xref: /openbsd/lib/libkvm/kvm_amd64.c (revision e5dd7070)
1 /*	$OpenBSD: kvm_amd64.c,v 1.13 2015/12/19 18:40:30 mmcc Exp $	*/
2 /*	$NetBSD: kvm_x86_64.c,v 1.3 2002/06/05 22:01:55 fvdl Exp $	*/
3 
4 /*-
5  * Copyright (c) 1989, 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software developed by the Computer Systems
9  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
10  * BG 91-66 and contributed to Berkeley.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 /*
38  * x86-64 machine dependent routines for kvm.
39  */
40 
41 #include <sys/param.h>	/* MAXCOMLEN */
42 #include <sys/proc.h>
43 #include <sys/stat.h>
44 #include <sys/kcore.h>
45 #include <machine/kcore.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include <nlist.h>
49 #include <kvm.h>
50 
51 #include <uvm/uvm_extern.h>
52 
53 #include <limits.h>
54 #include <db.h>
55 
56 #include "kvm_private.h"
57 
58 #include <machine/pmap.h>
59 #include <machine/pte.h>
60 #include <machine/vmparam.h>
61 
62 void
63 _kvm_freevtop(kvm_t *kd)
64 {
65 	/* Not actually used for anything right now, but safe. */
66 	free(kd->vmst);
67 	kd->vmst = NULL;
68 }
69 
70 /*ARGSUSED*/
71 int
72 _kvm_initvtop(kvm_t *kd)
73 {
74 
75 	return (0);
76 }
77 
78 /*
79  * Translate a kernel virtual address to a physical address.
80  */
81 int
82 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
83 {
84 	cpu_kcore_hdr_t *cpu_kh;
85 	paddr_t pde_pa, pte_pa;
86 	u_long page_off;
87 	pd_entry_t pde;
88 	pt_entry_t pte;
89 
90 	if (ISALIVE(kd)) {
91 		_kvm_err(kd, 0, "vatop called in live kernel!");
92 		return (0);
93 	}
94 
95 	page_off = va & (kd->nbpg - 1);
96 
97 	if (va >= PMAP_DIRECT_BASE && va <= PMAP_DIRECT_END) {
98 		*pa = va - PMAP_DIRECT_BASE;
99 		return (int)(kd->nbpg - page_off);
100 	}
101 
102 	cpu_kh = kd->cpu_data;
103 
104 	/*
105 	 * Find and read all entries to get to the pa.
106 	 */
107 
108 	/*
109 	 * Level 4.
110 	 */
111 	pde_pa = cpu_kh->ptdpaddr + (pl4_pi(va) * sizeof(pd_entry_t));
112 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
113 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
114 		_kvm_syserr(kd, 0, "could not read PT level 4 entry");
115 		goto lose;
116 	}
117 	if ((pde & PG_V) == 0) {
118 		_kvm_err(kd, 0, "invalid translation (invalid level 4 PDE)");
119 		goto lose;
120 	}
121 
122 	/*
123 	 * Level 3.
124 	 */
125 	pde_pa = (pde & PG_FRAME) + (pl3_pi(va) * sizeof(pd_entry_t));
126 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
127 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
128 		_kvm_syserr(kd, 0, "could not read PT level 3 entry");
129 		goto lose;
130 	}
131 	if ((pde & PG_V) == 0) {
132 		_kvm_err(kd, 0, "invalid translation (invalid level 3 PDE)");
133 		goto lose;
134 	}
135 
136 	/*
137 	 * Level 2.
138 	 */
139 	pde_pa = (pde & PG_FRAME) + (pl2_pi(va) * sizeof(pd_entry_t));
140 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
141 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
142 		_kvm_syserr(kd, 0, "could not read PT level 2 entry");
143 		goto lose;
144 	}
145 	if ((pde & PG_V) == 0) {
146 		_kvm_err(kd, 0, "invalid translation (invalid level 2 PDE)");
147 		goto lose;
148 	}
149 
150 	/*
151 	 * Might be a large page.
152 	 */
153 	if ((pde & PG_PS) != 0) {
154 		page_off = va & (NBPD_L2 - 1);
155 		*pa = (pde & PG_LGFRAME) | page_off;
156 		return (int)(NBPD_L2 - page_off);
157 	}
158 
159 	/*
160 	 * Level 1.
161 	 */
162 	pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
163 	if (pread(kd->pmfd, (void *) &pte, sizeof(pte),
164 	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
165 		_kvm_syserr(kd, 0, "could not read PTE");
166 		goto lose;
167 	}
168 	/*
169 	 * Validate the PTE and return the physical address.
170 	 */
171 	if ((pte & PG_V) == 0) {
172 		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
173 		goto lose;
174 	}
175 	*pa = (pte & PG_FRAME) + page_off;
176 	return (int)(kd->nbpg - page_off);
177 
178  lose:
179 	*pa = (u_long)~0L;
180 	return (0);
181 }
182 
183 /*
184  * Translate a physical address to a file-offset in the crash dump.
185  */
186 off_t
187 _kvm_pa2off(kvm_t *kd, paddr_t pa)
188 {
189 	cpu_kcore_hdr_t *cpu_kh;
190 	phys_ram_seg_t *ramsegs;
191 	off_t off;
192 	int i;
193 
194 	cpu_kh = kd->cpu_data;
195 	ramsegs = (void *)((char *)(void *)cpu_kh + ALIGN(sizeof *cpu_kh));
196 
197 	off = 0;
198 	for (i = 0; i < cpu_kh->nmemsegs; i++) {
199 		if (pa >= ramsegs[i].start &&
200 		    (pa - ramsegs[i].start) < ramsegs[i].size) {
201 			off += (pa - ramsegs[i].start);
202 			break;
203 		}
204 		off += ramsegs[i].size;
205 	}
206 
207 	if (i == cpu_kh->nmemsegs)
208 		_kvm_err(kd, 0, "pa %lx not in dump", pa);
209 
210 	return (kd->dump_off + off);
211 }
212