1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2011 NetApp, Inc. 5 * All rights reserved. 6 * Copyright (c) 2019 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: stable/11/usr.sbin/bhyve/pci_virtio_block.c 348375 2019-05-29 23:11:07Z jhb $ 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: stable/11/usr.sbin/bhyve/pci_virtio_block.c 348375 2019-05-29 23:11:07Z jhb $"); 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 "pci_emul.h" 56#include "virtio.h" 57#include "block_if.h" 58 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_SEG_MAX (1 << 2) /* Maximum request segments */ 71#define VTBLK_F_BLK_SIZE (1 << 6) /* cfg block size valid */ 72#define VTBLK_F_FLUSH (1 << 9) /* Cache flush support */ 73#define VTBLK_F_TOPOLOGY (1 << 10) /* Optimal I/O alignment */ 74 75/* 76 * Host capabilities 77 */ 78#define VTBLK_S_HOSTCAPS \ 79 ( VTBLK_F_SEG_MAX | \ 80 VTBLK_F_BLK_SIZE | \ 81 VTBLK_F_FLUSH | \ 82 VTBLK_F_TOPOLOGY | \ 83 VIRTIO_RING_F_INDIRECT_DESC ) /* indirect descriptors */ 84 85/* 86 * Config space "registers" 87 */ 88struct vtblk_config { 89 uint64_t vbc_capacity; 90 uint32_t vbc_size_max; 91 uint32_t vbc_seg_max; 92 struct { 93 uint16_t cylinders; 94 uint8_t heads; 95 uint8_t sectors; 96 } vbc_geometry; 97 uint32_t vbc_blk_size; 98 struct { 99 uint8_t physical_block_exp; 100 uint8_t alignment_offset; 101 uint16_t min_io_size; 102 uint32_t opt_io_size; 103 } vbc_topology; 104 uint8_t vbc_writeback; 105} __packed; 106 107/* 108 * Fixed-size block header 109 */ 110struct virtio_blk_hdr { 111#define VBH_OP_READ 0 112#define VBH_OP_WRITE 1 113#define VBH_OP_FLUSH 4 114#define VBH_OP_FLUSH_OUT 5 115#define VBH_OP_IDENT 8 116#define VBH_FLAG_BARRIER 0x80000000 /* OR'ed into vbh_type */ 117 uint32_t vbh_type; 118 uint32_t vbh_ioprio; 119 uint64_t vbh_sector; 120} __packed; 121 122/* 123 * Debug printf 124 */ 125static int pci_vtblk_debug; 126#define DPRINTF(params) if (pci_vtblk_debug) printf params 127#define WPRINTF(params) printf params 128 129struct pci_vtblk_ioreq { 130 struct blockif_req io_req; 131 struct pci_vtblk_softc *io_sc; 132 uint8_t *io_status; 133 uint16_t io_idx; 134}; 135 136/* 137 * Per-device softc 138 */ 139struct pci_vtblk_softc { 140 struct virtio_softc vbsc_vs; 141 pthread_mutex_t vsc_mtx; 142 struct vqueue_info vbsc_vq; 143 struct vtblk_config vbsc_cfg; 144 struct blockif_ctxt *bc; 145 char vbsc_ident[VTBLK_BLK_ID_BYTES]; 146 struct pci_vtblk_ioreq vbsc_ios[VTBLK_RINGSZ]; 147}; 148 149static void pci_vtblk_reset(void *); 150static void pci_vtblk_notify(void *, struct vqueue_info *); 151static int pci_vtblk_cfgread(void *, int, int, uint32_t *); 152static int pci_vtblk_cfgwrite(void *, int, int, uint32_t); 153 154static struct virtio_consts vtblk_vi_consts = { 155 "vtblk", /* our name */ 156 1, /* we support 1 virtqueue */ 157 sizeof(struct vtblk_config), /* config reg size */ 158 pci_vtblk_reset, /* reset */ 159 pci_vtblk_notify, /* device-wide qnotify */ 160 pci_vtblk_cfgread, /* read PCI config */ 161 pci_vtblk_cfgwrite, /* write PCI config */ 162 NULL, /* apply negotiated features */ 163 VTBLK_S_HOSTCAPS, /* our capabilities */ 164}; 165 166static void 167pci_vtblk_reset(void *vsc) 168{ 169 struct pci_vtblk_softc *sc = vsc; 170 171 DPRINTF(("vtblk: device reset requested !\n")); 172 vi_reset_dev(&sc->vbsc_vs); 173} 174 175static void 176pci_vtblk_done(struct blockif_req *br, int err) 177{ 178 struct pci_vtblk_ioreq *io = br->br_param; 179 struct pci_vtblk_softc *sc = io->io_sc; 180 181 /* convert errno into a virtio block error return */ 182 if (err == EOPNOTSUPP || err == ENOSYS) 183 *io->io_status = VTBLK_S_UNSUPP; 184 else if (err != 0) 185 *io->io_status = VTBLK_S_IOERR; 186 else 187 *io->io_status = VTBLK_S_OK; 188 189 /* 190 * Return the descriptor back to the host. 191 * We wrote 1 byte (our status) to host. 192 */ 193 pthread_mutex_lock(&sc->vsc_mtx); 194 vq_relchain(&sc->vbsc_vq, io->io_idx, 1); 195 vq_endchains(&sc->vbsc_vq, 0); 196 pthread_mutex_unlock(&sc->vsc_mtx); 197} 198 199static void 200pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq) 201{ 202 struct virtio_blk_hdr *vbh; 203 struct pci_vtblk_ioreq *io; 204 int i, n; 205 int err; 206 ssize_t iolen; 207 int writeop, type; 208 struct iovec iov[BLOCKIF_IOV_MAX + 2]; 209 uint16_t idx, flags[BLOCKIF_IOV_MAX + 2]; 210 211 n = vq_getchain(vq, &idx, iov, BLOCKIF_IOV_MAX + 2, flags); 212 213 /* 214 * The first descriptor will be the read-only fixed header, 215 * and the last is for status (hence +2 above and below). 216 * The remaining iov's are the actual data I/O vectors. 217 * 218 * XXX - note - this fails on crash dump, which does a 219 * VIRTIO_BLK_T_FLUSH with a zero transfer length 220 */ 221 assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2); 222 223 io = &sc->vbsc_ios[idx]; 224 assert((flags[0] & VRING_DESC_F_WRITE) == 0); 225 assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr)); 226 vbh = iov[0].iov_base; 227 memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2)); 228 io->io_req.br_iovcnt = n - 2; 229 io->io_req.br_offset = vbh->vbh_sector * DEV_BSIZE; 230 io->io_status = iov[--n].iov_base; 231 assert(iov[n].iov_len == 1); 232 assert(flags[n] & VRING_DESC_F_WRITE); 233 234 /* 235 * XXX 236 * The guest should not be setting the BARRIER flag because 237 * we don't advertise the capability. 238 */ 239 type = vbh->vbh_type & ~VBH_FLAG_BARRIER; 240 writeop = (type == VBH_OP_WRITE); 241 242 iolen = 0; 243 for (i = 1; i < n; i++) { 244 /* 245 * - write op implies read-only descriptor, 246 * - read/ident op implies write-only descriptor, 247 * therefore test the inverse of the descriptor bit 248 * to the op. 249 */ 250 assert(((flags[i] & VRING_DESC_F_WRITE) == 0) == writeop); 251 iolen += iov[i].iov_len; 252 } 253 io->io_req.br_resid = iolen; 254 255 DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld\n\r", 256 writeop ? "write" : "read/ident", iolen, i - 1, 257 io->io_req.br_offset)); 258 259 switch (type) { 260 case VBH_OP_READ: 261 err = blockif_read(sc->bc, &io->io_req); 262 break; 263 case VBH_OP_WRITE: 264 err = blockif_write(sc->bc, &io->io_req); 265 break; 266 case VBH_OP_FLUSH: 267 case VBH_OP_FLUSH_OUT: 268 err = blockif_flush(sc->bc, &io->io_req); 269 break; 270 case VBH_OP_IDENT: 271 /* Assume a single buffer */ 272 /* S/n equal to buffer is not zero-terminated. */ 273 memset(iov[1].iov_base, 0, iov[1].iov_len); 274 strncpy(iov[1].iov_base, sc->vbsc_ident, 275 MIN(iov[1].iov_len, sizeof(sc->vbsc_ident))); 276 pci_vtblk_done(&io->io_req, 0); 277 return; 278 default: 279 pci_vtblk_done(&io->io_req, EOPNOTSUPP); 280 return; 281 } 282 assert(err == 0); 283} 284 285static void 286pci_vtblk_notify(void *vsc, struct vqueue_info *vq) 287{ 288 struct pci_vtblk_softc *sc = vsc; 289 290 while (vq_has_descs(vq)) 291 pci_vtblk_proc(sc, vq); 292} 293 294static int 295pci_vtblk_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts) 296{ 297 char bident[sizeof("XX:X:X")]; 298 struct blockif_ctxt *bctxt; 299 MD5_CTX mdctx; 300 u_char digest[16]; 301 struct pci_vtblk_softc *sc; 302 off_t size; 303 int i, sectsz, sts, sto; 304 305 if (opts == NULL) { 306 printf("virtio-block: backing device required\n"); 307 return (1); 308 } 309 310 /* 311 * The supplied backing file has to exist 312 */ 313 snprintf(bident, sizeof(bident), "%d:%d", pi->pi_slot, pi->pi_func); 314 bctxt = blockif_open(opts, bident); 315 if (bctxt == NULL) { 316 perror("Could not open backing file"); 317 return (1); 318 } 319 320 size = blockif_size(bctxt); 321 sectsz = blockif_sectsz(bctxt); 322 blockif_psectsz(bctxt, &sts, &sto); 323 324 sc = calloc(1, sizeof(struct pci_vtblk_softc)); 325 sc->bc = bctxt; 326 for (i = 0; i < VTBLK_RINGSZ; i++) { 327 struct pci_vtblk_ioreq *io = &sc->vbsc_ios[i]; 328 io->io_req.br_callback = pci_vtblk_done; 329 io->io_req.br_param = io; 330 io->io_sc = sc; 331 io->io_idx = i; 332 } 333 334 pthread_mutex_init(&sc->vsc_mtx, NULL); 335 336 /* init virtio softc and virtqueues */ 337 vi_softc_linkup(&sc->vbsc_vs, &vtblk_vi_consts, sc, pi, &sc->vbsc_vq); 338 sc->vbsc_vs.vs_mtx = &sc->vsc_mtx; 339 340 sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ; 341 /* sc->vbsc_vq.vq_notify = we have no per-queue notify */ 342 343 /* 344 * Create an identifier for the backing file. Use parts of the 345 * md5 sum of the filename 346 */ 347 MD5Init(&mdctx); 348 MD5Update(&mdctx, opts, strlen(opts)); 349 MD5Final(digest, &mdctx); 350 snprintf(sc->vbsc_ident, VTBLK_BLK_ID_BYTES, 351 "BHYVE-%02X%02X-%02X%02X-%02X%02X", 352 digest[0], digest[1], digest[2], digest[3], digest[4], digest[5]); 353 354 /* setup virtio block config space */ 355 sc->vbsc_cfg.vbc_capacity = size / DEV_BSIZE; /* 512-byte units */ 356 sc->vbsc_cfg.vbc_size_max = 0; /* not negotiated */ 357 358 /* 359 * If Linux is presented with a seg_max greater than the virtio queue 360 * size, it can stumble into situations where it violates its own 361 * invariants and panics. For safety, we keep seg_max clamped, paying 362 * heed to the two extra descriptors needed for the header and status 363 * of a request. 364 */ 365 sc->vbsc_cfg.vbc_seg_max = MIN(VTBLK_RINGSZ - 2, BLOCKIF_IOV_MAX); 366 sc->vbsc_cfg.vbc_geometry.cylinders = 0; /* no geometry */ 367 sc->vbsc_cfg.vbc_geometry.heads = 0; 368 sc->vbsc_cfg.vbc_geometry.sectors = 0; 369 sc->vbsc_cfg.vbc_blk_size = sectsz; 370 sc->vbsc_cfg.vbc_topology.physical_block_exp = 371 (sts > sectsz) ? (ffsll(sts / sectsz) - 1) : 0; 372 sc->vbsc_cfg.vbc_topology.alignment_offset = 373 (sto != 0) ? ((sts - sto) / sectsz) : 0; 374 sc->vbsc_cfg.vbc_topology.min_io_size = 0; 375 sc->vbsc_cfg.vbc_topology.opt_io_size = 0; 376 sc->vbsc_cfg.vbc_writeback = 0; 377 378 /* 379 * Should we move some of this into virtio.c? Could 380 * have the device, class, and subdev_0 as fields in 381 * the virtio constants structure. 382 */ 383 pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK); 384 pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR); 385 pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE); 386 pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_BLOCK); 387 pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR); 388 389 if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix())) { 390 blockif_close(sc->bc); 391 free(sc); 392 return (1); 393 } 394 vi_set_io_bar(&sc->vbsc_vs, 0); 395 return (0); 396} 397 398static int 399pci_vtblk_cfgwrite(void *vsc, int offset, int size, uint32_t value) 400{ 401 402 DPRINTF(("vtblk: write to readonly reg %d\n\r", offset)); 403 return (1); 404} 405 406static int 407pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval) 408{ 409 struct pci_vtblk_softc *sc = vsc; 410 void *ptr; 411 412 /* our caller has already verified offset and size */ 413 ptr = (uint8_t *)&sc->vbsc_cfg + offset; 414 memcpy(retval, ptr, size); 415 return (0); 416} 417 418struct pci_devemu pci_de_vblk = { 419 .pe_emu = "virtio-blk", 420 .pe_init = pci_vtblk_init, 421 .pe_barwrite = vi_pci_write, 422 .pe_barread = vi_pci_read 423}; 424PCI_EMUL_SET(pci_de_vblk); 425