifp->if_input)(ifp, m);
1026 	}
1027 	xen_rmb();
1028 	sc->sc_rx_ring.rsp_cons = i;
1029 	RING_FINAL_CHECK_FOR_RESPONSES(&sc->sc_rx_ring, more_to_do);
1030 	if (more_to_do)
1031 		goto again;
1032 	return 1;
1033 }
1034 
1035 /*
1036  * The output routine of a xennet interface
1037  * Called at splnet.
1038  */
1039 void
1040 xennet_start(struct ifnet *ifp)
1041 {
1042 	struct xennet_xenbus_softc *sc = ifp->if_softc;
1043 
1044 	DPRINTFN(XEDB_FOLLOW, ("%s: xennet_start()\n", device_xname(sc->sc_dev)));
1045 
1046 #if NRND > 0
1047 	rnd_add_uint32(&sc->sc_rnd_source, sc->sc_tx_ring.req_prod_pvt);
1048 #endif
1049 
1050 	xennet_tx_complete(sc);
1051 
1052 	if (__predict_false(
1053 	    (ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING))
1054 		return;
1055 
1056 	/*
1057 	 * The Xen communication channel is much more efficient if we can
1058 	 * schedule batch of packets for domain0. To achieve this, we
1059 	 * schedule a soft interrupt, and just return. This way, the network
1060 	 * stack will enqueue all pending mbufs in the interface's send queue
1061 	 * before it is processed by xennet_softstart().
1062 	 */
1063 	softint_schedule(sc->sc_softintr);
1064 	return;
1065 }
1066 
1067 /*
1068  * Prepares mbufs for TX, and notify backend when finished
1069  * Called at splsoftnet
1070  */
1071 void
1072 xennet_softstart(void *arg)
1073 {
1074 	struct xennet_xenbus_softc *sc = arg;
1075 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1076 	struct mbuf *m, *new_m;
1077 	netif_tx_request_t *txreq;
1078 	RING_IDX req_prod;
1079 	paddr_t pa, pa2;
1080 	struct xennet_txreq *req;
1081 	int notify;
1082 	int do_notify = 0;
1083 	int s;
1084 
1085 	s = splnet();
1086 	if (__predict_false(
1087 	    (ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)) {
1088 		splx(s);
1089 		return;
1090 	}
1091 
1092 	req_prod = sc->sc_tx_ring.req_prod_pvt;
1093 	while (/*CONSTCOND*/1) {
1094 		uint16_t txflags;
1095 
1096 		req = SLIST_FIRST(&sc->sc_txreq_head);
1097 		if (__predict_false(req == NULL)) {
1098 			ifp->if_flags |= IFF_OACTIVE;
1099 			break;
1100 		}
1101 		IFQ_POLL(&ifp->if_snd, m);
1102 		if (m == NULL)
1103 			break;
1104 
1105 		switch (m->m_flags & (M_EXT|M_EXT_CLUSTER)) {
1106 		case M_EXT|M_EXT_CLUSTER:
1107 			KASSERT(m->m_ext.ext_paddr != M_PADDR_INVALID);
1108 			pa = m->m_ext.ext_paddr +
1109 				(m->m_data - m->m_ext.ext_buf);
1110 			break;
1111 		case 0:
1112 			KASSERT(m->m_paddr != M_PADDR_INVALID);
1113 			pa = m->m_paddr + M_BUFOFFSET(m) +
1114 				(m->m_data - M_BUFADDR(m));
1115 			break;
1116 		default:
1117 			if (__predict_false(
1118 			    !pmap_extract(pmap_kernel(), (vaddr_t)m->m_data,
1119 			    &pa))) {
1120 				panic("xennet_start: no pa");
1121 			}
1122 			break;
1123 		}
1124 
1125 		if ((m->m_pkthdr.csum_flags &
1126 		    (M_CSUM_TCPv4 | M_CSUM_UDPv4)) != 0) {
1127 			txflags = NETTXF_csum_blank;
1128 		} else {
1129 			txflags = 0;
1130 		}
1131 
1132 		if (m->m_pkthdr.len != m->m_len ||
1133 		    (pa ^ (pa + m->m_pkthdr.len - 1)) & PG_FRAME) {
1134 
1135 			MGETHDR(new_m, M_DONTWAIT, MT_DATA);
1136 			if (__predict_false(new_m == NULL)) {
1137 				printf("%s: cannot allocate new mbuf\n",
1138 				       device_xname(sc->sc_dev));
1139 				break;
1140 			}
1141 			if (m->m_pkthdr.len > MHLEN) {
1142 				MCLGET(new_m, M_DONTWAIT);
1143 				if (__predict_false(
1144 				    (new_m->m_flags & M_EXT) == 0)) {
1145 					DPRINTF(("%s: no mbuf cluster\n",
1146 					    device_xname(sc->sc_dev)));
1147 					m_freem(new_m);
1148 					break;
1149 				}
1150 			}
1151 
1152 			m_copydata(m, 0, m->m_pkthdr.len, mtod(new_m, void *));
1153 			new_m->m_len = new_m->m_pkthdr.len = m->m_pkthdr.len;
1154 
1155 			if ((new_m->m_flags & M_EXT) != 0) {
1156 				pa = new_m->m_ext.ext_paddr;
1157 				KASSERT(new_m->m_data == new_m->m_ext.ext_buf);
1158 				KASSERT(pa != M_PADDR_INVALID);
1159 			} else {
1160 				pa = new_m->m_paddr;
1161 				KASSERT(pa != M_PADDR_INVALID);
1162 				KASSERT(new_m->m_data == M_BUFADDR(new_m));
1163 				pa += M_BUFOFFSET(new_m);
1164 			}
1165 			if (__predict_false(xengnt_grant_access(
1166 			    sc->sc_xbusd->xbusd_otherend_id,
1167 			    xpmap_ptom_masked(pa),
1168 			    GNTMAP_readonly, &req->txreq_gntref) != 0)) {
1169 				m_freem(new_m);
1170 				ifp->if_flags |= IFF_OACTIVE;
1171 				break;
1172 			}
1173 			/* we will be able to send new_m */
1174 			IFQ_DEQUEUE(&ifp->if_snd, m);
1175 			m_freem(m);
1176 			m = new_m;
1177 		} else {
1178 			if (__predict_false(xengnt_grant_access(
1179 			    sc->sc_xbusd->xbusd_otherend_id,
1180 			    xpmap_ptom_masked(pa),
1181 			    GNTMAP_readonly, &req->txreq_gntref) != 0)) {
1182 				ifp->if_flags |= IFF_OACTIVE;
1183 				break;
1184 			}
1185 			/* we will be able to send m */
1186 			IFQ_DEQUEUE(&ifp->if_snd, m);
1187 		}
1188 		MCLAIM(m, &sc->sc_ethercom.ec_tx_mowner);
1189 
1190 		KASSERT(((pa ^ (pa + m->m_pkthdr.len -  1)) & PG_FRAME) == 0);
1191 
1192 		SLIST_REMOVE_HEAD(&sc->sc_txreq_head, txreq_next);
1193 		req->txreq_m = m;
1194 
1195 		DPRINTFN(XEDB_MBUF, ("xennet_start id %d, "
1196 		    "mbuf %p, buf %p/%p/%p, size %d\n",
1197 		    req->txreq_id, m, mtod(m, void *), (void *)pa,
1198 		    (void *)xpmap_ptom_masked(pa), m->m_pkthdr.len));
1199 		pmap_extract_ma(pmap_kernel(), mtod(m, vaddr_t), &pa2);
1200 		DPRINTFN(XEDB_MBUF, ("xennet_start pa %p ma %p/%p\n",
1201 		    (void *)pa, (void *)xpmap_ptom_masked(pa), (void *)pa2));
1202 #ifdef XENNET_DEBUG_DUMP
1203 		xennet_hex_dump(mtod(m, u_char *), m->m_pkthdr.len, "s",
1204 			       	req->txreq_id);
1205 #endif
1206 
1207 		txreq = RING_GET_REQUEST(&sc->sc_tx_ring, req_prod);
1208 		txreq->id = req->txreq_id;
1209 		txreq->gref = req->txreq_gntref;
1210 		txreq->offset = pa & ~PG_FRAME;
1211 		txreq->size = m->m_pkthdr.len;
1212 		txreq->flags = txflags;
1213 
1214 		req_prod++;
1215 		sc->sc_tx_ring.req_prod_pvt = req_prod;
1216 		RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->sc_tx_ring, notify);
1217 		if (notify)
1218 			do_notify = 1;
1219 
1220 #ifdef XENNET_DEBUG
1221 		DPRINTFN(XEDB_MEM, ("packet addr %p/%p, physical %p/%p, "
1222 		    "m_paddr %p, len %d/%d\n", M_BUFADDR(m), mtod(m, void *),
1223 		    (void *)*kvtopte(mtod(m, vaddr_t)),
1224 		    (void *)xpmap_mtop(*kvtopte(mtod(m, vaddr_t))),
1225 		    (void *)m->m_paddr, m->m_pkthdr.len, m->m_len));
1226 		DPRINTFN(XEDB_MEM, ("id %d gref %d offset %d size %d flags %d"
1227 		    " prod %d\n",
1228 		    txreq->id, txreq->gref, txreq->offset, txreq->size,
1229 		    txreq->flags, req_prod));
1230 #endif
1231 
1232 		/*
1233 		 * Pass packet to bpf if there is a listener.
1234 		 */
1235 		bpf_mtap(ifp, m);
1236 	}
1237 
1238 	if (do_notify) {
1239 		hypervisor_notify_via_evtchn(sc->sc_evtchn);
1240 		ifp->if_timer = 5;
1241 	}
1242 	splx(s);
1243 
1244 	DPRINTFN(XEDB_FOLLOW, ("%s: xennet_start() done\n",
1245 	    device_xname(sc->sc_dev)));
1246 }
1247 
1248 int
1249 xennet_ioctl(struct ifnet *ifp, u_long cmd, void *data)
1250 {
1251 #ifdef XENNET_DEBUG
1252 	struct xennet_xenbus_softc *sc = ifp->if_softc;
1253 #endif
1254 	int s, error = 0;
1255 
1256 	s = splnet();
1257 
1258 	DPRINTFN(XEDB_FOLLOW, ("%s: xennet_ioctl()\n",
1259 	    device_xname(sc->sc_dev)));
1260 	error = ether_ioctl(ifp, cmd, data);
1261 	if (error == ENETRESET)
1262 		error = 0;
1263 	splx(s);
1264 
1265 	DPRINTFN(XEDB_FOLLOW, ("%s: xennet_ioctl() returning %d\n",
1266 	    device_xname(sc->sc_dev), error));
1267 
1268 	return error;
1269 }
1270 
1271 void
1272 xennet_watchdog(struct ifnet *ifp)
1273 {
1274 	aprint_verbose_ifnet(ifp, "xennet_watchdog\n");
1275 }
1276 
1277 int
1278 xennet_init(struct ifnet *ifp)
1279 {
1280 	struct xennet_xenbus_softc *sc = ifp->if_softc;
1281 	int s = splnet();
1282 
1283 	DPRINTFN(XEDB_FOLLOW, ("%s: xennet_init()\n",
1284 	    device_xname(sc->sc_dev)));
1285 
1286 	if ((ifp->if_flags & IFF_RUNNING) == 0) {
1287 		sc->sc_rx_ring.sring->rsp_event =
1288 		    sc->sc_rx_ring.rsp_cons + 1;
1289 		hypervisor_enable_event(sc->sc_evtchn);
1290 		hypervisor_notify_via_evtchn(sc->sc_evtchn);
1291 		xennet_reset(sc);
1292 	}
1293 	ifp->if_flags |= IFF_RUNNING;
1294 	ifp->if_flags &= ~IFF_OACTIVE;
1295 	ifp->if_timer = 0;
1296 	splx(s);
1297 	return 0;
1298 }
1299 
1300 void
1301 xennet_stop(struct ifnet *ifp, int disable)
1302 {
1303 	struct xennet_xenbus_softc *sc = ifp->if_softc;
1304 	int s = splnet();
1305 
1306 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
1307 	hypervisor_mask_event(sc->sc_evtchn);
1308 	xennet_reset(sc);
1309 	splx(s);
1310 }
1311 
1312 void
1313 xennet_reset(struct xennet_xenbus_softc *sc)
1314 {
1315 
1316 	DPRINTFN(XEDB_FOLLOW, ("%s: xennet_reset()\n",
1317 	    device_xname(sc->sc_dev)));
1318 }
1319 
1320 #if defined(NFS_BOOT_BOOTSTATIC)
1321 int
1322 xennet_bootstatic_callback(struct nfs_diskless *nd)
1323 {
1324 #if 0
1325 	struct ifnet *ifp = nd->nd_ifp;
1326 	struct xennet_xenbus_softc *sc =
1327 	    (struct xennet_xenbus_softc *)ifp->if_softc;
1328 #endif
1329 	int flags = 0;
1330 	union xen_cmdline_parseinfo xcp;
1331 	struct sockaddr_in *sin;
1332 
1333 	memset(&xcp, 0, sizeof(xcp.xcp_netinfo));
1334 	xcp.xcp_netinfo.xi_ifno = /* XXX sc->sc_ifno */ 0;
1335 	xcp.xcp_netinfo.xi_root = nd->nd_root.ndm_host;
1336 	xen_parse_cmdline(XEN_PARSE_NETINFO, &xcp);
1337 
1338 	if (xcp.xcp_netinfo.xi_root[0] != '\0') {
1339 		flags |= NFS_BOOT_HAS_SERVER;
1340 		if (strchr(xcp.xcp_netinfo.xi_root, ':') != NULL)
1341 			flags |= NFS_BOOT_HAS_ROOTPATH;
1342 	}
1343 
1344 	nd->nd_myip.s_addr = ntohl(xcp.xcp_netinfo.xi_ip[0]);
1345 	nd->nd_gwip.s_addr = ntohl(xcp.xcp_netinfo.xi_ip[2]);
1346 	nd->nd_mask.s_addr = ntohl(xcp.xcp_netinfo.xi_ip[3]);
1347 
1348 	sin = (struct sockaddr_in *) &nd->nd_root.ndm_saddr;
1349 	memset((void *)sin, 0, sizeof(*sin));
1350 	sin->sin_len = sizeof(*sin);
1351 	sin->sin_family = AF_INET;
1352 	sin->sin_addr.s_addr = ntohl(xcp.xcp_netinfo.xi_ip[1]);
1353 
1354 	if (nd->nd_myip.s_addr)
1355 		flags |= NFS_BOOT_HAS_MYIP;
1356 	if (nd->nd_gwip.s_addr)
1357 		flags |= NFS_BOOT_HAS_GWIP;
1358 	if (nd->nd_mask.s_addr)
1359 		flags |= NFS_BOOT_HAS_MASK;
1360 	if (sin->sin_addr.s_addr)
1361 		flags |= NFS_BOOT_HAS_SERVADDR;
1362 
1363 	return flags;
1364 }
1365 #endif /* defined(NFS_BOOT_BOOTSTATIC) */
1366 
1367 #ifdef XENNET_DEBUG_DUMP
1368 #define XCHR(x) hexdigits[(x) & 0xf]
1369 static void
1370 xennet_hex_dump(const unsigned char *pkt, size_t len, const char *type, int id)
1371 {
1372 	size_t i, j;
1373 
1374 	printf("pkt %p len %zd/%zx type %s id %d\n", pkt, len, len, type, id);
1375 	printf("00000000  ");
1376 	for(i=0; i<len; i++) {
1377 		printf("%c%c ", XCHR(pkt[i]>>4), XCHR(pkt[i]));
1378 		if ((i+1) % 16 == 8)
1379 			printf(" ");
1380 		if ((i+1) % 16 == 0) {
1381 			printf(" %c", '|');
1382 			for(j=0; j<16; j++)
1383 				printf("%c", pkt[i-15+j]>=32 &&
1384 				    pkt[i-15+j]<127?pkt[i-15+j]:'.');
1385 			printf("%c\n%c%c%c%c%c%c%c%c  ", '|',
1386 			    XCHR((i+1)>>28), XCHR((i+1)>>24),
1387 			    XCHR((i+1)>>20), XCHR((i+1)>>16),
1388 			    XCHR((i+1)>>12), XCHR((i+1)>>8),
1389 			    XCHR((i+1)>>4), XCHR(i+1));
1390 		}
1391 	}
1392 	printf("\n");
1393 }
1394 #undef XCHR
1395 #endif
1396