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