1 /* $OpenBSD: kvm_amd64.c,v 1.16 2023/03/08 04:43:05 guenther 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/types.h>
42 #include <sys/signal.h>
43 #include <sys/proc.h>
44 #include <sys/stat.h>
45 #include <sys/kcore.h>
46 #include <machine/kcore.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <nlist.h>
50 #include <kvm.h>
51
52 #include <uvm/uvm_extern.h>
53
54 #include <limits.h>
55 #include <db.h>
56
57 #include "kvm_private.h"
58
59 #include <machine/pmap.h>
60 #include <machine/pte.h>
61 #include <machine/vmparam.h>
62
63 void
_kvm_freevtop(kvm_t * kd)64 _kvm_freevtop(kvm_t *kd)
65 {
66 /* Not actually used for anything right now, but safe. */
67 free(kd->vmst);
68 kd->vmst = NULL;
69 }
70
71 int
_kvm_initvtop(kvm_t * kd)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
_kvm_kvatop(kvm_t * kd,u_long va,paddr_t * pa)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
_kvm_pa2off(kvm_t * kd,paddr_t pa)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