xref: /freebsd/sys/amd64/vmm/intel/vtd.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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/kernel.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 
37 #include <vm/vm.h>
38 #include <vm/pmap.h>
39 
40 #include <dev/pci/pcireg.h>
41 
42 #include <machine/vmparam.h>
43 #include <contrib/dev/acpica/include/acpi.h>
44 
45 #include "io/iommu.h"
46 
47 /*
48  * Documented in the "Intel Virtualization Technology for Directed I/O",
49  * Architecture Spec, September 2008.
50  */
51 
52 /* Section 10.4 "Register Descriptions" */
53 struct vtdmap {
54 	volatile uint32_t	version;
55 	volatile uint32_t	res0;
56 	volatile uint64_t	cap;
57 	volatile uint64_t	ext_cap;
58 	volatile uint32_t	gcr;
59 	volatile uint32_t	gsr;
60 	volatile uint64_t	rta;
61 	volatile uint64_t	ccr;
62 };
63 
64 #define	VTD_CAP_SAGAW(cap)	(((cap) >> 8) & 0x1F)
65 #define	VTD_CAP_ND(cap)		((cap) & 0x7)
66 #define	VTD_CAP_CM(cap)		(((cap) >> 7) & 0x1)
67 #define	VTD_CAP_SPS(cap)	(((cap) >> 34) & 0xF)
68 #define	VTD_CAP_RWBF(cap)	(((cap) >> 4) & 0x1)
69 
70 #define	VTD_ECAP_DI(ecap)	(((ecap) >> 2) & 0x1)
71 #define	VTD_ECAP_COHERENCY(ecap) ((ecap) & 0x1)
72 #define	VTD_ECAP_IRO(ecap)	(((ecap) >> 8) & 0x3FF)
73 
74 #define	VTD_GCR_WBF		(1 << 27)
75 #define	VTD_GCR_SRTP		(1 << 30)
76 #define	VTD_GCR_TE		(1U << 31)
77 
78 #define	VTD_GSR_WBFS		(1 << 27)
79 #define	VTD_GSR_RTPS		(1 << 30)
80 #define	VTD_GSR_TES		(1U << 31)
81 
82 #define	VTD_CCR_ICC		(1UL << 63)	/* invalidate context cache */
83 #define	VTD_CCR_CIRG_GLOBAL	(1UL << 61)	/* global invalidation */
84 
85 #define	VTD_IIR_IVT		(1UL << 63)	/* invalidation IOTLB */
86 #define	VTD_IIR_IIRG_GLOBAL	(1ULL << 60)	/* global IOTLB invalidation */
87 #define	VTD_IIR_IIRG_DOMAIN	(2ULL << 60)	/* domain IOTLB invalidation */
88 #define	VTD_IIR_IIRG_PAGE	(3ULL << 60)	/* page IOTLB invalidation */
89 #define	VTD_IIR_DRAIN_READS	(1ULL << 49)	/* drain pending DMA reads */
90 #define	VTD_IIR_DRAIN_WRITES	(1ULL << 48)	/* drain pending DMA writes */
91 #define	VTD_IIR_DOMAIN_P	32
92 
93 #define	VTD_ROOT_PRESENT	0x1
94 #define	VTD_CTX_PRESENT		0x1
95 #define	VTD_CTX_TT_ALL		(1UL << 2)
96 
97 #define	VTD_PTE_RD		(1UL << 0)
98 #define	VTD_PTE_WR		(1UL << 1)
99 #define	VTD_PTE_SUPERPAGE	(1UL << 7)
100 #define	VTD_PTE_ADDR_M		(0x000FFFFFFFFFF000UL)
101 
102 #define VTD_RID2IDX(rid)	(((rid) & 0xff) * 2)
103 
104 struct domain {
105 	uint64_t	*ptp;		/* first level page table page */
106 	int		pt_levels;	/* number of page table levels */
107 	int		addrwidth;	/* 'AW' field in context entry */
108 	int		spsmask;	/* supported super page sizes */
109 	u_int		id;		/* domain id */
110 	vm_paddr_t	maxaddr;	/* highest address to be mapped */
111 	SLIST_ENTRY(domain) next;
112 };
113 
114 static SLIST_HEAD(, domain) domhead;
115 
116 #define	DRHD_MAX_UNITS	8
117 static int		drhd_num;
118 static struct vtdmap	*vtdmaps[DRHD_MAX_UNITS];
119 static int		max_domains;
120 typedef int		(*drhd_ident_func_t)(void);
121 
122 static uint64_t root_table[PAGE_SIZE / sizeof(uint64_t)] __aligned(4096);
123 static uint64_t ctx_tables[256][PAGE_SIZE / sizeof(uint64_t)] __aligned(4096);
124 
125 static MALLOC_DEFINE(M_VTD, "vtd", "vtd");
126 
127 static int
128 vtd_max_domains(struct vtdmap *vtdmap)
129 {
130 	int nd;
131 
132 	nd = VTD_CAP_ND(vtdmap->cap);
133 
134 	switch (nd) {
135 	case 0:
136 		return (16);
137 	case 1:
138 		return (64);
139 	case 2:
140 		return (256);
141 	case 3:
142 		return (1024);
143 	case 4:
144 		return (4 * 1024);
145 	case 5:
146 		return (16 * 1024);
147 	case 6:
148 		return (64 * 1024);
149 	default:
150 		panic("vtd_max_domains: invalid value of nd (0x%0x)", nd);
151 	}
152 }
153 
154 static u_int
155 domain_id(void)
156 {
157 	u_int id;
158 	struct domain *dom;
159 
160 	/* Skip domain id 0 - it is reserved when Caching Mode field is set */
161 	for (id = 1; id < max_domains; id++) {
162 		SLIST_FOREACH(dom, &domhead, next) {
163 			if (dom->id == id)
164 				break;
165 		}
166 		if (dom == NULL)
167 			break;		/* found it */
168 	}
169 
170 	if (id >= max_domains)
171 		panic("domain ids exhausted");
172 
173 	return (id);
174 }
175 
176 static void
177 vtd_wbflush(struct vtdmap *vtdmap)
178 {
179 
180 	if (VTD_ECAP_COHERENCY(vtdmap->ext_cap) == 0)
181 		pmap_invalidate_cache();
182 
183 	if (VTD_CAP_RWBF(vtdmap->cap)) {
184 		vtdmap->gcr = VTD_GCR_WBF;
185 		while ((vtdmap->gsr & VTD_GSR_WBFS) != 0)
186 			;
187 	}
188 }
189 
190 static void
191 vtd_ctx_global_invalidate(struct vtdmap *vtdmap)
192 {
193 
194 	vtdmap->ccr = VTD_CCR_ICC | VTD_CCR_CIRG_GLOBAL;
195 	while ((vtdmap->ccr & VTD_CCR_ICC) != 0)
196 		;
197 }
198 
199 static void
200 vtd_iotlb_global_invalidate(struct vtdmap *vtdmap)
201 {
202 	int offset;
203 	volatile uint64_t *iotlb_reg, val;
204 
205 	vtd_wbflush(vtdmap);
206 
207 	offset = VTD_ECAP_IRO(vtdmap->ext_cap) * 16;
208 	iotlb_reg = (volatile uint64_t *)((caddr_t)vtdmap + offset + 8);
209 
210 	*iotlb_reg =  VTD_IIR_IVT | VTD_IIR_IIRG_GLOBAL |
211 		      VTD_IIR_DRAIN_READS | VTD_IIR_DRAIN_WRITES;
212 
213 	while (1) {
214 		val = *iotlb_reg;
215 		if ((val & VTD_IIR_IVT) == 0)
216 			break;
217 	}
218 }
219 
220 static void
221 vtd_translation_enable(struct vtdmap *vtdmap)
222 {
223 
224 	vtdmap->gcr = VTD_GCR_TE;
225 	while ((vtdmap->gsr & VTD_GSR_TES) == 0)
226 		;
227 }
228 
229 static void
230 vtd_translation_disable(struct vtdmap *vtdmap)
231 {
232 
233 	vtdmap->gcr = 0;
234 	while ((vtdmap->gsr & VTD_GSR_TES) != 0)
235 		;
236 }
237 
238 static int
239 vtd_init(void)
240 {
241 	int i, units, remaining;
242 	struct vtdmap *vtdmap;
243 	vm_paddr_t ctx_paddr;
244 	char *end, envname[32];
245 	unsigned long mapaddr;
246 	ACPI_STATUS status;
247 	ACPI_TABLE_DMAR *dmar;
248 	ACPI_DMAR_HEADER *hdr;
249 	ACPI_DMAR_HARDWARE_UNIT *drhd;
250 
251 	/*
252 	 * Allow the user to override the ACPI DMAR table by specifying the
253 	 * physical address of each remapping unit.
254 	 *
255 	 * The following example specifies two remapping units at
256 	 * physical addresses 0xfed90000 and 0xfeda0000 respectively.
257 	 * set vtd.regmap.0.addr=0xfed90000
258 	 * set vtd.regmap.1.addr=0xfeda0000
259 	 */
260 	for (units = 0; units < DRHD_MAX_UNITS; units++) {
261 		snprintf(envname, sizeof(envname), "vtd.regmap.%d.addr", units);
262 		if (getenv_ulong(envname, &mapaddr) == 0)
263 			break;
264 		vtdmaps[units] = (struct vtdmap *)PHYS_TO_DMAP(mapaddr);
265 	}
266 
267 	if (units > 0)
268 		goto skip_dmar;
269 
270 	/* Search for DMAR table. */
271 	status = AcpiGetTable(ACPI_SIG_DMAR, 0, (ACPI_TABLE_HEADER **)&dmar);
272 	if (ACPI_FAILURE(status))
273 		return (ENXIO);
274 
275 	end = (char *)dmar + dmar->Header.Length;
276 	remaining = dmar->Header.Length - sizeof(ACPI_TABLE_DMAR);
277 	while (remaining > sizeof(ACPI_DMAR_HEADER)) {
278 		hdr = (ACPI_DMAR_HEADER *)(end - remaining);
279 		if (hdr->Length > remaining)
280 			break;
281 		/*
282 		 * From Intel VT-d arch spec, version 1.3:
283 		 * BIOS implementations must report mapping structures
284 		 * in numerical order, i.e. All remapping structures of
285 		 * type 0 (DRHD) enumerated before remapping structures of
286 		 * type 1 (RMRR) and so forth.
287 		 */
288 		if (hdr->Type != ACPI_DMAR_TYPE_HARDWARE_UNIT)
289 			break;
290 
291 		drhd = (ACPI_DMAR_HARDWARE_UNIT *)hdr;
292 		vtdmaps[units++] = (struct vtdmap *)PHYS_TO_DMAP(drhd->Address);
293 		if (units >= DRHD_MAX_UNITS)
294 			break;
295 		remaining -= hdr->Length;
296 	}
297 
298 	if (units <= 0)
299 		return (ENXIO);
300 
301 skip_dmar:
302 	drhd_num = units;
303 	vtdmap = vtdmaps[0];
304 
305 	if (VTD_CAP_CM(vtdmap->cap) != 0)
306 		panic("vtd_init: invalid caching mode");
307 
308 	max_domains = vtd_max_domains(vtdmap);
309 
310 	/*
311 	 * Set up the root-table to point to the context-entry tables
312 	 */
313 	for (i = 0; i < 256; i++) {
314 		ctx_paddr = vtophys(ctx_tables[i]);
315 		if (ctx_paddr & PAGE_MASK)
316 			panic("ctx table (0x%0lx) not page aligned", ctx_paddr);
317 
318 		root_table[i * 2] = ctx_paddr | VTD_ROOT_PRESENT;
319 	}
320 
321 	return (0);
322 }
323 
324 static void
325 vtd_cleanup(void)
326 {
327 }
328 
329 static void
330 vtd_enable(void)
331 {
332 	int i;
333 	struct vtdmap *vtdmap;
334 
335 	for (i = 0; i < drhd_num; i++) {
336 		vtdmap = vtdmaps[i];
337 		vtd_wbflush(vtdmap);
338 
339 		/* Update the root table address */
340 		vtdmap->rta = vtophys(root_table);
341 		vtdmap->gcr = VTD_GCR_SRTP;
342 		while ((vtdmap->gsr & VTD_GSR_RTPS) == 0)
343 			;
344 
345 		vtd_ctx_global_invalidate(vtdmap);
346 		vtd_iotlb_global_invalidate(vtdmap);
347 
348 		vtd_translation_enable(vtdmap);
349 	}
350 }
351 
352 static void
353 vtd_disable(void)
354 {
355 	int i;
356 	struct vtdmap *vtdmap;
357 
358 	for (i = 0; i < drhd_num; i++) {
359 		vtdmap = vtdmaps[i];
360 		vtd_translation_disable(vtdmap);
361 	}
362 }
363 
364 static void
365 vtd_add_device(void *arg, uint16_t rid)
366 {
367 	int idx;
368 	uint64_t *ctxp;
369 	struct domain *dom = arg;
370 	vm_paddr_t pt_paddr;
371 	struct vtdmap *vtdmap;
372 	uint8_t bus;
373 
374 	vtdmap = vtdmaps[0];
375 	bus = PCI_RID2BUS(rid);
376 	ctxp = ctx_tables[bus];
377 	pt_paddr = vtophys(dom->ptp);
378 	idx = VTD_RID2IDX(rid);
379 
380 	if (ctxp[idx] & VTD_CTX_PRESENT) {
381 		panic("vtd_add_device: device %x is already owned by "
382 		      "domain %d", rid,
383 		      (uint16_t)(ctxp[idx + 1] >> 8));
384 	}
385 
386 	/*
387 	 * Order is important. The 'present' bit is set only after all fields
388 	 * of the context pointer are initialized.
389 	 */
390 	ctxp[idx + 1] = dom->addrwidth | (dom->id << 8);
391 
392 	if (VTD_ECAP_DI(vtdmap->ext_cap))
393 		ctxp[idx] = VTD_CTX_TT_ALL;
394 	else
395 		ctxp[idx] = 0;
396 
397 	ctxp[idx] |= pt_paddr | VTD_CTX_PRESENT;
398 
399 	/*
400 	 * 'Not Present' entries are not cached in either the Context Cache
401 	 * or in the IOTLB, so there is no need to invalidate either of them.
402 	 */
403 }
404 
405 static void
406 vtd_remove_device(void *arg, uint16_t rid)
407 {
408 	int i, idx;
409 	uint64_t *ctxp;
410 	struct vtdmap *vtdmap;
411 	uint8_t bus;
412 
413 	bus = PCI_RID2BUS(rid);
414 	ctxp = ctx_tables[bus];
415 	idx = VTD_RID2IDX(rid);
416 
417 	/*
418 	 * Order is important. The 'present' bit is must be cleared first.
419 	 */
420 	ctxp[idx] = 0;
421 	ctxp[idx + 1] = 0;
422 
423 	/*
424 	 * Invalidate the Context Cache and the IOTLB.
425 	 *
426 	 * XXX use device-selective invalidation for Context Cache
427 	 * XXX use domain-selective invalidation for IOTLB
428 	 */
429 	for (i = 0; i < drhd_num; i++) {
430 		vtdmap = vtdmaps[i];
431 		vtd_ctx_global_invalidate(vtdmap);
432 		vtd_iotlb_global_invalidate(vtdmap);
433 	}
434 }
435 
436 #define	CREATE_MAPPING	0
437 #define	REMOVE_MAPPING	1
438 
439 static uint64_t
440 vtd_update_mapping(void *arg, vm_paddr_t gpa, vm_paddr_t hpa, uint64_t len,
441 		   int remove)
442 {
443 	struct domain *dom;
444 	int i, spshift, ptpshift, ptpindex, nlevels;
445 	uint64_t spsize, *ptp;
446 
447 	dom = arg;
448 	ptpindex = 0;
449 	ptpshift = 0;
450 
451 	KASSERT(gpa + len > gpa, ("%s: invalid gpa range %#lx/%#lx", __func__,
452 	    gpa, len));
453 	KASSERT(gpa + len <= dom->maxaddr, ("%s: gpa range %#lx/%#lx beyond "
454 	    "domain maxaddr %#lx", __func__, gpa, len, dom->maxaddr));
455 
456 	if (gpa & PAGE_MASK)
457 		panic("vtd_create_mapping: unaligned gpa 0x%0lx", gpa);
458 
459 	if (hpa & PAGE_MASK)
460 		panic("vtd_create_mapping: unaligned hpa 0x%0lx", hpa);
461 
462 	if (len & PAGE_MASK)
463 		panic("vtd_create_mapping: unaligned len 0x%0lx", len);
464 
465 	/*
466 	 * Compute the size of the mapping that we can accommodate.
467 	 *
468 	 * This is based on three factors:
469 	 * - supported super page size
470 	 * - alignment of the region starting at 'gpa' and 'hpa'
471 	 * - length of the region 'len'
472 	 */
473 	spshift = 48;
474 	for (i = 3; i >= 0; i--) {
475 		spsize = 1UL << spshift;
476 		if ((dom->spsmask & (1 << i)) != 0 &&
477 		    (gpa & (spsize - 1)) == 0 &&
478 		    (hpa & (spsize - 1)) == 0 &&
479 		    (len >= spsize)) {
480 			break;
481 		}
482 		spshift -= 9;
483 	}
484 
485 	ptp = dom->ptp;
486 	nlevels = dom->pt_levels;
487 	while (--nlevels >= 0) {
488 		ptpshift = 12 + nlevels * 9;
489 		ptpindex = (gpa >> ptpshift) & 0x1FF;
490 
491 		/* We have reached the leaf mapping */
492 		if (spshift >= ptpshift) {
493 			break;
494 		}
495 
496 		/*
497 		 * We are working on a non-leaf page table page.
498 		 *
499 		 * Create a downstream page table page if necessary and point
500 		 * to it from the current page table.
501 		 */
502 		if (ptp[ptpindex] == 0) {
503 			void *nlp = malloc(PAGE_SIZE, M_VTD, M_WAITOK | M_ZERO);
504 			ptp[ptpindex] = vtophys(nlp)| VTD_PTE_RD | VTD_PTE_WR;
505 		}
506 
507 		ptp = (uint64_t *)PHYS_TO_DMAP(ptp[ptpindex] & VTD_PTE_ADDR_M);
508 	}
509 
510 	if ((gpa & ((1UL << ptpshift) - 1)) != 0)
511 		panic("gpa 0x%lx and ptpshift %d mismatch", gpa, ptpshift);
512 
513 	/*
514 	 * Update the 'gpa' -> 'hpa' mapping
515 	 */
516 	if (remove) {
517 		ptp[ptpindex] = 0;
518 	} else {
519 		ptp[ptpindex] = hpa | VTD_PTE_RD | VTD_PTE_WR;
520 
521 		if (nlevels > 0)
522 			ptp[ptpindex] |= VTD_PTE_SUPERPAGE;
523 	}
524 
525 	return (1UL << ptpshift);
526 }
527 
528 static uint64_t
529 vtd_create_mapping(void *arg, vm_paddr_t gpa, vm_paddr_t hpa, uint64_t len)
530 {
531 
532 	return (vtd_update_mapping(arg, gpa, hpa, len, CREATE_MAPPING));
533 }
534 
535 static uint64_t
536 vtd_remove_mapping(void *arg, vm_paddr_t gpa, uint64_t len)
537 {
538 
539 	return (vtd_update_mapping(arg, gpa, 0, len, REMOVE_MAPPING));
540 }
541 
542 static void
543 vtd_invalidate_tlb(void *dom)
544 {
545 	int i;
546 	struct vtdmap *vtdmap;
547 
548 	/*
549 	 * Invalidate the IOTLB.
550 	 * XXX use domain-selective invalidation for IOTLB
551 	 */
552 	for (i = 0; i < drhd_num; i++) {
553 		vtdmap = vtdmaps[i];
554 		vtd_iotlb_global_invalidate(vtdmap);
555 	}
556 }
557 
558 static void *
559 vtd_create_domain(vm_paddr_t maxaddr)
560 {
561 	struct domain *dom;
562 	vm_paddr_t addr;
563 	int tmp, i, gaw, agaw, sagaw, res, pt_levels, addrwidth;
564 	struct vtdmap *vtdmap;
565 
566 	if (drhd_num <= 0)
567 		panic("vtd_create_domain: no dma remapping hardware available");
568 
569 	vtdmap = vtdmaps[0];
570 
571 	/*
572 	 * Calculate AGAW.
573 	 * Section 3.4.2 "Adjusted Guest Address Width", Architecture Spec.
574 	 */
575 	addr = 0;
576 	for (gaw = 0; addr < maxaddr; gaw++)
577 		addr = 1ULL << gaw;
578 
579 	res = (gaw - 12) % 9;
580 	if (res == 0)
581 		agaw = gaw;
582 	else
583 		agaw = gaw + 9 - res;
584 
585 	if (agaw > 64)
586 		agaw = 64;
587 
588 	/*
589 	 * Select the smallest Supported AGAW and the corresponding number
590 	 * of page table levels.
591 	 */
592 	pt_levels = 2;
593 	sagaw = 30;
594 	addrwidth = 0;
595 	tmp = VTD_CAP_SAGAW(vtdmap->cap);
596 	for (i = 0; i < 5; i++) {
597 		if ((tmp & (1 << i)) != 0 && sagaw >= agaw)
598 			break;
599 		pt_levels++;
600 		addrwidth++;
601 		sagaw += 9;
602 		if (sagaw > 64)
603 			sagaw = 64;
604 	}
605 
606 	if (i >= 5) {
607 		panic("vtd_create_domain: SAGAW 0x%lx does not support AGAW %d",
608 		      VTD_CAP_SAGAW(vtdmap->cap), agaw);
609 	}
610 
611 	dom = malloc(sizeof(struct domain), M_VTD, M_ZERO | M_WAITOK);
612 	dom->pt_levels = pt_levels;
613 	dom->addrwidth = addrwidth;
614 	dom->id = domain_id();
615 	dom->maxaddr = maxaddr;
616 	dom->ptp = malloc(PAGE_SIZE, M_VTD, M_ZERO | M_WAITOK);
617 	if ((uintptr_t)dom->ptp & PAGE_MASK)
618 		panic("vtd_create_domain: ptp (%p) not page aligned", dom->ptp);
619 
620 #ifdef notyet
621 	/*
622 	 * XXX superpage mappings for the iommu do not work correctly.
623 	 *
624 	 * By default all physical memory is mapped into the host_domain.
625 	 * When a VM is allocated wired memory the pages belonging to it
626 	 * are removed from the host_domain and added to the vm's domain.
627 	 *
628 	 * If the page being removed was mapped using a superpage mapping
629 	 * in the host_domain then we need to demote the mapping before
630 	 * removing the page.
631 	 *
632 	 * There is not any code to deal with the demotion at the moment
633 	 * so we disable superpage mappings altogether.
634 	 */
635 	dom->spsmask = VTD_CAP_SPS(vtdmap->cap);
636 #endif
637 
638 	SLIST_INSERT_HEAD(&domhead, dom, next);
639 
640 	return (dom);
641 }
642 
643 static void
644 vtd_free_ptp(uint64_t *ptp, int level)
645 {
646 	int i;
647 	uint64_t *nlp;
648 
649 	if (level > 1) {
650 		for (i = 0; i < 512; i++) {
651 			if ((ptp[i] & (VTD_PTE_RD | VTD_PTE_WR)) == 0)
652 				continue;
653 			if ((ptp[i] & VTD_PTE_SUPERPAGE) != 0)
654 				continue;
655 			nlp = (uint64_t *)PHYS_TO_DMAP(ptp[i] & VTD_PTE_ADDR_M);
656 			vtd_free_ptp(nlp, level - 1);
657 		}
658 	}
659 
660 	bzero(ptp, PAGE_SIZE);
661 	free(ptp, M_VTD);
662 }
663 
664 static void
665 vtd_destroy_domain(void *arg)
666 {
667 	struct domain *dom;
668 
669 	dom = arg;
670 
671 	SLIST_REMOVE(&domhead, dom, domain, next);
672 	vtd_free_ptp(dom->ptp, dom->pt_levels);
673 	free(dom, M_VTD);
674 }
675 
676 struct iommu_ops iommu_ops_intel = {
677 	vtd_init,
678 	vtd_cleanup,
679 	vtd_enable,
680 	vtd_disable,
681 	vtd_create_domain,
682 	vtd_destroy_domain,
683 	vtd_create_mapping,
684 	vtd_remove_mapping,
685 	vtd_add_device,
686 	vtd_remove_device,
687 	vtd_invalidate_tlb,
688 };
689