1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 NetApp, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 #include <sys/types.h>
35
36 #include <machine/specialreg.h>
37 #include <machine/segments.h>
38 #include <machine/vmm.h>
39
40 #include <errno.h>
41 #include <string.h>
42
43 #include "vmmapi.h"
44
45 #define I386_TSS_SIZE 104
46
47 #define DESC_PRESENT 0x00000080
48 #define DESC_LONGMODE 0x00002000
49 #define DESC_DEF32 0x00004000
50 #define DESC_GRAN 0x00008000
51 #define DESC_UNUSABLE 0x00010000
52
53 #define GUEST_NULL_SEL 0
54 #define GUEST_CODE_SEL 1
55 #define GUEST_DATA_SEL 2
56 #define GUEST_TSS_SEL 3
57 #define GUEST_GDTR_LIMIT64 (3 * 8 - 1)
58
59 static struct segment_descriptor i386_gdt[] = {
60 {}, /* NULL */
61 { .sd_lolimit = 0xffff, .sd_type = SDT_MEMER, /* CODE */
62 .sd_p = 1, .sd_hilimit = 0xf, .sd_def32 = 1, .sd_gran = 1 },
63 { .sd_lolimit = 0xffff, .sd_type = SDT_MEMRW, /* DATA */
64 .sd_p = 1, .sd_hilimit = 0xf, .sd_def32 = 1, .sd_gran = 1 },
65 { .sd_lolimit = I386_TSS_SIZE - 1, /* TSS */
66 .sd_type = SDT_SYS386TSS, .sd_p = 1 }
67 };
68
69 /*
70 * Setup the 'vcpu' register set such that it will begin execution at
71 * 'eip' in flat mode.
72 */
73 int
vm_setup_freebsd_registers_i386(struct vmctx * vmctx,int vcpu,uint32_t eip,uint32_t gdtbase,uint32_t esp)74 vm_setup_freebsd_registers_i386(struct vmctx *vmctx, int vcpu, uint32_t eip,
75 uint32_t gdtbase, uint32_t esp)
76 {
77 uint64_t cr0, rflags, desc_base;
78 uint32_t desc_access, desc_limit, tssbase;
79 uint16_t gsel;
80 struct segment_descriptor *gdt;
81 int error, tmp;
82
83 /* A 32-bit guest requires unrestricted mode. */
84 error = vm_get_capability(vmctx, vcpu, VM_CAP_UNRESTRICTED_GUEST, &tmp);
85 if (error)
86 goto done;
87 error = vm_set_capability(vmctx, vcpu, VM_CAP_UNRESTRICTED_GUEST, 1);
88 if (error)
89 goto done;
90
91 cr0 = CR0_PE | CR0_NE;
92 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR0, cr0)) != 0)
93 goto done;
94
95 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR4, 0)) != 0)
96 goto done;
97
98 /*
99 * Forcing EFER to 0 causes bhyve to clear the "IA-32e guest
100 * mode" entry control.
101 */
102 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_EFER, 0)))
103 goto done;
104
105 gdt = vm_map_gpa(vmctx, gdtbase, 0x1000);
106 if (gdt == NULL)
107 return (EFAULT);
108 memcpy(gdt, i386_gdt, sizeof(i386_gdt));
109 desc_base = gdtbase;
110 desc_limit = sizeof(i386_gdt) - 1;
111 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_GDTR,
112 desc_base, desc_limit, 0);
113 if (error != 0)
114 goto done;
115
116 /* Place the TSS one page above the GDT. */
117 tssbase = gdtbase + 0x1000;
118 gdt[3].sd_lobase = tssbase;
119
120 rflags = 0x2;
121 error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RFLAGS, rflags);
122 if (error)
123 goto done;
124
125 desc_base = 0;
126 desc_limit = 0xffffffff;
127 desc_access = DESC_GRAN | DESC_DEF32 | DESC_PRESENT | SDT_MEMERA;
128 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_CS,
129 desc_base, desc_limit, desc_access);
130
131 desc_access = DESC_GRAN | DESC_DEF32 | DESC_PRESENT | SDT_MEMRWA;
132 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_DS,
133 desc_base, desc_limit, desc_access);
134 if (error)
135 goto done;
136
137 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_ES,
138 desc_base, desc_limit, desc_access);
139 if (error)
140 goto done;
141
142 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_FS,
143 desc_base, desc_limit, desc_access);
144 if (error)
145 goto done;
146
147 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_GS,
148 desc_base, desc_limit, desc_access);
149 if (error)
150 goto done;
151
152 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_SS,
153 desc_base, desc_limit, desc_access);
154 if (error)
155 goto done;
156
157 desc_base = tssbase;
158 desc_limit = I386_TSS_SIZE - 1;
159 desc_access = DESC_PRESENT | SDT_SYS386BSY;
160 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_TR,
161 desc_base, desc_limit, desc_access);
162 if (error)
163 goto done;
164
165
166 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_LDTR, 0, 0,
167 DESC_UNUSABLE);
168 if (error)
169 goto done;
170
171 gsel = GSEL(GUEST_CODE_SEL, SEL_KPL);
172 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CS, gsel)) != 0)
173 goto done;
174
175 gsel = GSEL(GUEST_DATA_SEL, SEL_KPL);
176 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_DS, gsel)) != 0)
177 goto done;
178
179 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_ES, gsel)) != 0)
180 goto done;
181
182 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_FS, gsel)) != 0)
183 goto done;
184
185 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_GS, gsel)) != 0)
186 goto done;
187
188 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_SS, gsel)) != 0)
189 goto done;
190
191 gsel = GSEL(GUEST_TSS_SEL, SEL_KPL);
192 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_TR, gsel)) != 0)
193 goto done;
194
195 /* LDTR is pointing to the null selector */
196 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_LDTR, 0)) != 0)
197 goto done;
198
199 /* entry point */
200 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RIP, eip)) != 0)
201 goto done;
202
203 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RSP, esp)) != 0)
204 goto done;
205
206 error = 0;
207 done:
208 return (error);
209 }
210
211 void
vm_setup_freebsd_gdt(uint64_t * gdtr)212 vm_setup_freebsd_gdt(uint64_t *gdtr)
213 {
214 gdtr[GUEST_NULL_SEL] = 0;
215 gdtr[GUEST_CODE_SEL] = 0x0020980000000000;
216 gdtr[GUEST_DATA_SEL] = 0x0000900000000000;
217 }
218
219 /*
220 * Setup the 'vcpu' register set such that it will begin execution at
221 * 'rip' in long mode.
222 */
223 int
vm_setup_freebsd_registers(struct vmctx * vmctx,int vcpu,uint64_t rip,uint64_t cr3,uint64_t gdtbase,uint64_t rsp)224 vm_setup_freebsd_registers(struct vmctx *vmctx, int vcpu,
225 uint64_t rip, uint64_t cr3, uint64_t gdtbase,
226 uint64_t rsp)
227 {
228 int error;
229 uint64_t cr0, cr4, efer, rflags, desc_base;
230 uint32_t desc_access, desc_limit;
231 uint16_t gsel;
232
233 cr0 = CR0_PE | CR0_PG | CR0_NE;
234 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR0, cr0)) != 0)
235 goto done;
236
237 cr4 = CR4_PAE;
238 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR4, cr4)) != 0)
239 goto done;
240
241 efer = EFER_LME | EFER_LMA;
242 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_EFER, efer)))
243 goto done;
244
245 rflags = 0x2;
246 error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RFLAGS, rflags);
247 if (error)
248 goto done;
249
250 desc_base = 0;
251 desc_limit = 0;
252 desc_access = 0x0000209B;
253 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_CS,
254 desc_base, desc_limit, desc_access);
255 if (error)
256 goto done;
257
258 desc_access = 0x00000093;
259 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_DS,
260 desc_base, desc_limit, desc_access);
261 if (error)
262 goto done;
263
264 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_ES,
265 desc_base, desc_limit, desc_access);
266 if (error)
267 goto done;
268
269 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_FS,
270 desc_base, desc_limit, desc_access);
271 if (error)
272 goto done;
273
274 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_GS,
275 desc_base, desc_limit, desc_access);
276 if (error)
277 goto done;
278
279 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_SS,
280 desc_base, desc_limit, desc_access);
281 if (error)
282 goto done;
283
284 /*
285 * XXX TR is pointing to null selector even though we set the
286 * TSS segment to be usable with a base address and limit of 0.
287 */
288 desc_access = 0x0000008b;
289 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_TR, 0, 0, desc_access);
290 if (error)
291 goto done;
292
293 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_LDTR, 0, 0,
294 DESC_UNUSABLE);
295 if (error)
296 goto done;
297
298 gsel = GSEL(GUEST_CODE_SEL, SEL_KPL);
299 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CS, gsel)) != 0)
300 goto done;
301
302 gsel = GSEL(GUEST_DATA_SEL, SEL_KPL);
303 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_DS, gsel)) != 0)
304 goto done;
305
306 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_ES, gsel)) != 0)
307 goto done;
308
309 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_FS, gsel)) != 0)
310 goto done;
311
312 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_GS, gsel)) != 0)
313 goto done;
314
315 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_SS, gsel)) != 0)
316 goto done;
317
318 /* XXX TR is pointing to the null selector */
319 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_TR, 0)) != 0)
320 goto done;
321
322 /* LDTR is pointing to the null selector */
323 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_LDTR, 0)) != 0)
324 goto done;
325
326 /* entry point */
327 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RIP, rip)) != 0)
328 goto done;
329
330 /* page table base */
331 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR3, cr3)) != 0)
332 goto done;
333
334 desc_base = gdtbase;
335 desc_limit = GUEST_GDTR_LIMIT64;
336 error = vm_set_desc(vmctx, vcpu, VM_REG_GUEST_GDTR,
337 desc_base, desc_limit, 0);
338 if (error != 0)
339 goto done;
340
341 if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RSP, rsp)) != 0)
342 goto done;
343
344 error = 0;
345 done:
346 return (error);
347 }
348