xref: /netbsd-src/sys/dev/hyperv/vmbus.c (revision 53d1339bf7f9c7367b35a9e1ebe693f9b047a47b)
1 /*	$NetBSD: vmbus.c,v 1.13 2021/04/24 23:36:54 thorpej Exp $	*/
2 /*	$OpenBSD: hyperv.c,v 1.43 2017/06/27 13:56:15 mikeb Exp $	*/
3 
4 /*-
5  * Copyright (c) 2009-2012 Microsoft Corp.
6  * Copyright (c) 2012 NetApp Inc.
7  * Copyright (c) 2012 Citrix Inc.
8  * Copyright (c) 2016 Mike Belopuhov <mike@esdenera.com>
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice unmodified, this list of conditions, and the following
16  *    disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * The OpenBSD port was done under funding by Esdenera Networks GmbH.
35  */
36 
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: vmbus.c,v 1.13 2021/04/24 23:36:54 thorpej Exp $");
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/device.h>
43 #include <sys/atomic.h>
44 #include <sys/bitops.h>
45 #include <sys/bus.h>
46 #include <sys/cpu.h>
47 #include <sys/intr.h>
48 #include <sys/kmem.h>
49 #include <sys/kthread.h>
50 #include <sys/module.h>
51 #include <sys/mutex.h>
52 #include <sys/xcall.h>
53 
54 #include <uvm/uvm_extern.h>
55 
56 #include <dev/hyperv/vmbusvar.h>
57 
58 #define VMBUS_GPADL_START		0xffff /* 0x10000 effectively */
59 
60 /* Command submission flags */
61 #define HCF_SLEEPOK	0x0000
62 #define HCF_NOSLEEP	0x0002	/* M_NOWAIT */
63 #define HCF_NOREPLY	0x0004
64 
65 static void	vmbus_attach_deferred(device_t);
66 static int	vmbus_attach_print(void *, const char *);
67 static int	vmbus_alloc_dma(struct vmbus_softc *);
68 static void	vmbus_free_dma(struct vmbus_softc *);
69 static int	vmbus_init_interrupts(struct vmbus_softc *);
70 static void	vmbus_deinit_interrupts(struct vmbus_softc *);
71 static void	vmbus_init_synic(void *, void *);
72 static void	vmbus_deinit_synic(void *, void *);
73 
74 static int	vmbus_connect(struct vmbus_softc *);
75 static int	vmbus_cmd(struct vmbus_softc *, void *, size_t, void *, size_t,
76 		    int);
77 static int	vmbus_start(struct vmbus_softc *, struct vmbus_msg *, paddr_t);
78 static int	vmbus_reply(struct vmbus_softc *, struct vmbus_msg *);
79 static uint16_t vmbus_intr_signal(struct vmbus_softc *, paddr_t);
80 static void	vmbus_event_proc(void *, struct cpu_info *);
81 static void	vmbus_event_proc_compat(void *, struct cpu_info *);
82 static void	vmbus_message_proc(void *, struct cpu_info *);
83 static void	vmbus_message_softintr(void *);
84 static void	vmbus_channel_response(struct vmbus_softc *,
85 		    struct vmbus_chanmsg_hdr *);
86 static void	vmbus_channel_offer(struct vmbus_softc *,
87 		    struct vmbus_chanmsg_hdr *);
88 static void	vmbus_channel_rescind(struct vmbus_softc *,
89 		    struct vmbus_chanmsg_hdr *);
90 static void	vmbus_channel_delivered(struct vmbus_softc *,
91 		    struct vmbus_chanmsg_hdr *);
92 static int	vmbus_channel_scan(struct vmbus_softc *);
93 static void	vmbus_channel_cpu_default(struct vmbus_channel *);
94 static void	vmbus_process_offer(struct vmbus_softc *,
95 		    struct vmbus_chanmsg_choffer *);
96 static void	vmbus_process_rescind(struct vmbus_softc *,
97 		    struct vmbus_chanmsg_chrescind *);
98 static struct vmbus_channel *
99 		vmbus_channel_lookup(struct vmbus_softc *, uint32_t);
100 static int	vmbus_channel_ring_create(struct vmbus_channel *, uint32_t);
101 static void	vmbus_channel_ring_destroy(struct vmbus_channel *);
102 static void	vmbus_channel_detach(struct vmbus_channel *);
103 static void	vmbus_channel_pause(struct vmbus_channel *);
104 static uint32_t	vmbus_channel_unpause(struct vmbus_channel *);
105 static uint32_t	vmbus_channel_ready(struct vmbus_channel *);
106 static void	vmbus_chevq_enqueue(struct vmbus_softc *, int, void *);
107 static void	vmbus_process_chevq(void *);
108 static void	vmbus_chevq_thread(void *);
109 static void	vmbus_devq_enqueue(struct vmbus_softc *, int,
110 		    struct vmbus_channel *);
111 static void	vmbus_process_devq(void *);
112 static void	vmbus_devq_thread(void *);
113 static void	vmbus_subchannel_devq_thread(void *);
114 
115 static struct vmbus_softc *vmbus_sc;
116 
117 static const struct {
118 	int	hmd_response;
119 	int	hmd_request;
120 	void	(*hmd_handler)(struct vmbus_softc *,
121 		    struct vmbus_chanmsg_hdr *);
122 } vmbus_msg_dispatch[] = {
123 	{ 0,					0, NULL },
124 	{ VMBUS_CHANMSG_CHOFFER,		0, vmbus_channel_offer },
125 	{ VMBUS_CHANMSG_CHRESCIND,		0, vmbus_channel_rescind },
126 	{ VMBUS_CHANMSG_CHREQUEST,		VMBUS_CHANMSG_CHOFFER, NULL },
127 	{ VMBUS_CHANMSG_CHOFFER_DONE,		0, vmbus_channel_delivered },
128 	{ VMBUS_CHANMSG_CHOPEN,			0, NULL },
129 	{ VMBUS_CHANMSG_CHOPEN_RESP,		VMBUS_CHANMSG_CHOPEN,
130 	  vmbus_channel_response },
131 	{ VMBUS_CHANMSG_CHCLOSE,		0, NULL },
132 	{ VMBUS_CHANMSG_GPADL_CONN,		0, NULL },
133 	{ VMBUS_CHANMSG_GPADL_SUBCONN,		0, NULL },
134 	{ VMBUS_CHANMSG_GPADL_CONNRESP,		VMBUS_CHANMSG_GPADL_CONN,
135 	  vmbus_channel_response },
136 	{ VMBUS_CHANMSG_GPADL_DISCONN,		0, NULL },
137 	{ VMBUS_CHANMSG_GPADL_DISCONNRESP,	VMBUS_CHANMSG_GPADL_DISCONN,
138 	  vmbus_channel_response },
139 	{ VMBUS_CHANMSG_CHFREE,			0, NULL },
140 	{ VMBUS_CHANMSG_CONNECT,		0, NULL },
141 	{ VMBUS_CHANMSG_CONNECT_RESP,		VMBUS_CHANMSG_CONNECT,
142 	  vmbus_channel_response },
143 	{ VMBUS_CHANMSG_DISCONNECT,		0, NULL },
144 };
145 
146 const struct hyperv_guid hyperv_guid_network = {
147 	{ 0x63, 0x51, 0x61, 0xf8, 0x3e, 0xdf, 0xc5, 0x46,
148 	  0x91, 0x3f, 0xf2, 0xd2, 0xf9, 0x65, 0xed, 0x0e }
149 };
150 
151 const struct hyperv_guid hyperv_guid_ide = {
152 	{ 0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
153 	  0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5 }
154 };
155 
156 const struct hyperv_guid hyperv_guid_scsi = {
157 	{ 0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
158 	  0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f }
159 };
160 
161 const struct hyperv_guid hyperv_guid_shutdown = {
162 	{ 0x31, 0x60, 0x0b, 0x0e, 0x13, 0x52, 0x34, 0x49,
163 	  0x81, 0x8b, 0x38, 0xd9, 0x0c, 0xed, 0x39, 0xdb }
164 };
165 
166 const struct hyperv_guid hyperv_guid_timesync = {
167 	{ 0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
168 	  0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf }
169 };
170 
171 const struct hyperv_guid hyperv_guid_heartbeat = {
172 	{ 0x39, 0x4f, 0x16, 0x57, 0x15, 0x91, 0x78, 0x4e,
173 	  0xab, 0x55, 0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d }
174 };
175 
176 const struct hyperv_guid hyperv_guid_kvp = {
177 	{ 0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
178 	  0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x03, 0xe6 }
179 };
180 
181 const struct hyperv_guid hyperv_guid_vss = {
182 	{ 0x29, 0x2e, 0xfa, 0x35, 0x23, 0xea, 0x36, 0x42,
183 	  0x96, 0xae, 0x3a, 0x6e, 0xba, 0xcb, 0xa4, 0x40 }
184 };
185 
186 const struct hyperv_guid hyperv_guid_dynmem = {
187 	{ 0xdc, 0x74, 0x50, 0x52, 0x85, 0x89, 0xe2, 0x46,
188 	  0x80, 0x57, 0xa3, 0x07, 0xdc, 0x18, 0xa5, 0x02 }
189 };
190 
191 const struct hyperv_guid hyperv_guid_mouse = {
192 	{ 0x9e, 0xb6, 0xa8, 0xcf, 0x4a, 0x5b, 0xc0, 0x4c,
193 	  0xb9, 0x8b, 0x8b, 0xa1, 0xa1, 0xf3, 0xf9, 0x5a }
194 };
195 
196 const struct hyperv_guid hyperv_guid_kbd = {
197 	{ 0x6d, 0xad, 0x12, 0xf9, 0x17, 0x2b, 0xea, 0x48,
198 	  0xbd, 0x65, 0xf9, 0x27, 0xa6, 0x1c, 0x76, 0x84 }
199 };
200 
201 const struct hyperv_guid hyperv_guid_video = {
202 	{ 0x02, 0x78, 0x0a, 0xda, 0x77, 0xe3, 0xac, 0x4a,
203 	  0x8e, 0x77, 0x05, 0x58, 0xeb, 0x10, 0x73, 0xf8 }
204 };
205 
206 const struct hyperv_guid hyperv_guid_fc = {
207 	{ 0x4a, 0xcc, 0x9b, 0x2f, 0x69, 0x00, 0xf3, 0x4a,
208 	  0xb7, 0x6b, 0x6f, 0xd0, 0xbe, 0x52, 0x8c, 0xda }
209 };
210 
211 const struct hyperv_guid hyperv_guid_fcopy = {
212 	{ 0xe3, 0x4b, 0xd1, 0x34, 0xe4, 0xde, 0xc8, 0x41,
213 	  0x9a, 0xe7, 0x6b, 0x17, 0x49, 0x77, 0xc1, 0x92 }
214 };
215 
216 const struct hyperv_guid hyperv_guid_pcie = {
217 	{ 0x1d, 0xf6, 0xc4, 0x44, 0x44, 0x44, 0x00, 0x44,
218 	  0x9d, 0x52, 0x80, 0x2e, 0x27, 0xed, 0xe1, 0x9f }
219 };
220 
221 const struct hyperv_guid hyperv_guid_netdir = {
222 	{ 0x3d, 0xaf, 0x2e, 0x8c, 0xa7, 0x32, 0x09, 0x4b,
223 	  0xab, 0x99, 0xbd, 0x1f, 0x1c, 0x86, 0xb5, 0x01 }
224 };
225 
226 const struct hyperv_guid hyperv_guid_rdesktop = {
227 	{ 0xf4, 0xac, 0x6a, 0x27, 0x15, 0xac, 0x6c, 0x42,
228 	  0x98, 0xdd, 0x75, 0x21, 0xad, 0x3f, 0x01, 0xfe }
229 };
230 
231 /* Automatic Virtual Machine Activation (AVMA) Services */
232 const struct hyperv_guid hyperv_guid_avma1 = {
233 	{ 0x55, 0xb2, 0x87, 0x44, 0x8c, 0xb8, 0x3f, 0x40,
234 	  0xbb, 0x51, 0xd1, 0xf6, 0x9c, 0xf1, 0x7f, 0x87 }
235 };
236 
237 const struct hyperv_guid hyperv_guid_avma2 = {
238 	{ 0xf4, 0xba, 0x75, 0x33, 0x15, 0x9e, 0x30, 0x4b,
239 	  0xb7, 0x65, 0x67, 0xac, 0xb1, 0x0d, 0x60, 0x7b }
240 };
241 
242 const struct hyperv_guid hyperv_guid_avma3 = {
243 	{ 0xa0, 0x1f, 0x22, 0x99, 0xad, 0x24, 0xe2, 0x11,
244 	  0xbe, 0x98, 0x00, 0x1a, 0xa0, 0x1b, 0xbf, 0x6e }
245 };
246 
247 const struct hyperv_guid hyperv_guid_avma4 = {
248 	{ 0x16, 0x57, 0xe6, 0xf8, 0xb3, 0x3c, 0x06, 0x4a,
249 	  0x9a, 0x60, 0x18, 0x89, 0xc5, 0xcc, 0xca, 0xb5 }
250 };
251 
252 int
253 vmbus_match(device_t parent, cfdata_t cf, void *aux)
254 {
255 
256 	if (cf->cf_unit != 0 ||
257 	    !hyperv_hypercall_enabled() ||
258 	    !hyperv_synic_supported())
259 		return 0;
260 
261 	return 1;
262 }
263 
264 int
265 vmbus_attach(struct vmbus_softc *sc)
266 {
267 
268 	aprint_naive("\n");
269 	aprint_normal(": Hyper-V VMBus\n");
270 
271 	vmbus_sc = sc;
272 
273 	sc->sc_msgpool = pool_cache_init(sizeof(struct vmbus_msg), 8, 0, 0,
274 	    "hvmsg", NULL, IPL_NET, NULL, NULL, NULL);
275 	hyperv_set_message_proc(vmbus_message_proc, sc);
276 
277 	if (vmbus_alloc_dma(sc))
278 		goto cleanup;
279 
280 	if (vmbus_init_interrupts(sc))
281 		goto cleanup;
282 
283 	if (vmbus_connect(sc))
284 		goto cleanup;
285 
286 	aprint_normal_dev(sc->sc_dev, "protocol %d.%d\n",
287 	    VMBUS_VERSION_MAJOR(sc->sc_proto),
288 	    VMBUS_VERSION_MINOR(sc->sc_proto));
289 
290 	if (sc->sc_proto == VMBUS_VERSION_WS2008 ||
291 	    sc->sc_proto == VMBUS_VERSION_WIN7) {
292 		hyperv_set_event_proc(vmbus_event_proc_compat, sc);
293 		sc->sc_channel_max = VMBUS_CHAN_MAX_COMPAT;
294 	} else {
295 		hyperv_set_event_proc(vmbus_event_proc, sc);
296 		sc->sc_channel_max = VMBUS_CHAN_MAX;
297 	}
298 
299 	if (vmbus_channel_scan(sc))
300 		goto cleanup;
301 
302 	config_interrupts(sc->sc_dev, vmbus_attach_deferred);
303 
304 	return 0;
305 
306 cleanup:
307 	vmbus_deinit_interrupts(sc);
308 	vmbus_free_dma(sc);
309 	return -1;
310 }
311 
312 static void
313 vmbus_attach_deferred(device_t self)
314 {
315 	struct vmbus_softc *sc = device_private(self);
316 
317 	xc_wait(xc_broadcast(0, vmbus_init_synic, sc, NULL));
318 }
319 
320 int
321 vmbus_detach(struct vmbus_softc *sc, int flags)
322 {
323 
324 	vmbus_deinit_interrupts(sc);
325 	vmbus_free_dma(sc);
326 
327 	return 0;
328 }
329 
330 static int
331 vmbus_alloc_dma(struct vmbus_softc *sc)
332 {
333 	CPU_INFO_ITERATOR cii;
334 	struct cpu_info *ci;
335 	struct vmbus_percpu_data *pd;
336 	int i;
337 
338 	/*
339 	 * Per-CPU messages and event flags.
340 	 */
341 	for (CPU_INFO_FOREACH(cii, ci)) {
342 		pd = &sc->sc_percpu[cpu_index(ci)];
343 
344 		pd->simp = hyperv_dma_alloc(sc->sc_dmat, &pd->simp_dma,
345 		    PAGE_SIZE, PAGE_SIZE, 0, 1, HYPERV_DMA_SLEEPOK);
346 		if (pd->simp == NULL)
347 			return ENOMEM;
348 
349 		pd->siep = hyperv_dma_alloc(sc->sc_dmat, &pd->siep_dma,
350 		    PAGE_SIZE, PAGE_SIZE, 0, 1, HYPERV_DMA_SLEEPOK);
351 		if (pd->siep == NULL)
352 			return ENOMEM;
353 	}
354 
355 	sc->sc_events = hyperv_dma_alloc(sc->sc_dmat, &sc->sc_events_dma,
356 	    PAGE_SIZE, PAGE_SIZE, 0, 1, HYPERV_DMA_SLEEPOK);
357 	if (sc->sc_events == NULL)
358 		return ENOMEM;
359 	sc->sc_wevents = (u_long *)sc->sc_events;
360 	sc->sc_revents = (u_long *)((uint8_t *)sc->sc_events + (PAGE_SIZE / 2));
361 
362 	for (i = 0; i < __arraycount(sc->sc_monitor); i++) {
363 		sc->sc_monitor[i] = hyperv_dma_alloc(sc->sc_dmat,
364 		    &sc->sc_monitor_dma[i], PAGE_SIZE, PAGE_SIZE, 0, 1,
365 		    HYPERV_DMA_SLEEPOK);
366 		if (sc->sc_monitor[i] == NULL)
367 			return ENOMEM;
368 	}
369 
370 	return 0;
371 }
372 
373 static void
374 vmbus_free_dma(struct vmbus_softc *sc)
375 {
376 	CPU_INFO_ITERATOR cii;
377 	struct cpu_info *ci;
378 	int i;
379 
380 	if (sc->sc_events != NULL) {
381 		sc->sc_events = sc->sc_wevents = sc->sc_revents = NULL;
382 		hyperv_dma_free(sc->sc_dmat, &sc->sc_events_dma);
383 	}
384 
385 	for (i = 0; i < __arraycount(sc->sc_monitor); i++) {
386 		sc->sc_monitor[i] = NULL;
387 		hyperv_dma_free(sc->sc_dmat, &sc->sc_monitor_dma[i]);
388 	}
389 
390 	for (CPU_INFO_FOREACH(cii, ci)) {
391 		struct vmbus_percpu_data *pd = &sc->sc_percpu[cpu_index(ci)];
392 
393 		if (pd->simp != NULL) {
394 			pd->simp = NULL;
395 			hyperv_dma_free(sc->sc_dmat, &pd->simp_dma);
396 		}
397 		if (pd->siep != NULL) {
398 			pd->siep = NULL;
399 			hyperv_dma_free(sc->sc_dmat, &pd->siep_dma);
400 		}
401 	}
402 }
403 
404 static int
405 vmbus_init_interrupts(struct vmbus_softc *sc)
406 {
407 
408 	TAILQ_INIT(&sc->sc_reqs);
409 	mutex_init(&sc->sc_req_lock, MUTEX_DEFAULT, IPL_NET);
410 
411 	TAILQ_INIT(&sc->sc_rsps);
412 	mutex_init(&sc->sc_rsp_lock, MUTEX_DEFAULT, IPL_NET);
413 
414 	sc->sc_proto = VMBUS_VERSION_WS2008;
415 
416 	/* XXX event_tq */
417 
418 	sc->sc_msg_sih = softint_establish(SOFTINT_NET | SOFTINT_MPSAFE,
419 	    vmbus_message_softintr, sc);
420 	if (sc->sc_msg_sih == NULL)
421 		return -1;
422 
423 	vmbus_init_interrupts_md(sc);
424 
425 	kcpuset_create(&sc->sc_intr_cpuset, true);
426 	if (cold) {
427 		/* Initialize other CPUs later. */
428 		vmbus_init_synic(sc, NULL);
429 	} else
430 		xc_wait(xc_broadcast(0, vmbus_init_synic, sc, NULL));
431 	atomic_or_32(&sc->sc_flags, VMBUS_SCFLAG_SYNIC);
432 
433 	return 0;
434 }
435 
436 static void
437 vmbus_deinit_interrupts(struct vmbus_softc *sc)
438 {
439 
440 	if (ISSET(sc->sc_flags, VMBUS_SCFLAG_SYNIC)) {
441 		if (cold)
442 			vmbus_deinit_synic(sc, NULL);
443 		else
444 			xc_wait(xc_broadcast(0, vmbus_deinit_synic, sc, NULL));
445 		atomic_and_32(&sc->sc_flags, (uint32_t)~VMBUS_SCFLAG_SYNIC);
446 	}
447 
448 	/* XXX event_tq */
449 
450 	if (sc->sc_msg_sih != NULL) {
451 		softint_disestablish(sc->sc_msg_sih);
452 		sc->sc_msg_sih = NULL;
453 	}
454 
455 	vmbus_deinit_interrupts_md(sc);
456 }
457 
458 static void
459 vmbus_init_synic(void *arg1, void *arg2)
460 {
461 	struct vmbus_softc *sc = arg1;
462 	cpuid_t cpu;
463 	int s;
464 
465 	s = splhigh();
466 
467 	cpu = cpu_index(curcpu());
468 	if (!kcpuset_isset(sc->sc_intr_cpuset, cpu)) {
469 		kcpuset_atomic_set(sc->sc_intr_cpuset, cpu);
470 		vmbus_init_synic_md(sc, cpu);
471 	}
472 
473 	splx(s);
474 }
475 
476 static void
477 vmbus_deinit_synic(void *arg1, void *arg2)
478 {
479 	struct vmbus_softc *sc = arg1;
480 	cpuid_t cpu;
481 	int s;
482 
483 	s = splhigh();
484 
485 	cpu = cpu_index(curcpu());
486 	if (kcpuset_isset(sc->sc_intr_cpuset, cpu)) {
487 		vmbus_deinit_synic_md(sc, cpu);
488 		kcpuset_atomic_clear(sc->sc_intr_cpuset, cpu);
489 	}
490 
491 	splx(s);
492 }
493 
494 static int
495 vmbus_connect(struct vmbus_softc *sc)
496 {
497 	static const uint32_t versions[] = {
498 		VMBUS_VERSION_WIN8_1,
499 		VMBUS_VERSION_WIN8,
500 		VMBUS_VERSION_WIN7,
501 		VMBUS_VERSION_WS2008
502 	};
503 	struct vmbus_chanmsg_connect cmd;
504 	struct vmbus_chanmsg_connect_resp rsp;
505 	int i, rv;
506 
507 	memset(&cmd, 0, sizeof(cmd));
508 	cmd.chm_hdr.chm_type = VMBUS_CHANMSG_CONNECT;
509 	cmd.chm_evtflags = hyperv_dma_get_paddr(&sc->sc_events_dma);
510 	cmd.chm_mnf1 = hyperv_dma_get_paddr(&sc->sc_monitor_dma[0]);
511 	cmd.chm_mnf2 = hyperv_dma_get_paddr(&sc->sc_monitor_dma[1]);
512 
513 	memset(&rsp, 0, sizeof(rsp));
514 
515 	for (i = 0; i < __arraycount(versions); i++) {
516 		cmd.chm_ver = versions[i];
517 		rv = vmbus_cmd(sc, &cmd, sizeof(cmd), &rsp, sizeof(rsp),
518 		    cold ? HCF_NOSLEEP : HCF_SLEEPOK);
519 		if (rv) {
520 			DPRINTF("%s: CONNECT failed\n",
521 			    device_xname(sc->sc_dev));
522 			return rv;
523 		}
524 		if (rsp.chm_done) {
525 			atomic_or_32(&sc->sc_flags, VMBUS_SCFLAG_CONNECTED);
526 			sc->sc_proto = versions[i];
527 			sc->sc_handle = VMBUS_GPADL_START;
528 			break;
529 		}
530 	}
531 	if (i == __arraycount(versions)) {
532 		device_printf(sc->sc_dev,
533 		    "failed to negotiate protocol version\n");
534 		return ENXIO;
535 	}
536 
537 	return 0;
538 }
539 
540 static int
541 vmbus_cmd(struct vmbus_softc *sc, void *cmd, size_t cmdlen, void *rsp,
542     size_t rsplen, int flags)
543 {
544 	const int prflags = cold ? PR_NOWAIT : PR_WAITOK;
545 	struct vmbus_msg *msg;
546 	paddr_t pa;
547 	int rv;
548 
549 	if (cmdlen > VMBUS_MSG_DSIZE_MAX) {
550 		device_printf(sc->sc_dev, "payload too large (%zu)\n",
551 		    cmdlen);
552 		return EMSGSIZE;
553 	}
554 
555 	msg = pool_cache_get_paddr(sc->sc_msgpool, prflags, &pa);
556 	if (msg == NULL) {
557 		device_printf(sc->sc_dev, "couldn't get msgpool\n");
558 		return ENOMEM;
559 	}
560 	memset(msg, 0, sizeof(*msg));
561 	msg->msg_req.hc_dsize = cmdlen;
562 	memcpy(msg->msg_req.hc_data, cmd, cmdlen);
563 
564 	if (!(flags & HCF_NOREPLY)) {
565 		msg->msg_rsp = rsp;
566 		msg->msg_rsplen = rsplen;
567 	} else
568 		msg->msg_flags |= MSGF_NOQUEUE;
569 
570 	if (flags & HCF_NOSLEEP)
571 		msg->msg_flags |= MSGF_NOSLEEP;
572 
573 	rv = vmbus_start(sc, msg, pa);
574 	if (rv == 0)
575 		rv = vmbus_reply(sc, msg);
576 	pool_cache_put_paddr(sc->sc_msgpool, msg, pa);
577 	return rv;
578 }
579 
580 static int
581 vmbus_start(struct vmbus_softc *sc, struct vmbus_msg *msg, paddr_t msg_pa)
582 {
583 	static const int delays[] = {
584 		100, 100, 100, 500, 500, 5000, 5000, 5000
585 	};
586 	const char *wchan = "hvstart";
587 	uint16_t status;
588 	int i, s;
589 
590 	msg->msg_req.hc_connid = VMBUS_CONNID_MESSAGE;
591 	msg->msg_req.hc_msgtype = 1;
592 
593 	if (!(msg->msg_flags & MSGF_NOQUEUE)) {
594 		mutex_enter(&sc->sc_req_lock);
595 		TAILQ_INSERT_TAIL(&sc->sc_reqs, msg, msg_entry);
596 		mutex_exit(&sc->sc_req_lock);
597 	}
598 
599 	for (i = 0; i < __arraycount(delays); i++) {
600 		status = hyperv_hypercall_post_message(
601 		    msg_pa + offsetof(struct vmbus_msg, msg_req));
602 		if (status == HYPERCALL_STATUS_SUCCESS)
603 			break;
604 
605 		if (msg->msg_flags & MSGF_NOSLEEP) {
606 			delay(delays[i]);
607 			s = splnet();
608 			hyperv_intr();
609 			splx(s);
610 		} else
611 			tsleep(wchan, PRIBIO, wchan,
612 			    uimax(1, mstohz(delays[i] / 1000)));
613 	}
614 	if (status != HYPERCALL_STATUS_SUCCESS) {
615 		device_printf(sc->sc_dev,
616 		    "posting vmbus message failed with %d\n", status);
617 		if (!(msg->msg_flags & MSGF_NOQUEUE)) {
618 			mutex_enter(&sc->sc_req_lock);
619 			TAILQ_REMOVE(&sc->sc_reqs, msg, msg_entry);
620 			mutex_exit(&sc->sc_req_lock);
621 		}
622 		return EIO;
623 	}
624 
625 	return 0;
626 }
627 
628 static int
629 vmbus_reply_done(struct vmbus_softc *sc, struct vmbus_msg *msg)
630 {
631 	struct vmbus_msg *m;
632 
633 	mutex_enter(&sc->sc_rsp_lock);
634 	TAILQ_FOREACH(m, &sc->sc_rsps, msg_entry) {
635 		if (m == msg) {
636 			mutex_exit(&sc->sc_rsp_lock);
637 			return 1;
638 		}
639 	}
640 	mutex_exit(&sc->sc_rsp_lock);
641 	return 0;
642 }
643 
644 static int
645 vmbus_reply(struct vmbus_softc *sc, struct vmbus_msg *msg)
646 {
647 	int s;
648 
649 	if (msg->msg_flags & MSGF_NOQUEUE)
650 		return 0;
651 
652 	while (!vmbus_reply_done(sc, msg)) {
653 		if (msg->msg_flags & MSGF_NOSLEEP) {
654 			delay(1000);
655 			s = splnet();
656 			hyperv_intr();
657 			splx(s);
658 		} else
659 			tsleep(msg, PRIBIO, "hvreply", 1);
660 	}
661 
662 	mutex_enter(&sc->sc_rsp_lock);
663 	TAILQ_REMOVE(&sc->sc_rsps, msg, msg_entry);
664 	mutex_exit(&sc->sc_rsp_lock);
665 
666 	return 0;
667 }
668 
669 static uint16_t
670 vmbus_intr_signal(struct vmbus_softc *sc, paddr_t con_pa)
671 {
672 	uint64_t status;
673 
674 	status = hyperv_hypercall_signal_event(con_pa);
675 	return (uint16_t)status;
676 }
677 
678 #if LONG_BIT == 64
679 #define ffsl(v)	ffs64(v)
680 #elif LONG_BIT == 32
681 #define ffsl(v)	ffs32(v)
682 #else
683 #error unsupport LONG_BIT
684 #endif	/* LONG_BIT */
685 
686 static void
687 vmbus_event_flags_proc(struct vmbus_softc *sc, volatile u_long *revents,
688     int maxrow)
689 {
690 	struct vmbus_channel *ch;
691 	u_long pending;
692 	uint32_t chanid, chanid_base;
693 	int row, chanid_ofs;
694 
695 	for (row = 0; row < maxrow; row++) {
696 		if (revents[row] == 0)
697 			continue;
698 
699 		pending = atomic_swap_ulong(&revents[row], 0);
700 		chanid_base = row * LONG_BIT;
701 
702 		while ((chanid_ofs = ffsl(pending)) != 0) {
703 			chanid_ofs--;	/* NOTE: ffs is 1-based */
704 			pending &= ~(1UL << chanid_ofs);
705 
706 			chanid = chanid_base + chanid_ofs;
707 			/* vmbus channel protocol message */
708 			if (chanid == 0)
709 				continue;
710 
711 			ch = vmbus_channel_lookup(sc, chanid);
712 			if (ch == NULL) {
713 				device_printf(sc->sc_dev,
714 				    "unhandled event on %d\n", chanid);
715 				continue;
716 			}
717 			if (ch->ch_state != VMBUS_CHANSTATE_OPENED) {
718 				device_printf(sc->sc_dev,
719 				    "channel %d is not active\n", chanid);
720 				continue;
721 			}
722 			ch->ch_evcnt.ev_count++;
723 			vmbus_channel_schedule(ch);
724 		}
725 	}
726 }
727 
728 static void
729 vmbus_event_proc(void *arg, struct cpu_info *ci)
730 {
731 	struct vmbus_softc *sc = arg;
732 	struct vmbus_evtflags *evt;
733 
734 	/*
735 	 * On Host with Win8 or above, the event page can be
736 	 * checked directly to get the id of the channel
737 	 * that has the pending interrupt.
738 	 */
739 	evt = (struct vmbus_evtflags *)sc->sc_percpu[cpu_index(ci)].siep +
740 	    VMBUS_SINT_MESSAGE;
741 
742 	vmbus_event_flags_proc(sc, evt->evt_flags,
743 	    __arraycount(evt->evt_flags));
744 }
745 
746 static void
747 vmbus_event_proc_compat(void *arg, struct cpu_info *ci)
748 {
749 	struct vmbus_softc *sc = arg;
750 	struct vmbus_evtflags *evt;
751 
752 	evt = (struct vmbus_evtflags *)sc->sc_percpu[cpu_index(ci)].siep +
753 	    VMBUS_SINT_MESSAGE;
754 
755 	if (test_bit(0, &evt->evt_flags[0])) {
756 		clear_bit(0, &evt->evt_flags[0]);
757 		/*
758 		 * receive size is 1/2 page and divide that by 4 bytes
759 		 */
760 		vmbus_event_flags_proc(sc, sc->sc_revents,
761 		    VMBUS_CHAN_MAX_COMPAT / VMBUS_EVTFLAG_LEN);
762 	}
763 }
764 
765 static void
766 vmbus_message_proc(void *arg, struct cpu_info *ci)
767 {
768 	struct vmbus_softc *sc = arg;
769 	struct vmbus_message *msg;
770 
771 	msg = (struct vmbus_message *)sc->sc_percpu[cpu_index(ci)].simp +
772 	    VMBUS_SINT_MESSAGE;
773 	if (__predict_false(msg->msg_type != HYPERV_MSGTYPE_NONE)) {
774 		if (__predict_true(!cold))
775 			softint_schedule_cpu(sc->sc_msg_sih, ci);
776 		else
777 			vmbus_message_softintr(sc);
778 	}
779 }
780 
781 static void
782 vmbus_message_softintr(void *arg)
783 {
784 	struct vmbus_softc *sc = arg;
785 	struct vmbus_message *msg;
786 	struct vmbus_chanmsg_hdr *hdr;
787 	uint32_t type;
788 	cpuid_t cpu;
789 
790 	cpu = cpu_index(curcpu());
791 
792 	for (;;) {
793 		msg = (struct vmbus_message *)sc->sc_percpu[cpu].simp +
794 		    VMBUS_SINT_MESSAGE;
795 		if (msg->msg_type == HYPERV_MSGTYPE_NONE)
796 			break;
797 
798 		hdr = (struct vmbus_chanmsg_hdr *)msg->msg_data;
799 		type = hdr->chm_type;
800 		if (type >= VMBUS_CHANMSG_COUNT) {
801 			device_printf(sc->sc_dev,
802 			    "unhandled message type %u flags %#x\n", type,
803 			    msg->msg_flags);
804 		} else {
805 			if (vmbus_msg_dispatch[type].hmd_handler) {
806 				vmbus_msg_dispatch[type].hmd_handler(sc, hdr);
807 			} else {
808 				device_printf(sc->sc_dev,
809 				    "unhandled message type %u\n", type);
810 			}
811 		}
812 
813 		msg->msg_type = HYPERV_MSGTYPE_NONE;
814 		membar_sync();
815 		if (msg->msg_flags & VMBUS_MSGFLAG_PENDING)
816 			hyperv_send_eom();
817 	}
818 }
819 
820 static void
821 vmbus_channel_response(struct vmbus_softc *sc, struct vmbus_chanmsg_hdr *rsphdr)
822 {
823 	struct vmbus_msg *msg;
824 	struct vmbus_chanmsg_hdr *reqhdr;
825 	int req;
826 
827 	req = vmbus_msg_dispatch[rsphdr->chm_type].hmd_request;
828 	mutex_enter(&sc->sc_req_lock);
829 	TAILQ_FOREACH(msg, &sc->sc_reqs, msg_entry) {
830 		reqhdr = (struct vmbus_chanmsg_hdr *)&msg->msg_req.hc_data;
831 		if (reqhdr->chm_type == req) {
832 			TAILQ_REMOVE(&sc->sc_reqs, msg, msg_entry);
833 			break;
834 		}
835 	}
836 	mutex_exit(&sc->sc_req_lock);
837 	if (msg != NULL) {
838 		memcpy(msg->msg_rsp, rsphdr, msg->msg_rsplen);
839 		mutex_enter(&sc->sc_rsp_lock);
840 		TAILQ_INSERT_TAIL(&sc->sc_rsps, msg, msg_entry);
841 		mutex_exit(&sc->sc_rsp_lock);
842 		wakeup(msg);
843 	}
844 }
845 
846 static void
847 vmbus_channel_offer(struct vmbus_softc *sc, struct vmbus_chanmsg_hdr *hdr)
848 {
849 	struct vmbus_chanmsg_choffer *co;
850 
851 	co = kmem_intr_alloc(sizeof(*co), KM_NOSLEEP);
852 	if (co == NULL) {
853 		device_printf(sc->sc_dev,
854 		    "failed to allocate an offer object\n");
855 		return;
856 	}
857 
858 	memcpy(co, hdr, sizeof(*co));
859 	vmbus_chevq_enqueue(sc, VMBUS_CHEV_TYPE_OFFER, co);
860 }
861 
862 static void
863 vmbus_channel_rescind(struct vmbus_softc *sc, struct vmbus_chanmsg_hdr *hdr)
864 {
865 	struct vmbus_chanmsg_chrescind *cr;
866 
867 	cr = kmem_intr_alloc(sizeof(*cr), KM_NOSLEEP);
868 	if (cr == NULL) {
869 		device_printf(sc->sc_dev,
870 		    "failed to allocate an rescind object\n");
871 		return;
872 	}
873 
874 	memcpy(cr, hdr, sizeof(*cr));
875 	vmbus_chevq_enqueue(sc, VMBUS_CHEV_TYPE_RESCIND, cr);
876 }
877 
878 static void
879 vmbus_channel_delivered(struct vmbus_softc *sc, struct vmbus_chanmsg_hdr *hdr)
880 {
881 
882 	atomic_or_32(&sc->sc_flags, VMBUS_SCFLAG_OFFERS_DELIVERED);
883 	wakeup(&sc->sc_devq);
884 }
885 
886 static void
887 hyperv_guid_sprint(struct hyperv_guid *guid, char *str, size_t size)
888 {
889 	static const struct {
890 		const struct hyperv_guid *guid;
891 		const char *ident;
892 	} map[] = {
893 		{ &hyperv_guid_network,		"network" },
894 		{ &hyperv_guid_ide,		"ide" },
895 		{ &hyperv_guid_scsi,		"scsi" },
896 		{ &hyperv_guid_shutdown,	"shutdown" },
897 		{ &hyperv_guid_timesync,	"timesync" },
898 		{ &hyperv_guid_heartbeat,	"heartbeat" },
899 		{ &hyperv_guid_kvp,		"kvp" },
900 		{ &hyperv_guid_vss,		"vss" },
901 		{ &hyperv_guid_dynmem,		"dynamic-memory" },
902 		{ &hyperv_guid_mouse,		"mouse" },
903 		{ &hyperv_guid_kbd,		"keyboard" },
904 		{ &hyperv_guid_video,		"video" },
905 		{ &hyperv_guid_fc,		"fiber-channel" },
906 		{ &hyperv_guid_fcopy,		"file-copy" },
907 		{ &hyperv_guid_pcie,		"pcie-passthrough" },
908 		{ &hyperv_guid_netdir,		"network-direct" },
909 		{ &hyperv_guid_rdesktop,	"remote-desktop" },
910 		{ &hyperv_guid_avma1,		"avma-1" },
911 		{ &hyperv_guid_avma2,		"avma-2" },
912 		{ &hyperv_guid_avma3,		"avma-3" },
913 		{ &hyperv_guid_avma4,		"avma-4" },
914 	};
915 	int i;
916 
917 	for (i = 0; i < __arraycount(map); i++) {
918 		if (memcmp(guid, map[i].guid, sizeof(*guid)) == 0) {
919 			strlcpy(str, map[i].ident, size);
920 			return;
921 		}
922 	}
923 	hyperv_guid2str(guid, str, size);
924 }
925 
926 static int
927 vmbus_channel_scan(struct vmbus_softc *sc)
928 {
929 	struct vmbus_chanmsg_hdr hdr;
930 	struct vmbus_chanmsg_choffer rsp;
931 
932 	TAILQ_INIT(&sc->sc_prichans);
933 	mutex_init(&sc->sc_prichan_lock, MUTEX_DEFAULT, IPL_NET);
934 	TAILQ_INIT(&sc->sc_channels);
935 	mutex_init(&sc->sc_channel_lock, MUTEX_DEFAULT, IPL_NET);
936 
937 	/*
938 	 * This queue serializes vmbus channel offer and rescind messages.
939 	 */
940 	SIMPLEQ_INIT(&sc->sc_chevq);
941 	mutex_init(&sc->sc_chevq_lock, MUTEX_DEFAULT, IPL_NET);
942 	cv_init(&sc->sc_chevq_cv, "hvchevcv");
943 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
944 	    vmbus_chevq_thread, sc, NULL, "hvchevq") != 0) {
945 		DPRINTF("%s: failed to create prich chevq thread\n",
946 		    device_xname(sc->sc_dev));
947 		return -1;
948 	}
949 
950 	/*
951 	 * This queue serializes vmbus devices' attach and detach
952 	 * for channel offer and rescind messages.
953 	 */
954 	SIMPLEQ_INIT(&sc->sc_devq);
955 	mutex_init(&sc->sc_devq_lock, MUTEX_DEFAULT, IPL_NET);
956 	cv_init(&sc->sc_devq_cv, "hvdevqcv");
957 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
958 	    vmbus_devq_thread, sc, NULL, "hvdevq") != 0) {
959 		DPRINTF("%s: failed to create prich devq thread\n",
960 		    device_xname(sc->sc_dev));
961 		return -1;
962 	}
963 
964 	/*
965 	 * This queue handles sub-channel detach, so that vmbus
966 	 * device's detach running in sc_devq can drain its sub-channels.
967 	 */
968 	SIMPLEQ_INIT(&sc->sc_subch_devq);
969 	mutex_init(&sc->sc_subch_devq_lock, MUTEX_DEFAULT, IPL_NET);
970 	cv_init(&sc->sc_subch_devq_cv, "hvsdvqcv");
971 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
972 	    vmbus_subchannel_devq_thread, sc, NULL, "hvsdevq") != 0) {
973 		DPRINTF("%s: failed to create subch devq thread\n",
974 		    device_xname(sc->sc_dev));
975 		return -1;
976 	}
977 
978 	memset(&hdr, 0, sizeof(hdr));
979 	hdr.chm_type = VMBUS_CHANMSG_CHREQUEST;
980 
981 	if (vmbus_cmd(sc, &hdr, sizeof(hdr), &rsp, sizeof(rsp),
982 	    HCF_NOREPLY | (cold ? HCF_NOSLEEP : HCF_SLEEPOK))) {
983 		DPRINTF("%s: CHREQUEST failed\n", device_xname(sc->sc_dev));
984 		return -1;
985 	}
986 
987 	while (!ISSET(sc->sc_flags, VMBUS_SCFLAG_OFFERS_DELIVERED))
988 		tsleep(&sc->sc_devq, PRIBIO, "hvscan", 1);
989 
990 	mutex_enter(&sc->sc_chevq_lock);
991 	vmbus_process_chevq(sc);
992 	mutex_exit(&sc->sc_chevq_lock);
993 	mutex_enter(&sc->sc_devq_lock);
994 	vmbus_process_devq(sc);
995 	mutex_exit(&sc->sc_devq_lock);
996 
997 	return 0;
998 }
999 
1000 static struct vmbus_channel *
1001 vmbus_channel_alloc(struct vmbus_softc *sc)
1002 {
1003 	struct vmbus_channel *ch;
1004 
1005 	ch = kmem_zalloc(sizeof(*ch), KM_SLEEP);
1006 
1007 	ch->ch_monprm = hyperv_dma_alloc(sc->sc_dmat, &ch->ch_monprm_dma,
1008 	    sizeof(*ch->ch_monprm), 8, 0, 1, HYPERV_DMA_SLEEPOK);
1009 	if (ch->ch_monprm == NULL) {
1010 		device_printf(sc->sc_dev, "monprm alloc failed\n");
1011 		kmem_free(ch, sizeof(*ch));
1012 		return NULL;
1013 	}
1014 
1015 	ch->ch_refs = 1;
1016 	ch->ch_sc = sc;
1017 	mutex_init(&ch->ch_subchannel_lock, MUTEX_DEFAULT, IPL_NET);
1018 	TAILQ_INIT(&ch->ch_subchannels);
1019 
1020 	ch->ch_state = VMBUS_CHANSTATE_CLOSED;
1021 
1022 	return ch;
1023 }
1024 
1025 static void
1026 vmbus_channel_free(struct vmbus_channel *ch)
1027 {
1028 	struct vmbus_softc *sc = ch->ch_sc;
1029 
1030 	KASSERTMSG(TAILQ_EMPTY(&ch->ch_subchannels) &&
1031 	    ch->ch_subchannel_count == 0, "still owns sub-channels");
1032 	KASSERTMSG(ch->ch_state == 0 || ch->ch_state == VMBUS_CHANSTATE_CLOSED,
1033 	    "free busy channel");
1034 	KASSERTMSG(ch->ch_refs == 0, "channel %u: invalid refcnt %d",
1035 	    ch->ch_id, ch->ch_refs);
1036 
1037 	hyperv_dma_free(sc->sc_dmat, &ch->ch_monprm_dma);
1038 	mutex_destroy(&ch->ch_subchannel_lock);
1039 	/* XXX ch_evcnt */
1040 	if (ch->ch_taskq != NULL)
1041 		softint_disestablish(ch->ch_taskq);
1042 	kmem_free(ch, sizeof(*ch));
1043 }
1044 
1045 static int
1046 vmbus_channel_add(struct vmbus_channel *nch)
1047 {
1048 	struct vmbus_softc *sc = nch->ch_sc;
1049 	struct vmbus_channel *ch;
1050 	u_int refs __diagused;
1051 
1052 	if (nch->ch_id == 0) {
1053 		device_printf(sc->sc_dev, "got channel 0 offer, discard\n");
1054 		return EINVAL;
1055 	} else if (nch->ch_id >= sc->sc_channel_max) {
1056 		device_printf(sc->sc_dev, "invalid channel %u offer\n",
1057 		    nch->ch_id);
1058 		return EINVAL;
1059 	}
1060 
1061 	mutex_enter(&sc->sc_prichan_lock);
1062 	TAILQ_FOREACH(ch, &sc->sc_prichans, ch_prientry) {
1063 		if (!memcmp(&ch->ch_type, &nch->ch_type, sizeof(ch->ch_type)) &&
1064 		    !memcmp(&ch->ch_inst, &nch->ch_inst, sizeof(ch->ch_inst)))
1065 			break;
1066 	}
1067 	if (VMBUS_CHAN_ISPRIMARY(nch)) {
1068 		if (ch == NULL) {
1069 			TAILQ_INSERT_TAIL(&sc->sc_prichans, nch, ch_prientry);
1070 			mutex_exit(&sc->sc_prichan_lock);
1071 			goto done;
1072 		} else {
1073 			mutex_exit(&sc->sc_prichan_lock);
1074 			device_printf(sc->sc_dev,
1075 			    "duplicated primary channel%u\n", nch->ch_id);
1076 			return EINVAL;
1077 		}
1078 	} else {
1079 		if (ch == NULL) {
1080 			mutex_exit(&sc->sc_prichan_lock);
1081 			device_printf(sc->sc_dev, "no primary channel%u\n",
1082 			    nch->ch_id);
1083 			return EINVAL;
1084 		}
1085 	}
1086 	mutex_exit(&sc->sc_prichan_lock);
1087 
1088 	KASSERT(!VMBUS_CHAN_ISPRIMARY(nch));
1089 	KASSERT(ch != NULL);
1090 
1091 	refs = atomic_inc_uint_nv(&nch->ch_refs);
1092 	KASSERT(refs == 2);
1093 
1094 	nch->ch_primary_channel = ch;
1095 	nch->ch_dev = ch->ch_dev;
1096 
1097 	mutex_enter(&ch->ch_subchannel_lock);
1098 	TAILQ_INSERT_TAIL(&ch->ch_subchannels, nch, ch_subentry);
1099 	ch->ch_subchannel_count++;
1100 	mutex_exit(&ch->ch_subchannel_lock);
1101 	wakeup(ch);
1102 
1103 done:
1104 	mutex_enter(&sc->sc_channel_lock);
1105 	TAILQ_INSERT_TAIL(&sc->sc_channels, nch, ch_entry);
1106 	mutex_exit(&sc->sc_channel_lock);
1107 
1108 	vmbus_channel_cpu_default(nch);
1109 
1110 	return 0;
1111 }
1112 
1113 void
1114 vmbus_channel_cpu_set(struct vmbus_channel *ch, int cpu)
1115 {
1116 	struct vmbus_softc *sc = ch->ch_sc;
1117 
1118 	KASSERTMSG(cpu >= 0 && cpu < ncpu, "invalid cpu %d", cpu);
1119 
1120 	if (sc->sc_proto == VMBUS_VERSION_WS2008 ||
1121 	    sc->sc_proto == VMBUS_VERSION_WIN7) {
1122 		/* Only cpu0 is supported */
1123 		cpu = 0;
1124 	}
1125 
1126 	ch->ch_cpuid = cpu;
1127 	ch->ch_vcpu = hyperv_get_vcpuid(cpu);
1128 }
1129 
1130 void
1131 vmbus_channel_cpu_rr(struct vmbus_channel *ch)
1132 {
1133 	static uint32_t vmbus_channel_nextcpu;
1134 	int cpu;
1135 
1136 	cpu = atomic_inc_32_nv(&vmbus_channel_nextcpu) % ncpu;
1137 	vmbus_channel_cpu_set(ch, cpu);
1138 }
1139 
1140 static void
1141 vmbus_channel_cpu_default(struct vmbus_channel *ch)
1142 {
1143 
1144         /*
1145 	 * By default, pin the channel to cpu0.  Devices having
1146 	 * special channel-cpu mapping requirement should call
1147 	 * vmbus_channel_cpu_{set,rr}().
1148 	 */
1149 	vmbus_channel_cpu_set(ch, 0);
1150 }
1151 
1152 bool
1153 vmbus_channel_is_revoked(struct vmbus_channel *ch)
1154 {
1155 
1156 	return (ch->ch_flags & CHF_REVOKED) ? true : false;
1157 }
1158 
1159 static void
1160 vmbus_process_offer(struct vmbus_softc *sc, struct vmbus_chanmsg_choffer *co)
1161 {
1162 	struct vmbus_channel *ch;
1163 
1164 	ch = vmbus_channel_alloc(sc);
1165 	if (ch == NULL) {
1166 		device_printf(sc->sc_dev, "allocate channel %u failed\n",
1167 		    co->chm_chanid);
1168 		return;
1169 	}
1170 
1171 	/*
1172 	 * By default we setup state to enable batched reading.
1173 	 * A specific service can choose to disable this prior
1174 	 * to opening the channel.
1175 	 */
1176 	ch->ch_flags |= CHF_BATCHED;
1177 
1178 	hyperv_guid_sprint(&co->chm_chtype, ch->ch_ident,
1179 	    sizeof(ch->ch_ident));
1180 
1181 	ch->ch_monprm->mp_connid = VMBUS_CONNID_EVENT;
1182 	if (sc->sc_proto > VMBUS_VERSION_WS2008)
1183 		ch->ch_monprm->mp_connid = co->chm_connid;
1184 
1185 	if (co->chm_flags1 & VMBUS_CHOFFER_FLAG1_HASMNF) {
1186 		ch->ch_mgroup = co->chm_montrig / VMBUS_MONTRIG_LEN;
1187 		ch->ch_mindex = co->chm_montrig % VMBUS_MONTRIG_LEN;
1188 		ch->ch_flags |= CHF_MONITOR;
1189 	}
1190 
1191 	ch->ch_id = co->chm_chanid;
1192 	ch->ch_subidx = co->chm_subidx;
1193 
1194 	memcpy(&ch->ch_type, &co->chm_chtype, sizeof(ch->ch_type));
1195 	memcpy(&ch->ch_inst, &co->chm_chinst, sizeof(ch->ch_inst));
1196 
1197 	if (vmbus_channel_add(ch) != 0) {
1198 		atomic_dec_uint(&ch->ch_refs);
1199 		vmbus_channel_free(ch);
1200 		return;
1201 	}
1202 
1203 	ch->ch_state = VMBUS_CHANSTATE_OFFERED;
1204 
1205 	vmbus_devq_enqueue(sc, VMBUS_DEV_TYPE_ATTACH, ch);
1206 
1207 #ifdef HYPERV_DEBUG
1208 	printf("%s: channel %u: \"%s\"", device_xname(sc->sc_dev), ch->ch_id,
1209 	    ch->ch_ident);
1210 	if (ch->ch_flags & CHF_MONITOR)
1211 		printf(", monitor %u\n", co->chm_montrig);
1212 	else
1213 		printf("\n");
1214 #endif
1215 }
1216 
1217 static void
1218 vmbus_process_rescind(struct vmbus_softc *sc,
1219     struct vmbus_chanmsg_chrescind *cr)
1220 {
1221 	struct vmbus_channel *ch;
1222 
1223 	if (cr->chm_chanid > VMBUS_CHAN_MAX) {
1224 		device_printf(sc->sc_dev, "invalid revoked channel%u\n",
1225 		    cr->chm_chanid);
1226 		return;
1227 	}
1228 
1229 	mutex_enter(&sc->sc_channel_lock);
1230 	ch = vmbus_channel_lookup(sc, cr->chm_chanid);
1231 	if (ch == NULL) {
1232 		mutex_exit(&sc->sc_channel_lock);
1233 		device_printf(sc->sc_dev, "channel%u is not offered\n",
1234 		    cr->chm_chanid);
1235 		return;
1236 	}
1237 	TAILQ_REMOVE(&sc->sc_channels, ch, ch_entry);
1238 	mutex_exit(&sc->sc_channel_lock);
1239 
1240 	if (VMBUS_CHAN_ISPRIMARY(ch)) {
1241 		mutex_enter(&sc->sc_prichan_lock);
1242 		TAILQ_REMOVE(&sc->sc_prichans, ch, ch_prientry);
1243 		mutex_exit(&sc->sc_prichan_lock);
1244 	}
1245 
1246 	KASSERTMSG(!(ch->ch_flags & CHF_REVOKED),
1247 	    "channel%u has already been revoked", ch->ch_id);
1248 	atomic_or_uint(&ch->ch_flags, CHF_REVOKED);
1249 
1250 	vmbus_channel_detach(ch);
1251 }
1252 
1253 static int
1254 vmbus_channel_release(struct vmbus_channel *ch)
1255 {
1256 	struct vmbus_softc *sc = ch->ch_sc;
1257 	struct vmbus_chanmsg_chfree cmd;
1258 	int rv;
1259 
1260 	memset(&cmd, 0, sizeof(cmd));
1261 	cmd.chm_hdr.chm_type = VMBUS_CHANMSG_CHFREE;
1262 	cmd.chm_chanid = ch->ch_id;
1263 
1264 	rv = vmbus_cmd(sc, &cmd, sizeof(cmd), NULL, 0,
1265 	    HCF_NOREPLY | (cold ? HCF_NOSLEEP : HCF_SLEEPOK));
1266 	if (rv) {
1267 		DPRINTF("%s: CHFREE failed with %d\n", device_xname(sc->sc_dev),
1268 		    rv);
1269 	}
1270 	return rv;
1271 }
1272 
1273 struct vmbus_channel **
1274 vmbus_subchannel_get(struct vmbus_channel *prich, int cnt)
1275 {
1276 	struct vmbus_softc *sc = prich->ch_sc;
1277 	struct vmbus_channel **ret, *ch;
1278 	int i, s;
1279 
1280 	KASSERTMSG(cnt > 0, "invalid sub-channel count %d", cnt);
1281 
1282 	ret = kmem_zalloc(sizeof(struct vmbus_channel *) * cnt, KM_SLEEP);
1283 
1284 	mutex_enter(&prich->ch_subchannel_lock);
1285 
1286 	while (prich->ch_subchannel_count < cnt) {
1287 		if (cold) {
1288 			mutex_exit(&prich->ch_subchannel_lock);
1289 			delay(1000);
1290 			s = splnet();
1291 			hyperv_intr();
1292 			splx(s);
1293 			mutex_enter(&sc->sc_chevq_lock);
1294 			vmbus_process_chevq(sc);
1295 			mutex_exit(&sc->sc_chevq_lock);
1296 			mutex_enter(&prich->ch_subchannel_lock);
1297 		} else {
1298 			mtsleep(prich, PRIBIO, "hvsubch", 1,
1299 			    &prich->ch_subchannel_lock);
1300 		}
1301 	}
1302 
1303 	i = 0;
1304 	TAILQ_FOREACH(ch, &prich->ch_subchannels, ch_subentry) {
1305 		ret[i] = ch;	/* XXX inc refs */
1306 
1307 		if (++i == cnt)
1308 			break;
1309 	}
1310 
1311 	KASSERTMSG(i == cnt, "invalid subchan count %d, should be %d",
1312 	    prich->ch_subchannel_count, cnt);
1313 
1314 	mutex_exit(&prich->ch_subchannel_lock);
1315 
1316 	return ret;
1317 }
1318 
1319 void
1320 vmbus_subchannel_put(struct vmbus_channel **subch, int cnt)
1321 {
1322 
1323 	kmem_free(subch, sizeof(struct vmbus_channel *) * cnt);
1324 }
1325 
1326 static struct vmbus_channel *
1327 vmbus_channel_lookup(struct vmbus_softc *sc, uint32_t relid)
1328 {
1329 	struct vmbus_channel *ch;
1330 
1331 	TAILQ_FOREACH(ch, &sc->sc_channels, ch_entry) {
1332 		if (ch->ch_id == relid)
1333 			return ch;
1334 	}
1335 	return NULL;
1336 }
1337 
1338 static int
1339 vmbus_channel_ring_create(struct vmbus_channel *ch, uint32_t buflen)
1340 {
1341 	struct vmbus_softc *sc = ch->ch_sc;
1342 
1343 	buflen = roundup(buflen, PAGE_SIZE) + sizeof(struct vmbus_bufring);
1344 	ch->ch_ring_size = 2 * buflen;
1345 	/* page aligned memory */
1346 	ch->ch_ring = hyperv_dma_alloc(sc->sc_dmat, &ch->ch_ring_dma,
1347 	    ch->ch_ring_size, PAGE_SIZE, 0, 1, HYPERV_DMA_SLEEPOK);
1348 	if (ch->ch_ring == NULL) {
1349 		device_printf(sc->sc_dev,
1350 		    "failed to allocate channel ring\n");
1351 		return ENOMEM;
1352 	}
1353 
1354 	memset(&ch->ch_wrd, 0, sizeof(ch->ch_wrd));
1355 	ch->ch_wrd.rd_ring = (struct vmbus_bufring *)ch->ch_ring;
1356 	ch->ch_wrd.rd_size = buflen;
1357 	ch->ch_wrd.rd_dsize = buflen - sizeof(struct vmbus_bufring);
1358 	mutex_init(&ch->ch_wrd.rd_lock, MUTEX_DEFAULT, IPL_NET);
1359 
1360 	memset(&ch->ch_rrd, 0, sizeof(ch->ch_rrd));
1361 	ch->ch_rrd.rd_ring = (struct vmbus_bufring *)((uint8_t *)ch->ch_ring +
1362 	    buflen);
1363 	ch->ch_rrd.rd_size = buflen;
1364 	ch->ch_rrd.rd_dsize = buflen - sizeof(struct vmbus_bufring);
1365 	mutex_init(&ch->ch_rrd.rd_lock, MUTEX_DEFAULT, IPL_NET);
1366 
1367 	if (vmbus_handle_alloc(ch, &ch->ch_ring_dma, ch->ch_ring_size,
1368 	    &ch->ch_ring_gpadl)) {
1369 		device_printf(sc->sc_dev,
1370 		    "failed to obtain a PA handle for the ring\n");
1371 		vmbus_channel_ring_destroy(ch);
1372 		return ENOMEM;
1373 	}
1374 
1375 	return 0;
1376 }
1377 
1378 static void
1379 vmbus_channel_ring_destroy(struct vmbus_channel *ch)
1380 {
1381 	struct vmbus_softc *sc = ch->ch_sc;
1382 
1383 	hyperv_dma_free(sc->sc_dmat, &ch->ch_ring_dma);
1384 	ch->ch_ring = NULL;
1385 	vmbus_handle_free(ch, ch->ch_ring_gpadl);
1386 
1387 	mutex_destroy(&ch->ch_wrd.rd_lock);
1388 	memset(&ch->ch_wrd, 0, sizeof(ch->ch_wrd));
1389 	mutex_destroy(&ch->ch_rrd.rd_lock);
1390 	memset(&ch->ch_rrd, 0, sizeof(ch->ch_rrd));
1391 }
1392 
1393 int
1394 vmbus_channel_open(struct vmbus_channel *ch, size_t buflen, void *udata,
1395     size_t udatalen, void (*handler)(void *), void *arg)
1396 {
1397 	struct vmbus_softc *sc = ch->ch_sc;
1398 	struct vmbus_chanmsg_chopen cmd;
1399 	struct vmbus_chanmsg_chopen_resp rsp;
1400 	int rv = EINVAL;
1401 
1402 	if (ch->ch_ring == NULL &&
1403 	    (rv = vmbus_channel_ring_create(ch, buflen))) {
1404 		DPRINTF("%s: failed to create channel ring\n",
1405 		    device_xname(sc->sc_dev));
1406 		return rv;
1407 	}
1408 
1409 	memset(&cmd, 0, sizeof(cmd));
1410 	cmd.chm_hdr.chm_type = VMBUS_CHANMSG_CHOPEN;
1411 	cmd.chm_openid = ch->ch_id;
1412 	cmd.chm_chanid = ch->ch_id;
1413 	cmd.chm_gpadl = ch->ch_ring_gpadl;
1414 	cmd.chm_txbr_pgcnt = atop(ch->ch_wrd.rd_size);
1415 	cmd.chm_vcpuid = ch->ch_vcpu;
1416 	if (udata && udatalen > 0)
1417 		memcpy(cmd.chm_udata, udata, udatalen);
1418 
1419 	memset(&rsp, 0, sizeof(rsp));
1420 
1421 	ch->ch_handler = handler;
1422 	ch->ch_ctx = arg;
1423 	ch->ch_state = VMBUS_CHANSTATE_OPENED;
1424 
1425 	rv = vmbus_cmd(sc, &cmd, sizeof(cmd), &rsp, sizeof(rsp),
1426 	    cold ? HCF_NOSLEEP : HCF_SLEEPOK);
1427 	if (rv) {
1428 		vmbus_channel_ring_destroy(ch);
1429 		DPRINTF("%s: CHOPEN failed with %d\n", device_xname(sc->sc_dev),
1430 		    rv);
1431 		ch->ch_handler = NULL;
1432 		ch->ch_ctx = NULL;
1433 		ch->ch_state = VMBUS_CHANSTATE_OFFERED;
1434 		return rv;
1435 	}
1436 	return 0;
1437 }
1438 
1439 static void
1440 vmbus_channel_detach(struct vmbus_channel *ch)
1441 {
1442 	u_int refs;
1443 
1444 	KASSERTMSG(ch->ch_refs > 0, "channel%u: invalid refcnt %d",
1445 	    ch->ch_id, ch->ch_refs);
1446 
1447 	refs = atomic_dec_uint_nv(&ch->ch_refs);
1448 	if (refs == 0) {
1449 		/* Detach the target channel. */
1450 		vmbus_devq_enqueue(ch->ch_sc, VMBUS_DEV_TYPE_DETACH, ch);
1451 	}
1452 }
1453 
1454 static int
1455 vmbus_channel_close_internal(struct vmbus_channel *ch)
1456 {
1457 	struct vmbus_softc *sc = ch->ch_sc;
1458 	struct vmbus_chanmsg_chclose cmd;
1459 	int rv;
1460 
1461 	memset(&cmd, 0, sizeof(cmd));
1462 	cmd.chm_hdr.chm_type = VMBUS_CHANMSG_CHCLOSE;
1463 	cmd.chm_chanid = ch->ch_id;
1464 
1465 	ch->ch_state = VMBUS_CHANSTATE_CLOSING;
1466 	rv = vmbus_cmd(sc, &cmd, sizeof(cmd), NULL, 0,
1467 	    HCF_NOREPLY | (cold ? HCF_NOSLEEP : HCF_SLEEPOK));
1468 	if (rv) {
1469 		DPRINTF("%s: CHCLOSE failed with %d\n",
1470 		    device_xname(sc->sc_dev), rv);
1471 		return rv;
1472 	}
1473 	ch->ch_state = VMBUS_CHANSTATE_CLOSED;
1474 	vmbus_channel_ring_destroy(ch);
1475 	return 0;
1476 }
1477 
1478 int
1479 vmbus_channel_close_direct(struct vmbus_channel *ch)
1480 {
1481 	int rv;
1482 
1483 	rv = vmbus_channel_close_internal(ch);
1484 	if (!VMBUS_CHAN_ISPRIMARY(ch))
1485 		vmbus_channel_detach(ch);
1486 	return rv;
1487 }
1488 
1489 int
1490 vmbus_channel_close(struct vmbus_channel *ch)
1491 {
1492 	struct vmbus_channel **subch;
1493 	int i, cnt, rv;
1494 
1495 	if (!VMBUS_CHAN_ISPRIMARY(ch))
1496 		return 0;
1497 
1498 	cnt = ch->ch_subchannel_count;
1499 	if (cnt > 0) {
1500 		subch = vmbus_subchannel_get(ch, cnt);
1501 		for (i = 0; i < ch->ch_subchannel_count; i++) {
1502 			rv = vmbus_channel_close_internal(subch[i]);
1503 			(void) rv;	/* XXX */
1504 			vmbus_channel_detach(ch);
1505 		}
1506 		vmbus_subchannel_put(subch, cnt);
1507 	}
1508 
1509 	return vmbus_channel_close_internal(ch);
1510 }
1511 
1512 static inline void
1513 vmbus_channel_setevent(struct vmbus_softc *sc, struct vmbus_channel *ch)
1514 {
1515 	struct vmbus_mon_trig *mtg;
1516 
1517 	/* Each uint32_t represents 32 channels */
1518 	set_bit(ch->ch_id, sc->sc_wevents);
1519 	if (ch->ch_flags & CHF_MONITOR) {
1520 		mtg = &sc->sc_monitor[1]->mnf_trigs[ch->ch_mgroup];
1521 		set_bit(ch->ch_mindex, &mtg->mt_pending);
1522 	} else
1523 		vmbus_intr_signal(sc, hyperv_dma_get_paddr(&ch->ch_monprm_dma));
1524 }
1525 
1526 static void
1527 vmbus_channel_intr(void *arg)
1528 {
1529 	struct vmbus_channel *ch = arg;
1530 
1531 	if (vmbus_channel_ready(ch))
1532 		ch->ch_handler(ch->ch_ctx);
1533 
1534 	if (vmbus_channel_unpause(ch) == 0)
1535 		return;
1536 
1537 	vmbus_channel_pause(ch);
1538 	vmbus_channel_schedule(ch);
1539 }
1540 
1541 int
1542 vmbus_channel_setdeferred(struct vmbus_channel *ch, const char *name)
1543 {
1544 
1545 	ch->ch_taskq = softint_establish(SOFTINT_NET | SOFTINT_MPSAFE,
1546 	    vmbus_channel_intr, ch);
1547 	if (ch->ch_taskq == NULL)
1548 		return -1;
1549 	return 0;
1550 }
1551 
1552 void
1553 vmbus_channel_schedule(struct vmbus_channel *ch)
1554 {
1555 
1556 	if (ch->ch_handler) {
1557 		if (!cold && (ch->ch_flags & CHF_BATCHED)) {
1558 			vmbus_channel_pause(ch);
1559 			softint_schedule(ch->ch_taskq);
1560 		} else
1561 			ch->ch_handler(ch->ch_ctx);
1562 	}
1563 }
1564 
1565 static __inline void
1566 vmbus_ring_put(struct vmbus_ring_data *wrd, uint8_t *data, uint32_t datalen)
1567 {
1568 	int left = MIN(datalen, wrd->rd_dsize - wrd->rd_prod);
1569 
1570 	memcpy(&wrd->rd_ring->br_data[wrd->rd_prod], data, left);
1571 	memcpy(&wrd->rd_ring->br_data[0], data + left, datalen - left);
1572 	wrd->rd_prod += datalen;
1573 	if (wrd->rd_prod >= wrd->rd_dsize)
1574 		wrd->rd_prod -= wrd->rd_dsize;
1575 }
1576 
1577 static inline void
1578 vmbus_ring_get(struct vmbus_ring_data *rrd, uint8_t *data, uint32_t datalen,
1579     int peek)
1580 {
1581 	int left = MIN(datalen, rrd->rd_dsize - rrd->rd_cons);
1582 
1583 	memcpy(data, &rrd->rd_ring->br_data[rrd->rd_cons], left);
1584 	memcpy(data + left, &rrd->rd_ring->br_data[0], datalen - left);
1585 	if (!peek) {
1586 		rrd->rd_cons += datalen;
1587 		if (rrd->rd_cons >= rrd->rd_dsize)
1588 			rrd->rd_cons -= rrd->rd_dsize;
1589 	}
1590 }
1591 
1592 static __inline void
1593 vmbus_ring_avail(struct vmbus_ring_data *rd, uint32_t *towrite,
1594     uint32_t *toread)
1595 {
1596 	uint32_t ridx = rd->rd_ring->br_rindex;
1597 	uint32_t widx = rd->rd_ring->br_windex;
1598 	uint32_t r, w;
1599 
1600 	if (widx >= ridx)
1601 		w = rd->rd_dsize - (widx - ridx);
1602 	else
1603 		w = ridx - widx;
1604 	r = rd->rd_dsize - w;
1605 	if (towrite)
1606 		*towrite = w;
1607 	if (toread)
1608 		*toread = r;
1609 }
1610 
1611 static int
1612 vmbus_ring_write(struct vmbus_ring_data *wrd, struct iovec *iov, int iov_cnt,
1613     int *needsig)
1614 {
1615 	uint64_t indices = 0;
1616 	uint32_t avail, oprod, datalen = sizeof(indices);
1617 	int i;
1618 
1619 	for (i = 0; i < iov_cnt; i++)
1620 		datalen += iov[i].iov_len;
1621 
1622 	KASSERT(datalen <= wrd->rd_dsize);
1623 
1624 	vmbus_ring_avail(wrd, &avail, NULL);
1625 	if (avail <= datalen) {
1626 		DPRINTF("%s: avail %u datalen %u\n", __func__, avail, datalen);
1627 		return EAGAIN;
1628 	}
1629 
1630 	oprod = wrd->rd_prod;
1631 
1632 	for (i = 0; i < iov_cnt; i++)
1633 		vmbus_ring_put(wrd, iov[i].iov_base, iov[i].iov_len);
1634 
1635 	indices = (uint64_t)oprod << 32;
1636 	vmbus_ring_put(wrd, (uint8_t *)&indices, sizeof(indices));
1637 
1638 	membar_sync();
1639 	wrd->rd_ring->br_windex = wrd->rd_prod;
1640 	membar_sync();
1641 
1642 	/* Signal when the ring transitions from being empty to non-empty */
1643 	if (wrd->rd_ring->br_imask == 0 &&
1644 	    wrd->rd_ring->br_rindex == oprod)
1645 		*needsig = 1;
1646 	else
1647 		*needsig = 0;
1648 
1649 	return 0;
1650 }
1651 
1652 int
1653 vmbus_channel_send(struct vmbus_channel *ch, void *data, uint32_t datalen,
1654     uint64_t rid, int type, uint32_t flags)
1655 {
1656 	struct vmbus_softc *sc = ch->ch_sc;
1657 	struct vmbus_chanpkt cp;
1658 	struct iovec iov[3];
1659 	uint32_t pktlen, pktlen_aligned;
1660 	uint64_t zeropad = 0;
1661 	int rv, needsig = 0;
1662 
1663 	pktlen = sizeof(cp) + datalen;
1664 	pktlen_aligned = roundup(pktlen, sizeof(uint64_t));
1665 
1666 	cp.cp_hdr.cph_type = type;
1667 	cp.cp_hdr.cph_flags = flags;
1668 	VMBUS_CHANPKT_SETLEN(cp.cp_hdr.cph_hlen, sizeof(cp));
1669 	VMBUS_CHANPKT_SETLEN(cp.cp_hdr.cph_tlen, pktlen_aligned);
1670 	cp.cp_hdr.cph_tid = rid;
1671 
1672 	iov[0].iov_base = &cp;
1673 	iov[0].iov_len = sizeof(cp);
1674 
1675 	iov[1].iov_base = data;
1676 	iov[1].iov_len = datalen;
1677 
1678 	iov[2].iov_base = &zeropad;
1679 	iov[2].iov_len = pktlen_aligned - pktlen;
1680 
1681 	mutex_enter(&ch->ch_wrd.rd_lock);
1682 	rv = vmbus_ring_write(&ch->ch_wrd, iov, 3, &needsig);
1683 	mutex_exit(&ch->ch_wrd.rd_lock);
1684 	if (rv == 0 && needsig)
1685 		vmbus_channel_setevent(sc, ch);
1686 
1687 	return rv;
1688 }
1689 
1690 int
1691 vmbus_channel_send_sgl(struct vmbus_channel *ch, struct vmbus_gpa *sgl,
1692     uint32_t nsge, void *data, uint32_t datalen, uint64_t rid)
1693 {
1694 	struct vmbus_softc *sc = ch->ch_sc;
1695 	struct vmbus_chanpkt_sglist cp;
1696 	struct iovec iov[4];
1697 	uint32_t buflen, pktlen, pktlen_aligned;
1698 	uint64_t zeropad = 0;
1699 	int rv, needsig = 0;
1700 
1701 	buflen = sizeof(struct vmbus_gpa) * nsge;
1702 	pktlen = sizeof(cp) + datalen + buflen;
1703 	pktlen_aligned = roundup(pktlen, sizeof(uint64_t));
1704 
1705 	cp.cp_hdr.cph_type = VMBUS_CHANPKT_TYPE_GPA;
1706 	cp.cp_hdr.cph_flags = VMBUS_CHANPKT_FLAG_RC;
1707 	VMBUS_CHANPKT_SETLEN(cp.cp_hdr.cph_hlen, sizeof(cp) + buflen);
1708 	VMBUS_CHANPKT_SETLEN(cp.cp_hdr.cph_tlen, pktlen_aligned);
1709 	cp.cp_hdr.cph_tid = rid;
1710 	cp.cp_gpa_cnt = nsge;
1711 	cp.cp_rsvd = 0;
1712 
1713 	iov[0].iov_base = &cp;
1714 	iov[0].iov_len = sizeof(cp);
1715 
1716 	iov[1].iov_base = sgl;
1717 	iov[1].iov_len = buflen;
1718 
1719 	iov[2].iov_base = data;
1720 	iov[2].iov_len = datalen;
1721 
1722 	iov[3].iov_base = &zeropad;
1723 	iov[3].iov_len = pktlen_aligned - pktlen;
1724 
1725 	mutex_enter(&ch->ch_wrd.rd_lock);
1726 	rv = vmbus_ring_write(&ch->ch_wrd, iov, 4, &needsig);
1727 	mutex_exit(&ch->ch_wrd.rd_lock);
1728 	if (rv == 0 && needsig)
1729 		vmbus_channel_setevent(sc, ch);
1730 
1731 	return rv;
1732 }
1733 
1734 int
1735 vmbus_channel_send_prpl(struct vmbus_channel *ch, struct vmbus_gpa_range *prpl,
1736     uint32_t nprp, void *data, uint32_t datalen, uint64_t rid)
1737 {
1738 	struct vmbus_softc *sc = ch->ch_sc;
1739 	struct vmbus_chanpkt_prplist cp;
1740 	struct iovec iov[4];
1741 	uint32_t buflen, pktlen, pktlen_aligned;
1742 	uint64_t zeropad = 0;
1743 	int rv, needsig = 0;
1744 
1745 	buflen = sizeof(struct vmbus_gpa_range) * (nprp + 1);
1746 	pktlen = sizeof(cp) + datalen + buflen;
1747 	pktlen_aligned = roundup(pktlen, sizeof(uint64_t));
1748 
1749 	cp.cp_hdr.cph_type = VMBUS_CHANPKT_TYPE_GPA;
1750 	cp.cp_hdr.cph_flags = VMBUS_CHANPKT_FLAG_RC;
1751 	VMBUS_CHANPKT_SETLEN(cp.cp_hdr.cph_hlen, sizeof(cp) + buflen);
1752 	VMBUS_CHANPKT_SETLEN(cp.cp_hdr.cph_tlen, pktlen_aligned);
1753 	cp.cp_hdr.cph_tid = rid;
1754 	cp.cp_range_cnt = 1;
1755 	cp.cp_rsvd = 0;
1756 
1757 	iov[0].iov_base = &cp;
1758 	iov[0].iov_len = sizeof(cp);
1759 
1760 	iov[1].iov_base = prpl;
1761 	iov[1].iov_len = buflen;
1762 
1763 	iov[2].iov_base = data;
1764 	iov[2].iov_len = datalen;
1765 
1766 	iov[3].iov_base = &zeropad;
1767 	iov[3].iov_len = pktlen_aligned - pktlen;
1768 
1769 	mutex_enter(&ch->ch_wrd.rd_lock);
1770 	rv = vmbus_ring_write(&ch->ch_wrd, iov, 4, &needsig);
1771 	mutex_exit(&ch->ch_wrd.rd_lock);
1772 	if (rv == 0 && needsig)
1773 		vmbus_channel_setevent(sc, ch);
1774 
1775 	return rv;
1776 }
1777 
1778 static int
1779 vmbus_ring_peek(struct vmbus_ring_data *rrd, void *data, uint32_t datalen)
1780 {
1781 	uint32_t avail;
1782 
1783 	KASSERT(datalen <= rrd->rd_dsize);
1784 
1785 	vmbus_ring_avail(rrd, NULL, &avail);
1786 	if (avail < datalen)
1787 		return EAGAIN;
1788 
1789 	vmbus_ring_get(rrd, (uint8_t *)data, datalen, 1);
1790 	return 0;
1791 }
1792 
1793 static int
1794 vmbus_ring_read(struct vmbus_ring_data *rrd, void *data, uint32_t datalen,
1795     uint32_t offset)
1796 {
1797 	uint64_t indices;
1798 	uint32_t avail;
1799 
1800 	KASSERT(datalen <= rrd->rd_dsize);
1801 
1802 	vmbus_ring_avail(rrd, NULL, &avail);
1803 	if (avail < datalen) {
1804 		DPRINTF("%s: avail %u datalen %u\n", __func__, avail, datalen);
1805 		return EAGAIN;
1806 	}
1807 
1808 	if (offset) {
1809 		rrd->rd_cons += offset;
1810 		if (rrd->rd_cons >= rrd->rd_dsize)
1811 			rrd->rd_cons -= rrd->rd_dsize;
1812 	}
1813 
1814 	vmbus_ring_get(rrd, (uint8_t *)data, datalen, 0);
1815 	vmbus_ring_get(rrd, (uint8_t *)&indices, sizeof(indices), 0);
1816 
1817 	membar_sync();
1818 	rrd->rd_ring->br_rindex = rrd->rd_cons;
1819 
1820 	return 0;
1821 }
1822 
1823 int
1824 vmbus_channel_recv(struct vmbus_channel *ch, void *data, uint32_t datalen,
1825     uint32_t *rlen, uint64_t *rid, int raw)
1826 {
1827 	struct vmbus_softc *sc = ch->ch_sc;
1828 	struct vmbus_chanpkt_hdr cph;
1829 	uint32_t offset, pktlen;
1830 	int rv;
1831 
1832 	*rlen = 0;
1833 
1834 	mutex_enter(&ch->ch_rrd.rd_lock);
1835 
1836 	if ((rv = vmbus_ring_peek(&ch->ch_rrd, &cph, sizeof(cph))) != 0) {
1837 		mutex_exit(&ch->ch_rrd.rd_lock);
1838 		return rv;
1839 	}
1840 
1841 	offset = raw ? 0 : VMBUS_CHANPKT_GETLEN(cph.cph_hlen);
1842 	pktlen = VMBUS_CHANPKT_GETLEN(cph.cph_tlen) - offset;
1843 	if (pktlen > datalen) {
1844 		mutex_exit(&ch->ch_rrd.rd_lock);
1845 		device_printf(sc->sc_dev, "%s: pktlen %u datalen %u\n",
1846 		    __func__, pktlen, datalen);
1847 		return EINVAL;
1848 	}
1849 
1850 	rv = vmbus_ring_read(&ch->ch_rrd, data, pktlen, offset);
1851 	if (rv == 0) {
1852 		*rlen = pktlen;
1853 		*rid = cph.cph_tid;
1854 	}
1855 
1856 	mutex_exit(&ch->ch_rrd.rd_lock);
1857 
1858 	return rv;
1859 }
1860 
1861 static inline void
1862 vmbus_ring_mask(struct vmbus_ring_data *rd)
1863 {
1864 
1865 	membar_sync();
1866 	rd->rd_ring->br_imask = 1;
1867 	membar_sync();
1868 }
1869 
1870 static inline void
1871 vmbus_ring_unmask(struct vmbus_ring_data *rd)
1872 {
1873 
1874 	membar_sync();
1875 	rd->rd_ring->br_imask = 0;
1876 	membar_sync();
1877 }
1878 
1879 static void
1880 vmbus_channel_pause(struct vmbus_channel *ch)
1881 {
1882 
1883 	vmbus_ring_mask(&ch->ch_rrd);
1884 }
1885 
1886 static uint32_t
1887 vmbus_channel_unpause(struct vmbus_channel *ch)
1888 {
1889 	uint32_t avail;
1890 
1891 	vmbus_ring_unmask(&ch->ch_rrd);
1892 	vmbus_ring_avail(&ch->ch_rrd, NULL, &avail);
1893 
1894 	return avail;
1895 }
1896 
1897 static uint32_t
1898 vmbus_channel_ready(struct vmbus_channel *ch)
1899 {
1900 	uint32_t avail;
1901 
1902 	vmbus_ring_avail(&ch->ch_rrd, NULL, &avail);
1903 
1904 	return avail;
1905 }
1906 
1907 /* How many PFNs can be referenced by the header */
1908 #define VMBUS_NPFNHDR	((VMBUS_MSG_DSIZE_MAX -	\
1909 	  sizeof(struct vmbus_chanmsg_gpadl_conn)) / sizeof(uint64_t))
1910 
1911 /* How many PFNs can be referenced by the body */
1912 #define VMBUS_NPFNBODY	((VMBUS_MSG_DSIZE_MAX -	\
1913 	  sizeof(struct vmbus_chanmsg_gpadl_subconn)) / sizeof(uint64_t))
1914 
1915 int
1916 vmbus_handle_alloc(struct vmbus_channel *ch, const struct hyperv_dma *dma,
1917     uint32_t buflen, uint32_t *handle)
1918 {
1919 	const int prflags = cold ? PR_NOWAIT : PR_WAITOK;
1920 	const int kmemflags = cold ? KM_NOSLEEP : KM_SLEEP;
1921 	const int msgflags = cold ? MSGF_NOSLEEP : 0;
1922 	const int hcflags = cold ? HCF_NOSLEEP : HCF_SLEEPOK;
1923 	struct vmbus_softc *sc = ch->ch_sc;
1924 	struct vmbus_chanmsg_gpadl_conn *hdr;
1925 	struct vmbus_chanmsg_gpadl_subconn *cmd;
1926 	struct vmbus_chanmsg_gpadl_connresp rsp;
1927 	struct vmbus_msg *msg;
1928 	int i, j, last, left, rv;
1929 	int bodylen = 0, ncmds = 0, pfn = 0;
1930 	uint64_t *frames;
1931 	paddr_t pa;
1932 	uint8_t *body;
1933 	/* Total number of pages to reference */
1934 	int total = atop(buflen);
1935 	/* Number of pages that will fit the header */
1936 	int inhdr = MIN(total, VMBUS_NPFNHDR);
1937 
1938 	KASSERT((buflen & PAGE_MASK) == 0);
1939 	KASSERT(buflen == (uint32_t)dma->map->dm_mapsize);
1940 
1941 	msg = pool_cache_get_paddr(sc->sc_msgpool, prflags, &pa);
1942 	if (msg == NULL)
1943 		return ENOMEM;
1944 
1945 	/* Prepare array of frame addresses */
1946 	frames = kmem_zalloc(total * sizeof(*frames), kmemflags);
1947 	if (frames == NULL) {
1948 		pool_cache_put_paddr(sc->sc_msgpool, msg, pa);
1949 		return ENOMEM;
1950 	}
1951 	for (i = 0, j = 0; i < dma->map->dm_nsegs && j < total; i++) {
1952 		bus_dma_segment_t *seg = &dma->map->dm_segs[i];
1953 		bus_addr_t addr = seg->ds_addr;
1954 
1955 		KASSERT((addr & PAGE_MASK) == 0);
1956 		KASSERT((seg->ds_len & PAGE_MASK) == 0);
1957 
1958 		while (addr < seg->ds_addr + seg->ds_len && j < total) {
1959 			frames[j++] = atop(addr);
1960 			addr += PAGE_SIZE;
1961 		}
1962 	}
1963 
1964 	memset(msg, 0, sizeof(*msg));
1965 	msg->msg_req.hc_dsize = sizeof(struct vmbus_chanmsg_gpadl_conn) +
1966 	    inhdr * sizeof(uint64_t);
1967 	hdr = (struct vmbus_chanmsg_gpadl_conn *)msg->msg_req.hc_data;
1968 	msg->msg_rsp = &rsp;
1969 	msg->msg_rsplen = sizeof(rsp);
1970 	msg->msg_flags = msgflags;
1971 
1972 	left = total - inhdr;
1973 
1974 	/* Allocate additional gpadl_body structures if required */
1975 	if (left > 0) {
1976 		ncmds = howmany(left, VMBUS_NPFNBODY);
1977 		bodylen = ncmds * VMBUS_MSG_DSIZE_MAX;
1978 		body = kmem_zalloc(bodylen, kmemflags);
1979 		if (body == NULL) {
1980 			kmem_free(frames, total * sizeof(*frames));
1981 			pool_cache_put_paddr(sc->sc_msgpool, msg, pa);
1982 			return ENOMEM;
1983 		}
1984 	}
1985 
1986 	*handle = atomic_inc_32_nv(&sc->sc_handle);
1987 
1988 	hdr->chm_hdr.chm_type = VMBUS_CHANMSG_GPADL_CONN;
1989 	hdr->chm_chanid = ch->ch_id;
1990 	hdr->chm_gpadl = *handle;
1991 
1992 	/* Single range for a contiguous buffer */
1993 	hdr->chm_range_cnt = 1;
1994 	hdr->chm_range_len = sizeof(struct vmbus_gpa_range) + total *
1995 	    sizeof(uint64_t);
1996 	hdr->chm_range.gpa_ofs = 0;
1997 	hdr->chm_range.gpa_len = buflen;
1998 
1999 	/* Fit as many pages as possible into the header */
2000 	for (i = 0; i < inhdr; i++)
2001 		hdr->chm_range.gpa_page[i] = frames[pfn++];
2002 
2003 	for (i = 0; i < ncmds; i++) {
2004 		cmd = (struct vmbus_chanmsg_gpadl_subconn *)(body +
2005 		    VMBUS_MSG_DSIZE_MAX * i);
2006 		cmd->chm_hdr.chm_type = VMBUS_CHANMSG_GPADL_SUBCONN;
2007 		cmd->chm_gpadl = *handle;
2008 		last = MIN(left, VMBUS_NPFNBODY);
2009 		for (j = 0; j < last; j++)
2010 			cmd->chm_gpa_page[j] = frames[pfn++];
2011 		left -= last;
2012 	}
2013 
2014 	rv = vmbus_start(sc, msg, pa);
2015 	if (rv != 0) {
2016 		DPRINTF("%s: GPADL_CONN failed\n", device_xname(sc->sc_dev));
2017 		goto out;
2018 	}
2019 	for (i = 0; i < ncmds; i++) {
2020 		int cmdlen = sizeof(*cmd);
2021 		cmd = (struct vmbus_chanmsg_gpadl_subconn *)(body +
2022 		    VMBUS_MSG_DSIZE_MAX * i);
2023 		/* Last element can be short */
2024 		if (i == ncmds - 1)
2025 			cmdlen += last * sizeof(uint64_t);
2026 		else
2027 			cmdlen += VMBUS_NPFNBODY * sizeof(uint64_t);
2028 		rv = vmbus_cmd(sc, cmd, cmdlen, NULL, 0, HCF_NOREPLY | hcflags);
2029 		if (rv != 0) {
2030 			DPRINTF("%s: GPADL_SUBCONN (iteration %d/%d) failed "
2031 			    "with %d\n", device_xname(sc->sc_dev), i, ncmds,
2032 			    rv);
2033 			goto out;
2034 		}
2035 	}
2036 	rv = vmbus_reply(sc, msg);
2037 	if (rv != 0) {
2038 		DPRINTF("%s: GPADL allocation failed with %d\n",
2039 		    device_xname(sc->sc_dev), rv);
2040 	}
2041 
2042  out:
2043 	if (bodylen > 0)
2044 		kmem_free(body, bodylen);
2045 	kmem_free(frames, total * sizeof(*frames));
2046 	pool_cache_put_paddr(sc->sc_msgpool, msg, pa);
2047 	if (rv)
2048 		return rv;
2049 
2050 	KASSERT(*handle == rsp.chm_gpadl);
2051 
2052 	return 0;
2053 }
2054 
2055 void
2056 vmbus_handle_free(struct vmbus_channel *ch, uint32_t handle)
2057 {
2058 	struct vmbus_softc *sc = ch->ch_sc;
2059 	struct vmbus_chanmsg_gpadl_disconn cmd;
2060 	struct vmbus_chanmsg_gpadl_disconn rsp;
2061 	int rv;
2062 
2063 	memset(&cmd, 0, sizeof(cmd));
2064 	cmd.chm_hdr.chm_type = VMBUS_CHANMSG_GPADL_DISCONN;
2065 	cmd.chm_chanid = ch->ch_id;
2066 	cmd.chm_gpadl = handle;
2067 
2068 	rv = vmbus_cmd(sc, &cmd, sizeof(cmd), &rsp, sizeof(rsp),
2069 	    cold ? HCF_NOSLEEP : HCF_SLEEPOK);
2070 	if (rv) {
2071 		DPRINTF("%s: GPADL_DISCONN failed with %d\n",
2072 		    device_xname(sc->sc_dev), rv);
2073 	}
2074 }
2075 
2076  static void
2077 vmbus_chevq_enqueue(struct vmbus_softc *sc, int type, void *arg)
2078 {
2079 	struct vmbus_chev *vce;
2080 
2081 	vce = kmem_intr_alloc(sizeof(*vce), KM_NOSLEEP);
2082 	if (vce == NULL) {
2083 		device_printf(sc->sc_dev, "failed to allocate chev\n");
2084 		return;
2085 	}
2086 
2087 	vce->vce_type = type;
2088 	vce->vce_arg = arg;
2089 
2090 	mutex_enter(&sc->sc_chevq_lock);
2091 	SIMPLEQ_INSERT_TAIL(&sc->sc_chevq, vce, vce_entry);
2092 	cv_broadcast(&sc->sc_chevq_cv);
2093 	mutex_exit(&sc->sc_chevq_lock);
2094 }
2095 
2096 static void
2097 vmbus_process_chevq(void *arg)
2098 {
2099 	struct vmbus_softc *sc = arg;
2100 	struct vmbus_chev *vce;
2101 	struct vmbus_chanmsg_choffer *co;
2102 	struct vmbus_chanmsg_chrescind *cr;
2103 
2104 	KASSERT(mutex_owned(&sc->sc_chevq_lock));
2105 
2106 	while (!SIMPLEQ_EMPTY(&sc->sc_chevq)) {
2107 		vce = SIMPLEQ_FIRST(&sc->sc_chevq);
2108 		SIMPLEQ_REMOVE_HEAD(&sc->sc_chevq, vce_entry);
2109 		mutex_exit(&sc->sc_chevq_lock);
2110 
2111 		switch (vce->vce_type) {
2112 		case VMBUS_CHEV_TYPE_OFFER:
2113 			co = vce->vce_arg;
2114 			vmbus_process_offer(sc, co);
2115 			kmem_free(co, sizeof(*co));
2116 			break;
2117 
2118 		case VMBUS_CHEV_TYPE_RESCIND:
2119 			cr = vce->vce_arg;
2120 			vmbus_process_rescind(sc, cr);
2121 			kmem_free(cr, sizeof(*cr));
2122 			break;
2123 
2124 		default:
2125 			DPRINTF("%s: unknown chevq type %d\n",
2126 			    device_xname(sc->sc_dev), vce->vce_type);
2127 			break;
2128 		}
2129 		kmem_free(vce, sizeof(*vce));
2130 
2131 		mutex_enter(&sc->sc_chevq_lock);
2132 	}
2133 }
2134 
2135 static void
2136 vmbus_chevq_thread(void *arg)
2137 {
2138 	struct vmbus_softc *sc = arg;
2139 
2140 	mutex_enter(&sc->sc_chevq_lock);
2141 	for (;;) {
2142 		if (SIMPLEQ_EMPTY(&sc->sc_chevq)) {
2143 			cv_wait(&sc->sc_chevq_cv, &sc->sc_chevq_lock);
2144 			continue;
2145 		}
2146 
2147 		vmbus_process_chevq(sc);
2148 	}
2149 	mutex_exit(&sc->sc_chevq_lock);
2150 
2151 	kthread_exit(0);
2152 }
2153 
2154 static void
2155 vmbus_devq_enqueue(struct vmbus_softc *sc, int type, struct vmbus_channel *ch)
2156 {
2157 	struct vmbus_dev *vd;
2158 
2159 	vd = kmem_zalloc(sizeof(*vd), KM_SLEEP);
2160 	if (vd == NULL) {
2161 		device_printf(sc->sc_dev, "failed to allocate devq\n");
2162 		return;
2163 	}
2164 
2165 	vd->vd_type = type;
2166 	vd->vd_chan = ch;
2167 
2168 	if (VMBUS_CHAN_ISPRIMARY(ch)) {
2169 		mutex_enter(&sc->sc_devq_lock);
2170 		SIMPLEQ_INSERT_TAIL(&sc->sc_devq, vd, vd_entry);
2171 		cv_broadcast(&sc->sc_devq_cv);
2172 		mutex_exit(&sc->sc_devq_lock);
2173 	} else {
2174 		mutex_enter(&sc->sc_subch_devq_lock);
2175 		SIMPLEQ_INSERT_TAIL(&sc->sc_subch_devq, vd, vd_entry);
2176 		cv_broadcast(&sc->sc_subch_devq_cv);
2177 		mutex_exit(&sc->sc_subch_devq_lock);
2178 	}
2179 }
2180 
2181 static void
2182 vmbus_process_devq(void *arg)
2183 {
2184 	struct vmbus_softc *sc = arg;
2185 	struct vmbus_dev *vd;
2186 	struct vmbus_channel *ch;
2187 	struct vmbus_attach_args vaa;
2188 
2189 	KASSERT(mutex_owned(&sc->sc_devq_lock));
2190 
2191 	while (!SIMPLEQ_EMPTY(&sc->sc_devq)) {
2192 		vd = SIMPLEQ_FIRST(&sc->sc_devq);
2193 		SIMPLEQ_REMOVE_HEAD(&sc->sc_devq, vd_entry);
2194 		mutex_exit(&sc->sc_devq_lock);
2195 
2196 		switch (vd->vd_type) {
2197 		case VMBUS_DEV_TYPE_ATTACH:
2198 			ch = vd->vd_chan;
2199 			vaa.aa_type = &ch->ch_type;
2200 			vaa.aa_inst = &ch->ch_inst;
2201 			vaa.aa_ident = ch->ch_ident;
2202 			vaa.aa_chan = ch;
2203 			vaa.aa_iot = sc->sc_iot;
2204 			vaa.aa_memt = sc->sc_memt;
2205 			ch->ch_dev = config_found(sc->sc_dev,
2206 			    &vaa, vmbus_attach_print, CFARG_EOL);
2207 			break;
2208 
2209 		case VMBUS_DEV_TYPE_DETACH:
2210 			ch = vd->vd_chan;
2211 			if (ch->ch_dev != NULL) {
2212 				config_detach(ch->ch_dev, DETACH_FORCE);
2213 				ch->ch_dev = NULL;
2214 			}
2215 			vmbus_channel_release(ch);
2216 			vmbus_channel_free(ch);
2217 			break;
2218 
2219 		default:
2220 			DPRINTF("%s: unknown devq type %d\n",
2221 			    device_xname(sc->sc_dev), vd->vd_type);
2222 			break;
2223 		}
2224 		kmem_free(vd, sizeof(*vd));
2225 
2226 		mutex_enter(&sc->sc_devq_lock);
2227 	}
2228 }
2229 
2230 static void
2231 vmbus_devq_thread(void *arg)
2232 {
2233 	struct vmbus_softc *sc = arg;
2234 
2235 	mutex_enter(&sc->sc_devq_lock);
2236 	for (;;) {
2237 		if (SIMPLEQ_EMPTY(&sc->sc_devq)) {
2238 			cv_wait(&sc->sc_devq_cv, &sc->sc_devq_lock);
2239 			continue;
2240 		}
2241 
2242 		vmbus_process_devq(sc);
2243 	}
2244 	mutex_exit(&sc->sc_devq_lock);
2245 
2246 	kthread_exit(0);
2247 }
2248 
2249 static void
2250 vmbus_subchannel_devq_thread(void *arg)
2251 {
2252 	struct vmbus_softc *sc = arg;
2253 	struct vmbus_dev *vd;
2254 	struct vmbus_channel *ch, *prich;
2255 
2256 	mutex_enter(&sc->sc_subch_devq_lock);
2257 	for (;;) {
2258 		if (SIMPLEQ_EMPTY(&sc->sc_subch_devq)) {
2259 			cv_wait(&sc->sc_subch_devq_cv, &sc->sc_subch_devq_lock);
2260 			continue;
2261 		}
2262 
2263 		while (!SIMPLEQ_EMPTY(&sc->sc_subch_devq)) {
2264 			vd = SIMPLEQ_FIRST(&sc->sc_subch_devq);
2265 			SIMPLEQ_REMOVE_HEAD(&sc->sc_subch_devq, vd_entry);
2266 			mutex_exit(&sc->sc_subch_devq_lock);
2267 
2268 			switch (vd->vd_type) {
2269 			case VMBUS_DEV_TYPE_ATTACH:
2270 				/* Nothing to do */
2271 				break;
2272 
2273 			case VMBUS_DEV_TYPE_DETACH:
2274 				ch = vd->vd_chan;
2275 
2276 				vmbus_channel_release(ch);
2277 
2278 				prich = ch->ch_primary_channel;
2279 				mutex_enter(&prich->ch_subchannel_lock);
2280 				TAILQ_REMOVE(&prich->ch_subchannels, ch,
2281 				    ch_subentry);
2282 				prich->ch_subchannel_count--;
2283 				mutex_exit(&prich->ch_subchannel_lock);
2284 				wakeup(prich);
2285 
2286 				vmbus_channel_free(ch);
2287 				break;
2288 
2289 			default:
2290 				DPRINTF("%s: unknown devq type %d\n",
2291 				    device_xname(sc->sc_dev), vd->vd_type);
2292 				break;
2293 			}
2294 
2295 			kmem_free(vd, sizeof(*vd));
2296 
2297 			mutex_enter(&sc->sc_subch_devq_lock);
2298 		}
2299 	}
2300 	mutex_exit(&sc->sc_subch_devq_lock);
2301 
2302 	kthread_exit(0);
2303 }
2304 
2305 
2306 static int
2307 vmbus_attach_print(void *aux, const char *name)
2308 {
2309 	struct vmbus_attach_args *aa = aux;
2310 
2311 	if (name)
2312 		printf("\"%s\" at %s", aa->aa_ident, name);
2313 
2314 	return UNCONF;
2315 }
2316 
2317 MODULE(MODULE_CLASS_DRIVER, vmbus, "hyperv");
2318 
2319 #ifdef _MODULE
2320 #include "ioconf.c"
2321 #endif
2322 
2323 static int
2324 vmbus_modcmd(modcmd_t cmd, void *aux)
2325 {
2326 	int rv = 0;
2327 
2328 	switch (cmd) {
2329 	case MODULE_CMD_INIT:
2330 #ifdef _MODULE
2331 		rv = config_init_component(cfdriver_ioconf_vmbus,
2332 		    cfattach_ioconf_vmbus, cfdata_ioconf_vmbus);
2333 #endif
2334 		break;
2335 
2336 	case MODULE_CMD_FINI:
2337 #ifdef _MODULE
2338 		rv = config_fini_component(cfdriver_ioconf_vmbus,
2339 		    cfattach_ioconf_vmbus, cfdata_ioconf_vmbus);
2340 #endif
2341 		break;
2342 
2343 	default:
2344 		rv = ENOTTY;
2345 		break;
2346 	}
2347 
2348 	return rv;
2349 }
2350