virtio_pci.c revision 268010 
1/*-
2 * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    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/* Driver for the VirtIO PCI interface. */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: stable/10/sys/dev/virtio/pci/virtio_pci.c 268010 2014-06-29 00:37:59Z bryanv $");
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/bus.h>
35#include <sys/kernel.h>
36#include <sys/module.h>
37#include <sys/malloc.h>
38
39#include <machine/bus.h>
40#include <machine/resource.h>
41#include <sys/bus.h>
42#include <sys/rman.h>
43
44#include <dev/pci/pcivar.h>
45#include <dev/pci/pcireg.h>
46
47#include <dev/virtio/virtio.h>
48#include <dev/virtio/virtqueue.h>
49#include <dev/virtio/pci/virtio_pci.h>
50
51#include "virtio_bus_if.h"
52#include "virtio_if.h"
53
54struct vtpci_interrupt {
55	struct resource		*vti_irq;
56	int			 vti_rid;
57	void			*vti_handler;
58};
59
60struct vtpci_virtqueue {
61	struct virtqueue	*vtv_vq;
62	int			 vtv_no_intr;
63};
64
65struct vtpci_softc {
66	device_t			 vtpci_dev;
67	struct resource			*vtpci_res;
68	struct resource			*vtpci_msix_res;
69	uint64_t			 vtpci_features;
70	uint32_t			 vtpci_flags;
71#define VTPCI_FLAG_NO_MSI		0x0001
72#define VTPCI_FLAG_NO_MSIX		0x0002
73#define VTPCI_FLAG_LEGACY		0x1000
74#define VTPCI_FLAG_MSI			0x2000
75#define VTPCI_FLAG_MSIX			0x4000
76#define VTPCI_FLAG_SHARED_MSIX		0x8000
77#define VTPCI_FLAG_ITYPE_MASK		0xF000
78
79	/* This "bus" will only ever have one child. */
80	device_t			 vtpci_child_dev;
81	struct virtio_feature_desc	*vtpci_child_feat_desc;
82
83	int				 vtpci_nvqs;
84	struct vtpci_virtqueue		*vtpci_vqs;
85
86	/*
87	 * Ideally, each virtqueue that the driver provides a callback for will
88	 * receive its own MSIX vector. If there are not sufficient vectors
89	 * available, then attempt to have all the VQs share one vector. For
90	 * MSIX, the configuration changed notifications must be on their own
91	 * vector.
92	 *
93	 * If MSIX is not available, we will attempt to have the whole device
94	 * share one MSI vector, and then, finally, one legacy interrupt.
95	 */
96	struct vtpci_interrupt		 vtpci_device_interrupt;
97	struct vtpci_interrupt		*vtpci_msix_vq_interrupts;
98	int				 vtpci_nmsix_resources;
99};
100
101static int	vtpci_probe(device_t);
102static int	vtpci_attach(device_t);
103static int	vtpci_detach(device_t);
104static int	vtpci_suspend(device_t);
105static int	vtpci_resume(device_t);
106static int	vtpci_shutdown(device_t);
107static void	vtpci_driver_added(device_t, driver_t *);
108static void	vtpci_child_detached(device_t, device_t);
109static int	vtpci_read_ivar(device_t, device_t, int, uintptr_t *);
110static int	vtpci_write_ivar(device_t, device_t, int, uintptr_t);
111
112static uint64_t	vtpci_negotiate_features(device_t, uint64_t);
113static int	vtpci_with_feature(device_t, uint64_t);
114static int	vtpci_alloc_virtqueues(device_t, int, int,
115		    struct vq_alloc_info *);
116static int	vtpci_setup_intr(device_t, enum intr_type);
117static void	vtpci_stop(device_t);
118static int	vtpci_reinit(device_t, uint64_t);
119static void	vtpci_reinit_complete(device_t);
120static void	vtpci_notify_virtqueue(device_t, uint16_t);
121static uint8_t	vtpci_get_status(device_t);
122static void	vtpci_set_status(device_t, uint8_t);
123static void	vtpci_read_dev_config(device_t, bus_size_t, void *, int);
124static void	vtpci_write_dev_config(device_t, bus_size_t, void *, int);
125
126static void	vtpci_describe_features(struct vtpci_softc *, const char *,
127		    uint64_t);
128static void	vtpci_probe_and_attach_child(struct vtpci_softc *);
129
130static int	vtpci_alloc_msix(struct vtpci_softc *, int);
131static int	vtpci_alloc_msi(struct vtpci_softc *);
132static int	vtpci_alloc_intr_msix_pervq(struct vtpci_softc *);
133static int	vtpci_alloc_intr_msix_shared(struct vtpci_softc *);
134static int	vtpci_alloc_intr_msi(struct vtpci_softc *);
135static int	vtpci_alloc_intr_legacy(struct vtpci_softc *);
136static int	vtpci_alloc_interrupt(struct vtpci_softc *, int, int,
137		    struct vtpci_interrupt *);
138static int	vtpci_alloc_intr_resources(struct vtpci_softc *);
139
140static int	vtpci_setup_legacy_interrupt(struct vtpci_softc *,
141		    enum intr_type);
142static int	vtpci_setup_pervq_msix_interrupts(struct vtpci_softc *,
143		    enum intr_type);
144static int	vtpci_setup_msix_interrupts(struct vtpci_softc *,
145		    enum intr_type);
146static int	vtpci_setup_interrupts(struct vtpci_softc *, enum intr_type);
147
148static int	vtpci_register_msix_vector(struct vtpci_softc *, int,
149		    struct vtpci_interrupt *);
150static int	vtpci_set_host_msix_vectors(struct vtpci_softc *);
151static int	vtpci_reinit_virtqueue(struct vtpci_softc *, int);
152
153static void	vtpci_free_interrupt(struct vtpci_softc *,
154		    struct vtpci_interrupt *);
155static void	vtpci_free_interrupts(struct vtpci_softc *);
156static void	vtpci_free_virtqueues(struct vtpci_softc *);
157static void	vtpci_release_child_resources(struct vtpci_softc *);
158static void	vtpci_cleanup_setup_intr_attempt(struct vtpci_softc *);
159static void	vtpci_reset(struct vtpci_softc *);
160
161static void	vtpci_select_virtqueue(struct vtpci_softc *, int);
162
163static void	vtpci_legacy_intr(void *);
164static int	vtpci_vq_shared_intr_filter(void *);
165static void	vtpci_vq_shared_intr(void *);
166static int	vtpci_vq_intr_filter(void *);
167static void	vtpci_vq_intr(void *);
168static void	vtpci_config_intr(void *);
169
170#define vtpci_setup_msi_interrupt vtpci_setup_legacy_interrupt
171
172#define VIRTIO_PCI_CONFIG(_sc) \
173    VIRTIO_PCI_CONFIG_OFF((((_sc)->vtpci_flags & VTPCI_FLAG_MSIX)) != 0)
174
175/*
176 * I/O port read/write wrappers.
177 */
178#define vtpci_read_config_1(sc, o)	bus_read_1((sc)->vtpci_res, (o))
179#define vtpci_read_config_2(sc, o)	bus_read_2((sc)->vtpci_res, (o))
180#define vtpci_read_config_4(sc, o)	bus_read_4((sc)->vtpci_res, (o))
181#define vtpci_write_config_1(sc, o, v)	bus_write_1((sc)->vtpci_res, (o), (v))
182#define vtpci_write_config_2(sc, o, v)	bus_write_2((sc)->vtpci_res, (o), (v))
183#define vtpci_write_config_4(sc, o, v)	bus_write_4((sc)->vtpci_res, (o), (v))
184
185/* Tunables. */
186static int vtpci_disable_msix = 0;
187TUNABLE_INT("hw.virtio.pci.disable_msix", &vtpci_disable_msix);
188
189static device_method_t vtpci_methods[] = {
190	/* Device interface. */
191	DEVMETHOD(device_probe,			  vtpci_probe),
192	DEVMETHOD(device_attach,		  vtpci_attach),
193	DEVMETHOD(device_detach,		  vtpci_detach),
194	DEVMETHOD(device_suspend,		  vtpci_suspend),
195	DEVMETHOD(device_resume,		  vtpci_resume),
196	DEVMETHOD(device_shutdown,		  vtpci_shutdown),
197
198	/* Bus interface. */
199	DEVMETHOD(bus_driver_added,		  vtpci_driver_added),
200	DEVMETHOD(bus_child_detached,		  vtpci_child_detached),
201	DEVMETHOD(bus_read_ivar,		  vtpci_read_ivar),
202	DEVMETHOD(bus_write_ivar,		  vtpci_write_ivar),
203
204	/* VirtIO bus interface. */
205	DEVMETHOD(virtio_bus_negotiate_features,  vtpci_negotiate_features),
206	DEVMETHOD(virtio_bus_with_feature,	  vtpci_with_feature),
207	DEVMETHOD(virtio_bus_alloc_virtqueues,	  vtpci_alloc_virtqueues),
208	DEVMETHOD(virtio_bus_setup_intr,	  vtpci_setup_intr),
209	DEVMETHOD(virtio_bus_stop,		  vtpci_stop),
210	DEVMETHOD(virtio_bus_reinit,		  vtpci_reinit),
211	DEVMETHOD(virtio_bus_reinit_complete,	  vtpci_reinit_complete),
212	DEVMETHOD(virtio_bus_notify_vq,		  vtpci_notify_virtqueue),
213	DEVMETHOD(virtio_bus_read_device_config,  vtpci_read_dev_config),
214	DEVMETHOD(virtio_bus_write_device_config, vtpci_write_dev_config),
215
216	DEVMETHOD_END
217};
218
219static driver_t vtpci_driver = {
220	"virtio_pci",
221	vtpci_methods,
222	sizeof(struct vtpci_softc)
223};
224
225devclass_t vtpci_devclass;
226
227DRIVER_MODULE(virtio_pci, pci, vtpci_driver, vtpci_devclass, 0, 0);
228MODULE_VERSION(virtio_pci, 1);
229MODULE_DEPEND(virtio_pci, pci, 1, 1, 1);
230MODULE_DEPEND(virtio_pci, virtio, 1, 1, 1);
231
232static int
233vtpci_probe(device_t dev)
234{
235	char desc[36];
236	const char *name;
237
238	if (pci_get_vendor(dev) != VIRTIO_PCI_VENDORID)
239		return (ENXIO);
240
241	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MIN ||
242	    pci_get_device(dev) > VIRTIO_PCI_DEVICEID_MAX)
243		return (ENXIO);
244
245	if (pci_get_revid(dev) != VIRTIO_PCI_ABI_VERSION)
246		return (ENXIO);
247
248	name = virtio_device_name(pci_get_subdevice(dev));
249	if (name == NULL)
250		name = "Unknown";
251
252	snprintf(desc, sizeof(desc), "VirtIO PCI %s adapter", name);
253	device_set_desc_copy(dev, desc);
254
255	return (BUS_PROBE_DEFAULT);
256}
257
258static int
259vtpci_attach(device_t dev)
260{
261	struct vtpci_softc *sc;
262	device_t child;
263	int rid;
264
265	sc = device_get_softc(dev);
266	sc->vtpci_dev = dev;
267
268	pci_enable_busmaster(dev);
269
270	rid = PCIR_BAR(0);
271	sc->vtpci_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &rid,
272	    RF_ACTIVE);
273	if (sc->vtpci_res == NULL) {
274		device_printf(dev, "cannot map I/O space\n");
275		return (ENXIO);
276	}
277
278	if (pci_find_cap(dev, PCIY_MSI, NULL) != 0)
279		sc->vtpci_flags |= VTPCI_FLAG_NO_MSI;
280
281	if (pci_find_cap(dev, PCIY_MSIX, NULL) == 0) {
282		rid = PCIR_BAR(1);
283		sc->vtpci_msix_res = bus_alloc_resource_any(dev,
284		    SYS_RES_MEMORY, &rid, RF_ACTIVE);
285	}
286
287	if (sc->vtpci_msix_res == NULL)
288		sc->vtpci_flags |= VTPCI_FLAG_NO_MSIX;
289
290	vtpci_reset(sc);
291
292	/* Tell the host we've noticed this device. */
293	vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
294
295	if ((child = device_add_child(dev, NULL, -1)) == NULL) {
296		device_printf(dev, "cannot create child device\n");
297		vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
298		vtpci_detach(dev);
299		return (ENOMEM);
300	}
301
302	sc->vtpci_child_dev = child;
303	vtpci_probe_and_attach_child(sc);
304
305	return (0);
306}
307
308static int
309vtpci_detach(device_t dev)
310{
311	struct vtpci_softc *sc;
312	device_t child;
313	int error;
314
315	sc = device_get_softc(dev);
316
317	if ((child = sc->vtpci_child_dev) != NULL) {
318		error = device_delete_child(dev, child);
319		if (error)
320			return (error);
321		sc->vtpci_child_dev = NULL;
322	}
323
324	vtpci_reset(sc);
325
326	if (sc->vtpci_msix_res != NULL) {
327		bus_release_resource(dev, SYS_RES_MEMORY, PCIR_BAR(1),
328		    sc->vtpci_msix_res);
329		sc->vtpci_msix_res = NULL;
330	}
331
332	if (sc->vtpci_res != NULL) {
333		bus_release_resource(dev, SYS_RES_IOPORT, PCIR_BAR(0),
334		    sc->vtpci_res);
335		sc->vtpci_res = NULL;
336	}
337
338	return (0);
339}
340
341static int
342vtpci_suspend(device_t dev)
343{
344
345	return (bus_generic_suspend(dev));
346}
347
348static int
349vtpci_resume(device_t dev)
350{
351
352	return (bus_generic_resume(dev));
353}
354
355static int
356vtpci_shutdown(device_t dev)
357{
358
359	(void) bus_generic_shutdown(dev);
360	/* Forcibly stop the host device. */
361	vtpci_stop(dev);
362
363	return (0);
364}
365
366static void
367vtpci_driver_added(device_t dev, driver_t *driver)
368{
369	struct vtpci_softc *sc;
370
371	sc = device_get_softc(dev);
372
373	vtpci_probe_and_attach_child(sc);
374}
375
376static void
377vtpci_child_detached(device_t dev, device_t child)
378{
379	struct vtpci_softc *sc;
380
381	sc = device_get_softc(dev);
382
383	vtpci_reset(sc);
384	vtpci_release_child_resources(sc);
385}
386
387static int
388vtpci_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
389{
390	struct vtpci_softc *sc;
391
392	sc = device_get_softc(dev);
393
394	if (sc->vtpci_child_dev != child)
395		return (ENOENT);
396
397	switch (index) {
398	case VIRTIO_IVAR_DEVTYPE:
399	case VIRTIO_IVAR_SUBDEVICE:
400		*result = pci_get_subdevice(dev);
401		break;
402	case VIRTIO_IVAR_VENDOR:
403		*result = pci_get_vendor(dev);
404		break;
405	case VIRTIO_IVAR_DEVICE:
406		*result = pci_get_device(dev);
407		break;
408	case VIRTIO_IVAR_SUBVENDOR:
409		*result = pci_get_subdevice(dev);
410		break;
411	default:
412		return (ENOENT);
413	}
414
415	return (0);
416}
417
418static int
419vtpci_write_ivar(device_t dev, device_t child, int index, uintptr_t value)
420{
421	struct vtpci_softc *sc;
422
423	sc = device_get_softc(dev);
424
425	if (sc->vtpci_child_dev != child)
426		return (ENOENT);
427
428	switch (index) {
429	case VIRTIO_IVAR_FEATURE_DESC:
430		sc->vtpci_child_feat_desc = (void *) value;
431		break;
432	default:
433		return (ENOENT);
434	}
435
436	return (0);
437}
438
439static uint64_t
440vtpci_negotiate_features(device_t dev, uint64_t child_features)
441{
442	struct vtpci_softc *sc;
443	uint64_t host_features, features;
444
445	sc = device_get_softc(dev);
446
447	host_features = vtpci_read_config_4(sc, VIRTIO_PCI_HOST_FEATURES);
448	vtpci_describe_features(sc, "host", host_features);
449
450	/*
451	 * Limit negotiated features to what the driver, virtqueue, and
452	 * host all support.
453	 */
454	features = host_features & child_features;
455	features = virtqueue_filter_features(features);
456	sc->vtpci_features = features;
457
458	vtpci_describe_features(sc, "negotiated", features);
459	vtpci_write_config_4(sc, VIRTIO_PCI_GUEST_FEATURES, features);
460
461	return (features);
462}
463
464static int
465vtpci_with_feature(device_t dev, uint64_t feature)
466{
467	struct vtpci_softc *sc;
468
469	sc = device_get_softc(dev);
470
471	return ((sc->vtpci_features & feature) != 0);
472}
473
474static int
475vtpci_alloc_virtqueues(device_t dev, int flags, int nvqs,
476    struct vq_alloc_info *vq_info)
477{
478	struct vtpci_softc *sc;
479	struct virtqueue *vq;
480	struct vtpci_virtqueue *vqx;
481	struct vq_alloc_info *info;
482	int idx, error;
483	uint16_t size;
484
485	sc = device_get_softc(dev);
486
487	if (sc->vtpci_nvqs != 0)
488		return (EALREADY);
489	if (nvqs <= 0)
490		return (EINVAL);
491
492	sc->vtpci_vqs = malloc(nvqs * sizeof(struct vtpci_virtqueue),
493	    M_DEVBUF, M_NOWAIT | M_ZERO);
494	if (sc->vtpci_vqs == NULL)
495		return (ENOMEM);
496
497	for (idx = 0; idx < nvqs; idx++) {
498		vqx = &sc->vtpci_vqs[idx];
499		info = &vq_info[idx];
500
501		vtpci_select_virtqueue(sc, idx);
502		size = vtpci_read_config_2(sc, VIRTIO_PCI_QUEUE_NUM);
503
504		error = virtqueue_alloc(dev, idx, size, VIRTIO_PCI_VRING_ALIGN,
505		    0xFFFFFFFFUL, info, &vq);
506		if (error) {
507			device_printf(dev,
508			    "cannot allocate virtqueue %d: %d\n", idx, error);
509			break;
510		}
511
512		vtpci_write_config_4(sc, VIRTIO_PCI_QUEUE_PFN,
513		    virtqueue_paddr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
514
515		vqx->vtv_vq = *info->vqai_vq = vq;
516		vqx->vtv_no_intr = info->vqai_intr == NULL;
517
518		sc->vtpci_nvqs++;
519	}
520
521	if (error)
522		vtpci_free_virtqueues(sc);
523
524	return (error);
525}
526
527static int
528vtpci_setup_intr(device_t dev, enum intr_type type)
529{
530	struct vtpci_softc *sc;
531	int attempt, error;
532
533	sc = device_get_softc(dev);
534
535	for (attempt = 0; attempt < 5; attempt++) {
536		/*
537		 * Start with the most desirable interrupt configuration and
538		 * fallback towards less desirable ones.
539		 */
540		switch (attempt) {
541		case 0:
542			error = vtpci_alloc_intr_msix_pervq(sc);
543			break;
544		case 1:
545			error = vtpci_alloc_intr_msix_shared(sc);
546			break;
547		case 2:
548			error = vtpci_alloc_intr_msi(sc);
549			break;
550		case 3:
551			error = vtpci_alloc_intr_legacy(sc);
552			break;
553		default:
554			device_printf(dev,
555			    "exhausted all interrupt allocation attempts\n");
556			return (ENXIO);
557		}
558
559		if (error == 0 && vtpci_setup_interrupts(sc, type) == 0)
560			break;
561
562		vtpci_cleanup_setup_intr_attempt(sc);
563	}
564
565	if (bootverbose) {
566		if (sc->vtpci_flags & VTPCI_FLAG_LEGACY)
567			device_printf(dev, "using legacy interrupt\n");
568		else if (sc->vtpci_flags & VTPCI_FLAG_MSI)
569			device_printf(dev, "using MSI interrupt\n");
570		else if (sc->vtpci_flags & VTPCI_FLAG_SHARED_MSIX)
571			device_printf(dev, "using shared MSIX interrupts\n");
572		else
573			device_printf(dev, "using per VQ MSIX interrupts\n");
574	}
575
576	return (0);
577}
578
579static void
580vtpci_stop(device_t dev)
581{
582
583	vtpci_reset(device_get_softc(dev));
584}
585
586static int
587vtpci_reinit(device_t dev, uint64_t features)
588{
589	struct vtpci_softc *sc;
590	int idx, error;
591
592	sc = device_get_softc(dev);
593
594	/*
595	 * Redrive the device initialization. This is a bit of an abuse of
596	 * the specification, but VirtualBox, QEMU/KVM, and BHyVe seem to
597	 * play nice.
598	 *
599	 * We do not allow the host device to change from what was originally
600	 * negotiated beyond what the guest driver changed. MSIX state should
601	 * not change, number of virtqueues and their size remain the same, etc.
602	 * This will need to be rethought when we want to support migration.
603	 */
604
605	if (vtpci_get_status(dev) != VIRTIO_CONFIG_STATUS_RESET)
606		vtpci_stop(dev);
607
608	/*
609	 * Quickly drive the status through ACK and DRIVER. The device
610	 * does not become usable again until vtpci_reinit_complete().
611	 */
612	vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
613	vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
614
615	vtpci_negotiate_features(dev, features);
616
617	for (idx = 0; idx < sc->vtpci_nvqs; idx++) {
618		error = vtpci_reinit_virtqueue(sc, idx);
619		if (error)
620			return (error);
621	}
622
623	if (sc->vtpci_flags & VTPCI_FLAG_MSIX) {
624		error = vtpci_set_host_msix_vectors(sc);
625		if (error)
626			return (error);
627	}
628
629	return (0);
630}
631
632static void
633vtpci_reinit_complete(device_t dev)
634{
635
636	vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
637}
638
639static void
640vtpci_notify_virtqueue(device_t dev, uint16_t queue)
641{
642	struct vtpci_softc *sc;
643
644	sc = device_get_softc(dev);
645
646	vtpci_write_config_2(sc, VIRTIO_PCI_QUEUE_NOTIFY, queue);
647}
648
649static uint8_t
650vtpci_get_status(device_t dev)
651{
652	struct vtpci_softc *sc;
653
654	sc = device_get_softc(dev);
655
656	return (vtpci_read_config_1(sc, VIRTIO_PCI_STATUS));
657}
658
659static void
660vtpci_set_status(device_t dev, uint8_t status)
661{
662	struct vtpci_softc *sc;
663
664	sc = device_get_softc(dev);
665
666	if (status != VIRTIO_CONFIG_STATUS_RESET)
667		status |= vtpci_get_status(dev);
668
669	vtpci_write_config_1(sc, VIRTIO_PCI_STATUS, status);
670}
671
672static void
673vtpci_read_dev_config(device_t dev, bus_size_t offset,
674    void *dst, int length)
675{
676	struct vtpci_softc *sc;
677	bus_size_t off;
678	uint8_t *d;
679	int size;
680
681	sc = device_get_softc(dev);
682	off = VIRTIO_PCI_CONFIG(sc) + offset;
683
684	for (d = dst; length > 0; d += size, off += size, length -= size) {
685		if (length >= 4) {
686			size = 4;
687			*(uint32_t *)d = vtpci_read_config_4(sc, off);
688		} else if (length >= 2) {
689			size = 2;
690			*(uint16_t *)d = vtpci_read_config_2(sc, off);
691		} else {
692			size = 1;
693			*d = vtpci_read_config_1(sc, off);
694		}
695	}
696}
697
698static void
699vtpci_write_dev_config(device_t dev, bus_size_t offset,
700    void *src, int length)
701{
702	struct vtpci_softc *sc;
703	bus_size_t off;
704	uint8_t *s;
705	int size;
706
707	sc = device_get_softc(dev);
708	off = VIRTIO_PCI_CONFIG(sc) + offset;
709
710	for (s = src; length > 0; s += size, off += size, length -= size) {
711		if (length >= 4) {
712			size = 4;
713			vtpci_write_config_4(sc, off, *(uint32_t *)s);
714		} else if (length >= 2) {
715			size = 2;
716			vtpci_write_config_2(sc, off, *(uint16_t *)s);
717		} else {
718			size = 1;
719			vtpci_write_config_1(sc, off, *s);
720		}
721	}
722}
723
724static void
725vtpci_describe_features(struct vtpci_softc *sc, const char *msg,
726    uint64_t features)
727{
728	device_t dev, child;
729
730	dev = sc->vtpci_dev;
731	child = sc->vtpci_child_dev;
732
733	if (device_is_attached(child) && bootverbose == 0)
734		return;
735
736	virtio_describe(dev, msg, features, sc->vtpci_child_feat_desc);
737}
738
739static void
740vtpci_probe_and_attach_child(struct vtpci_softc *sc)
741{
742	device_t dev, child;
743
744	dev = sc->vtpci_dev;
745	child = sc->vtpci_child_dev;
746
747	if (child == NULL)
748		return;
749
750	if (device_get_state(child) != DS_NOTPRESENT)
751		return;
752
753	if (device_probe(child) != 0)
754		return;
755
756	vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
757	if (device_attach(child) != 0) {
758		vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
759		vtpci_reset(sc);
760		vtpci_release_child_resources(sc);
761		/* Reset status for future attempt. */
762		vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
763	} else {
764		vtpci_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
765		VIRTIO_ATTACH_COMPLETED(child);
766	}
767}
768
769static int
770vtpci_alloc_msix(struct vtpci_softc *sc, int nvectors)
771{
772	device_t dev;
773	int nmsix, cnt, required;
774
775	dev = sc->vtpci_dev;
776
777	/* Allocate an additional vector for the config changes. */
778	required = nvectors + 1;
779
780	nmsix = pci_msix_count(dev);
781	if (nmsix < required)
782		return (1);
783
784	cnt = required;
785	if (pci_alloc_msix(dev, &cnt) == 0 && cnt >= required) {
786		sc->vtpci_nmsix_resources = required;
787		return (0);
788	}
789
790	pci_release_msi(dev);
791
792	return (1);
793}
794
795static int
796vtpci_alloc_msi(struct vtpci_softc *sc)
797{
798	device_t dev;
799	int nmsi, cnt, required;
800
801	dev = sc->vtpci_dev;
802	required = 1;
803
804	nmsi = pci_msi_count(dev);
805	if (nmsi < required)
806		return (1);
807
808	cnt = required;
809	if (pci_alloc_msi(dev, &cnt) == 0 && cnt >= required)
810		return (0);
811
812	pci_release_msi(dev);
813
814	return (1);
815}
816
817static int
818vtpci_alloc_intr_msix_pervq(struct vtpci_softc *sc)
819{
820	int i, nvectors, error;
821
822	if (vtpci_disable_msix != 0 ||
823	    sc->vtpci_flags & VTPCI_FLAG_NO_MSIX)
824		return (ENOTSUP);
825
826	for (nvectors = 0, i = 0; i < sc->vtpci_nvqs; i++) {
827		if (sc->vtpci_vqs[i].vtv_no_intr == 0)
828			nvectors++;
829	}
830
831	error = vtpci_alloc_msix(sc, nvectors);
832	if (error)
833		return (error);
834
835	sc->vtpci_flags |= VTPCI_FLAG_MSIX;
836
837	return (0);
838}
839
840static int
841vtpci_alloc_intr_msix_shared(struct vtpci_softc *sc)
842{
843	int error;
844
845	if (vtpci_disable_msix != 0 ||
846	    sc->vtpci_flags & VTPCI_FLAG_NO_MSIX)
847		return (ENOTSUP);
848
849	error = vtpci_alloc_msix(sc, 1);
850	if (error)
851		return (error);
852
853	sc->vtpci_flags |= VTPCI_FLAG_MSIX | VTPCI_FLAG_SHARED_MSIX;
854
855	return (0);
856}
857
858static int
859vtpci_alloc_intr_msi(struct vtpci_softc *sc)
860{
861	int error;
862
863	/* Only BHyVe supports MSI. */
864	if (sc->vtpci_flags & VTPCI_FLAG_NO_MSI)
865		return (ENOTSUP);
866
867	error = vtpci_alloc_msi(sc);
868	if (error)
869		return (error);
870
871	sc->vtpci_flags |= VTPCI_FLAG_MSI;
872
873	return (0);
874}
875
876static int
877vtpci_alloc_intr_legacy(struct vtpci_softc *sc)
878{
879
880	sc->vtpci_flags |= VTPCI_FLAG_LEGACY;
881
882	return (0);
883}
884
885static int
886vtpci_alloc_interrupt(struct vtpci_softc *sc, int rid, int flags,
887    struct vtpci_interrupt *intr)
888{
889	struct resource *irq;
890
891	irq = bus_alloc_resource_any(sc->vtpci_dev, SYS_RES_IRQ, &rid, flags);
892	if (irq == NULL)
893		return (ENXIO);
894
895	intr->vti_irq = irq;
896	intr->vti_rid = rid;
897
898	return (0);
899}
900
901static int
902vtpci_alloc_intr_resources(struct vtpci_softc *sc)
903{
904	struct vtpci_interrupt *intr;
905	int i, rid, flags, nvq_intrs, error;
906
907	rid = 0;
908	flags = RF_ACTIVE;
909
910	if (sc->vtpci_flags & VTPCI_FLAG_LEGACY)
911		flags |= RF_SHAREABLE;
912	else
913		rid = 1;
914
915	/*
916	 * For legacy and MSI interrupts, this single resource handles all
917	 * interrupts. For MSIX, this resource is used for the configuration
918	 * changed interrupt.
919	 */
920	intr = &sc->vtpci_device_interrupt;
921	error = vtpci_alloc_interrupt(sc, rid, flags, intr);
922	if (error || sc->vtpci_flags & (VTPCI_FLAG_LEGACY | VTPCI_FLAG_MSI))
923		return (error);
924
925	/* Subtract one for the configuration changed interrupt. */
926	nvq_intrs = sc->vtpci_nmsix_resources - 1;
927
928	intr = sc->vtpci_msix_vq_interrupts = malloc(nvq_intrs *
929	    sizeof(struct vtpci_interrupt), M_DEVBUF, M_NOWAIT | M_ZERO);
930	if (sc->vtpci_msix_vq_interrupts == NULL)
931		return (ENOMEM);
932
933	for (i = 0, rid++; i < nvq_intrs; i++, rid++, intr++) {
934		error = vtpci_alloc_interrupt(sc, rid, flags, intr);
935		if (error)
936			return (error);
937	}
938
939	return (0);
940}
941
942static int
943vtpci_setup_legacy_interrupt(struct vtpci_softc *sc, enum intr_type type)
944{
945	struct vtpci_interrupt *intr;
946	int error;
947
948	intr = &sc->vtpci_device_interrupt;
949	error = bus_setup_intr(sc->vtpci_dev, intr->vti_irq, type, NULL,
950	    vtpci_legacy_intr, sc, &intr->vti_handler);
951
952	return (error);
953}
954
955static int
956vtpci_setup_pervq_msix_interrupts(struct vtpci_softc *sc, enum intr_type type)
957{
958	struct vtpci_virtqueue *vqx;
959	struct vtpci_interrupt *intr;
960	int i, error;
961
962	intr = sc->vtpci_msix_vq_interrupts;
963
964	for (i = 0; i < sc->vtpci_nvqs; i++) {
965		vqx = &sc->vtpci_vqs[i];
966
967		if (vqx->vtv_no_intr)
968			continue;
969
970		error = bus_setup_intr(sc->vtpci_dev, intr->vti_irq, type,
971		    vtpci_vq_intr_filter, vtpci_vq_intr, vqx->vtv_vq,
972		    &intr->vti_handler);
973		if (error)
974			return (error);
975
976		intr++;
977	}
978
979	return (0);
980}
981
982static int
983vtpci_setup_msix_interrupts(struct vtpci_softc *sc, enum intr_type type)
984{
985	device_t dev;
986	struct vtpci_interrupt *intr;
987	int error;
988
989	dev = sc->vtpci_dev;
990	intr = &sc->vtpci_device_interrupt;
991
992	error = bus_setup_intr(dev, intr->vti_irq, type, NULL,
993	    vtpci_config_intr, sc, &intr->vti_handler);
994	if (error)
995		return (error);
996
997	if (sc->vtpci_flags & VTPCI_FLAG_SHARED_MSIX) {
998		intr = sc->vtpci_msix_vq_interrupts;
999		error = bus_setup_intr(dev, intr->vti_irq, type,
1000		    vtpci_vq_shared_intr_filter, vtpci_vq_shared_intr, sc,
1001		    &intr->vti_handler);
1002	} else
1003		error = vtpci_setup_pervq_msix_interrupts(sc, type);
1004
1005	return (error ? error : vtpci_set_host_msix_vectors(sc));
1006}
1007
1008static int
1009vtpci_setup_interrupts(struct vtpci_softc *sc, enum intr_type type)
1010{
1011	int error;
1012
1013	type |= INTR_MPSAFE;
1014	KASSERT(sc->vtpci_flags & VTPCI_FLAG_ITYPE_MASK,
1015	    ("%s: no interrupt type selected %#x", __func__, sc->vtpci_flags));
1016
1017	error = vtpci_alloc_intr_resources(sc);
1018	if (error)
1019		return (error);
1020
1021	if (sc->vtpci_flags & VTPCI_FLAG_LEGACY)
1022		error = vtpci_setup_legacy_interrupt(sc, type);
1023	else if (sc->vtpci_flags & VTPCI_FLAG_MSI)
1024		error = vtpci_setup_msi_interrupt(sc, type);
1025	else
1026		error = vtpci_setup_msix_interrupts(sc, type);
1027
1028	return (error);
1029}
1030
1031static int
1032vtpci_register_msix_vector(struct vtpci_softc *sc, int offset,
1033    struct vtpci_interrupt *intr)
1034{
1035	device_t dev;
1036	uint16_t vector;
1037
1038	dev = sc->vtpci_dev;
1039
1040	if (intr != NULL) {
1041		/* Map from guest rid to host vector. */
1042		vector = intr->vti_rid - 1;
1043	} else
1044		vector = VIRTIO_MSI_NO_VECTOR;
1045
1046	vtpci_write_config_2(sc, offset, vector);
1047
1048	/* Read vector to determine if the host had sufficient resources. */
1049	if (vtpci_read_config_2(sc, offset) != vector) {
1050		device_printf(dev,
1051		    "insufficient host resources for MSIX interrupts\n");
1052		return (ENODEV);
1053	}
1054
1055	return (0);
1056}
1057
1058static int
1059vtpci_set_host_msix_vectors(struct vtpci_softc *sc)
1060{
1061	struct vtpci_interrupt *intr, *tintr;
1062	int idx, offset, error;
1063
1064	intr = &sc->vtpci_device_interrupt;
1065	offset = VIRTIO_MSI_CONFIG_VECTOR;
1066
1067	error = vtpci_register_msix_vector(sc, offset, intr);
1068	if (error)
1069		return (error);
1070
1071	intr = sc->vtpci_msix_vq_interrupts;
1072	offset = VIRTIO_MSI_QUEUE_VECTOR;
1073
1074	for (idx = 0; idx < sc->vtpci_nvqs; idx++) {
1075		vtpci_select_virtqueue(sc, idx);
1076
1077		if (sc->vtpci_vqs[idx].vtv_no_intr)
1078			tintr = NULL;
1079		else
1080			tintr = intr;
1081
1082		error = vtpci_register_msix_vector(sc, offset, tintr);
1083		if (error)
1084			break;
1085
1086		/*
1087		 * For shared MSIX, all the virtqueues share the first
1088		 * interrupt.
1089		 */
1090		if ((sc->vtpci_flags & VTPCI_FLAG_SHARED_MSIX) == 0)
1091			intr++;
1092	}
1093
1094	return (error);
1095}
1096
1097static int
1098vtpci_reinit_virtqueue(struct vtpci_softc *sc, int idx)
1099{
1100	struct vtpci_virtqueue *vqx;
1101	struct virtqueue *vq;
1102	int error;
1103	uint16_t size;
1104
1105	vqx = &sc->vtpci_vqs[idx];
1106	vq = vqx->vtv_vq;
1107
1108	KASSERT(vq != NULL, ("%s: vq %d not allocated", __func__, idx));
1109
1110	vtpci_select_virtqueue(sc, idx);
1111	size = vtpci_read_config_2(sc, VIRTIO_PCI_QUEUE_NUM);
1112
1113	error = virtqueue_reinit(vq, size);
1114	if (error)
1115		return (error);
1116
1117	vtpci_write_config_4(sc, VIRTIO_PCI_QUEUE_PFN,
1118	    virtqueue_paddr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
1119
1120	return (0);
1121}
1122
1123static void
1124vtpci_free_interrupt(struct vtpci_softc *sc, struct vtpci_interrupt *intr)
1125{
1126	device_t dev;
1127
1128	dev = sc->vtpci_dev;
1129
1130	if (intr->vti_handler != NULL) {
1131		bus_teardown_intr(dev, intr->vti_irq, intr->vti_handler);
1132		intr->vti_handler = NULL;
1133	}
1134
1135	if (intr->vti_irq != NULL) {
1136		bus_release_resource(dev, SYS_RES_IRQ, intr->vti_rid,
1137		    intr->vti_irq);
1138		intr->vti_irq = NULL;
1139		intr->vti_rid = -1;
1140	}
1141}
1142
1143static void
1144vtpci_free_interrupts(struct vtpci_softc *sc)
1145{
1146	struct vtpci_interrupt *intr;
1147	int i, nvq_intrs;
1148
1149	vtpci_free_interrupt(sc, &sc->vtpci_device_interrupt);
1150
1151	if (sc->vtpci_nmsix_resources != 0) {
1152		nvq_intrs = sc->vtpci_nmsix_resources - 1;
1153		sc->vtpci_nmsix_resources = 0;
1154
1155		intr = sc->vtpci_msix_vq_interrupts;
1156		if (intr != NULL) {
1157			for (i = 0; i < nvq_intrs; i++, intr++)
1158				vtpci_free_interrupt(sc, intr);
1159
1160			free(sc->vtpci_msix_vq_interrupts, M_DEVBUF);
1161			sc->vtpci_msix_vq_interrupts = NULL;
1162		}
1163	}
1164
1165	if (sc->vtpci_flags & (VTPCI_FLAG_MSI | VTPCI_FLAG_MSIX))
1166		pci_release_msi(sc->vtpci_dev);
1167
1168	sc->vtpci_flags &= ~VTPCI_FLAG_ITYPE_MASK;
1169}
1170
1171static void
1172vtpci_free_virtqueues(struct vtpci_softc *sc)
1173{
1174	struct vtpci_virtqueue *vqx;
1175	int idx;
1176
1177	for (idx = 0; idx < sc->vtpci_nvqs; idx++) {
1178		vqx = &sc->vtpci_vqs[idx];
1179
1180		vtpci_select_virtqueue(sc, idx);
1181		vtpci_write_config_4(sc, VIRTIO_PCI_QUEUE_PFN, 0);
1182
1183		virtqueue_free(vqx->vtv_vq);
1184		vqx->vtv_vq = NULL;
1185	}
1186
1187	free(sc->vtpci_vqs, M_DEVBUF);
1188	sc->vtpci_vqs = NULL;
1189	sc->vtpci_nvqs = 0;
1190}
1191
1192static void
1193vtpci_release_child_resources(struct vtpci_softc *sc)
1194{
1195
1196	vtpci_free_interrupts(sc);
1197	vtpci_free_virtqueues(sc);
1198}
1199
1200static void
1201vtpci_cleanup_setup_intr_attempt(struct vtpci_softc *sc)
1202{
1203	int idx;
1204
1205	if (sc->vtpci_flags & VTPCI_FLAG_MSIX) {
1206		vtpci_write_config_2(sc, VIRTIO_MSI_CONFIG_VECTOR,
1207		    VIRTIO_MSI_NO_VECTOR);
1208
1209		for (idx = 0; idx < sc->vtpci_nvqs; idx++) {
1210			vtpci_select_virtqueue(sc, idx);
1211			vtpci_write_config_2(sc, VIRTIO_MSI_QUEUE_VECTOR,
1212			    VIRTIO_MSI_NO_VECTOR);
1213		}
1214	}
1215
1216	vtpci_free_interrupts(sc);
1217}
1218
1219static void
1220vtpci_reset(struct vtpci_softc *sc)
1221{
1222
1223	/*
1224	 * Setting the status to RESET sets the host device to
1225	 * the original, uninitialized state.
1226	 */
1227	vtpci_set_status(sc->vtpci_dev, VIRTIO_CONFIG_STATUS_RESET);
1228}
1229
1230static void
1231vtpci_select_virtqueue(struct vtpci_softc *sc, int idx)
1232{
1233
1234	vtpci_write_config_2(sc, VIRTIO_PCI_QUEUE_SEL, idx);
1235}
1236
1237static void
1238vtpci_legacy_intr(void *xsc)
1239{
1240	struct vtpci_softc *sc;
1241	struct vtpci_virtqueue *vqx;
1242	int i;
1243	uint8_t isr;
1244
1245	sc = xsc;
1246	vqx = &sc->vtpci_vqs[0];
1247
1248	/* Reading the ISR also clears it. */
1249	isr = vtpci_read_config_1(sc, VIRTIO_PCI_ISR);
1250
1251	if (isr & VIRTIO_PCI_ISR_CONFIG)
1252		vtpci_config_intr(sc);
1253
1254	if (isr & VIRTIO_PCI_ISR_INTR) {
1255		for (i = 0; i < sc->vtpci_nvqs; i++, vqx++) {
1256			if (vqx->vtv_no_intr == 0)
1257				virtqueue_intr(vqx->vtv_vq);
1258		}
1259	}
1260}
1261
1262static int
1263vtpci_vq_shared_intr_filter(void *xsc)
1264{
1265	struct vtpci_softc *sc;
1266	struct vtpci_virtqueue *vqx;
1267	int i, rc;
1268
1269	rc = 0;
1270	sc = xsc;
1271	vqx = &sc->vtpci_vqs[0];
1272
1273	for (i = 0; i < sc->vtpci_nvqs; i++, vqx++) {
1274		if (vqx->vtv_no_intr == 0)
1275			rc |= virtqueue_intr_filter(vqx->vtv_vq);
1276	}
1277
1278	return (rc ? FILTER_SCHEDULE_THREAD : FILTER_STRAY);
1279}
1280
1281static void
1282vtpci_vq_shared_intr(void *xsc)
1283{
1284	struct vtpci_softc *sc;
1285	struct vtpci_virtqueue *vqx;
1286	int i;
1287
1288	sc = xsc;
1289	vqx = &sc->vtpci_vqs[0];
1290
1291	for (i = 0; i < sc->vtpci_nvqs; i++, vqx++) {
1292		if (vqx->vtv_no_intr == 0)
1293			virtqueue_intr(vqx->vtv_vq);
1294	}
1295}
1296
1297static int
1298vtpci_vq_intr_filter(void *xvq)
1299{
1300	struct virtqueue *vq;
1301	int rc;
1302
1303	vq = xvq;
1304	rc = virtqueue_intr_filter(vq);
1305
1306	return (rc ? FILTER_SCHEDULE_THREAD : FILTER_STRAY);
1307}
1308
1309static void
1310vtpci_vq_intr(void *xvq)
1311{
1312	struct virtqueue *vq;
1313
1314	vq = xvq;
1315	virtqueue_intr(vq);
1316}
1317
1318static void
1319vtpci_config_intr(void *xsc)
1320{
1321	struct vtpci_softc *sc;
1322	device_t child;
1323
1324	sc = xsc;
1325	child = sc->vtpci_child_dev;
1326
1327	if (child != NULL)
1328		VIRTIO_CONFIG_CHANGE(child);
1329}
1330