xref: /freebsd/usr.sbin/bhyve/pci_passthru.c (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
1 /*-
2  * Copyright (c) 2011 NetApp, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/types.h>
34 #include <sys/pciio.h>
35 #include <sys/ioctl.h>
36 
37 #include <dev/io/iodev.h>
38 #include <dev/pci/pcireg.h>
39 
40 #include <machine/iodev.h>
41 
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <unistd.h>
48 
49 #include <machine/vmm.h>
50 #include <vmmapi.h>
51 #include "pci_emul.h"
52 #include "mem.h"
53 
54 #ifndef _PATH_DEVPCI
55 #define	_PATH_DEVPCI	"/dev/pci"
56 #endif
57 
58 #ifndef	_PATH_DEVIO
59 #define	_PATH_DEVIO	"/dev/io"
60 #endif
61 
62 #define	LEGACY_SUPPORT	1
63 
64 #define MSIX_TABLE_COUNT(ctrl) (((ctrl) & PCIM_MSIXCTRL_TABLE_SIZE) + 1)
65 #define MSIX_CAPLEN 12
66 
67 static int pcifd = -1;
68 static int iofd = -1;
69 
70 struct passthru_softc {
71 	struct pci_devinst *psc_pi;
72 	struct pcibar psc_bar[PCI_BARMAX + 1];
73 	struct {
74 		int		capoff;
75 		int		msgctrl;
76 		int		emulated;
77 	} psc_msi;
78 	struct {
79 		int		capoff;
80 	} psc_msix;
81 	struct pcisel psc_sel;
82 };
83 
84 static int
85 msi_caplen(int msgctrl)
86 {
87 	int len;
88 
89 	len = 10;		/* minimum length of msi capability */
90 
91 	if (msgctrl & PCIM_MSICTRL_64BIT)
92 		len += 4;
93 
94 #if 0
95 	/*
96 	 * Ignore the 'mask' and 'pending' bits in the MSI capability.
97 	 * We'll let the guest manipulate them directly.
98 	 */
99 	if (msgctrl & PCIM_MSICTRL_VECTOR)
100 		len += 10;
101 #endif
102 
103 	return (len);
104 }
105 
106 static uint32_t
107 read_config(const struct pcisel *sel, long reg, int width)
108 {
109 	struct pci_io pi;
110 
111 	bzero(&pi, sizeof(pi));
112 	pi.pi_sel = *sel;
113 	pi.pi_reg = reg;
114 	pi.pi_width = width;
115 
116 	if (ioctl(pcifd, PCIOCREAD, &pi) < 0)
117 		return (0);				/* XXX */
118 	else
119 		return (pi.pi_data);
120 }
121 
122 static void
123 write_config(const struct pcisel *sel, long reg, int width, uint32_t data)
124 {
125 	struct pci_io pi;
126 
127 	bzero(&pi, sizeof(pi));
128 	pi.pi_sel = *sel;
129 	pi.pi_reg = reg;
130 	pi.pi_width = width;
131 	pi.pi_data = data;
132 
133 	(void)ioctl(pcifd, PCIOCWRITE, &pi);		/* XXX */
134 }
135 
136 #ifdef LEGACY_SUPPORT
137 static int
138 passthru_add_msicap(struct pci_devinst *pi, int msgnum, int nextptr)
139 {
140 	int capoff, i;
141 	struct msicap msicap;
142 	u_char *capdata;
143 
144 	pci_populate_msicap(&msicap, msgnum, nextptr);
145 
146 	/*
147 	 * XXX
148 	 * Copy the msi capability structure in the last 16 bytes of the
149 	 * config space. This is wrong because it could shadow something
150 	 * useful to the device.
151 	 */
152 	capoff = 256 - roundup(sizeof(msicap), 4);
153 	capdata = (u_char *)&msicap;
154 	for (i = 0; i < sizeof(msicap); i++)
155 		pci_set_cfgdata8(pi, capoff + i, capdata[i]);
156 
157 	return (capoff);
158 }
159 #endif	/* LEGACY_SUPPORT */
160 
161 static int
162 cfginitmsi(struct passthru_softc *sc)
163 {
164 	int i, ptr, capptr, cap, sts, caplen, table_size;
165 	uint32_t u32;
166 	struct pcisel sel;
167 	struct pci_devinst *pi;
168 	struct msixcap msixcap;
169 	uint32_t *msixcap_ptr;
170 
171 	pi = sc->psc_pi;
172 	sel = sc->psc_sel;
173 
174 	/*
175 	 * Parse the capabilities and cache the location of the MSI
176 	 * and MSI-X capabilities.
177 	 */
178 	sts = read_config(&sel, PCIR_STATUS, 2);
179 	if (sts & PCIM_STATUS_CAPPRESENT) {
180 		ptr = read_config(&sel, PCIR_CAP_PTR, 1);
181 		while (ptr != 0 && ptr != 0xff) {
182 			cap = read_config(&sel, ptr + PCICAP_ID, 1);
183 			if (cap == PCIY_MSI) {
184 				/*
185 				 * Copy the MSI capability into the config
186 				 * space of the emulated pci device
187 				 */
188 				sc->psc_msi.capoff = ptr;
189 				sc->psc_msi.msgctrl = read_config(&sel,
190 								  ptr + 2, 2);
191 				sc->psc_msi.emulated = 0;
192 				caplen = msi_caplen(sc->psc_msi.msgctrl);
193 				capptr = ptr;
194 				while (caplen > 0) {
195 					u32 = read_config(&sel, capptr, 4);
196 					pci_set_cfgdata32(pi, capptr, u32);
197 					caplen -= 4;
198 					capptr += 4;
199 				}
200 			} else if (cap == PCIY_MSIX) {
201 				/*
202 				 * Copy the MSI-X capability
203 				 */
204 				sc->psc_msix.capoff = ptr;
205 				caplen = 12;
206 				msixcap_ptr = (uint32_t*) &msixcap;
207 				capptr = ptr;
208 				while (caplen > 0) {
209 					u32 = read_config(&sel, capptr, 4);
210 					*msixcap_ptr = u32;
211 					pci_set_cfgdata32(pi, capptr, u32);
212 					caplen -= 4;
213 					capptr += 4;
214 					msixcap_ptr++;
215 				}
216 			}
217 			ptr = read_config(&sel, ptr + PCICAP_NEXTPTR, 1);
218 		}
219 	}
220 
221 	if (sc->psc_msix.capoff != 0) {
222 		pi->pi_msix.pba_bar =
223 		    msixcap.pba_info & PCIM_MSIX_BIR_MASK;
224 		pi->pi_msix.pba_offset =
225 		    msixcap.pba_info & ~PCIM_MSIX_BIR_MASK;
226 		pi->pi_msix.table_bar =
227 		    msixcap.table_info & PCIM_MSIX_BIR_MASK;
228 		pi->pi_msix.table_offset =
229 		    msixcap.table_info & ~PCIM_MSIX_BIR_MASK;
230 		pi->pi_msix.table_count = MSIX_TABLE_COUNT(msixcap.msgctrl);
231 		pi->pi_msix.pba_size = PBA_SIZE(pi->pi_msix.table_count);
232 
233 		/* Allocate the emulated MSI-X table array */
234 		table_size = pi->pi_msix.table_count * MSIX_TABLE_ENTRY_SIZE;
235 		pi->pi_msix.table = calloc(1, table_size);
236 
237 		/* Mask all table entries */
238 		for (i = 0; i < pi->pi_msix.table_count; i++) {
239 			pi->pi_msix.table[i].vector_control |=
240 						PCIM_MSIX_VCTRL_MASK;
241 		}
242 	}
243 
244 #ifdef LEGACY_SUPPORT
245 	/*
246 	 * If the passthrough device does not support MSI then craft a
247 	 * MSI capability for it. We link the new MSI capability at the
248 	 * head of the list of capabilities.
249 	 */
250 	if ((sts & PCIM_STATUS_CAPPRESENT) != 0 && sc->psc_msi.capoff == 0) {
251 		int origptr, msiptr;
252 		origptr = read_config(&sel, PCIR_CAP_PTR, 1);
253 		msiptr = passthru_add_msicap(pi, 1, origptr);
254 		sc->psc_msi.capoff = msiptr;
255 		sc->psc_msi.msgctrl = pci_get_cfgdata16(pi, msiptr + 2);
256 		sc->psc_msi.emulated = 1;
257 		pci_set_cfgdata8(pi, PCIR_CAP_PTR, msiptr);
258 	}
259 #endif
260 
261 	/* Make sure one of the capabilities is present */
262 	if (sc->psc_msi.capoff == 0 && sc->psc_msix.capoff == 0)
263 		return (-1);
264 	else
265 		return (0);
266 }
267 
268 static uint64_t
269 msix_table_read(struct passthru_softc *sc, uint64_t offset, int size)
270 {
271 	struct pci_devinst *pi;
272 	struct msix_table_entry *entry;
273 	uint8_t *src8;
274 	uint16_t *src16;
275 	uint32_t *src32;
276 	uint64_t *src64;
277 	uint64_t data;
278 	size_t entry_offset;
279 	int index;
280 
281 	pi = sc->psc_pi;
282 	if (offset < pi->pi_msix.table_offset)
283 		return (-1);
284 
285 	offset -= pi->pi_msix.table_offset;
286 	index = offset / MSIX_TABLE_ENTRY_SIZE;
287 	if (index >= pi->pi_msix.table_count)
288 		return (-1);
289 
290 	entry = &pi->pi_msix.table[index];
291 	entry_offset = offset % MSIX_TABLE_ENTRY_SIZE;
292 
293 	switch(size) {
294 	case 1:
295 		src8 = (uint8_t *)((void *)entry + entry_offset);
296 		data = *src8;
297 		break;
298 	case 2:
299 		src16 = (uint16_t *)((void *)entry + entry_offset);
300 		data = *src16;
301 		break;
302 	case 4:
303 		src32 = (uint32_t *)((void *)entry + entry_offset);
304 		data = *src32;
305 		break;
306 	case 8:
307 		src64 = (uint64_t *)((void *)entry + entry_offset);
308 		data = *src64;
309 		break;
310 	default:
311 		return (-1);
312 	}
313 
314 	return (data);
315 }
316 
317 static void
318 msix_table_write(struct vmctx *ctx, int vcpu, struct passthru_softc *sc,
319 		 uint64_t offset, int size, uint64_t data)
320 {
321 	struct pci_devinst *pi;
322 	struct msix_table_entry *entry;
323 	uint32_t *dest;
324 	size_t entry_offset;
325 	uint32_t vector_control;
326 	int error, index;
327 
328 	pi = sc->psc_pi;
329 	if (offset < pi->pi_msix.table_offset)
330 		return;
331 
332 	offset -= pi->pi_msix.table_offset;
333 	index = offset / MSIX_TABLE_ENTRY_SIZE;
334 	if (index >= pi->pi_msix.table_count)
335 		return;
336 
337 	entry = &pi->pi_msix.table[index];
338 	entry_offset = offset % MSIX_TABLE_ENTRY_SIZE;
339 
340 	/* Only 4 byte naturally-aligned writes are supported */
341 	assert(size == 4);
342 	assert(entry_offset % 4 == 0);
343 
344 	vector_control = entry->vector_control;
345 	dest = (uint32_t *)((void *)entry + entry_offset);
346 	*dest = data;
347 	/* If MSI-X hasn't been enabled, do nothing */
348 	if (pi->pi_msix.enabled) {
349 		/* If the entry is masked, don't set it up */
350 		if ((entry->vector_control & PCIM_MSIX_VCTRL_MASK) == 0 ||
351 		    (vector_control & PCIM_MSIX_VCTRL_MASK) == 0) {
352 			error = vm_setup_pptdev_msix(ctx, vcpu,
353 			    sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
354 			    sc->psc_sel.pc_func, index, entry->addr,
355 			    entry->msg_data, entry->vector_control);
356 		}
357 	}
358 }
359 
360 static int
361 init_msix_table(struct vmctx *ctx, struct passthru_softc *sc, uint64_t base)
362 {
363 	int b, s, f;
364 	int error, idx;
365 	size_t len, remaining;
366 	uint32_t table_size, table_offset;
367 	uint32_t pba_size, pba_offset;
368 	vm_paddr_t start;
369 	struct pci_devinst *pi = sc->psc_pi;
370 
371 	assert(pci_msix_table_bar(pi) >= 0 && pci_msix_pba_bar(pi) >= 0);
372 
373 	b = sc->psc_sel.pc_bus;
374 	s = sc->psc_sel.pc_dev;
375 	f = sc->psc_sel.pc_func;
376 
377 	/*
378 	 * If the MSI-X table BAR maps memory intended for
379 	 * other uses, it is at least assured that the table
380 	 * either resides in its own page within the region,
381 	 * or it resides in a page shared with only the PBA.
382 	 */
383 	table_offset = rounddown2(pi->pi_msix.table_offset, 4096);
384 
385 	table_size = pi->pi_msix.table_offset - table_offset;
386 	table_size += pi->pi_msix.table_count * MSIX_TABLE_ENTRY_SIZE;
387 	table_size = roundup2(table_size, 4096);
388 
389 	if (pi->pi_msix.pba_bar == pi->pi_msix.table_bar) {
390 		pba_offset = pi->pi_msix.pba_offset;
391 		pba_size = pi->pi_msix.pba_size;
392 		if (pba_offset >= table_offset + table_size ||
393 		    table_offset >= pba_offset + pba_size) {
394 			/*
395 			 * The PBA can reside in the same BAR as the MSI-x
396 			 * tables as long as it does not overlap with any
397 			 * naturally aligned page occupied by the tables.
398 			 */
399 		} else {
400 			/* Need to also emulate the PBA, not supported yet */
401 			printf("Unsupported MSI-X configuration: %d/%d/%d\n",
402 		            b, s, f);
403 			return (-1);
404 		}
405 	}
406 
407 	idx = pi->pi_msix.table_bar;
408 	start = pi->pi_bar[idx].addr;
409 	remaining = pi->pi_bar[idx].size;
410 
411 	/* Map everything before the MSI-X table */
412 	if (table_offset > 0) {
413 		len = table_offset;
414 		error = vm_map_pptdev_mmio(ctx, b, s, f, start, len, base);
415 		if (error)
416 			return (error);
417 
418 		base += len;
419 		start += len;
420 		remaining -= len;
421 	}
422 
423 	/* Skip the MSI-X table */
424 	base += table_size;
425 	start += table_size;
426 	remaining -= table_size;
427 
428 	/* Map everything beyond the end of the MSI-X table */
429 	if (remaining > 0) {
430 		len = remaining;
431 		error = vm_map_pptdev_mmio(ctx, b, s, f, start, len, base);
432 		if (error)
433 			return (error);
434 	}
435 
436 	return (0);
437 }
438 
439 static int
440 cfginitbar(struct vmctx *ctx, struct passthru_softc *sc)
441 {
442 	int i, error;
443 	struct pci_devinst *pi;
444 	struct pci_bar_io bar;
445 	enum pcibar_type bartype;
446 	uint64_t base, size;
447 
448 	pi = sc->psc_pi;
449 
450 	/*
451 	 * Initialize BAR registers
452 	 */
453 	for (i = 0; i <= PCI_BARMAX; i++) {
454 		bzero(&bar, sizeof(bar));
455 		bar.pbi_sel = sc->psc_sel;
456 		bar.pbi_reg = PCIR_BAR(i);
457 
458 		if (ioctl(pcifd, PCIOCGETBAR, &bar) < 0)
459 			continue;
460 
461 		if (PCI_BAR_IO(bar.pbi_base)) {
462 			bartype = PCIBAR_IO;
463 			base = bar.pbi_base & PCIM_BAR_IO_BASE;
464 		} else {
465 			switch (bar.pbi_base & PCIM_BAR_MEM_TYPE) {
466 			case PCIM_BAR_MEM_64:
467 				bartype = PCIBAR_MEM64;
468 				break;
469 			default:
470 				bartype = PCIBAR_MEM32;
471 				break;
472 			}
473 			base = bar.pbi_base & PCIM_BAR_MEM_BASE;
474 		}
475 		size = bar.pbi_length;
476 
477 		if (bartype != PCIBAR_IO) {
478 			if (((base | size) & PAGE_MASK) != 0) {
479 				printf("passthru device %d/%d/%d BAR %d: "
480 				    "base %#lx or size %#lx not page aligned\n",
481 				    sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
482 				    sc->psc_sel.pc_func, i, base, size);
483 				return (-1);
484 			}
485 		}
486 
487 		/* Cache information about the "real" BAR */
488 		sc->psc_bar[i].type = bartype;
489 		sc->psc_bar[i].size = size;
490 		sc->psc_bar[i].addr = base;
491 
492 		/* Allocate the BAR in the guest I/O or MMIO space */
493 		error = pci_emul_alloc_pbar(pi, i, base, bartype, size);
494 		if (error)
495 			return (-1);
496 
497 		/* The MSI-X table needs special handling */
498 		if (i == pci_msix_table_bar(pi)) {
499 			error = init_msix_table(ctx, sc, base);
500 			if (error)
501 				return (-1);
502 		} else if (bartype != PCIBAR_IO) {
503 			/* Map the physical BAR in the guest MMIO space */
504 			error = vm_map_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
505 				sc->psc_sel.pc_dev, sc->psc_sel.pc_func,
506 				pi->pi_bar[i].addr, pi->pi_bar[i].size, base);
507 			if (error)
508 				return (-1);
509 		}
510 
511 		/*
512 		 * 64-bit BAR takes up two slots so skip the next one.
513 		 */
514 		if (bartype == PCIBAR_MEM64) {
515 			i++;
516 			assert(i <= PCI_BARMAX);
517 			sc->psc_bar[i].type = PCIBAR_MEMHI64;
518 		}
519 	}
520 	return (0);
521 }
522 
523 static int
524 cfginit(struct vmctx *ctx, struct pci_devinst *pi, int bus, int slot, int func)
525 {
526 	int error;
527 	struct passthru_softc *sc;
528 
529 	error = 1;
530 	sc = pi->pi_arg;
531 
532 	bzero(&sc->psc_sel, sizeof(struct pcisel));
533 	sc->psc_sel.pc_bus = bus;
534 	sc->psc_sel.pc_dev = slot;
535 	sc->psc_sel.pc_func = func;
536 
537 	if (cfginitmsi(sc) != 0)
538 		goto done;
539 
540 	if (cfginitbar(ctx, sc) != 0)
541 		goto done;
542 
543 	error = 0;				/* success */
544 done:
545 	return (error);
546 }
547 
548 static int
549 passthru_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
550 {
551 	int bus, slot, func, error, memflags;
552 	struct passthru_softc *sc;
553 
554 	sc = NULL;
555 	error = 1;
556 
557 	memflags = vm_get_memflags(ctx);
558 	if (!(memflags & VM_MEM_F_WIRED)) {
559 		fprintf(stderr, "passthru requires guest memory to be wired\n");
560 		goto done;
561 	}
562 
563 	if (pcifd < 0) {
564 		pcifd = open(_PATH_DEVPCI, O_RDWR, 0);
565 		if (pcifd < 0)
566 			goto done;
567 	}
568 
569 	if (iofd < 0) {
570 		iofd = open(_PATH_DEVIO, O_RDWR, 0);
571 		if (iofd < 0)
572 			goto done;
573 	}
574 
575 	if (opts == NULL ||
576 	    sscanf(opts, "%d/%d/%d", &bus, &slot, &func) != 3)
577 		goto done;
578 
579 	if (vm_assign_pptdev(ctx, bus, slot, func) != 0)
580 		goto done;
581 
582 	sc = calloc(1, sizeof(struct passthru_softc));
583 
584 	pi->pi_arg = sc;
585 	sc->psc_pi = pi;
586 
587 	/* initialize config space */
588 	if ((error = cfginit(ctx, pi, bus, slot, func)) != 0)
589 		goto done;
590 
591 	error = 0;		/* success */
592 done:
593 	if (error) {
594 		free(sc);
595 		vm_unassign_pptdev(ctx, bus, slot, func);
596 	}
597 	return (error);
598 }
599 
600 static int
601 bar_access(int coff)
602 {
603 	if (coff >= PCIR_BAR(0) && coff < PCIR_BAR(PCI_BARMAX + 1))
604 		return (1);
605 	else
606 		return (0);
607 }
608 
609 static int
610 msicap_access(struct passthru_softc *sc, int coff)
611 {
612 	int caplen;
613 
614 	if (sc->psc_msi.capoff == 0)
615 		return (0);
616 
617 	caplen = msi_caplen(sc->psc_msi.msgctrl);
618 
619 	if (coff >= sc->psc_msi.capoff && coff < sc->psc_msi.capoff + caplen)
620 		return (1);
621 	else
622 		return (0);
623 }
624 
625 static int
626 msixcap_access(struct passthru_softc *sc, int coff)
627 {
628 	if (sc->psc_msix.capoff == 0)
629 		return (0);
630 
631 	return (coff >= sc->psc_msix.capoff &&
632 	        coff < sc->psc_msix.capoff + MSIX_CAPLEN);
633 }
634 
635 static int
636 passthru_cfgread(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
637 		 int coff, int bytes, uint32_t *rv)
638 {
639 	struct passthru_softc *sc;
640 
641 	sc = pi->pi_arg;
642 
643 	/*
644 	 * PCI BARs and MSI capability is emulated.
645 	 */
646 	if (bar_access(coff) || msicap_access(sc, coff))
647 		return (-1);
648 
649 #ifdef LEGACY_SUPPORT
650 	/*
651 	 * Emulate PCIR_CAP_PTR if this device does not support MSI capability
652 	 * natively.
653 	 */
654 	if (sc->psc_msi.emulated) {
655 		if (coff >= PCIR_CAP_PTR && coff < PCIR_CAP_PTR + 4)
656 			return (-1);
657 	}
658 #endif
659 
660 	/* Everything else just read from the device's config space */
661 	*rv = read_config(&sc->psc_sel, coff, bytes);
662 
663 	return (0);
664 }
665 
666 static int
667 passthru_cfgwrite(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
668 		  int coff, int bytes, uint32_t val)
669 {
670 	int error, msix_table_entries, i;
671 	struct passthru_softc *sc;
672 
673 	sc = pi->pi_arg;
674 
675 	/*
676 	 * PCI BARs are emulated
677 	 */
678 	if (bar_access(coff))
679 		return (-1);
680 
681 	/*
682 	 * MSI capability is emulated
683 	 */
684 	if (msicap_access(sc, coff)) {
685 		msicap_cfgwrite(pi, sc->psc_msi.capoff, coff, bytes, val);
686 
687 		error = vm_setup_pptdev_msi(ctx, vcpu, sc->psc_sel.pc_bus,
688 			sc->psc_sel.pc_dev, sc->psc_sel.pc_func,
689 			pi->pi_msi.addr, pi->pi_msi.msg_data,
690 			pi->pi_msi.maxmsgnum);
691 		if (error != 0) {
692 			printf("vm_setup_pptdev_msi error %d\r\n", errno);
693 			exit(1);
694 		}
695 		return (0);
696 	}
697 
698 	if (msixcap_access(sc, coff)) {
699 		msixcap_cfgwrite(pi, sc->psc_msix.capoff, coff, bytes, val);
700 		if (pi->pi_msix.enabled) {
701 			msix_table_entries = pi->pi_msix.table_count;
702 			for (i = 0; i < msix_table_entries; i++) {
703 				error = vm_setup_pptdev_msix(ctx, vcpu,
704 				    sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
705 				    sc->psc_sel.pc_func, i,
706 				    pi->pi_msix.table[i].addr,
707 				    pi->pi_msix.table[i].msg_data,
708 				    pi->pi_msix.table[i].vector_control);
709 
710 				if (error) {
711 					printf("vm_setup_pptdev_msix error "
712 					    "%d\r\n", errno);
713 					exit(1);
714 				}
715 			}
716 		}
717 		return (0);
718 	}
719 
720 #ifdef LEGACY_SUPPORT
721 	/*
722 	 * If this device does not support MSI natively then we cannot let
723 	 * the guest disable legacy interrupts from the device. It is the
724 	 * legacy interrupt that is triggering the virtual MSI to the guest.
725 	 */
726 	if (sc->psc_msi.emulated && pci_msi_enabled(pi)) {
727 		if (coff == PCIR_COMMAND && bytes == 2)
728 			val &= ~PCIM_CMD_INTxDIS;
729 	}
730 #endif
731 
732 	write_config(&sc->psc_sel, coff, bytes, val);
733 
734 	return (0);
735 }
736 
737 static void
738 passthru_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, int baridx,
739 	       uint64_t offset, int size, uint64_t value)
740 {
741 	struct passthru_softc *sc;
742 	struct iodev_pio_req pio;
743 
744 	sc = pi->pi_arg;
745 
746 	if (baridx == pci_msix_table_bar(pi)) {
747 		msix_table_write(ctx, vcpu, sc, offset, size, value);
748 	} else {
749 		assert(pi->pi_bar[baridx].type == PCIBAR_IO);
750 		bzero(&pio, sizeof(struct iodev_pio_req));
751 		pio.access = IODEV_PIO_WRITE;
752 		pio.port = sc->psc_bar[baridx].addr + offset;
753 		pio.width = size;
754 		pio.val = value;
755 
756 		(void)ioctl(iofd, IODEV_PIO, &pio);
757 	}
758 }
759 
760 static uint64_t
761 passthru_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, int baridx,
762 	      uint64_t offset, int size)
763 {
764 	struct passthru_softc *sc;
765 	struct iodev_pio_req pio;
766 	uint64_t val;
767 
768 	sc = pi->pi_arg;
769 
770 	if (baridx == pci_msix_table_bar(pi)) {
771 		val = msix_table_read(sc, offset, size);
772 	} else {
773 		assert(pi->pi_bar[baridx].type == PCIBAR_IO);
774 		bzero(&pio, sizeof(struct iodev_pio_req));
775 		pio.access = IODEV_PIO_READ;
776 		pio.port = sc->psc_bar[baridx].addr + offset;
777 		pio.width = size;
778 		pio.val = 0;
779 
780 		(void)ioctl(iofd, IODEV_PIO, &pio);
781 
782 		val = pio.val;
783 	}
784 
785 	return (val);
786 }
787 
788 struct pci_devemu passthru = {
789 	.pe_emu		= "passthru",
790 	.pe_init	= passthru_init,
791 	.pe_cfgwrite	= passthru_cfgwrite,
792 	.pe_cfgread	= passthru_cfgread,
793 	.pe_barwrite 	= passthru_write,
794 	.pe_barread    	= passthru_read,
795 };
796 PCI_EMUL_SET(passthru);
797