xref: /dragonfly/lib/libkvm/kvm_x86_64.c (revision 28c26f7e)
1 /*-
2  * Copyright (c) 1989, 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software developed by the Computer Systems
6  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
7  * BG 91-66 and contributed to Berkeley.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * @(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93
38  * $FreeBSD: src/lib/libkvm/kvm_amd64.c,v 1.16 2003/04/30 21:05:33 peter Exp $
39  */
40 
41 /*
42  * x86_64 machine dependent routines for kvm.  Hopefully, the forthcoming
43  * vm code will one day obsolete this module.
44  */
45 
46 #include <sys/user.h>	/* MUST BE FIRST */
47 #include <sys/param.h>
48 #include <sys/proc.h>
49 #include <sys/stat.h>
50 #include <stdlib.h>
51 #include <unistd.h>
52 #include <nlist.h>
53 #include <kvm.h>
54 
55 #include <vm/vm.h>
56 #include <vm/vm_param.h>
57 
58 #include <limits.h>
59 
60 #include "kvm_private.h"
61 
62 #ifndef btop
63 #define	btop(x)		(x86_64_btop(x))
64 #define	ptob(x)		(x86_64_ptob(x))
65 #endif
66 
67 struct vmstate {
68 	pml4_entry_t	*PML4;
69 };
70 
71 void
72 _kvm_freevtop(kvm_t *kd)
73 {
74 	if (kd->vmst != 0) {
75 		if (kd->vmst->PML4) {
76 			free(kd->vmst->PML4);
77 		}
78 		free(kd->vmst);
79 	}
80 }
81 
82 int
83 _kvm_initvtop(kvm_t *kd)
84 {
85 	struct vmstate *vm;
86 	struct nlist nlist[2];
87 	u_long pa;
88 	u_long kernbase;
89 	pml4_entry_t	*PML4;
90 
91 	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
92 	if (vm == 0) {
93 		_kvm_err(kd, kd->program, "cannot allocate vm");
94 		return (-1);
95 	}
96 	kd->vmst = vm;
97 	vm->PML4 = 0;
98 
99 	nlist[0].n_name = "kernbase";
100 	nlist[1].n_name = 0;
101 
102 	if (kvm_nlist(kd, nlist) != 0) {
103 		_kvm_err(kd, kd->program, "bad namelist - no kernbase");
104 		return (-1);
105 	}
106 	kernbase = nlist[0].n_value;
107 
108 	nlist[0].n_name = "KPML4phys";
109 	nlist[1].n_name = 0;
110 
111 	if (kvm_nlist(kd, nlist) != 0) {
112 		_kvm_err(kd, kd->program, "bad namelist - no KPML4phys");
113 		return (-1);
114 	}
115 	if (kvm_read(kd, (nlist[0].n_value - kernbase), &pa, sizeof(pa)) !=
116 	    sizeof(pa)) {
117 		_kvm_err(kd, kd->program, "cannot read KPML4phys");
118 		return (-1);
119 	}
120 	PML4 = _kvm_malloc(kd, PAGE_SIZE);
121 	if (kvm_read(kd, pa, PML4, PAGE_SIZE) != PAGE_SIZE) {
122 		_kvm_err(kd, kd->program, "cannot read KPML4phys");
123 		return (-1);
124 	}
125 	vm->PML4 = PML4;
126 	return (0);
127 }
128 
129 static int
130 _kvm_vatop(kvm_t *kd, u_long va, u_long *pa)
131 {
132 	struct vmstate *vm;
133 	u_long offset;
134 	u_long pdpe_pa;
135 	u_long pde_pa;
136 	u_long pte_pa;
137 	pml4_entry_t pml4e;
138 	pdp_entry_t pdpe;
139 	pd_entry_t pde;
140 	pt_entry_t pte;
141 	u_long pml4eindex;
142 	u_long pdpeindex;
143 	u_long pdeindex;
144 	u_long pteindex;
145 
146 	if (kvm_ishost(kd)) {
147 		_kvm_err(kd, 0, "kvm_vatop called in live kernel!");
148 		return((off_t)0);
149 	}
150 
151 	vm = kd->vmst;
152 	offset = va & (PAGE_SIZE - 1);
153 
154 	/*
155 	 * If we are initializing (kernel page table descriptor pointer
156 	 * not yet set) then return pa == va to avoid infinite recursion.
157 	 */
158 	if (vm->PML4 == 0) {
159 		*pa = va;
160 		return (PAGE_SIZE - offset);
161 	}
162 
163 	pml4eindex = (va >> PML4SHIFT) & (NPML4EPG - 1);
164 	pml4e = vm->PML4[pml4eindex];
165 	if (((u_long)pml4e & PG_V) == 0)
166 		goto invalid;
167 
168 	pdpeindex = (va >> PDPSHIFT) & (NPDPEPG-1);
169 	pdpe_pa = ((u_long)pml4e & PG_FRAME) + (pdpeindex * sizeof(pdp_entry_t));
170 
171 	/* XXX This has to be a physical address read, kvm_read is virtual */
172 	if (lseek(kd->pmfd, pdpe_pa, 0) == -1) {
173 		_kvm_syserr(kd, kd->program, "_kvm_vatop: lseek pdpe_pa");
174 		goto invalid;
175 	}
176 	if (read(kd->pmfd, &pdpe, sizeof pdpe) != sizeof pdpe) {
177 		_kvm_syserr(kd, kd->program, "_kvm_vatop: read pdpe");
178 		goto invalid;
179 	}
180 	if (((u_long)pdpe & PG_V) == 0)
181 		goto invalid;
182 
183 
184 	pdeindex = (va >> PDRSHIFT) & (NPDEPG-1);
185 	pde_pa = ((u_long)pdpe & PG_FRAME) + (pdeindex * sizeof(pd_entry_t));
186 
187 	/* XXX This has to be a physical address read, kvm_read is virtual */
188 	if (lseek(kd->pmfd, pde_pa, 0) == -1) {
189 		_kvm_syserr(kd, kd->program, "_kvm_vatop: lseek pde_pa");
190 		goto invalid;
191 	}
192 	if (read(kd->pmfd, &pde, sizeof pde) != sizeof pde) {
193 		_kvm_syserr(kd, kd->program, "_kvm_vatop: read pde");
194 		goto invalid;
195 	}
196 	if (((u_long)pde & PG_V) == 0)
197 		goto invalid;
198 
199 	if ((u_long)pde & PG_PS) {
200 	      /*
201 	       * No final-level page table; ptd describes one 2MB page.
202 	       */
203 #define	PAGE2M_MASK	(NBPDR - 1)
204 #define	PG_FRAME2M	(~PAGE2M_MASK)
205 		*pa = ((u_long)pde & PG_FRAME2M) + (va & PAGE2M_MASK);
206 		return (NBPDR - (va & PAGE2M_MASK));
207 	}
208 
209 	pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
210 	pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));
211 
212 	/* XXX This has to be a physical address read, kvm_read is virtual */
213 	if (lseek(kd->pmfd, pte_pa, 0) == -1) {
214 		_kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
215 		goto invalid;
216 	}
217 	if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
218 		_kvm_syserr(kd, kd->program, "_kvm_vatop: read");
219 		goto invalid;
220 	}
221 	if (((u_long)pte & PG_V) == 0)
222 		goto invalid;
223 
224 	*pa = ((u_long)pte & PG_FRAME) + offset;
225 	return (PAGE_SIZE - offset);
226 
227 invalid:
228 	_kvm_err(kd, 0, "invalid address (%jx)", (intmax_t)va);
229 	return (0);
230 }
231 
232 int
233 _kvm_kvatop(kvm_t *kd, u_long va, u_long *pa)
234 {
235 	return (_kvm_vatop(kd, va, pa));
236 }
237