xref: /netbsd-src/sys/arch/xen/x86/x86_xpmap.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: x86_xpmap.c,v 1.75 2018/06/24 20:28:57 jdolecek Exp $	*/
2 
3 /*
4  * Copyright (c) 2017 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Maxime Villard.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 2006 Mathieu Ropert <mro@adviseo.fr>
34  *
35  * Permission to use, copy, modify, and distribute this software for any
36  * purpose with or without fee is hereby granted, provided that the above
37  * copyright notice and this permission notice appear in all copies.
38  *
39  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
40  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
41  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
42  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
43  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
44  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
45  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
46  */
47 
48 /*
49  * Copyright (c) 2006, 2007 Manuel Bouyer.
50  *
51  * Redistribution and use in source and binary forms, with or without
52  * modification, are permitted provided that the following conditions
53  * are met:
54  * 1. Redistributions of source code must retain the above copyright
55  *    notice, this list of conditions and the following disclaimer.
56  * 2. Redistributions in binary form must reproduce the above copyright
57  *    notice, this list of conditions and the following disclaimer in the
58  *    documentation and/or other materials provided with the distribution.
59  *
60  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
61  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
62  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
63  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
64  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
65  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
66  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
67  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
68  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
69  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
70  */
71 
72 /*
73  * Copyright (c) 2004 Christian Limpach.
74  * All rights reserved.
75  *
76  * Redistribution and use in source and binary forms, with or without
77  * modification, are permitted provided that the following conditions
78  * are met:
79  * 1. Redistributions of source code must retain the above copyright
80  *    notice, this list of conditions and the following disclaimer.
81  * 2. Redistributions in binary form must reproduce the above copyright
82  *    notice, this list of conditions and the following disclaimer in the
83  *    documentation and/or other materials provided with the distribution.
84  *
85  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
86  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
87  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
88  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
89  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
90  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
91  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
92  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
93  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
94  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
95  */
96 
97 #include <sys/cdefs.h>
98 __KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.75 2018/06/24 20:28:57 jdolecek Exp $");
99 
100 #include "opt_xen.h"
101 #include "opt_ddb.h"
102 #include "ksyms.h"
103 
104 #include <sys/param.h>
105 #include <sys/systm.h>
106 #include <sys/mutex.h>
107 #include <sys/cpu.h>
108 
109 #include <uvm/uvm.h>
110 
111 #include <x86/pmap.h>
112 #include <machine/gdt.h>
113 #include <xen/xenfunc.h>
114 
115 #include <dev/isa/isareg.h>
116 #include <machine/isa_machdep.h>
117 
118 #undef	XENDEBUG
119 
120 #ifdef XENDEBUG
121 #define	XENPRINTF(x) printf x
122 #else
123 #define	XENPRINTF(x)
124 #endif
125 
126 /* Xen requires the start_info struct to be page aligned */
127 union start_info_union start_info_union __aligned(PAGE_SIZE);
128 
129 volatile shared_info_t *HYPERVISOR_shared_info __read_mostly;
130 unsigned long *xpmap_phys_to_machine_mapping __read_mostly;
131 kmutex_t pte_lock __cacheline_aligned;
132 vaddr_t xen_dummy_page;
133 pt_entry_t xpmap_pg_nx __read_mostly;
134 
135 #define XPQUEUE_SIZE 2048
136 static mmu_update_t xpq_queue_array[MAXCPUS][XPQUEUE_SIZE];
137 
138 void xen_failsafe_handler(void);
139 
140 extern volatile struct xencons_interface *xencons_interface; /* XXX */
141 extern struct xenstore_domain_interface *xenstore_interface; /* XXX */
142 
143 static void xen_bt_set_readonly(vaddr_t);
144 static void xen_bootstrap_tables(vaddr_t, vaddr_t, size_t, size_t, bool);
145 
146 vaddr_t xen_locore(void);
147 
148 /*
149  * kcpuset internally uses an array of uint32_t while xen uses an array of
150  * u_long. As we're little-endian we can cast one to the other.
151  */
152 typedef union {
153 #ifdef _LP64
154 	uint32_t xcpum_km[2];
155 #else
156 	uint32_t xcpum_km[1];
157 #endif
158 	u_long xcpum_xm;
159 } xcpumask_t;
160 
161 void
162 xen_failsafe_handler(void)
163 {
164 
165 	panic("xen_failsafe_handler called!\n");
166 }
167 
168 void
169 xen_set_ldt(vaddr_t base, uint32_t entries)
170 {
171 	vaddr_t va;
172 	vaddr_t end;
173 	pt_entry_t *ptp;
174 	int s;
175 
176 #ifdef __x86_64__
177 	end = base + (entries << 3);
178 #else
179 	end = base + entries * sizeof(union descriptor);
180 #endif
181 
182 	for (va = base; va < end; va += PAGE_SIZE) {
183 		KASSERT(va >= VM_MIN_KERNEL_ADDRESS);
184 		ptp = kvtopte(va);
185 		XENPRINTF(("xen_set_ldt %#" PRIxVADDR " %d %p\n",
186 		    base, entries, ptp));
187 		pmap_pte_clearbits(ptp, PG_RW);
188 	}
189 	s = splvm(); /* XXXSMP */
190 	xpq_queue_set_ldt(base, entries);
191 	splx(s);
192 }
193 
194 void
195 xpq_flush_queue(void)
196 {
197 	mmu_update_t *xpq_queue;
198 	int done = 0, ret;
199 	size_t xpq_idx;
200 
201 	xpq_idx = curcpu()->ci_xpq_idx;
202 	xpq_queue = xpq_queue_array[curcpu()->ci_cpuid];
203 
204 retry:
205 	ret = HYPERVISOR_mmu_update(xpq_queue, xpq_idx, &done, DOMID_SELF);
206 
207 	if (ret < 0 && xpq_idx != 0) {
208 		printf("xpq_flush_queue: %zu entries (%d successful) on "
209 		    "cpu%d (%ld)\n",
210 		    xpq_idx, done, curcpu()->ci_index, curcpu()->ci_cpuid);
211 
212 		if (done != 0) {
213 			xpq_queue += done;
214 			xpq_idx -= done;
215 			done = 0;
216 			goto retry;
217 		}
218 
219 		panic("HYPERVISOR_mmu_update failed, ret: %d\n", ret);
220 	}
221 	curcpu()->ci_xpq_idx = 0;
222 }
223 
224 static inline void
225 xpq_increment_idx(void)
226 {
227 
228 	if (__predict_false(++curcpu()->ci_xpq_idx == XPQUEUE_SIZE))
229 		xpq_flush_queue();
230 }
231 
232 void
233 xpq_queue_machphys_update(paddr_t ma, paddr_t pa)
234 {
235 	mmu_update_t *xpq_queue = xpq_queue_array[curcpu()->ci_cpuid];
236 	size_t xpq_idx = curcpu()->ci_xpq_idx;
237 
238 	xpq_queue[xpq_idx].ptr = ma | MMU_MACHPHYS_UPDATE;
239 	xpq_queue[xpq_idx].val = pa >> PAGE_SHIFT;
240 	xpq_increment_idx();
241 }
242 
243 void
244 xpq_queue_pte_update(paddr_t ptr, pt_entry_t val)
245 {
246 	mmu_update_t *xpq_queue = xpq_queue_array[curcpu()->ci_cpuid];
247 	size_t xpq_idx = curcpu()->ci_xpq_idx;
248 
249 	xpq_queue[xpq_idx].ptr = ptr | MMU_NORMAL_PT_UPDATE;
250 	xpq_queue[xpq_idx].val = val;
251 	xpq_increment_idx();
252 }
253 
254 void
255 xpq_queue_pt_switch(paddr_t pa)
256 {
257 	struct mmuext_op op;
258 
259 	xpq_flush_queue();
260 
261 	op.cmd = MMUEXT_NEW_BASEPTR;
262 	op.arg1.mfn = pa >> PAGE_SHIFT;
263 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
264 		panic(__func__);
265 }
266 
267 void
268 xpq_queue_pin_table(paddr_t pa, int lvl)
269 {
270 	struct mmuext_op op;
271 
272 	xpq_flush_queue();
273 
274 	op.cmd = lvl;
275 	op.arg1.mfn = pa >> PAGE_SHIFT;
276 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
277 		panic(__func__);
278 }
279 
280 void
281 xpq_queue_unpin_table(paddr_t pa)
282 {
283 	struct mmuext_op op;
284 
285 	xpq_flush_queue();
286 
287 	op.cmd = MMUEXT_UNPIN_TABLE;
288 	op.arg1.mfn = pa >> PAGE_SHIFT;
289 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
290 		panic(__func__);
291 }
292 
293 void
294 xpq_queue_set_ldt(vaddr_t va, uint32_t entries)
295 {
296 	struct mmuext_op op;
297 
298 	xpq_flush_queue();
299 
300 	KASSERT(va == (va & ~PAGE_MASK));
301 	op.cmd = MMUEXT_SET_LDT;
302 	op.arg1.linear_addr = va;
303 	op.arg2.nr_ents = entries;
304 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
305 		panic(__func__);
306 }
307 
308 void
309 xpq_queue_tlb_flush(void)
310 {
311 	struct mmuext_op op;
312 
313 	xpq_flush_queue();
314 
315 	op.cmd = MMUEXT_TLB_FLUSH_LOCAL;
316 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
317 		panic(__func__);
318 }
319 
320 void
321 xpq_flush_cache(void)
322 {
323 	int s = splvm(); /* XXXSMP */
324 
325 	xpq_flush_queue();
326 
327 	asm("wbinvd":::"memory");
328 	splx(s); /* XXX: removeme */
329 }
330 
331 void
332 xpq_queue_invlpg(vaddr_t va)
333 {
334 	struct mmuext_op op;
335 
336 	xpq_flush_queue();
337 
338 	op.cmd = MMUEXT_INVLPG_LOCAL;
339 	op.arg1.linear_addr = (va & ~PAGE_MASK);
340 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
341 		panic(__func__);
342 }
343 
344 void
345 xen_mcast_invlpg(vaddr_t va, kcpuset_t *kc)
346 {
347 	xcpumask_t xcpumask;
348 	mmuext_op_t op;
349 
350 	kcpuset_export_u32(kc, &xcpumask.xcpum_km[0], sizeof(xcpumask));
351 
352 	xpq_flush_queue();
353 
354 	op.cmd = MMUEXT_INVLPG_MULTI;
355 	op.arg1.linear_addr = va;
356 	op.arg2.vcpumask = &xcpumask.xcpum_xm;
357 
358 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
359 		panic(__func__);
360 }
361 
362 void
363 xen_bcast_invlpg(vaddr_t va)
364 {
365 	mmuext_op_t op;
366 
367 	xpq_flush_queue();
368 
369 	op.cmd = MMUEXT_INVLPG_ALL;
370 	op.arg1.linear_addr = va;
371 
372 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
373 		panic(__func__);
374 }
375 
376 /* This is a synchronous call. */
377 void
378 xen_mcast_tlbflush(kcpuset_t *kc)
379 {
380 	xcpumask_t xcpumask;
381 	mmuext_op_t op;
382 
383 	kcpuset_export_u32(kc, &xcpumask.xcpum_km[0], sizeof(xcpumask));
384 
385 	xpq_flush_queue();
386 
387 	op.cmd = MMUEXT_TLB_FLUSH_MULTI;
388 	op.arg2.vcpumask = &xcpumask.xcpum_xm;
389 
390 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
391 		panic(__func__);
392 }
393 
394 /* This is a synchronous call. */
395 void
396 xen_bcast_tlbflush(void)
397 {
398 	mmuext_op_t op;
399 
400 	xpq_flush_queue();
401 
402 	op.cmd = MMUEXT_TLB_FLUSH_ALL;
403 
404 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
405 		panic(__func__);
406 }
407 
408 void
409 xen_copy_page(paddr_t srcpa, paddr_t dstpa)
410 {
411 	mmuext_op_t op;
412 
413 	op.cmd = MMUEXT_COPY_PAGE;
414 	op.arg1.mfn = xpmap_ptom(dstpa) >> PAGE_SHIFT;
415 	op.arg2.src_mfn = xpmap_ptom(srcpa) >> PAGE_SHIFT;
416 
417 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
418 		panic(__func__);
419 }
420 
421 void
422 xen_pagezero(paddr_t pa)
423 {
424 	mmuext_op_t op;
425 
426 	op.cmd = MMUEXT_CLEAR_PAGE;
427 	op.arg1.mfn = xpmap_ptom(pa) >> PAGE_SHIFT;
428 
429 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
430 		panic(__func__);
431 }
432 
433 int
434 xpq_update_foreign(paddr_t ptr, pt_entry_t val, int dom)
435 {
436 	mmu_update_t op;
437 	int ok;
438 
439 	xpq_flush_queue();
440 
441 	op.ptr = ptr;
442 	op.val = val;
443 	if (HYPERVISOR_mmu_update(&op, 1, &ok, dom) < 0)
444 		return EFAULT;
445 	return 0;
446 }
447 
448 #if L2_SLOT_KERNBASE > 0
449 #define TABLE_L2_ENTRIES (2 * (NKL2_KIMG_ENTRIES + 1))
450 #else
451 #define TABLE_L2_ENTRIES (NKL2_KIMG_ENTRIES + 1)
452 #endif
453 
454 #ifdef PAE
455 /*
456  * For PAE, we consider a single contiguous L2 "superpage" of 4 pages, all of
457  * them mapped by the L3 page. We also need a shadow page for L3[3].
458  */
459 static const int l2_4_count = 6;
460 #elif defined(__x86_64__)
461 static const int l2_4_count = PTP_LEVELS;
462 #else
463 static const int l2_4_count = PTP_LEVELS - 1;
464 #endif
465 
466 /*
467  * Xen locore: get rid of the Xen bootstrap tables. Build and switch to new page
468  * tables.
469  *
470  * Virtual address space of the kernel when leaving this function:
471  * +--------------+------------------+-------------+------------+---------------
472  * | KERNEL IMAGE | BOOTSTRAP TABLES | PROC0 UAREA | DUMMY PAGE | HYPER. SHARED
473  * +--------------+------------------+-------------+------------+---------------
474  *
475  * ------+-----------------+-------------+
476  *  INFO | EARLY ZERO PAGE | ISA I/O MEM |
477  * ------+-----------------+-------------+
478  *
479  * DUMMY PAGE is either a PDG for amd64 or a GDT for i386.
480  *
481  * (HYPER. SHARED INFO + EARLY ZERO PAGE + ISA I/O MEM) have no physical
482  * addresses preallocated.
483  */
484 vaddr_t
485 xen_locore(void)
486 {
487 	size_t count, oldcount, mapsize;
488 	vaddr_t bootstrap_tables, init_tables;
489 	u_int descs[4];
490 
491 	xen_init_features();
492 
493 	xpmap_phys_to_machine_mapping =
494 	    (unsigned long *)xen_start_info.mfn_list;
495 
496 	/* Set the NX/XD bit, if available. descs[3] = %edx. */
497 	x86_cpuid(0x80000001, descs);
498 	xpmap_pg_nx = (descs[3] & CPUID_NOX) ? PG_NX : 0;
499 
500 	/* Space after Xen boostrap tables should be free */
501 	init_tables = xen_start_info.pt_base;
502 	bootstrap_tables = init_tables +
503 	    (xen_start_info.nr_pt_frames * PAGE_SIZE);
504 
505 	/*
506 	 * Calculate how much space we need. First, everything mapped before
507 	 * the Xen bootstrap tables.
508 	 */
509 	mapsize = init_tables - KERNTEXTOFF;
510 	/* after the tables we'll have:
511 	 *  - UAREA
512 	 *  - dummy user PGD (x86_64)
513 	 *  - HYPERVISOR_shared_info
514 	 *  - early_zerop
515 	 *  - ISA I/O mem (if needed)
516 	 */
517 	mapsize += UPAGES * PAGE_SIZE;
518 #ifdef __x86_64__
519 	mapsize += PAGE_SIZE;
520 #endif
521 	mapsize += PAGE_SIZE;
522 	mapsize += PAGE_SIZE;
523 #ifdef DOM0OPS
524 	if (xendomain_is_dom0()) {
525 		mapsize += IOM_SIZE;
526 	}
527 #endif
528 
529 	/*
530 	 * At this point, mapsize doesn't include the table size.
531 	 */
532 #ifdef __x86_64__
533 	count = TABLE_L2_ENTRIES;
534 #else
535 	count = (mapsize + (NBPD_L2 - 1)) >> L2_SHIFT;
536 #endif
537 
538 	/*
539 	 * Now compute how many L2 pages we need exactly. This is useful only
540 	 * on i386, since the initial count for amd64 is already enough.
541 	 */
542 	while (KERNTEXTOFF + mapsize + (count + l2_4_count) * PAGE_SIZE >
543 	    KERNBASE + (count << L2_SHIFT)) {
544 		count++;
545 	}
546 
547 #ifdef i386
548 	/*
549 	 * One more L2 page: we'll allocate several pages after kva_start
550 	 * in pmap_bootstrap() before pmap_growkernel(), which have not been
551 	 * counted here. It's not a big issue to allocate one more L2 as
552 	 * pmap_growkernel() will be called anyway.
553 	 */
554 	count++;
555 	nkptp[1] = count;
556 #endif
557 
558 	/*
559 	 * Install bootstrap pages. We may need more L2 pages than will
560 	 * have the final table here, as it's installed after the final table.
561 	 */
562 	oldcount = count;
563 
564 bootstrap_again:
565 
566 	/*
567 	 * Xen space we'll reclaim may not be enough for our new page tables,
568 	 * move bootstrap tables if necessary.
569 	 */
570 	if (bootstrap_tables < init_tables + ((count + l2_4_count) * PAGE_SIZE))
571 		bootstrap_tables = init_tables +
572 		    ((count + l2_4_count) * PAGE_SIZE);
573 
574 	/*
575 	 * Make sure the number of L2 pages we have is enough to map everything
576 	 * from KERNBASE to the bootstrap tables themselves.
577 	 */
578 	if (bootstrap_tables + ((oldcount + l2_4_count) * PAGE_SIZE) >
579 	    KERNBASE + (oldcount << L2_SHIFT)) {
580 		oldcount++;
581 		goto bootstrap_again;
582 	}
583 
584 	/* Create temporary tables */
585 	xen_bootstrap_tables(init_tables, bootstrap_tables,
586 	    xen_start_info.nr_pt_frames, oldcount, false);
587 
588 	/* Create final tables */
589 	xen_bootstrap_tables(bootstrap_tables, init_tables,
590 	    oldcount + l2_4_count, count, true);
591 
592 	/* Zero out PROC0 UAREA and DUMMY PAGE. */
593 	memset((void *)(init_tables + ((count + l2_4_count) * PAGE_SIZE)), 0,
594 	    (UPAGES + 1) * PAGE_SIZE);
595 
596 	/* Finally, flush TLB. */
597 	xpq_queue_tlb_flush();
598 
599 	return (init_tables + ((count + l2_4_count) * PAGE_SIZE));
600 }
601 
602 /*
603  * Build a new table and switch to it.
604  * old_count is # of old tables (including PGD, PDTPE and PDE).
605  * new_count is # of new tables (PTE only).
606  * We assume the areas don't overlap.
607  */
608 static void
609 xen_bootstrap_tables(vaddr_t old_pgd, vaddr_t new_pgd, size_t old_count,
610     size_t new_count, bool final)
611 {
612 	pd_entry_t *pdtpe, *pde, *pte;
613 	pd_entry_t *bt_pgd;
614 	paddr_t addr;
615 	vaddr_t page, avail, map_end;
616 	int i;
617 	extern char __rodata_start;
618 	extern char __data_start;
619 	extern char __kernel_end;
620 	extern char *early_zerop; /* from pmap.c */
621 #ifdef i386
622 	extern union descriptor tmpgdt[];
623 #endif
624 
625 	/*
626 	 * Layout of RW area after the kernel image:
627 	 *     xencons_interface (if present)
628 	 *     xenstore_interface (if present)
629 	 *     table pages (new_count + l2_4_count entries)
630 	 * Extra mappings (only when final is true):
631 	 *     UAREA
632 	 *     dummy user PGD (x86_64 only) / GDT page (i386 only)
633 	 *     HYPERVISOR_shared_info
634 	 *     early_zerop
635 	 *     ISA I/O mem (if needed)
636 	 */
637 	map_end = new_pgd + ((new_count + l2_4_count) * PAGE_SIZE);
638 	if (final) {
639 		map_end += UPAGES * PAGE_SIZE;
640 		xen_dummy_page = (vaddr_t)map_end;
641 		map_end += PAGE_SIZE;
642 		HYPERVISOR_shared_info = (shared_info_t *)map_end;
643 		map_end += PAGE_SIZE;
644 		early_zerop = (char *)map_end;
645 		map_end += PAGE_SIZE;
646 	}
647 
648 	/*
649 	 * We always set atdevbase, as it's used by init386 to find the first
650 	 * available VA. map_end is updated only if we are dom0, so
651 	 * atdevbase -> atdevbase + IOM_SIZE will be mapped only in
652 	 * this case.
653 	 */
654 	if (final) {
655 		atdevbase = map_end;
656 #ifdef DOM0OPS
657 		if (xendomain_is_dom0()) {
658 			/* ISA I/O mem */
659 			map_end += IOM_SIZE;
660 		}
661 #endif
662 	}
663 
664 	__PRINTK(("xen_bootstrap_tables map_end 0x%lx\n", map_end));
665 	__PRINTK(("console %#lx ", xen_start_info.console_mfn));
666 	__PRINTK(("xenstore %#" PRIx32 "\n", xen_start_info.store_mfn));
667 
668 	/*
669 	 * Create bootstrap page tables. What we need:
670 	 * - a PGD (level 4)
671 	 * - a PDTPE (level 3)
672 	 * - a PDE (level 2)
673 	 * - some PTEs (level 1)
674 	 */
675 
676 	bt_pgd = (pd_entry_t *)new_pgd;
677 	memset(bt_pgd, 0, PAGE_SIZE);
678 	avail = new_pgd + PAGE_SIZE;
679 
680 #if PTP_LEVELS > 3
681 	/* Per-cpu L4 */
682 	pd_entry_t *bt_cpu_pgd = bt_pgd;
683 	/* pmap_kernel() "shadow" L4 */
684 	bt_pgd = (pd_entry_t *)avail;
685 	memset(bt_pgd, 0, PAGE_SIZE);
686 	avail += PAGE_SIZE;
687 
688 	/* Install L3 */
689 	pdtpe = (pd_entry_t *)avail;
690 	memset(pdtpe, 0, PAGE_SIZE);
691 	avail += PAGE_SIZE;
692 
693 	addr = ((u_long)pdtpe) - KERNBASE;
694 	bt_pgd[pl4_pi(KERNTEXTOFF)] = bt_cpu_pgd[pl4_pi(KERNTEXTOFF)] =
695 	    xpmap_ptom_masked(addr) | PG_V | PG_RW;
696 #else
697 	pdtpe = bt_pgd;
698 #endif
699 
700 #if PTP_LEVELS > 2
701 	/* Level 2 */
702 	pde = (pd_entry_t *)avail;
703 	memset(pde, 0, PAGE_SIZE);
704 	avail += PAGE_SIZE;
705 
706 	addr = ((u_long)pde) - KERNBASE;
707 	pdtpe[pl3_pi(KERNTEXTOFF)] =
708 	    xpmap_ptom_masked(addr) | PG_V | PG_RW;
709 #elif defined(PAE)
710 	/*
711 	 * Our PAE-style level 2, 5 contiguous pages (4 L2 + 1 shadow).
712 	 *                  +-----------------+----------------+---------+
713 	 * Physical layout: | 3 * USERLAND L2 | L2 KERN SHADOW | L2 KERN |
714 	 *                  +-----------------+----------------+---------+
715 	 * However, we enter pdtpte[3] into L2 KERN, and not L2 KERN SHADOW.
716 	 * This way, pde[L2_SLOT_KERN] always points to the shadow.
717 	 */
718 	pde = (pd_entry_t *)avail;
719 	memset(pde, 0, PAGE_SIZE * 5);
720 	avail += PAGE_SIZE * 5;
721 
722 	/*
723 	 * Link L2 pages in L3, with a special case for L2 KERN. Xen doesn't
724 	 * want RW permissions in L3 entries, it'll add them itself.
725 	 */
726 	addr = ((u_long)pde) - KERNBASE;
727 	for (i = 0; i < 3; i++, addr += PAGE_SIZE) {
728 		pdtpe[i] = xpmap_ptom_masked(addr) | PG_V;
729 	}
730 	addr += PAGE_SIZE;
731 	pdtpe[3] = xpmap_ptom_masked(addr) | PG_V;
732 #else
733 	pde = bt_pgd;
734 #endif
735 
736 	/* Level 1 */
737 	page = KERNTEXTOFF;
738 	for (i = 0; i < new_count; i ++) {
739 		vaddr_t cur_page = page;
740 
741 		pte = (pd_entry_t *)avail;
742 		avail += PAGE_SIZE;
743 
744 		memset(pte, 0, PAGE_SIZE);
745 		while (pl2_pi(page) == pl2_pi(cur_page)) {
746 			if (page >= map_end) {
747 				/* not mapped at all */
748 				pte[pl1_pi(page)] = 0;
749 				page += PAGE_SIZE;
750 				continue;
751 			}
752 			pte[pl1_pi(page)] = xpmap_ptom_masked(page - KERNBASE);
753 			if (page == (vaddr_t)HYPERVISOR_shared_info) {
754 				pte[pl1_pi(page)] = xen_start_info.shared_info;
755 			}
756 			if ((xpmap_ptom_masked(page - KERNBASE) >> PAGE_SHIFT)
757 			    == xen_start_info.console.domU.mfn) {
758 				xencons_interface = (void *)page;
759 				pte[pl1_pi(page)] = xen_start_info.console_mfn;
760 				pte[pl1_pi(page)] <<= PAGE_SHIFT;
761 			}
762 			if ((xpmap_ptom_masked(page - KERNBASE) >> PAGE_SHIFT)
763 			    == xen_start_info.store_mfn) {
764 				xenstore_interface = (void *)page;
765 				pte[pl1_pi(page)] = xen_start_info.store_mfn;
766 				pte[pl1_pi(page)] <<= PAGE_SHIFT;
767 			}
768 #ifdef DOM0OPS
769 			if (page >= (vaddr_t)atdevbase &&
770 			    page < (vaddr_t)atdevbase + IOM_SIZE) {
771 				pte[pl1_pi(page)] =
772 				    IOM_BEGIN + (page - (vaddr_t)atdevbase);
773 				pte[pl1_pi(page)] |= xpmap_pg_nx;
774 			}
775 #endif
776 
777 			pte[pl1_pi(page)] |= PG_V;
778 			if (page < (vaddr_t)&__rodata_start) {
779 				/* Map the kernel text RX. */
780 				pte[pl1_pi(page)] |= PG_RO;
781 			} else if (page >= (vaddr_t)&__rodata_start &&
782 			    page < (vaddr_t)&__data_start) {
783 				/* Map the kernel rodata R. */
784 				pte[pl1_pi(page)] |= PG_RO | xpmap_pg_nx;
785 			} else if (page >= old_pgd &&
786 			    page < old_pgd + (old_count * PAGE_SIZE)) {
787 				/* Map the old page tables R. */
788 				pte[pl1_pi(page)] |= PG_RO | xpmap_pg_nx;
789 			} else if (page >= new_pgd &&
790 			    page < new_pgd + ((new_count + l2_4_count) * PAGE_SIZE)) {
791 				/* Map the new page tables R. */
792 				pte[pl1_pi(page)] |= PG_RO | xpmap_pg_nx;
793 #ifdef i386
794 			} else if (page == (vaddr_t)tmpgdt) {
795 				/*
796 				 * Map bootstrap gdt R/O. Later, we will re-add
797 				 * this page to uvm after making it writable.
798 				 */
799 				pte[pl1_pi(page)] = 0;
800 				page += PAGE_SIZE;
801 				continue;
802 #endif
803 			} else if (page >= (vaddr_t)&__data_start &&
804 			    page < (vaddr_t)&__kernel_end) {
805 				/* Map the kernel data+bss RW. */
806 				pte[pl1_pi(page)] |= PG_RW | xpmap_pg_nx;
807 			} else {
808 				/* Map the page RW. */
809 				pte[pl1_pi(page)] |= PG_RW | xpmap_pg_nx;
810 			}
811 
812 			page += PAGE_SIZE;
813 		}
814 
815 		addr = ((u_long)pte) - KERNBASE;
816 		pde[pl2_pi(cur_page)] =
817 		    xpmap_ptom_masked(addr) | PG_RW | PG_V;
818 
819 		/* Mark readonly */
820 		xen_bt_set_readonly((vaddr_t)pte);
821 	}
822 
823 	/* Install recursive page tables mapping */
824 #ifdef PAE
825 	/* Copy L2 KERN into L2 KERN SHADOW, and reference the latter in cpu0. */
826 	memcpy(&pde[L2_SLOT_KERN + NPDPG], &pde[L2_SLOT_KERN], PAGE_SIZE);
827 	cpu_info_primary.ci_kpm_pdir = &pde[L2_SLOT_KERN + NPDPG];
828 	cpu_info_primary.ci_kpm_pdirpa =
829 	    (vaddr_t)cpu_info_primary.ci_kpm_pdir - KERNBASE;
830 
831 	/*
832 	 * We don't enter a recursive entry from the L3 PD. Instead, we enter
833 	 * the first 4 L2 pages, which includes the kernel's L2 shadow. But we
834 	 * have to enter the shadow after switching %cr3, or Xen will refcount
835 	 * some PTEs with the wrong type.
836 	 */
837 	addr = (u_long)pde - KERNBASE;
838 	for (i = 0; i < 3; i++, addr += PAGE_SIZE) {
839 		pde[PDIR_SLOT_PTE + i] = xpmap_ptom_masked(addr) | PG_V |
840 		    xpmap_pg_nx;
841 	}
842 
843 	/* Mark tables RO, and pin L2 KERN SHADOW. */
844 	addr = (u_long)pde - KERNBASE;
845 	for (i = 0; i < 5; i++, addr += PAGE_SIZE) {
846 		xen_bt_set_readonly(((vaddr_t)pde) + PAGE_SIZE * i);
847 	}
848 	if (final) {
849 		addr = (u_long)pde - KERNBASE + 3 * PAGE_SIZE;
850 		xpq_queue_pin_l2_table(xpmap_ptom_masked(addr));
851 	}
852 #else /* PAE */
853 
854 	/* Recursive entry in pmap_kernel(). */
855 	bt_pgd[PDIR_SLOT_PTE] = xpmap_ptom_masked((paddr_t)bt_pgd - KERNBASE)
856 	    | PG_RO | PG_V | xpmap_pg_nx;
857 #ifdef __x86_64__
858 	/* Recursive entry in higher-level per-cpu PD. */
859 	bt_cpu_pgd[PDIR_SLOT_PTE] = xpmap_ptom_masked((paddr_t)bt_cpu_pgd - KERNBASE)
860 	    | PG_RO | PG_V | xpmap_pg_nx;
861 #endif
862 
863 	/* Mark tables RO */
864 	xen_bt_set_readonly((vaddr_t)pde);
865 #endif /* PAE */
866 
867 #if PTP_LEVELS > 2 || defined(PAE)
868 	xen_bt_set_readonly((vaddr_t)pdtpe);
869 #endif
870 #if PTP_LEVELS > 3
871 	xen_bt_set_readonly(new_pgd);
872 #endif
873 
874 	/* Pin the PGD */
875 #ifdef __x86_64__
876 	xpq_queue_pin_l4_table(xpmap_ptom_masked(new_pgd - KERNBASE));
877 #elif PAE
878 	xpq_queue_pin_l3_table(xpmap_ptom_masked(new_pgd - KERNBASE));
879 #else
880 	xpq_queue_pin_l2_table(xpmap_ptom_masked(new_pgd - KERNBASE));
881 #endif
882 
883 	/* Save phys. addr of PDP, for libkvm. */
884 #ifdef PAE
885 	PDPpaddr = (u_long)pde - KERNBASE; /* PDP is the L2 with PAE */
886 #else
887 	PDPpaddr = (u_long)bt_pgd - KERNBASE;
888 #endif
889 
890 	/* Switch to new tables */
891 	xpq_queue_pt_switch(xpmap_ptom_masked(new_pgd - KERNBASE));
892 
893 #ifdef PAE
894 	if (final) {
895 		/* Save the address of the L3 page */
896 		cpu_info_primary.ci_pae_l3_pdir = pdtpe;
897 		cpu_info_primary.ci_pae_l3_pdirpa = (new_pgd - KERNBASE);
898 
899 		/* Now enter the kernel's PTE mappings */
900 		addr = (u_long)pde - KERNBASE + PAGE_SIZE * 3;
901 		xpq_queue_pte_update(
902 		    xpmap_ptom(((vaddr_t)&pde[PDIR_SLOT_PTE + 3]) - KERNBASE),
903 		    xpmap_ptom_masked(addr) | PG_V);
904 		xpq_flush_queue();
905 	}
906 #elif defined(__x86_64__)
907 	if (final) {
908 		/* Save the address of the real per-cpu L4 page. */
909 		cpu_info_primary.ci_kpm_pdir = bt_cpu_pgd;
910 		cpu_info_primary.ci_kpm_pdirpa = ((paddr_t)bt_cpu_pgd - KERNBASE);
911 	}
912 #endif
913 	__USE(pdtpe);
914 
915 	/*
916 	 * Now we can safely reclaim the space taken by the old tables.
917 	 */
918 
919 	/* Unpin old PGD */
920 	xpq_queue_unpin_table(xpmap_ptom_masked(old_pgd - KERNBASE));
921 
922 	/* Mark old tables RW */
923 	page = old_pgd;
924 	addr = xpmap_mtop((paddr_t)pde[pl2_pi(page)] & PG_FRAME);
925 	pte = (pd_entry_t *)((u_long)addr + KERNBASE);
926 	pte += pl1_pi(page);
927 	while (page < old_pgd + (old_count * PAGE_SIZE) && page < map_end) {
928 		addr = xpmap_ptom(((u_long)pte) - KERNBASE);
929 		xpq_queue_pte_update(addr, *pte | PG_RW);
930 		page += PAGE_SIZE;
931 		/*
932 		 * Our PTEs are contiguous so it's safe to just "++" here.
933 		 */
934 		pte++;
935 	}
936 	xpq_flush_queue();
937 }
938 
939 /*
940  * Mark a page read-only, assuming vaddr = paddr + KERNBASE.
941  */
942 static void
943 xen_bt_set_readonly(vaddr_t page)
944 {
945 	pt_entry_t entry;
946 
947 	entry = xpmap_ptom_masked(page - KERNBASE);
948 	entry |= PG_V | xpmap_pg_nx;
949 
950 	HYPERVISOR_update_va_mapping(page, entry, UVMF_INVLPG);
951 }
952 
953 #ifdef __x86_64__
954 void
955 xen_set_user_pgd(paddr_t page)
956 {
957 	struct mmuext_op op;
958 	int s = splvm(); /* XXXSMP */
959 
960 	xpq_flush_queue();
961 	op.cmd = MMUEXT_NEW_USER_BASEPTR;
962 	op.arg1.mfn = xpmap_ptom_masked(page) >> PAGE_SHIFT;
963 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0)
964 		panic("xen_set_user_pgd: failed to install new user page"
965 			" directory %#" PRIxPADDR, page);
966 	splx(s);
967 }
968 #endif /* __x86_64__ */
969