1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2013 Chris Torek <torek @ torek net> 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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR 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__FBSDID("$FreeBSD: stable/11/usr.sbin/bhyve/virtio.c 349704 2019-07-03 20:22:36Z vmaffione $"); 32 33#include <sys/param.h> 34#include <sys/uio.h> 35 36#include <machine/atomic.h> 37 38#include <stdio.h> 39#include <stdint.h> 40#include <pthread.h> 41#include <pthread_np.h> 42 43#include "bhyverun.h" 44#include "pci_emul.h" 45#include "virtio.h" 46 47/* 48 * Functions for dealing with generalized "virtual devices" as 49 * defined by <https://www.google.com/#output=search&q=virtio+spec> 50 */ 51 52/* 53 * In case we decide to relax the "virtio softc comes at the 54 * front of virtio-based device softc" constraint, let's use 55 * this to convert. 56 */ 57#define DEV_SOFTC(vs) ((void *)(vs)) 58 59/* 60 * Link a virtio_softc to its constants, the device softc, and 61 * the PCI emulation. 62 */ 63void 64vi_softc_linkup(struct virtio_softc *vs, struct virtio_consts *vc, 65 void *dev_softc, struct pci_devinst *pi, 66 struct vqueue_info *queues) 67{ 68 int i; 69 70 /* vs and dev_softc addresses must match */ 71 assert((void *)vs == dev_softc); 72 vs->vs_vc = vc; 73 vs->vs_pi = pi; 74 pi->pi_arg = vs; 75 76 vs->vs_queues = queues; 77 for (i = 0; i < vc->vc_nvq; i++) { 78 queues[i].vq_vs = vs; 79 queues[i].vq_num = i; 80 } 81} 82 83/* 84 * Reset device (device-wide). This erases all queues, i.e., 85 * all the queues become invalid (though we don't wipe out the 86 * internal pointers, we just clear the VQ_ALLOC flag). 87 * 88 * It resets negotiated features to "none". 89 * 90 * If MSI-X is enabled, this also resets all the vectors to NO_VECTOR. 91 */ 92void 93vi_reset_dev(struct virtio_softc *vs) 94{ 95 struct vqueue_info *vq; 96 int i, nvq; 97 98 if (vs->vs_mtx) 99 assert(pthread_mutex_isowned_np(vs->vs_mtx)); 100 101 nvq = vs->vs_vc->vc_nvq; 102 for (vq = vs->vs_queues, i = 0; i < nvq; vq++, i++) { 103 vq->vq_flags = 0; 104 vq->vq_last_avail = 0; 105 vq->vq_save_used = 0; 106 vq->vq_pfn = 0; 107 vq->vq_msix_idx = VIRTIO_MSI_NO_VECTOR; 108 } 109 vs->vs_negotiated_caps = 0; 110 vs->vs_curq = 0; 111 /* vs->vs_status = 0; -- redundant */ 112 if (vs->vs_isr) 113 pci_lintr_deassert(vs->vs_pi); 114 vs->vs_isr = 0; 115 vs->vs_msix_cfg_idx = VIRTIO_MSI_NO_VECTOR; 116} 117 118/* 119 * Set I/O BAR (usually 0) to map PCI config registers. 120 */ 121void 122vi_set_io_bar(struct virtio_softc *vs, int barnum) 123{ 124 size_t size; 125 126 /* 127 * ??? should we use CFG0 if MSI-X is disabled? 128 * Existing code did not... 129 */ 130 size = VTCFG_R_CFG1 + vs->vs_vc->vc_cfgsize; 131 pci_emul_alloc_bar(vs->vs_pi, barnum, PCIBAR_IO, size); 132} 133 134/* 135 * Initialize MSI-X vector capabilities if we're to use MSI-X, 136 * or MSI capabilities if not. 137 * 138 * We assume we want one MSI-X vector per queue, here, plus one 139 * for the config vec. 140 */ 141int 142vi_intr_init(struct virtio_softc *vs, int barnum, int use_msix) 143{ 144 int nvec; 145 146 if (use_msix) { 147 vs->vs_flags |= VIRTIO_USE_MSIX; 148 VS_LOCK(vs); 149 vi_reset_dev(vs); /* set all vectors to NO_VECTOR */ 150 VS_UNLOCK(vs); 151 nvec = vs->vs_vc->vc_nvq + 1; 152 if (pci_emul_add_msixcap(vs->vs_pi, nvec, barnum)) 153 return (1); 154 } else 155 vs->vs_flags &= ~VIRTIO_USE_MSIX; 156 157 /* Only 1 MSI vector for bhyve */ 158 pci_emul_add_msicap(vs->vs_pi, 1); 159 160 /* Legacy interrupts are mandatory for virtio devices */ 161 pci_lintr_request(vs->vs_pi); 162 163 return (0); 164} 165 166/* 167 * Initialize the currently-selected virtio queue (vs->vs_curq). 168 * The guest just gave us a page frame number, from which we can 169 * calculate the addresses of the queue. 170 */ 171void 172vi_vq_init(struct virtio_softc *vs, uint32_t pfn) 173{ 174 struct vqueue_info *vq; 175 uint64_t phys; 176 size_t size; 177 char *base; 178 179 vq = &vs->vs_queues[vs->vs_curq]; 180 vq->vq_pfn = pfn; 181 phys = (uint64_t)pfn << VRING_PFN; 182 size = vring_size(vq->vq_qsize); 183 base = paddr_guest2host(vs->vs_pi->pi_vmctx, phys, size); 184 185 /* First page(s) are descriptors... */ 186 vq->vq_desc = (struct virtio_desc *)base; 187 base += vq->vq_qsize * sizeof(struct virtio_desc); 188 189 /* ... immediately followed by "avail" ring (entirely uint16_t's) */ 190 vq->vq_avail = (struct vring_avail *)base; 191 base += (2 + vq->vq_qsize + 1) * sizeof(uint16_t); 192 193 /* Then it's rounded up to the next page... */ 194 base = (char *)roundup2((uintptr_t)base, VRING_ALIGN); 195 196 /* ... and the last page(s) are the used ring. */ 197 vq->vq_used = (struct vring_used *)base; 198 199 /* Mark queue as allocated, and start at 0 when we use it. */ 200 vq->vq_flags = VQ_ALLOC; 201 vq->vq_last_avail = 0; 202 vq->vq_save_used = 0; 203} 204 205/* 206 * Helper inline for vq_getchain(): record the i'th "real" 207 * descriptor. 208 */ 209static inline void 210_vq_record(int i, volatile struct virtio_desc *vd, struct vmctx *ctx, 211 struct iovec *iov, int n_iov, uint16_t *flags) { 212 213 if (i >= n_iov) 214 return; 215 iov[i].iov_base = paddr_guest2host(ctx, vd->vd_addr, vd->vd_len); 216 iov[i].iov_len = vd->vd_len; 217 if (flags != NULL) 218 flags[i] = vd->vd_flags; 219} 220#define VQ_MAX_DESCRIPTORS 512 /* see below */ 221 222/* 223 * Examine the chain of descriptors starting at the "next one" to 224 * make sure that they describe a sensible request. If so, return 225 * the number of "real" descriptors that would be needed/used in 226 * acting on this request. This may be smaller than the number of 227 * available descriptors, e.g., if there are two available but 228 * they are two separate requests, this just returns 1. Or, it 229 * may be larger: if there are indirect descriptors involved, 230 * there may only be one descriptor available but it may be an 231 * indirect pointing to eight more. We return 8 in this case, 232 * i.e., we do not count the indirect descriptors, only the "real" 233 * ones. 234 * 235 * Basically, this vets the vd_flags and vd_next field of each 236 * descriptor and tells you how many are involved. Since some may 237 * be indirect, this also needs the vmctx (in the pci_devinst 238 * at vs->vs_pi) so that it can find indirect descriptors. 239 * 240 * As we process each descriptor, we copy and adjust it (guest to 241 * host address wise, also using the vmtctx) into the given iov[] 242 * array (of the given size). If the array overflows, we stop 243 * placing values into the array but keep processing descriptors, 244 * up to VQ_MAX_DESCRIPTORS, before giving up and returning -1. 245 * So you, the caller, must not assume that iov[] is as big as the 246 * return value (you can process the same thing twice to allocate 247 * a larger iov array if needed, or supply a zero length to find 248 * out how much space is needed). 249 * 250 * If you want to verify the WRITE flag on each descriptor, pass a 251 * non-NULL "flags" pointer to an array of "uint16_t" of the same size 252 * as n_iov and we'll copy each vd_flags field after unwinding any 253 * indirects. 254 * 255 * If some descriptor(s) are invalid, this prints a diagnostic message 256 * and returns -1. If no descriptors are ready now it simply returns 0. 257 * 258 * You are assumed to have done a vq_ring_ready() if needed (note 259 * that vq_has_descs() does one). 260 */ 261int 262vq_getchain(struct vqueue_info *vq, uint16_t *pidx, 263 struct iovec *iov, int n_iov, uint16_t *flags) 264{ 265 int i; 266 u_int ndesc, n_indir; 267 u_int idx, next; 268 volatile struct virtio_desc *vdir, *vindir, *vp; 269 struct vmctx *ctx; 270 struct virtio_softc *vs; 271 const char *name; 272 273 vs = vq->vq_vs; 274 name = vs->vs_vc->vc_name; 275 276 /* 277 * Note: it's the responsibility of the guest not to 278 * update vq->vq_avail->va_idx until all of the descriptors 279 * the guest has written are valid (including all their 280 * vd_next fields and vd_flags). 281 * 282 * Compute (last_avail - va_idx) in integers mod 2**16. This is 283 * the number of descriptors the device has made available 284 * since the last time we updated vq->vq_last_avail. 285 * 286 * We just need to do the subtraction as an unsigned int, 287 * then trim off excess bits. 288 */ 289 idx = vq->vq_last_avail; 290 ndesc = (uint16_t)((u_int)vq->vq_avail->va_idx - idx); 291 if (ndesc == 0) 292 return (0); 293 if (ndesc > vq->vq_qsize) { 294 /* XXX need better way to diagnose issues */ 295 fprintf(stderr, 296 "%s: ndesc (%u) out of range, driver confused?\r\n", 297 name, (u_int)ndesc); 298 return (-1); 299 } 300 301 /* 302 * Now count/parse "involved" descriptors starting from 303 * the head of the chain. 304 * 305 * To prevent loops, we could be more complicated and 306 * check whether we're re-visiting a previously visited 307 * index, but we just abort if the count gets excessive. 308 */ 309 ctx = vs->vs_pi->pi_vmctx; 310 *pidx = next = vq->vq_avail->va_ring[idx & (vq->vq_qsize - 1)]; 311 vq->vq_last_avail++; 312 for (i = 0; i < VQ_MAX_DESCRIPTORS; next = vdir->vd_next) { 313 if (next >= vq->vq_qsize) { 314 fprintf(stderr, 315 "%s: descriptor index %u out of range, " 316 "driver confused?\r\n", 317 name, next); 318 return (-1); 319 } 320 vdir = &vq->vq_desc[next]; 321 if ((vdir->vd_flags & VRING_DESC_F_INDIRECT) == 0) { 322 _vq_record(i, vdir, ctx, iov, n_iov, flags); 323 i++; 324 } else if ((vs->vs_vc->vc_hv_caps & 325 VIRTIO_RING_F_INDIRECT_DESC) == 0) { 326 fprintf(stderr, 327 "%s: descriptor has forbidden INDIRECT flag, " 328 "driver confused?\r\n", 329 name); 330 return (-1); 331 } else { 332 n_indir = vdir->vd_len / 16; 333 if ((vdir->vd_len & 0xf) || n_indir == 0) { 334 fprintf(stderr, 335 "%s: invalid indir len 0x%x, " 336 "driver confused?\r\n", 337 name, (u_int)vdir->vd_len); 338 return (-1); 339 } 340 vindir = paddr_guest2host(ctx, 341 vdir->vd_addr, vdir->vd_len); 342 /* 343 * Indirects start at the 0th, then follow 344 * their own embedded "next"s until those run 345 * out. Each one's indirect flag must be off 346 * (we don't really have to check, could just 347 * ignore errors...). 348 */ 349 next = 0; 350 for (;;) { 351 vp = &vindir[next]; 352 if (vp->vd_flags & VRING_DESC_F_INDIRECT) { 353 fprintf(stderr, 354 "%s: indirect desc has INDIR flag," 355 " driver confused?\r\n", 356 name); 357 return (-1); 358 } 359 _vq_record(i, vp, ctx, iov, n_iov, flags); 360 if (++i > VQ_MAX_DESCRIPTORS) 361 goto loopy; 362 if ((vp->vd_flags & VRING_DESC_F_NEXT) == 0) 363 break; 364 next = vp->vd_next; 365 if (next >= n_indir) { 366 fprintf(stderr, 367 "%s: invalid next %u > %u, " 368 "driver confused?\r\n", 369 name, (u_int)next, n_indir); 370 return (-1); 371 } 372 } 373 } 374 if ((vdir->vd_flags & VRING_DESC_F_NEXT) == 0) 375 return (i); 376 } 377loopy: 378 fprintf(stderr, 379 "%s: descriptor loop? count > %d - driver confused?\r\n", 380 name, i); 381 return (-1); 382} 383 384/* 385 * Return the currently-first request chain back to the available queue. 386 * 387 * (This chain is the one you handled when you called vq_getchain() 388 * and used its positive return value.) 389 */ 390void 391vq_retchain(struct vqueue_info *vq) 392{ 393 394 vq->vq_last_avail--; 395} 396 397/* 398 * Return specified request chain to the guest, setting its I/O length 399 * to the provided value. 400 * 401 * (This chain is the one you handled when you called vq_getchain() 402 * and used its positive return value.) 403 */ 404void 405vq_relchain(struct vqueue_info *vq, uint16_t idx, uint32_t iolen) 406{ 407 uint16_t uidx, mask; 408 volatile struct vring_used *vuh; 409 volatile struct virtio_used *vue; 410 411 /* 412 * Notes: 413 * - mask is N-1 where N is a power of 2 so computes x % N 414 * - vuh points to the "used" data shared with guest 415 * - vue points to the "used" ring entry we want to update 416 * - head is the same value we compute in vq_iovecs(). 417 * 418 * (I apologize for the two fields named vu_idx; the 419 * virtio spec calls the one that vue points to, "id"...) 420 */ 421 mask = vq->vq_qsize - 1; 422 vuh = vq->vq_used; 423 424 uidx = vuh->vu_idx; 425 vue = &vuh->vu_ring[uidx++ & mask]; 426 vue->vu_idx = idx; 427 vue->vu_tlen = iolen; 428 429 /* 430 * Ensure the used descriptor is visible before updating the index. 431 * This is necessary on ISAs with memory ordering less strict than x86 432 * (and even on x86 to act as a compiler barrier). 433 */ 434 atomic_thread_fence_rel(); 435 vuh->vu_idx = uidx; 436} 437 438/* 439 * Driver has finished processing "available" chains and calling 440 * vq_relchain on each one. If driver used all the available 441 * chains, used_all should be set. 442 * 443 * If the "used" index moved we may need to inform the guest, i.e., 444 * deliver an interrupt. Even if the used index did NOT move we 445 * may need to deliver an interrupt, if the avail ring is empty and 446 * we are supposed to interrupt on empty. 447 * 448 * Note that used_all_avail is provided by the caller because it's 449 * a snapshot of the ring state when he decided to finish interrupt 450 * processing -- it's possible that descriptors became available after 451 * that point. (It's also typically a constant 1/True as well.) 452 */ 453void 454vq_endchains(struct vqueue_info *vq, int used_all_avail) 455{ 456 struct virtio_softc *vs; 457 uint16_t event_idx, new_idx, old_idx; 458 int intr; 459 460 /* 461 * Interrupt generation: if we're using EVENT_IDX, 462 * interrupt if we've crossed the event threshold. 463 * Otherwise interrupt is generated if we added "used" entries, 464 * but suppressed by VRING_AVAIL_F_NO_INTERRUPT. 465 * 466 * In any case, though, if NOTIFY_ON_EMPTY is set and the 467 * entire avail was processed, we need to interrupt always. 468 */ 469 vs = vq->vq_vs; 470 old_idx = vq->vq_save_used; 471 vq->vq_save_used = new_idx = vq->vq_used->vu_idx; 472 473 /* 474 * Use full memory barrier between vu_idx store from preceding 475 * vq_relchain() call and the loads from VQ_USED_EVENT_IDX() or 476 * va_flags below. 477 */ 478 atomic_thread_fence_seq_cst(); 479 if (used_all_avail && 480 (vs->vs_negotiated_caps & VIRTIO_F_NOTIFY_ON_EMPTY)) 481 intr = 1; 482 else if (vs->vs_negotiated_caps & VIRTIO_RING_F_EVENT_IDX) { 483 event_idx = VQ_USED_EVENT_IDX(vq); 484 /* 485 * This calculation is per docs and the kernel 486 * (see src/sys/dev/virtio/virtio_ring.h). 487 */ 488 intr = (uint16_t)(new_idx - event_idx - 1) < 489 (uint16_t)(new_idx - old_idx); 490 } else { 491 intr = new_idx != old_idx && 492 !(vq->vq_avail->va_flags & VRING_AVAIL_F_NO_INTERRUPT); 493 } 494 if (intr) 495 vq_interrupt(vs, vq); 496} 497 498/* Note: these are in sorted order to make for a fast search */ 499static struct config_reg { 500 uint16_t cr_offset; /* register offset */ 501 uint8_t cr_size; /* size (bytes) */ 502 uint8_t cr_ro; /* true => reg is read only */ 503 const char *cr_name; /* name of reg */ 504} config_regs[] = { 505 { VTCFG_R_HOSTCAP, 4, 1, "HOSTCAP" }, 506 { VTCFG_R_GUESTCAP, 4, 0, "GUESTCAP" }, 507 { VTCFG_R_PFN, 4, 0, "PFN" }, 508 { VTCFG_R_QNUM, 2, 1, "QNUM" }, 509 { VTCFG_R_QSEL, 2, 0, "QSEL" }, 510 { VTCFG_R_QNOTIFY, 2, 0, "QNOTIFY" }, 511 { VTCFG_R_STATUS, 1, 0, "STATUS" }, 512 { VTCFG_R_ISR, 1, 0, "ISR" }, 513 { VTCFG_R_CFGVEC, 2, 0, "CFGVEC" }, 514 { VTCFG_R_QVEC, 2, 0, "QVEC" }, 515}; 516 517static inline struct config_reg * 518vi_find_cr(int offset) { 519 u_int hi, lo, mid; 520 struct config_reg *cr; 521 522 lo = 0; 523 hi = sizeof(config_regs) / sizeof(*config_regs) - 1; 524 while (hi >= lo) { 525 mid = (hi + lo) >> 1; 526 cr = &config_regs[mid]; 527 if (cr->cr_offset == offset) 528 return (cr); 529 if (cr->cr_offset < offset) 530 lo = mid + 1; 531 else 532 hi = mid - 1; 533 } 534 return (NULL); 535} 536 537/* 538 * Handle pci config space reads. 539 * If it's to the MSI-X info, do that. 540 * If it's part of the virtio standard stuff, do that. 541 * Otherwise dispatch to the actual driver. 542 */ 543uint64_t 544vi_pci_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, 545 int baridx, uint64_t offset, int size) 546{ 547 struct virtio_softc *vs = pi->pi_arg; 548 struct virtio_consts *vc; 549 struct config_reg *cr; 550 uint64_t virtio_config_size, max; 551 const char *name; 552 uint32_t newoff; 553 uint32_t value; 554 int error; 555 556 if (vs->vs_flags & VIRTIO_USE_MSIX) { 557 if (baridx == pci_msix_table_bar(pi) || 558 baridx == pci_msix_pba_bar(pi)) { 559 return (pci_emul_msix_tread(pi, offset, size)); 560 } 561 } 562 563 /* XXX probably should do something better than just assert() */ 564 assert(baridx == 0); 565 566 if (vs->vs_mtx) 567 pthread_mutex_lock(vs->vs_mtx); 568 569 vc = vs->vs_vc; 570 name = vc->vc_name; 571 value = size == 1 ? 0xff : size == 2 ? 0xffff : 0xffffffff; 572 573 if (size != 1 && size != 2 && size != 4) 574 goto bad; 575 576 if (pci_msix_enabled(pi)) 577 virtio_config_size = VTCFG_R_CFG1; 578 else 579 virtio_config_size = VTCFG_R_CFG0; 580 581 if (offset >= virtio_config_size) { 582 /* 583 * Subtract off the standard size (including MSI-X 584 * registers if enabled) and dispatch to underlying driver. 585 * If that fails, fall into general code. 586 */ 587 newoff = offset - virtio_config_size; 588 max = vc->vc_cfgsize ? vc->vc_cfgsize : 0x100000000; 589 if (newoff + size > max) 590 goto bad; 591 error = (*vc->vc_cfgread)(DEV_SOFTC(vs), newoff, size, &value); 592 if (!error) 593 goto done; 594 } 595 596bad: 597 cr = vi_find_cr(offset); 598 if (cr == NULL || cr->cr_size != size) { 599 if (cr != NULL) { 600 /* offset must be OK, so size must be bad */ 601 fprintf(stderr, 602 "%s: read from %s: bad size %d\r\n", 603 name, cr->cr_name, size); 604 } else { 605 fprintf(stderr, 606 "%s: read from bad offset/size %jd/%d\r\n", 607 name, (uintmax_t)offset, size); 608 } 609 goto done; 610 } 611 612 switch (offset) { 613 case VTCFG_R_HOSTCAP: 614 value = vc->vc_hv_caps; 615 break; 616 case VTCFG_R_GUESTCAP: 617 value = vs->vs_negotiated_caps; 618 break; 619 case VTCFG_R_PFN: 620 if (vs->vs_curq < vc->vc_nvq) 621 value = vs->vs_queues[vs->vs_curq].vq_pfn; 622 break; 623 case VTCFG_R_QNUM: 624 value = vs->vs_curq < vc->vc_nvq ? 625 vs->vs_queues[vs->vs_curq].vq_qsize : 0; 626 break; 627 case VTCFG_R_QSEL: 628 value = vs->vs_curq; 629 break; 630 case VTCFG_R_QNOTIFY: 631 value = 0; /* XXX */ 632 break; 633 case VTCFG_R_STATUS: 634 value = vs->vs_status; 635 break; 636 case VTCFG_R_ISR: 637 value = vs->vs_isr; 638 vs->vs_isr = 0; /* a read clears this flag */ 639 if (value) 640 pci_lintr_deassert(pi); 641 break; 642 case VTCFG_R_CFGVEC: 643 value = vs->vs_msix_cfg_idx; 644 break; 645 case VTCFG_R_QVEC: 646 value = vs->vs_curq < vc->vc_nvq ? 647 vs->vs_queues[vs->vs_curq].vq_msix_idx : 648 VIRTIO_MSI_NO_VECTOR; 649 break; 650 } 651done: 652 if (vs->vs_mtx) 653 pthread_mutex_unlock(vs->vs_mtx); 654 return (value); 655} 656 657/* 658 * Handle pci config space writes. 659 * If it's to the MSI-X info, do that. 660 * If it's part of the virtio standard stuff, do that. 661 * Otherwise dispatch to the actual driver. 662 */ 663void 664vi_pci_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, 665 int baridx, uint64_t offset, int size, uint64_t value) 666{ 667 struct virtio_softc *vs = pi->pi_arg; 668 struct vqueue_info *vq; 669 struct virtio_consts *vc; 670 struct config_reg *cr; 671 uint64_t virtio_config_size, max; 672 const char *name; 673 uint32_t newoff; 674 int error; 675 676 if (vs->vs_flags & VIRTIO_USE_MSIX) { 677 if (baridx == pci_msix_table_bar(pi) || 678 baridx == pci_msix_pba_bar(pi)) { 679 pci_emul_msix_twrite(pi, offset, size, value); 680 return; 681 } 682 } 683 684 /* XXX probably should do something better than just assert() */ 685 assert(baridx == 0); 686 687 if (vs->vs_mtx) 688 pthread_mutex_lock(vs->vs_mtx); 689 690 vc = vs->vs_vc; 691 name = vc->vc_name; 692 693 if (size != 1 && size != 2 && size != 4) 694 goto bad; 695 696 if (pci_msix_enabled(pi)) 697 virtio_config_size = VTCFG_R_CFG1; 698 else 699 virtio_config_size = VTCFG_R_CFG0; 700 701 if (offset >= virtio_config_size) { 702 /* 703 * Subtract off the standard size (including MSI-X 704 * registers if enabled) and dispatch to underlying driver. 705 */ 706 newoff = offset - virtio_config_size; 707 max = vc->vc_cfgsize ? vc->vc_cfgsize : 0x100000000; 708 if (newoff + size > max) 709 goto bad; 710 error = (*vc->vc_cfgwrite)(DEV_SOFTC(vs), newoff, size, value); 711 if (!error) 712 goto done; 713 } 714 715bad: 716 cr = vi_find_cr(offset); 717 if (cr == NULL || cr->cr_size != size || cr->cr_ro) { 718 if (cr != NULL) { 719 /* offset must be OK, wrong size and/or reg is R/O */ 720 if (cr->cr_size != size) 721 fprintf(stderr, 722 "%s: write to %s: bad size %d\r\n", 723 name, cr->cr_name, size); 724 if (cr->cr_ro) 725 fprintf(stderr, 726 "%s: write to read-only reg %s\r\n", 727 name, cr->cr_name); 728 } else { 729 fprintf(stderr, 730 "%s: write to bad offset/size %jd/%d\r\n", 731 name, (uintmax_t)offset, size); 732 } 733 goto done; 734 } 735 736 switch (offset) { 737 case VTCFG_R_GUESTCAP: 738 vs->vs_negotiated_caps = value & vc->vc_hv_caps; 739 if (vc->vc_apply_features) 740 (*vc->vc_apply_features)(DEV_SOFTC(vs), 741 vs->vs_negotiated_caps); 742 break; 743 case VTCFG_R_PFN: 744 if (vs->vs_curq >= vc->vc_nvq) 745 goto bad_qindex; 746 vi_vq_init(vs, value); 747 break; 748 case VTCFG_R_QSEL: 749 /* 750 * Note that the guest is allowed to select an 751 * invalid queue; we just need to return a QNUM 752 * of 0 while the bad queue is selected. 753 */ 754 vs->vs_curq = value; 755 break; 756 case VTCFG_R_QNOTIFY: 757 if (value >= vc->vc_nvq) { 758 fprintf(stderr, "%s: queue %d notify out of range\r\n", 759 name, (int)value); 760 goto done; 761 } 762 vq = &vs->vs_queues[value]; 763 if (vq->vq_notify) 764 (*vq->vq_notify)(DEV_SOFTC(vs), vq); 765 else if (vc->vc_qnotify) 766 (*vc->vc_qnotify)(DEV_SOFTC(vs), vq); 767 else 768 fprintf(stderr, 769 "%s: qnotify queue %d: missing vq/vc notify\r\n", 770 name, (int)value); 771 break; 772 case VTCFG_R_STATUS: 773 vs->vs_status = value; 774 if (value == 0) 775 (*vc->vc_reset)(DEV_SOFTC(vs)); 776 break; 777 case VTCFG_R_CFGVEC: 778 vs->vs_msix_cfg_idx = value; 779 break; 780 case VTCFG_R_QVEC: 781 if (vs->vs_curq >= vc->vc_nvq) 782 goto bad_qindex; 783 vq = &vs->vs_queues[vs->vs_curq]; 784 vq->vq_msix_idx = value; 785 break; 786 } 787 goto done; 788 789bad_qindex: 790 fprintf(stderr, 791 "%s: write config reg %s: curq %d >= max %d\r\n", 792 name, cr->cr_name, vs->vs_curq, vc->vc_nvq); 793done: 794 if (vs->vs_mtx) 795 pthread_mutex_unlock(vs->vs_mtx); 796} 797