1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2011 NetApp, Inc.
5 * All rights reserved.
6 * Copyright 2020-2021 Joyent, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/param.h>
31#include <sys/linker_set.h>
32#include <sys/stat.h>
33#include <sys/uio.h>
34#include <sys/ioctl.h>
35#include <sys/disk.h>
36
37#include <machine/vmm_snapshot.h>
38
39#include <errno.h>
40#include <fcntl.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <stdint.h>
44#include <string.h>
45#include <strings.h>
46#include <unistd.h>
47#include <assert.h>
48#include <pthread.h>
49#include <md5.h>
50
51#include "bhyverun.h"
52#include "config.h"
53#include "debug.h"
54#include "pci_emul.h"
55#include "virtio.h"
56#include "block_if.h"
57
58#define	VTBLK_BSIZE	512
59#define	VTBLK_RINGSZ	128
60
61_Static_assert(VTBLK_RINGSZ <= BLOCKIF_RING_MAX, "Each ring entry must be able to queue a request");
62
63#define	VTBLK_S_OK	0
64#define	VTBLK_S_IOERR	1
65#define	VTBLK_S_UNSUPP	2
66
67#define	VTBLK_BLK_ID_BYTES	20 + 1
68
69/* Capability bits */
70#define	VTBLK_F_BARRIER		(1 << 0)	/* Does host support barriers? */
71#define	VTBLK_F_SIZE_MAX	(1 << 1)	/* Indicates maximum segment size */
72#define	VTBLK_F_SEG_MAX		(1 << 2)	/* Indicates maximum # of segments */
73#define	VTBLK_F_GEOMETRY	(1 << 4)	/* Legacy geometry available  */
74#define	VTBLK_F_RO		(1 << 5)	/* Disk is read-only */
75#define	VTBLK_F_BLK_SIZE	(1 << 6)	/* Block size of disk is available*/
76#define	VTBLK_F_SCSI		(1 << 7)	/* Supports scsi command passthru */
77#define	VTBLK_F_FLUSH		(1 << 9)	/* Writeback mode enabled after reset */
78#define	VTBLK_F_WCE		(1 << 9)	/* Legacy alias for FLUSH */
79#define	VTBLK_F_TOPOLOGY	(1 << 10)	/* Topology information is available */
80#define	VTBLK_F_CONFIG_WCE	(1 << 11)	/* Writeback mode available in config */
81#define	VTBLK_F_MQ		(1 << 12)	/* Multi-Queue */
82#define	VTBLK_F_DISCARD		(1 << 13)	/* Trim blocks */
83#define	VTBLK_F_WRITE_ZEROES	(1 << 14)	/* Write zeros */
84
85/*
86 * Host capabilities
87 */
88#define	VTBLK_S_HOSTCAPS      \
89  ( VTBLK_F_SEG_MAX  |						    \
90    VTBLK_F_BLK_SIZE |						    \
91    VTBLK_F_FLUSH    |						    \
92    VTBLK_F_TOPOLOGY |						    \
93    VIRTIO_RING_F_INDIRECT_DESC )	/* indirect descriptors */
94
95/*
96 * The current blockif_delete() interface only allows a single delete
97 * request at a time.
98 */
99#define	VTBLK_MAX_DISCARD_SEG	1
100
101/*
102 * An arbitrary limit to prevent excessive latency due to large
103 * delete requests.
104 */
105#define	VTBLK_MAX_DISCARD_SECT	((16 << 20) / VTBLK_BSIZE)	/* 16 MiB */
106
107/*
108 * Config space "registers"
109 */
110struct vtblk_config {
111	uint64_t	vbc_capacity;
112	uint32_t	vbc_size_max;
113	uint32_t	vbc_seg_max;
114	struct {
115		uint16_t cylinders;
116		uint8_t heads;
117		uint8_t sectors;
118	} vbc_geometry;
119	uint32_t	vbc_blk_size;
120	struct {
121		uint8_t physical_block_exp;
122		uint8_t alignment_offset;
123		uint16_t min_io_size;
124		uint32_t opt_io_size;
125	} vbc_topology;
126	uint8_t		vbc_writeback;
127	uint8_t		unused0[1];
128	uint16_t	num_queues;
129	uint32_t	max_discard_sectors;
130	uint32_t	max_discard_seg;
131	uint32_t	discard_sector_alignment;
132	uint32_t	max_write_zeroes_sectors;
133	uint32_t	max_write_zeroes_seg;
134	uint8_t		write_zeroes_may_unmap;
135	uint8_t		unused1[3];
136} __packed;
137
138/*
139 * Fixed-size block header
140 */
141struct virtio_blk_hdr {
142#define	VBH_OP_READ		0
143#define	VBH_OP_WRITE		1
144#define	VBH_OP_SCSI_CMD		2
145#define	VBH_OP_SCSI_CMD_OUT	3
146#define	VBH_OP_FLUSH		4
147#define	VBH_OP_FLUSH_OUT	5
148#define	VBH_OP_IDENT		8
149#define	VBH_OP_DISCARD		11
150#define	VBH_OP_WRITE_ZEROES	13
151
152#define	VBH_FLAG_BARRIER	0x80000000	/* OR'ed into vbh_type */
153	uint32_t	vbh_type;
154	uint32_t	vbh_ioprio;
155	uint64_t	vbh_sector;
156} __packed;
157
158/*
159 * Debug printf
160 */
161static int pci_vtblk_debug;
162#define	DPRINTF(params) if (pci_vtblk_debug) PRINTLN params
163#define	WPRINTF(params) PRINTLN params
164
165struct pci_vtblk_ioreq {
166	struct blockif_req		io_req;
167	struct pci_vtblk_softc		*io_sc;
168	uint8_t				*io_status;
169	uint16_t			io_idx;
170};
171
172struct virtio_blk_discard_write_zeroes {
173	uint64_t	sector;
174	uint32_t	num_sectors;
175	struct {
176		uint32_t unmap:1;
177		uint32_t reserved:31;
178	} flags;
179};
180
181/*
182 * Per-device softc
183 */
184struct pci_vtblk_softc {
185	struct virtio_softc vbsc_vs;
186	pthread_mutex_t vsc_mtx;
187	struct vqueue_info vbsc_vq;
188	struct vtblk_config vbsc_cfg;
189	struct virtio_consts vbsc_consts;
190	struct blockif_ctxt *bc;
191	char vbsc_ident[VTBLK_BLK_ID_BYTES];
192	struct pci_vtblk_ioreq vbsc_ios[VTBLK_RINGSZ];
193};
194
195static void pci_vtblk_reset(void *);
196static void pci_vtblk_notify(void *, struct vqueue_info *);
197static int pci_vtblk_cfgread(void *, int, int, uint32_t *);
198static int pci_vtblk_cfgwrite(void *, int, int, uint32_t);
199#ifdef BHYVE_SNAPSHOT
200static void pci_vtblk_pause(void *);
201static void pci_vtblk_resume(void *);
202static int pci_vtblk_snapshot(void *, struct vm_snapshot_meta *);
203#endif
204
205static struct virtio_consts vtblk_vi_consts = {
206	.vc_name =	"vtblk",
207	.vc_nvq =	1,
208	.vc_cfgsize =	sizeof(struct vtblk_config),
209	.vc_reset =	pci_vtblk_reset,
210	.vc_qnotify =	pci_vtblk_notify,
211	.vc_cfgread =	pci_vtblk_cfgread,
212	.vc_cfgwrite =	pci_vtblk_cfgwrite,
213	.vc_apply_features = NULL,
214	.vc_hv_caps =	VTBLK_S_HOSTCAPS,
215#ifdef BHYVE_SNAPSHOT
216	.vc_pause =	pci_vtblk_pause,
217	.vc_resume =	pci_vtblk_resume,
218	.vc_snapshot =	pci_vtblk_snapshot,
219#endif
220};
221
222static void
223pci_vtblk_reset(void *vsc)
224{
225	struct pci_vtblk_softc *sc = vsc;
226
227	DPRINTF(("vtblk: device reset requested !"));
228	vi_reset_dev(&sc->vbsc_vs);
229}
230
231static void
232pci_vtblk_done_locked(struct pci_vtblk_ioreq *io, int err)
233{
234	struct pci_vtblk_softc *sc = io->io_sc;
235
236	/* convert errno into a virtio block error return */
237	if (err == EOPNOTSUPP || err == ENOSYS)
238		*io->io_status = VTBLK_S_UNSUPP;
239	else if (err != 0)
240		*io->io_status = VTBLK_S_IOERR;
241	else
242		*io->io_status = VTBLK_S_OK;
243
244	/*
245	 * Return the descriptor back to the host.
246	 * We wrote 1 byte (our status) to host.
247	 */
248	vq_relchain(&sc->vbsc_vq, io->io_idx, 1);
249	vq_endchains(&sc->vbsc_vq, 0);
250}
251
252#ifdef BHYVE_SNAPSHOT
253static void
254pci_vtblk_pause(void *vsc)
255{
256	struct pci_vtblk_softc *sc = vsc;
257
258	DPRINTF(("vtblk: device pause requested !\n"));
259	blockif_pause(sc->bc);
260}
261
262static void
263pci_vtblk_resume(void *vsc)
264{
265	struct pci_vtblk_softc *sc = vsc;
266
267	DPRINTF(("vtblk: device resume requested !\n"));
268	blockif_resume(sc->bc);
269}
270
271static int
272pci_vtblk_snapshot(void *vsc, struct vm_snapshot_meta *meta)
273{
274	int ret;
275	struct pci_vtblk_softc *sc = vsc;
276
277	SNAPSHOT_VAR_OR_LEAVE(sc->vbsc_cfg, meta, ret, done);
278	SNAPSHOT_BUF_OR_LEAVE(sc->vbsc_ident, sizeof(sc->vbsc_ident),
279			      meta, ret, done);
280
281done:
282	return (ret);
283}
284#endif
285
286static void
287pci_vtblk_done(struct blockif_req *br, int err)
288{
289	struct pci_vtblk_ioreq *io = br->br_param;
290	struct pci_vtblk_softc *sc = io->io_sc;
291
292	pthread_mutex_lock(&sc->vsc_mtx);
293	pci_vtblk_done_locked(io, err);
294	pthread_mutex_unlock(&sc->vsc_mtx);
295}
296
297static void
298pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
299{
300	struct virtio_blk_hdr *vbh;
301	struct pci_vtblk_ioreq *io;
302	int i, n;
303	int err;
304	ssize_t iolen;
305	int writeop, type;
306	struct vi_req req;
307	struct iovec iov[BLOCKIF_IOV_MAX + 2];
308	struct virtio_blk_discard_write_zeroes *discard;
309
310	n = vq_getchain(vq, iov, BLOCKIF_IOV_MAX + 2, &req);
311
312	/*
313	 * The first descriptor will be the read-only fixed header,
314	 * and the last is for status (hence +2 above and below).
315	 * The remaining iov's are the actual data I/O vectors.
316	 *
317	 * XXX - note - this fails on crash dump, which does a
318	 * VIRTIO_BLK_T_FLUSH with a zero transfer length
319	 */
320	assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2);
321
322	io = &sc->vbsc_ios[req.idx];
323	assert(req.readable != 0);
324	assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr));
325	vbh = (struct virtio_blk_hdr *)iov[0].iov_base;
326	memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2));
327	io->io_req.br_iovcnt = n - 2;
328	io->io_req.br_offset = vbh->vbh_sector * VTBLK_BSIZE;
329	io->io_status = (uint8_t *)iov[--n].iov_base;
330	assert(req.writable != 0);
331	assert(iov[n].iov_len == 1);
332
333	/*
334	 * XXX
335	 * The guest should not be setting the BARRIER flag because
336	 * we don't advertise the capability.
337	 */
338	type = vbh->vbh_type & ~VBH_FLAG_BARRIER;
339	writeop = (type == VBH_OP_WRITE || type == VBH_OP_DISCARD);
340	/*
341	 * - Write op implies read-only descriptor
342	 * - Read/ident op implies write-only descriptor
343	 *
344	 * By taking away either the read-only fixed header or the write-only
345	 * status iovec, the following condition should hold true.
346	 */
347	assert(n == (writeop ? req.readable : req.writable));
348
349	iolen = 0;
350	for (i = 1; i < n; i++) {
351		iolen += iov[i].iov_len;
352	}
353	io->io_req.br_resid = iolen;
354
355	DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld",
356		 writeop ? "write/discard" : "read/ident", iolen, i - 1,
357		 io->io_req.br_offset));
358
359	switch (type) {
360	case VBH_OP_READ:
361		err = blockif_read(sc->bc, &io->io_req);
362		break;
363	case VBH_OP_WRITE:
364		err = blockif_write(sc->bc, &io->io_req);
365		break;
366	case VBH_OP_DISCARD:
367		/*
368		 * We currently only support a single request, if the guest
369		 * has submitted a request that doesn't conform to the
370		 * requirements, we return a error.
371		 */
372		if (iov[1].iov_len != sizeof (*discard)) {
373			pci_vtblk_done_locked(io, EINVAL);
374			return;
375		}
376
377		/* The segments to discard are provided rather than data */
378		discard = (struct virtio_blk_discard_write_zeroes *)
379		    iov[1].iov_base;
380
381		/*
382		 * virtio v1.1 5.2.6.2:
383		 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP
384		 * for discard and write zeroes commands if any unknown flag is
385		 * set. Furthermore, the device MUST set the status byte to
386		 * VIRTIO_BLK_S_UNSUPP for discard commands if the unmap flag
387		 * is set.
388		 *
389		 * Currently there are no known flags for a DISCARD request.
390		 */
391		if (discard->flags.unmap != 0 || discard->flags.reserved != 0) {
392			pci_vtblk_done_locked(io, ENOTSUP);
393			return;
394		}
395
396		/* Make sure the request doesn't exceed our size limit */
397		if (discard->num_sectors > VTBLK_MAX_DISCARD_SECT) {
398			pci_vtblk_done_locked(io, EINVAL);
399			return;
400		}
401
402		io->io_req.br_offset = discard->sector * VTBLK_BSIZE;
403		io->io_req.br_resid = discard->num_sectors * VTBLK_BSIZE;
404		err = blockif_delete(sc->bc, &io->io_req);
405		break;
406	case VBH_OP_FLUSH:
407	case VBH_OP_FLUSH_OUT:
408		err = blockif_flush(sc->bc, &io->io_req);
409		break;
410	case VBH_OP_IDENT:
411		/* Assume a single buffer */
412		/* S/n equal to buffer is not zero-terminated. */
413		memset(iov[1].iov_base, 0, iov[1].iov_len);
414		strncpy(iov[1].iov_base, sc->vbsc_ident,
415		    MIN(iov[1].iov_len, sizeof(sc->vbsc_ident)));
416		pci_vtblk_done_locked(io, 0);
417		return;
418	default:
419		pci_vtblk_done_locked(io, EOPNOTSUPP);
420		return;
421	}
422	assert(err == 0);
423}
424
425static void
426pci_vtblk_notify(void *vsc, struct vqueue_info *vq)
427{
428	struct pci_vtblk_softc *sc = vsc;
429
430	while (vq_has_descs(vq))
431		pci_vtblk_proc(sc, vq);
432}
433
434static void
435pci_vtblk_resized(struct blockif_ctxt *bctxt __unused, void *arg,
436    size_t new_size)
437{
438	struct pci_vtblk_softc *sc;
439
440	sc = arg;
441
442	sc->vbsc_cfg.vbc_capacity = new_size / VTBLK_BSIZE; /* 512-byte units */
443	vi_interrupt(&sc->vbsc_vs, VIRTIO_PCI_ISR_CONFIG,
444	    sc->vbsc_vs.vs_msix_cfg_idx);
445}
446
447static int
448pci_vtblk_init(struct pci_devinst *pi, nvlist_t *nvl)
449{
450	char bident[sizeof("XXX:XXX")];
451	struct blockif_ctxt *bctxt;
452	const char *path, *serial;
453	MD5_CTX mdctx;
454	u_char digest[16];
455	struct pci_vtblk_softc *sc;
456	off_t size;
457	int i, sectsz, sts, sto;
458
459	/*
460	 * The supplied backing file has to exist
461	 */
462	snprintf(bident, sizeof(bident), "%u:%u", pi->pi_slot, pi->pi_func);
463	bctxt = blockif_open(nvl, bident);
464	if (bctxt == NULL) {
465		perror("Could not open backing file");
466		return (1);
467	}
468
469	if (blockif_add_boot_device(pi, bctxt)) {
470		perror("Invalid boot device");
471		return (1);
472	}
473
474	size = blockif_size(bctxt);
475	sectsz = blockif_sectsz(bctxt);
476	blockif_psectsz(bctxt, &sts, &sto);
477
478	sc = calloc(1, sizeof(struct pci_vtblk_softc));
479	sc->bc = bctxt;
480	for (i = 0; i < VTBLK_RINGSZ; i++) {
481		struct pci_vtblk_ioreq *io = &sc->vbsc_ios[i];
482		io->io_req.br_callback = pci_vtblk_done;
483		io->io_req.br_param = io;
484		io->io_sc = sc;
485		io->io_idx = i;
486	}
487
488	bcopy(&vtblk_vi_consts, &sc->vbsc_consts, sizeof (vtblk_vi_consts));
489	if (blockif_candelete(sc->bc))
490		sc->vbsc_consts.vc_hv_caps |= VTBLK_F_DISCARD;
491
492	pthread_mutex_init(&sc->vsc_mtx, NULL);
493
494	/* init virtio softc and virtqueues */
495	vi_softc_linkup(&sc->vbsc_vs, &sc->vbsc_consts, sc, pi, &sc->vbsc_vq);
496	sc->vbsc_vs.vs_mtx = &sc->vsc_mtx;
497
498	sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ;
499	/* sc->vbsc_vq.vq_notify = we have no per-queue notify */
500
501	/*
502	 * If an explicit identifier is not given, create an
503	 * identifier using parts of the md5 sum of the filename.
504	 */
505	bzero(sc->vbsc_ident, VTBLK_BLK_ID_BYTES);
506	if ((serial = get_config_value_node(nvl, "serial")) != NULL ||
507	    (serial = get_config_value_node(nvl, "ser")) != NULL) {
508		strlcpy(sc->vbsc_ident, serial, VTBLK_BLK_ID_BYTES);
509	} else {
510		path = get_config_value_node(nvl, "path");
511		MD5Init(&mdctx);
512		MD5Update(&mdctx, path, strlen(path));
513		MD5Final(digest, &mdctx);
514		snprintf(sc->vbsc_ident, VTBLK_BLK_ID_BYTES,
515		    "BHYVE-%02X%02X-%02X%02X-%02X%02X",
516		    digest[0], digest[1], digest[2], digest[3], digest[4],
517		    digest[5]);
518	}
519
520	/* setup virtio block config space */
521	sc->vbsc_cfg.vbc_capacity = size / VTBLK_BSIZE; /* 512-byte units */
522	sc->vbsc_cfg.vbc_size_max = 0;	/* not negotiated */
523
524	/*
525	 * If Linux is presented with a seg_max greater than the virtio queue
526	 * size, it can stumble into situations where it violates its own
527	 * invariants and panics.  For safety, we keep seg_max clamped, paying
528	 * heed to the two extra descriptors needed for the header and status
529	 * of a request.
530	 */
531	sc->vbsc_cfg.vbc_seg_max = MIN(VTBLK_RINGSZ - 2, BLOCKIF_IOV_MAX);
532	sc->vbsc_cfg.vbc_geometry.cylinders = 0;	/* no geometry */
533	sc->vbsc_cfg.vbc_geometry.heads = 0;
534	sc->vbsc_cfg.vbc_geometry.sectors = 0;
535	sc->vbsc_cfg.vbc_blk_size = sectsz;
536	sc->vbsc_cfg.vbc_topology.physical_block_exp =
537	    (sts > sectsz) ? (ffsll(sts / sectsz) - 1) : 0;
538	sc->vbsc_cfg.vbc_topology.alignment_offset =
539	    (sto != 0) ? ((sts - sto) / sectsz) : 0;
540	sc->vbsc_cfg.vbc_topology.min_io_size = 0;
541	sc->vbsc_cfg.vbc_topology.opt_io_size = 0;
542	sc->vbsc_cfg.vbc_writeback = 0;
543	sc->vbsc_cfg.max_discard_sectors = VTBLK_MAX_DISCARD_SECT;
544	sc->vbsc_cfg.max_discard_seg = VTBLK_MAX_DISCARD_SEG;
545	sc->vbsc_cfg.discard_sector_alignment = MAX(sectsz, sts) / VTBLK_BSIZE;
546
547	/*
548	 * Should we move some of this into virtio.c?  Could
549	 * have the device, class, and subdev_0 as fields in
550	 * the virtio constants structure.
551	 */
552	pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK);
553	pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
554	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
555	pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_ID_BLOCK);
556	pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
557
558	if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix())) {
559		blockif_close(sc->bc);
560		free(sc);
561		return (1);
562	}
563	vi_set_io_bar(&sc->vbsc_vs, 0);
564	blockif_register_resize_callback(sc->bc, pci_vtblk_resized, sc);
565	return (0);
566}
567
568static int
569pci_vtblk_cfgwrite(void *vsc __unused, int offset, int size __unused,
570    uint32_t value __unused)
571{
572
573	DPRINTF(("vtblk: write to readonly reg %d", offset));
574	return (1);
575}
576
577static int
578pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval)
579{
580	struct pci_vtblk_softc *sc = vsc;
581	void *ptr;
582
583	/* our caller has already verified offset and size */
584	ptr = (uint8_t *)&sc->vbsc_cfg + offset;
585	memcpy(retval, ptr, size);
586	return (0);
587}
588
589static const struct pci_devemu pci_de_vblk = {
590	.pe_emu =	"virtio-blk",
591	.pe_init =	pci_vtblk_init,
592	.pe_legacy_config = blockif_legacy_config,
593	.pe_barwrite =	vi_pci_write,
594	.pe_barread =	vi_pci_read,
595#ifdef BHYVE_SNAPSHOT
596	.pe_snapshot =	vi_pci_snapshot,
597	.pe_pause =     vi_pci_pause,
598	.pe_resume =    vi_pci_resume,
599#endif
600};
601PCI_EMUL_SET(pci_de_vblk);
602