1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software developed by the Computer Systems
8 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
9 * BG 91-66 and contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36
37 /*
38 * AMD64 machine dependent routines for kvm. Hopefully, the forthcoming
39 * vm code will one day obsolete this module.
40 */
41
42 #include <sys/param.h>
43 #include <sys/endian.h>
44 #include <stdint.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <vm/vm.h>
49 #include <kvm.h>
50
51 #include <limits.h>
52
53 #include "kvm_private.h"
54 #include "kvm_amd64.h"
55
56 struct vmstate {
57 size_t phnum;
58 GElf_Phdr *phdr;
59 amd64_pml4e_t *PML4;
60 };
61
62 /*
63 * Translate a physical memory address to a file-offset in the crash-dump.
64 */
65 static size_t
_kvm_pa2off(kvm_t * kd,uint64_t pa,off_t * ofs)66 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
67 {
68 struct vmstate *vm = kd->vmst;
69 GElf_Phdr *p;
70 size_t n;
71
72 if (kd->rawdump) {
73 *ofs = pa;
74 return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
75 }
76
77 p = vm->phdr;
78 n = vm->phnum;
79 while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
80 p++, n--;
81 if (n == 0)
82 return (0);
83 *ofs = (pa - p->p_paddr) + p->p_offset;
84 return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
85 }
86
87 static void
_amd64_freevtop(kvm_t * kd)88 _amd64_freevtop(kvm_t *kd)
89 {
90 struct vmstate *vm = kd->vmst;
91
92 if (vm->PML4)
93 free(vm->PML4);
94 free(vm->phdr);
95 free(vm);
96 kd->vmst = NULL;
97 }
98
99 static int
_amd64_probe(kvm_t * kd)100 _amd64_probe(kvm_t *kd)
101 {
102
103 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) &&
104 !_kvm_is_minidump(kd));
105 }
106
107 static int
_amd64_initvtop(kvm_t * kd)108 _amd64_initvtop(kvm_t *kd)
109 {
110 struct kvm_nlist nl[2];
111 amd64_physaddr_t pa;
112 kvaddr_t kernbase;
113 amd64_pml4e_t *PML4;
114
115 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
116 if (kd->vmst == NULL) {
117 _kvm_err(kd, kd->program, "cannot allocate vm");
118 return (-1);
119 }
120 kd->vmst->PML4 = 0;
121
122 if (kd->rawdump == 0) {
123 if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum,
124 &kd->vmst->phdr) == -1)
125 return (-1);
126 }
127
128 nl[0].n_name = "kernbase";
129 nl[1].n_name = 0;
130
131 if (kvm_nlist2(kd, nl) != 0) {
132 _kvm_err(kd, kd->program, "bad namelist - no kernbase");
133 return (-1);
134 }
135 kernbase = nl[0].n_value;
136
137 nl[0].n_name = "KPML4phys";
138 nl[1].n_name = 0;
139
140 if (kvm_nlist2(kd, nl) != 0) {
141 _kvm_err(kd, kd->program, "bad namelist - no KPML4phys");
142 return (-1);
143 }
144 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa, sizeof(pa)) !=
145 sizeof(pa)) {
146 _kvm_err(kd, kd->program, "cannot read KPML4phys");
147 return (-1);
148 }
149 pa = le64toh(pa);
150 PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE);
151 if (PML4 == NULL) {
152 _kvm_err(kd, kd->program, "cannot allocate PML4");
153 return (-1);
154 }
155 if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) {
156 _kvm_err(kd, kd->program, "cannot read KPML4phys");
157 free(PML4);
158 return (-1);
159 }
160 kd->vmst->PML4 = PML4;
161 return (0);
162 }
163
164 static int
_amd64_vatop(kvm_t * kd,kvaddr_t va,off_t * pa)165 _amd64_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
166 {
167 struct vmstate *vm;
168 amd64_physaddr_t offset;
169 amd64_physaddr_t pdpe_pa;
170 amd64_physaddr_t pde_pa;
171 amd64_physaddr_t pte_pa;
172 amd64_pml4e_t pml4e;
173 amd64_pdpe_t pdpe;
174 amd64_pde_t pde;
175 amd64_pte_t pte;
176 kvaddr_t pml4eindex;
177 kvaddr_t pdpeindex;
178 kvaddr_t pdeindex;
179 kvaddr_t pteindex;
180 amd64_physaddr_t a;
181 off_t ofs;
182 size_t s;
183
184 vm = kd->vmst;
185 offset = va & AMD64_PAGE_MASK;
186
187 /*
188 * If we are initializing (kernel page table descriptor pointer
189 * not yet set) then return pa == va to avoid infinite recursion.
190 */
191 if (vm->PML4 == NULL) {
192 s = _kvm_pa2off(kd, va, pa);
193 if (s == 0) {
194 _kvm_err(kd, kd->program,
195 "_amd64_vatop: bootstrap data not in dump");
196 goto invalid;
197 } else
198 return (AMD64_PAGE_SIZE - offset);
199 }
200
201 pml4eindex = (va >> AMD64_PML4SHIFT) & (AMD64_NPML4EPG - 1);
202 pml4e = le64toh(vm->PML4[pml4eindex]);
203 if ((pml4e & AMD64_PG_V) == 0) {
204 _kvm_err(kd, kd->program, "_amd64_vatop: pml4e not valid");
205 goto invalid;
206 }
207
208 pdpeindex = (va >> AMD64_PDPSHIFT) & (AMD64_NPDPEPG - 1);
209 pdpe_pa = (pml4e & AMD64_PG_FRAME) + (pdpeindex * sizeof(amd64_pdpe_t));
210
211 s = _kvm_pa2off(kd, pdpe_pa, &ofs);
212 if (s < sizeof(pdpe)) {
213 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe_pa not found");
214 goto invalid;
215 }
216 if (pread(kd->pmfd, &pdpe, sizeof(pdpe), ofs) != sizeof(pdpe)) {
217 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pdpe");
218 goto invalid;
219 }
220 pdpe = le64toh(pdpe);
221 if ((pdpe & AMD64_PG_V) == 0) {
222 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe not valid");
223 goto invalid;
224 }
225
226 if (pdpe & AMD64_PG_PS) {
227 /*
228 * No next-level page table; pdpe describes one 1GB page.
229 */
230 a = (pdpe & AMD64_PG_1GB_FRAME) + (va & AMD64_PDPMASK);
231 s = _kvm_pa2off(kd, a, pa);
232 if (s == 0) {
233 _kvm_err(kd, kd->program,
234 "_amd64_vatop: 1GB page address not in dump");
235 goto invalid;
236 } else
237 return (AMD64_NBPDP - (va & AMD64_PDPMASK));
238 }
239
240 pdeindex = (va >> AMD64_PDRSHIFT) & (AMD64_NPDEPG - 1);
241 pde_pa = (pdpe & AMD64_PG_FRAME) + (pdeindex * sizeof(amd64_pde_t));
242
243 s = _kvm_pa2off(kd, pde_pa, &ofs);
244 if (s < sizeof(pde)) {
245 _kvm_syserr(kd, kd->program, "_amd64_vatop: pde_pa not found");
246 goto invalid;
247 }
248 if (pread(kd->pmfd, &pde, sizeof(pde), ofs) != sizeof(pde)) {
249 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pde");
250 goto invalid;
251 }
252 pde = le64toh(pde);
253 if ((pde & AMD64_PG_V) == 0) {
254 _kvm_err(kd, kd->program, "_amd64_vatop: pde not valid");
255 goto invalid;
256 }
257
258 if (pde & AMD64_PG_PS) {
259 /*
260 * No final-level page table; pde describes one 2MB page.
261 */
262 a = (pde & AMD64_PG_PS_FRAME) + (va & AMD64_PDRMASK);
263 s = _kvm_pa2off(kd, a, pa);
264 if (s == 0) {
265 _kvm_err(kd, kd->program,
266 "_amd64_vatop: 2MB page address not in dump");
267 goto invalid;
268 } else
269 return (AMD64_NBPDR - (va & AMD64_PDRMASK));
270 }
271
272 pteindex = (va >> AMD64_PAGE_SHIFT) & (AMD64_NPTEPG - 1);
273 pte_pa = (pde & AMD64_PG_FRAME) + (pteindex * sizeof(amd64_pte_t));
274
275 s = _kvm_pa2off(kd, pte_pa, &ofs);
276 if (s < sizeof(pte)) {
277 _kvm_err(kd, kd->program, "_amd64_vatop: pte_pa not found");
278 goto invalid;
279 }
280 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
281 _kvm_syserr(kd, kd->program, "_amd64_vatop: read");
282 goto invalid;
283 }
284 if ((pte & AMD64_PG_V) == 0) {
285 _kvm_err(kd, kd->program, "_amd64_vatop: pte not valid");
286 goto invalid;
287 }
288
289 a = (pte & AMD64_PG_FRAME) + offset;
290 s = _kvm_pa2off(kd, a, pa);
291 if (s == 0) {
292 _kvm_err(kd, kd->program, "_amd64_vatop: address not in dump");
293 goto invalid;
294 } else
295 return (AMD64_PAGE_SIZE - offset);
296
297 invalid:
298 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
299 return (0);
300 }
301
302 static int
_amd64_kvatop(kvm_t * kd,kvaddr_t va,off_t * pa)303 _amd64_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
304 {
305
306 if (ISALIVE(kd)) {
307 _kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
308 return (0);
309 }
310 return (_amd64_vatop(kd, va, pa));
311 }
312
313 int
_amd64_native(kvm_t * kd __unused)314 _amd64_native(kvm_t *kd __unused)
315 {
316
317 #ifdef __amd64__
318 return (1);
319 #else
320 return (0);
321 #endif
322 }
323
324 static struct kvm_arch kvm_amd64 = {
325 .ka_probe = _amd64_probe,
326 .ka_initvtop = _amd64_initvtop,
327 .ka_freevtop = _amd64_freevtop,
328 .ka_kvatop = _amd64_kvatop,
329 .ka_native = _amd64_native,
330 };
331
332 KVM_ARCH(kvm_amd64);
333