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