1/*-
2 * Copyright (c) 2006 Peter Wemm
3 * Copyright (c) 2019 Mitchell Horne
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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR 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 * From: FreeBSD: src/lib/libkvm/kvm_minidump_amd64.c r261799
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32/*
33 * RISC-V machine dependent routines for kvm and minidumps.
34 */
35
36#include <sys/param.h>
37#include <stdint.h>
38#include <stdlib.h>
39#include <string.h>
40#include <unistd.h>
41#include <vm/vm.h>
42#include <kvm.h>
43
44#include "../../sys/riscv/include/minidump.h"
45
46#include <limits.h>
47
48#include "kvm_private.h"
49#include "kvm_riscv.h"
50
51#define	riscv_round_page(x)	roundup2((kvaddr_t)(x), RISCV_PAGE_SIZE)
52
53struct vmstate {
54	struct minidumphdr hdr;
55};
56
57static riscv_pt_entry_t
58_riscv_pte_get(kvm_t *kd, u_long pteindex)
59{
60	riscv_pt_entry_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
61
62	return le64toh(*pte);
63}
64
65static int
66_riscv_minidump_probe(kvm_t *kd)
67{
68
69	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_RISCV) &&
70	    _kvm_is_minidump(kd));
71}
72
73static void
74_riscv_minidump_freevtop(kvm_t *kd)
75{
76	struct vmstate *vm = kd->vmst;
77
78	free(vm);
79	kd->vmst = NULL;
80}
81
82static int
83_riscv_minidump_initvtop(kvm_t *kd)
84{
85	struct vmstate *vmst;
86	off_t off, sparse_off;
87
88	vmst = _kvm_malloc(kd, sizeof(*vmst));
89	if (vmst == NULL) {
90		_kvm_err(kd, kd->program, "cannot allocate vm");
91		return (-1);
92	}
93	kd->vmst = vmst;
94	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
95	    sizeof(vmst->hdr)) {
96		_kvm_err(kd, kd->program, "cannot read dump header");
97		return (-1);
98	}
99	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
100	    sizeof(vmst->hdr.magic)) != 0) {
101		_kvm_err(kd, kd->program, "not a minidump for this platform");
102		return (-1);
103	}
104
105	vmst->hdr.version = le32toh(vmst->hdr.version);
106	if (vmst->hdr.version != MINIDUMP_VERSION) {
107		_kvm_err(kd, kd->program, "wrong minidump version. "
108		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
109		return (-1);
110	}
111	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
112	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
113	vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
114	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
115	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
116	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
117	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
118
119	/* Skip header and msgbuf */
120	off = RISCV_PAGE_SIZE + riscv_round_page(vmst->hdr.msgbufsize);
121
122	/* build physical address lookup table for sparse pages */
123	sparse_off = off + riscv_round_page(vmst->hdr.bitmapsize) +
124	    riscv_round_page(vmst->hdr.pmapsize);
125	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
126	    RISCV_PAGE_SIZE, sizeof(uint64_t)) == -1) {
127		return (-1);
128	}
129	off += riscv_round_page(vmst->hdr.bitmapsize);
130
131	if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
132		return (-1);
133	}
134	off += riscv_round_page(vmst->hdr.pmapsize);
135
136	return (0);
137}
138
139static int
140_riscv_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
141{
142	struct vmstate *vm;
143	riscv_physaddr_t offset;
144	riscv_pt_entry_t l3;
145	kvaddr_t l3_index;
146	riscv_physaddr_t a;
147	off_t ofs;
148
149	vm = kd->vmst;
150	offset = va & RISCV_PAGE_MASK;
151
152	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
153		a = (va - vm->hdr.dmapbase + vm->hdr.dmapphys) &
154		    ~RISCV_PAGE_MASK;
155		ofs = _kvm_pt_find(kd, a, RISCV_PAGE_SIZE);
156		if (ofs == -1) {
157			_kvm_err(kd, kd->program, "_riscv_minidump_vatop: "
158			    "direct map address 0x%jx not in minidump",
159			    (uintmax_t)va);
160			goto invalid;
161		}
162		*pa = ofs + offset;
163		return (RISCV_PAGE_SIZE - offset);
164	} else if (va >= vm->hdr.kernbase) {
165		l3_index = (va - vm->hdr.kernbase) >> RISCV_L3_SHIFT;
166		if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
167			goto invalid;
168		l3 = _riscv_pte_get(kd, l3_index);
169		if ((l3 & RISCV_PTE_V) == 0 || (l3 & RISCV_PTE_RWX) == 0) {
170			_kvm_err(kd, kd->program,
171			    "_riscv_minidump_vatop: pte not valid");
172			goto invalid;
173		}
174		a = (l3 >> RISCV_PTE_PPN0_S) << RISCV_L3_SHIFT;
175		ofs = _kvm_pt_find(kd, a, RISCV_PAGE_SIZE);
176		if (ofs == -1) {
177			_kvm_err(kd, kd->program, "_riscv_minidump_vatop: "
178			    "physical address 0x%jx not in minidump",
179			    (uintmax_t)a);
180			goto invalid;
181		}
182		*pa = ofs + offset;
183		return (RISCV_PAGE_SIZE - offset);
184	} else {
185		_kvm_err(kd, kd->program,
186	    "_riscv_minidump_vatop: virtual address 0x%jx not minidumped",
187		    (uintmax_t)va);
188		goto invalid;
189	}
190
191invalid:
192	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
193	return (0);
194}
195
196static int
197_riscv_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
198{
199
200	if (ISALIVE(kd)) {
201		_kvm_err(kd, 0,
202		    "_riscv_minidump_kvatop called in live kernel!");
203		return (0);
204	}
205	return (_riscv_minidump_vatop(kd, va, pa));
206}
207
208static int
209_riscv_native(kvm_t *kd __unused)
210{
211
212#ifdef __riscv
213	return (1);
214#else
215	return (0);
216#endif
217}
218
219static vm_prot_t
220_riscv_entry_to_prot(riscv_pt_entry_t pte)
221{
222	vm_prot_t prot = VM_PROT_READ;
223
224	if ((pte & RISCV_PTE_W) != 0)
225		prot |= VM_PROT_WRITE;
226	if ((pte & RISCV_PTE_X) != 0)
227		prot |= VM_PROT_EXECUTE;
228	return prot;
229}
230
231static int
232_riscv_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
233{
234	struct vmstate *vm = kd->vmst;
235	u_long nptes = vm->hdr.pmapsize / sizeof(riscv_pt_entry_t);
236	u_long bmindex, dva, pa, pteindex, va;
237	struct kvm_bitmap bm;
238	vm_prot_t prot;
239	int ret = 0;
240
241	if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
242		return (0);
243
244	for (pteindex = 0; pteindex < nptes; pteindex++) {
245		riscv_pt_entry_t pte = _riscv_pte_get(kd, pteindex);
246
247		if (((pte & RISCV_PTE_V) == 0) ||
248		    ((pte & RISCV_PTE_RWX) == 0))
249			continue;
250
251		va = vm->hdr.kernbase + (pteindex << RISCV_L3_SHIFT);
252		pa = (pte >> RISCV_PTE_PPN0_S) << RISCV_L3_SHIFT;
253		dva = vm->hdr.dmapbase + pa;
254		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
255		    _riscv_entry_to_prot(pte), RISCV_PAGE_SIZE, 0)) {
256			goto out;
257		}
258	}
259
260	while (_kvm_bitmap_next(&bm, &bmindex)) {
261		pa = bmindex * RISCV_PAGE_SIZE;
262		dva = vm->hdr.dmapbase + pa;
263		if (vm->hdr.dmapend < (dva + RISCV_PAGE_SIZE))
264			break;
265		va = 0;
266		prot = VM_PROT_READ | VM_PROT_WRITE;
267		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
268		    prot, RISCV_PAGE_SIZE, 0)) {
269			goto out;
270		}
271	}
272	ret = 1;
273
274out:
275	_kvm_bitmap_deinit(&bm);
276	return (ret);
277}
278
279static struct kvm_arch kvm_riscv_minidump = {
280	.ka_probe = _riscv_minidump_probe,
281	.ka_initvtop = _riscv_minidump_initvtop,
282	.ka_freevtop = _riscv_minidump_freevtop,
283	.ka_kvatop = _riscv_minidump_kvatop,
284	.ka_native = _riscv_native,
285	.ka_walk_pages = _riscv_minidump_walk_pages,
286};
287
288KVM_ARCH(kvm_riscv_minidump);
289