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/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/linker_set.h>
33 #include <sys/stat.h>
34 #include <sys/uio.h>
35 #include <sys/ioctl.h>
36 #include <sys/disk.h>
37
38 #include <machine/vmm_snapshot.h>
39
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <stdint.h>
45 #include <string.h>
46 #include <strings.h>
47 #include <unistd.h>
48 #include <assert.h>
49 #include <pthread.h>
50 #include <md5.h>
51
52 #include "bhyverun.h"
53 #include "config.h"
54 #include "debug.h"
55 #include "pci_emul.h"
56 #include "virtio.h"
57 #include "block_if.h"
58
59 #define VTBLK_BSIZE 512
60 #define VTBLK_RINGSZ 128
61
62 _Static_assert(VTBLK_RINGSZ <= BLOCKIF_RING_MAX, "Each ring entry must be able to queue a request");
63
64 #define VTBLK_S_OK 0
65 #define VTBLK_S_IOERR 1
66 #define VTBLK_S_UNSUPP 2
67
68 #define VTBLK_BLK_ID_BYTES 20 + 1
69
70 /* Capability bits */
71 #define VTBLK_F_BARRIER (1 << 0) /* Does host support barriers? */
72 #define VTBLK_F_SIZE_MAX (1 << 1) /* Indicates maximum segment size */
73 #define VTBLK_F_SEG_MAX (1 << 2) /* Indicates maximum # of segments */
74 #define VTBLK_F_GEOMETRY (1 << 4) /* Legacy geometry available */
75 #define VTBLK_F_RO (1 << 5) /* Disk is read-only */
76 #define VTBLK_F_BLK_SIZE (1 << 6) /* Block size of disk is available*/
77 #define VTBLK_F_SCSI (1 << 7) /* Supports scsi command passthru */
78 #define VTBLK_F_FLUSH (1 << 9) /* Writeback mode enabled after reset */
79 #define VTBLK_F_WCE (1 << 9) /* Legacy alias for FLUSH */
80 #define VTBLK_F_TOPOLOGY (1 << 10) /* Topology information is available */
81 #define VTBLK_F_CONFIG_WCE (1 << 11) /* Writeback mode available in config */
82 #define VTBLK_F_MQ (1 << 12) /* Multi-Queue */
83 #define VTBLK_F_DISCARD (1 << 13) /* Trim blocks */
84 #define VTBLK_F_WRITE_ZEROES (1 << 14) /* Write zeros */
85
86 /*
87 * Host capabilities
88 */
89 #define VTBLK_S_HOSTCAPS \
90 ( VTBLK_F_SEG_MAX | \
91 VTBLK_F_BLK_SIZE | \
92 VTBLK_F_FLUSH | \
93 VTBLK_F_TOPOLOGY | \
94 VIRTIO_RING_F_INDIRECT_DESC ) /* indirect descriptors */
95
96 /*
97 * The current blockif_delete() interface only allows a single delete
98 * request at a time.
99 */
100 #define VTBLK_MAX_DISCARD_SEG 1
101
102 /*
103 * An arbitrary limit to prevent excessive latency due to large
104 * delete requests.
105 */
106 #define VTBLK_MAX_DISCARD_SECT ((16 << 20) / VTBLK_BSIZE) /* 16 MiB */
107
108 /*
109 * Config space "registers"
110 */
111 struct vtblk_config {
112 uint64_t vbc_capacity;
113 uint32_t vbc_size_max;
114 uint32_t vbc_seg_max;
115 struct {
116 uint16_t cylinders;
117 uint8_t heads;
118 uint8_t sectors;
119 } vbc_geometry;
120 uint32_t vbc_blk_size;
121 struct {
122 uint8_t physical_block_exp;
123 uint8_t alignment_offset;
124 uint16_t min_io_size;
125 uint32_t opt_io_size;
126 } vbc_topology;
127 uint8_t vbc_writeback;
128 uint8_t unused0[1];
129 uint16_t num_queues;
130 uint32_t max_discard_sectors;
131 uint32_t max_discard_seg;
132 uint32_t discard_sector_alignment;
133 uint32_t max_write_zeroes_sectors;
134 uint32_t max_write_zeroes_seg;
135 uint8_t write_zeroes_may_unmap;
136 uint8_t unused1[3];
137 } __packed;
138
139 /*
140 * Fixed-size block header
141 */
142 struct virtio_blk_hdr {
143 #define VBH_OP_READ 0
144 #define VBH_OP_WRITE 1
145 #define VBH_OP_SCSI_CMD 2
146 #define VBH_OP_SCSI_CMD_OUT 3
147 #define VBH_OP_FLUSH 4
148 #define VBH_OP_FLUSH_OUT 5
149 #define VBH_OP_IDENT 8
150 #define VBH_OP_DISCARD 11
151 #define VBH_OP_WRITE_ZEROES 13
152
153 #define VBH_FLAG_BARRIER 0x80000000 /* OR'ed into vbh_type */
154 uint32_t vbh_type;
155 uint32_t vbh_ioprio;
156 uint64_t vbh_sector;
157 } __packed;
158
159 /*
160 * Debug printf
161 */
162 static int pci_vtblk_debug;
163 #define DPRINTF(params) if (pci_vtblk_debug) PRINTLN params
164 #define WPRINTF(params) PRINTLN params
165
166 struct pci_vtblk_ioreq {
167 struct blockif_req io_req;
168 struct pci_vtblk_softc *io_sc;
169 uint8_t *io_status;
170 uint16_t io_idx;
171 };
172
173 struct virtio_blk_discard_write_zeroes {
174 uint64_t sector;
175 uint32_t num_sectors;
176 struct {
177 uint32_t unmap:1;
178 uint32_t reserved:31;
179 } flags;
180 };
181
182 /*
183 * Per-device softc
184 */
185 struct pci_vtblk_softc {
186 struct virtio_softc vbsc_vs;
187 pthread_mutex_t vsc_mtx;
188 struct vqueue_info vbsc_vq;
189 struct vtblk_config vbsc_cfg;
190 struct virtio_consts vbsc_consts;
191 struct blockif_ctxt *bc;
192 char vbsc_ident[VTBLK_BLK_ID_BYTES];
193 struct pci_vtblk_ioreq vbsc_ios[VTBLK_RINGSZ];
194 };
195
196 static void pci_vtblk_reset(void *);
197 static void pci_vtblk_notify(void *, struct vqueue_info *);
198 static int pci_vtblk_cfgread(void *, int, int, uint32_t *);
199 static int pci_vtblk_cfgwrite(void *, int, int, uint32_t);
200 #ifdef BHYVE_SNAPSHOT
201 static void pci_vtblk_pause(void *);
202 static void pci_vtblk_resume(void *);
203 static int pci_vtblk_snapshot(void *, struct vm_snapshot_meta *);
204 #endif
205
206 static struct virtio_consts vtblk_vi_consts = {
207 .vc_name = "vtblk",
208 .vc_nvq = 1,
209 .vc_cfgsize = sizeof(struct vtblk_config),
210 .vc_reset = pci_vtblk_reset,
211 .vc_qnotify = pci_vtblk_notify,
212 .vc_cfgread = pci_vtblk_cfgread,
213 .vc_cfgwrite = pci_vtblk_cfgwrite,
214 .vc_apply_features = NULL,
215 .vc_hv_caps = VTBLK_S_HOSTCAPS,
216 #ifdef BHYVE_SNAPSHOT
217 .vc_pause = pci_vtblk_pause,
218 .vc_resume = pci_vtblk_resume,
219 .vc_snapshot = pci_vtblk_snapshot,
220 #endif
221 };
222
223 static void
pci_vtblk_reset(void * vsc)224 pci_vtblk_reset(void *vsc)
225 {
226 struct pci_vtblk_softc *sc = vsc;
227
228 DPRINTF(("vtblk: device reset requested !"));
229 vi_reset_dev(&sc->vbsc_vs);
230 }
231
232 static void
pci_vtblk_done_locked(struct pci_vtblk_ioreq * io,int err)233 pci_vtblk_done_locked(struct pci_vtblk_ioreq *io, int err)
234 {
235 struct pci_vtblk_softc *sc = io->io_sc;
236
237 /* convert errno into a virtio block error return */
238 if (err == EOPNOTSUPP || err == ENOSYS)
239 *io->io_status = VTBLK_S_UNSUPP;
240 else if (err != 0)
241 *io->io_status = VTBLK_S_IOERR;
242 else
243 *io->io_status = VTBLK_S_OK;
244
245 /*
246 * Return the descriptor back to the host.
247 * We wrote 1 byte (our status) to host.
248 */
249 vq_relchain(&sc->vbsc_vq, io->io_idx, 1);
250 vq_endchains(&sc->vbsc_vq, 0);
251 }
252
253 #ifdef BHYVE_SNAPSHOT
254 static void
pci_vtblk_pause(void * vsc)255 pci_vtblk_pause(void *vsc)
256 {
257 struct pci_vtblk_softc *sc = vsc;
258
259 DPRINTF(("vtblk: device pause requested !\n"));
260 blockif_pause(sc->bc);
261 }
262
263 static void
pci_vtblk_resume(void * vsc)264 pci_vtblk_resume(void *vsc)
265 {
266 struct pci_vtblk_softc *sc = vsc;
267
268 DPRINTF(("vtblk: device resume requested !\n"));
269 blockif_resume(sc->bc);
270 }
271
272 static int
pci_vtblk_snapshot(void * vsc,struct vm_snapshot_meta * meta)273 pci_vtblk_snapshot(void *vsc, struct vm_snapshot_meta *meta)
274 {
275 int ret;
276 struct pci_vtblk_softc *sc = vsc;
277
278 SNAPSHOT_VAR_OR_LEAVE(sc->vbsc_cfg, meta, ret, done);
279 SNAPSHOT_BUF_OR_LEAVE(sc->vbsc_ident, sizeof(sc->vbsc_ident),
280 meta, ret, done);
281
282 done:
283 return (ret);
284 }
285 #endif
286
287 static void
pci_vtblk_done(struct blockif_req * br,int err)288 pci_vtblk_done(struct blockif_req *br, int err)
289 {
290 struct pci_vtblk_ioreq *io = br->br_param;
291 struct pci_vtblk_softc *sc = io->io_sc;
292
293 pthread_mutex_lock(&sc->vsc_mtx);
294 pci_vtblk_done_locked(io, err);
295 pthread_mutex_unlock(&sc->vsc_mtx);
296 }
297
298 static void
pci_vtblk_proc(struct pci_vtblk_softc * sc,struct vqueue_info * vq)299 pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
300 {
301 struct virtio_blk_hdr *vbh;
302 struct pci_vtblk_ioreq *io;
303 int i, n;
304 int err;
305 ssize_t iolen;
306 int writeop, type;
307 struct vi_req req;
308 struct iovec iov[BLOCKIF_IOV_MAX + 2];
309 struct virtio_blk_discard_write_zeroes *discard;
310
311 n = vq_getchain(vq, iov, BLOCKIF_IOV_MAX + 2, &req);
312
313 /*
314 * The first descriptor will be the read-only fixed header,
315 * and the last is for status (hence +2 above and below).
316 * The remaining iov's are the actual data I/O vectors.
317 *
318 * XXX - note - this fails on crash dump, which does a
319 * VIRTIO_BLK_T_FLUSH with a zero transfer length
320 */
321 assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2);
322
323 io = &sc->vbsc_ios[req.idx];
324 assert(req.readable != 0);
325 assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr));
326 vbh = (struct virtio_blk_hdr *)iov[0].iov_base;
327 memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2));
328 io->io_req.br_iovcnt = n - 2;
329 io->io_req.br_offset = vbh->vbh_sector * VTBLK_BSIZE;
330 io->io_status = (uint8_t *)iov[--n].iov_base;
331 assert(req.writable != 0);
332 assert(iov[n].iov_len == 1);
333
334 /*
335 * XXX
336 * The guest should not be setting the BARRIER flag because
337 * we don't advertise the capability.
338 */
339 type = vbh->vbh_type & ~VBH_FLAG_BARRIER;
340 writeop = (type == VBH_OP_WRITE || type == VBH_OP_DISCARD);
341 /*
342 * - Write op implies read-only descriptor
343 * - Read/ident op implies write-only descriptor
344 *
345 * By taking away either the read-only fixed header or the write-only
346 * status iovec, the following condition should hold true.
347 */
348 assert(n == (writeop ? req.readable : req.writable));
349
350 iolen = 0;
351 for (i = 1; i < n; i++) {
352 iolen += iov[i].iov_len;
353 }
354 io->io_req.br_resid = iolen;
355
356 DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld",
357 writeop ? "write/discard" : "read/ident", iolen, i - 1,
358 io->io_req.br_offset));
359
360 switch (type) {
361 case VBH_OP_READ:
362 err = blockif_read(sc->bc, &io->io_req);
363 break;
364 case VBH_OP_WRITE:
365 err = blockif_write(sc->bc, &io->io_req);
366 break;
367 case VBH_OP_DISCARD:
368 /*
369 * We currently only support a single request, if the guest
370 * has submitted a request that doesn't conform to the
371 * requirements, we return a error.
372 */
373 if (iov[1].iov_len != sizeof (*discard)) {
374 pci_vtblk_done_locked(io, EINVAL);
375 return;
376 }
377
378 /* The segments to discard are provided rather than data */
379 discard = (struct virtio_blk_discard_write_zeroes *)
380 iov[1].iov_base;
381
382 /*
383 * virtio v1.1 5.2.6.2:
384 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP
385 * for discard and write zeroes commands if any unknown flag is
386 * set. Furthermore, the device MUST set the status byte to
387 * VIRTIO_BLK_S_UNSUPP for discard commands if the unmap flag
388 * is set.
389 *
390 * Currently there are no known flags for a DISCARD request.
391 */
392 if (discard->flags.unmap != 0 || discard->flags.reserved != 0) {
393 pci_vtblk_done_locked(io, ENOTSUP);
394 return;
395 }
396
397 /* Make sure the request doesn't exceed our size limit */
398 if (discard->num_sectors > VTBLK_MAX_DISCARD_SECT) {
399 pci_vtblk_done_locked(io, EINVAL);
400 return;
401 }
402
403 io->io_req.br_offset = discard->sector * VTBLK_BSIZE;
404 io->io_req.br_resid = discard->num_sectors * VTBLK_BSIZE;
405 err = blockif_delete(sc->bc, &io->io_req);
406 break;
407 case VBH_OP_FLUSH:
408 case VBH_OP_FLUSH_OUT:
409 err = blockif_flush(sc->bc, &io->io_req);
410 break;
411 case VBH_OP_IDENT:
412 /* Assume a single buffer */
413 /* S/n equal to buffer is not zero-terminated. */
414 memset(iov[1].iov_base, 0, iov[1].iov_len);
415 strncpy(iov[1].iov_base, sc->vbsc_ident,
416 MIN(iov[1].iov_len, sizeof(sc->vbsc_ident)));
417 pci_vtblk_done_locked(io, 0);
418 return;
419 default:
420 pci_vtblk_done_locked(io, EOPNOTSUPP);
421 return;
422 }
423 assert(err == 0);
424 }
425
426 static void
pci_vtblk_notify(void * vsc,struct vqueue_info * vq)427 pci_vtblk_notify(void *vsc, struct vqueue_info *vq)
428 {
429 struct pci_vtblk_softc *sc = vsc;
430
431 while (vq_has_descs(vq))
432 pci_vtblk_proc(sc, vq);
433 }
434
435 static void
pci_vtblk_resized(struct blockif_ctxt * bctxt __unused,void * arg,size_t new_size)436 pci_vtblk_resized(struct blockif_ctxt *bctxt __unused, void *arg,
437 size_t new_size)
438 {
439 struct pci_vtblk_softc *sc;
440
441 sc = arg;
442
443 sc->vbsc_cfg.vbc_capacity = new_size / VTBLK_BSIZE; /* 512-byte units */
444 vi_interrupt(&sc->vbsc_vs, VIRTIO_PCI_ISR_CONFIG,
445 sc->vbsc_vs.vs_msix_cfg_idx);
446 }
447
448 static int
pci_vtblk_init(struct pci_devinst * pi,nvlist_t * nvl)449 pci_vtblk_init(struct pci_devinst *pi, nvlist_t *nvl)
450 {
451 char bident[sizeof("XXX:XXX")];
452 struct blockif_ctxt *bctxt;
453 const char *path, *serial;
454 MD5_CTX mdctx;
455 u_char digest[16];
456 struct pci_vtblk_softc *sc;
457 off_t size;
458 int i, sectsz, sts, sto;
459
460 /*
461 * The supplied backing file has to exist
462 */
463 snprintf(bident, sizeof(bident), "%u:%u", pi->pi_slot, pi->pi_func);
464 bctxt = blockif_open(nvl, bident);
465 if (bctxt == NULL) {
466 perror("Could not open backing file");
467 return (1);
468 }
469
470 if (blockif_add_boot_device(pi, bctxt)) {
471 perror("Invalid boot device");
472 return (1);
473 }
474
475 size = blockif_size(bctxt);
476 sectsz = blockif_sectsz(bctxt);
477 blockif_psectsz(bctxt, &sts, &sto);
478
479 sc = calloc(1, sizeof(struct pci_vtblk_softc));
480 sc->bc = bctxt;
481 for (i = 0; i < VTBLK_RINGSZ; i++) {
482 struct pci_vtblk_ioreq *io = &sc->vbsc_ios[i];
483 io->io_req.br_callback = pci_vtblk_done;
484 io->io_req.br_param = io;
485 io->io_sc = sc;
486 io->io_idx = i;
487 }
488
489 bcopy(&vtblk_vi_consts, &sc->vbsc_consts, sizeof (vtblk_vi_consts));
490 if (blockif_candelete(sc->bc))
491 sc->vbsc_consts.vc_hv_caps |= VTBLK_F_DISCARD;
492
493 pthread_mutex_init(&sc->vsc_mtx, NULL);
494
495 /* init virtio softc and virtqueues */
496 vi_softc_linkup(&sc->vbsc_vs, &sc->vbsc_consts, sc, pi, &sc->vbsc_vq);
497 sc->vbsc_vs.vs_mtx = &sc->vsc_mtx;
498
499 sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ;
500 /* sc->vbsc_vq.vq_notify = we have no per-queue notify */
501
502 /*
503 * If an explicit identifier is not given, create an
504 * identifier using parts of the md5 sum of the filename.
505 */
506 bzero(sc->vbsc_ident, VTBLK_BLK_ID_BYTES);
507 if ((serial = get_config_value_node(nvl, "serial")) != NULL ||
508 (serial = get_config_value_node(nvl, "ser")) != NULL) {
509 strlcpy(sc->vbsc_ident, serial, VTBLK_BLK_ID_BYTES);
510 } else {
511 path = get_config_value_node(nvl, "path");
512 MD5Init(&mdctx);
513 MD5Update(&mdctx, path, strlen(path));
514 MD5Final(digest, &mdctx);
515 snprintf(sc->vbsc_ident, VTBLK_BLK_ID_BYTES,
516 "BHYVE-%02X%02X-%02X%02X-%02X%02X",
517 digest[0], digest[1], digest[2], digest[3], digest[4],
518 digest[5]);
519 }
520
521 /* setup virtio block config space */
522 sc->vbsc_cfg.vbc_capacity = size / VTBLK_BSIZE; /* 512-byte units */
523 sc->vbsc_cfg.vbc_size_max = 0; /* not negotiated */
524
525 /*
526 * If Linux is presented with a seg_max greater than the virtio queue
527 * size, it can stumble into situations where it violates its own
528 * invariants and panics. For safety, we keep seg_max clamped, paying
529 * heed to the two extra descriptors needed for the header and status
530 * of a request.
531 */
532 sc->vbsc_cfg.vbc_seg_max = MIN(VTBLK_RINGSZ - 2, BLOCKIF_IOV_MAX);
533 sc->vbsc_cfg.vbc_geometry.cylinders = 0; /* no geometry */
534 sc->vbsc_cfg.vbc_geometry.heads = 0;
535 sc->vbsc_cfg.vbc_geometry.sectors = 0;
536 sc->vbsc_cfg.vbc_blk_size = sectsz;
537 sc->vbsc_cfg.vbc_topology.physical_block_exp =
538 (sts > sectsz) ? (ffsll(sts / sectsz) - 1) : 0;
539 sc->vbsc_cfg.vbc_topology.alignment_offset =
540 (sto != 0) ? ((sts - sto) / sectsz) : 0;
541 sc->vbsc_cfg.vbc_topology.min_io_size = 0;
542 sc->vbsc_cfg.vbc_topology.opt_io_size = 0;
543 sc->vbsc_cfg.vbc_writeback = 0;
544 sc->vbsc_cfg.max_discard_sectors = VTBLK_MAX_DISCARD_SECT;
545 sc->vbsc_cfg.max_discard_seg = VTBLK_MAX_DISCARD_SEG;
546 sc->vbsc_cfg.discard_sector_alignment = MAX(sectsz, sts) / VTBLK_BSIZE;
547
548 /*
549 * Should we move some of this into virtio.c? Could
550 * have the device, class, and subdev_0 as fields in
551 * the virtio constants structure.
552 */
553 pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK);
554 pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
555 pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
556 pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_ID_BLOCK);
557 pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
558
559 if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix())) {
560 blockif_close(sc->bc);
561 free(sc);
562 return (1);
563 }
564 vi_set_io_bar(&sc->vbsc_vs, 0);
565 blockif_register_resize_callback(sc->bc, pci_vtblk_resized, sc);
566 return (0);
567 }
568
569 static int
pci_vtblk_cfgwrite(void * vsc __unused,int offset,int size __unused,uint32_t value __unused)570 pci_vtblk_cfgwrite(void *vsc __unused, int offset, int size __unused,
571 uint32_t value __unused)
572 {
573
574 DPRINTF(("vtblk: write to readonly reg %d", offset));
575 return (1);
576 }
577
578 static int
pci_vtblk_cfgread(void * vsc,int offset,int size,uint32_t * retval)579 pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval)
580 {
581 struct pci_vtblk_softc *sc = vsc;
582 void *ptr;
583
584 /* our caller has already verified offset and size */
585 ptr = (uint8_t *)&sc->vbsc_cfg + offset;
586 memcpy(retval, ptr, size);
587 return (0);
588 }
589
590 static const struct pci_devemu pci_de_vblk = {
591 .pe_emu = "virtio-blk",
592 .pe_init = pci_vtblk_init,
593 .pe_legacy_config = blockif_legacy_config,
594 .pe_barwrite = vi_pci_write,
595 .pe_barread = vi_pci_read,
596 #ifdef BHYVE_SNAPSHOT
597 .pe_snapshot = vi_pci_snapshot,
598 .pe_pause = vi_pci_pause,
599 .pe_resume = vi_pci_resume,
600 #endif
601 };
602 PCI_EMUL_SET(pci_de_vblk);
603