xref: /freebsd/sys/amd64/vmm/intel/vmcs.c (revision 3b8f08459569bf0faa21473e5cec2491e95c9349)
1 /*-
2  * Copyright (c) 2011 NetApp, Inc.
3  * All rights reserved.
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 NETAPP, INC ``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 NETAPP, INC 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  * $FreeBSD$
27  */
28 
29 #include "opt_ddb.h"
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/pcpu.h>
37 
38 #include <vm/vm.h>
39 #include <vm/pmap.h>
40 
41 #include <machine/segments.h>
42 #include <machine/vmm.h>
43 #include "vmm_host.h"
44 #include "vmx_cpufunc.h"
45 #include "vmcs.h"
46 #include "ept.h"
47 #include "vmx.h"
48 
49 #ifdef DDB
50 #include <ddb/ddb.h>
51 #endif
52 
53 static uint64_t
54 vmcs_fix_regval(uint32_t encoding, uint64_t val)
55 {
56 
57 	switch (encoding) {
58 	case VMCS_GUEST_CR0:
59 		val = vmx_fix_cr0(val);
60 		break;
61 	case VMCS_GUEST_CR4:
62 		val = vmx_fix_cr4(val);
63 		break;
64 	default:
65 		break;
66 	}
67 	return (val);
68 }
69 
70 static uint32_t
71 vmcs_field_encoding(int ident)
72 {
73 	switch (ident) {
74 	case VM_REG_GUEST_CR0:
75 		return (VMCS_GUEST_CR0);
76 	case VM_REG_GUEST_CR3:
77 		return (VMCS_GUEST_CR3);
78 	case VM_REG_GUEST_CR4:
79 		return (VMCS_GUEST_CR4);
80 	case VM_REG_GUEST_DR7:
81 		return (VMCS_GUEST_DR7);
82 	case VM_REG_GUEST_RSP:
83 		return (VMCS_GUEST_RSP);
84 	case VM_REG_GUEST_RIP:
85 		return (VMCS_GUEST_RIP);
86 	case VM_REG_GUEST_RFLAGS:
87 		return (VMCS_GUEST_RFLAGS);
88 	case VM_REG_GUEST_ES:
89 		return (VMCS_GUEST_ES_SELECTOR);
90 	case VM_REG_GUEST_CS:
91 		return (VMCS_GUEST_CS_SELECTOR);
92 	case VM_REG_GUEST_SS:
93 		return (VMCS_GUEST_SS_SELECTOR);
94 	case VM_REG_GUEST_DS:
95 		return (VMCS_GUEST_DS_SELECTOR);
96 	case VM_REG_GUEST_FS:
97 		return (VMCS_GUEST_FS_SELECTOR);
98 	case VM_REG_GUEST_GS:
99 		return (VMCS_GUEST_GS_SELECTOR);
100 	case VM_REG_GUEST_TR:
101 		return (VMCS_GUEST_TR_SELECTOR);
102 	case VM_REG_GUEST_LDTR:
103 		return (VMCS_GUEST_LDTR_SELECTOR);
104 	case VM_REG_GUEST_EFER:
105 		return (VMCS_GUEST_IA32_EFER);
106 	default:
107 		return (-1);
108 	}
109 
110 }
111 
112 static int
113 vmcs_seg_desc_encoding(int seg, uint32_t *base, uint32_t *lim, uint32_t *acc)
114 {
115 
116 	switch (seg) {
117 	case VM_REG_GUEST_ES:
118 		*base = VMCS_GUEST_ES_BASE;
119 		*lim = VMCS_GUEST_ES_LIMIT;
120 		*acc = VMCS_GUEST_ES_ACCESS_RIGHTS;
121 		break;
122 	case VM_REG_GUEST_CS:
123 		*base = VMCS_GUEST_CS_BASE;
124 		*lim = VMCS_GUEST_CS_LIMIT;
125 		*acc = VMCS_GUEST_CS_ACCESS_RIGHTS;
126 		break;
127 	case VM_REG_GUEST_SS:
128 		*base = VMCS_GUEST_SS_BASE;
129 		*lim = VMCS_GUEST_SS_LIMIT;
130 		*acc = VMCS_GUEST_SS_ACCESS_RIGHTS;
131 		break;
132 	case VM_REG_GUEST_DS:
133 		*base = VMCS_GUEST_DS_BASE;
134 		*lim = VMCS_GUEST_DS_LIMIT;
135 		*acc = VMCS_GUEST_DS_ACCESS_RIGHTS;
136 		break;
137 	case VM_REG_GUEST_FS:
138 		*base = VMCS_GUEST_FS_BASE;
139 		*lim = VMCS_GUEST_FS_LIMIT;
140 		*acc = VMCS_GUEST_FS_ACCESS_RIGHTS;
141 		break;
142 	case VM_REG_GUEST_GS:
143 		*base = VMCS_GUEST_GS_BASE;
144 		*lim = VMCS_GUEST_GS_LIMIT;
145 		*acc = VMCS_GUEST_GS_ACCESS_RIGHTS;
146 		break;
147 	case VM_REG_GUEST_TR:
148 		*base = VMCS_GUEST_TR_BASE;
149 		*lim = VMCS_GUEST_TR_LIMIT;
150 		*acc = VMCS_GUEST_TR_ACCESS_RIGHTS;
151 		break;
152 	case VM_REG_GUEST_LDTR:
153 		*base = VMCS_GUEST_LDTR_BASE;
154 		*lim = VMCS_GUEST_LDTR_LIMIT;
155 		*acc = VMCS_GUEST_LDTR_ACCESS_RIGHTS;
156 		break;
157 	case VM_REG_GUEST_IDTR:
158 		*base = VMCS_GUEST_IDTR_BASE;
159 		*lim = VMCS_GUEST_IDTR_LIMIT;
160 		*acc = VMCS_INVALID_ENCODING;
161 		break;
162 	case VM_REG_GUEST_GDTR:
163 		*base = VMCS_GUEST_GDTR_BASE;
164 		*lim = VMCS_GUEST_GDTR_LIMIT;
165 		*acc = VMCS_INVALID_ENCODING;
166 		break;
167 	default:
168 		return (EINVAL);
169 	}
170 
171 	return (0);
172 }
173 
174 int
175 vmcs_getreg(struct vmcs *vmcs, int running, int ident, uint64_t *retval)
176 {
177 	int error;
178 	uint32_t encoding;
179 
180 	/*
181 	 * If we need to get at vmx-specific state in the VMCS we can bypass
182 	 * the translation of 'ident' to 'encoding' by simply setting the
183 	 * sign bit. As it so happens the upper 16 bits are reserved (i.e
184 	 * set to 0) in the encodings for the VMCS so we are free to use the
185 	 * sign bit.
186 	 */
187 	if (ident < 0)
188 		encoding = ident & 0x7fffffff;
189 	else
190 		encoding = vmcs_field_encoding(ident);
191 
192 	if (encoding == (uint32_t)-1)
193 		return (EINVAL);
194 
195 	if (!running)
196 		VMPTRLD(vmcs);
197 
198 	error = vmread(encoding, retval);
199 
200 	if (!running)
201 		VMCLEAR(vmcs);
202 
203 	return (error);
204 }
205 
206 int
207 vmcs_setreg(struct vmcs *vmcs, int running, int ident, uint64_t val)
208 {
209 	int error;
210 	uint32_t encoding;
211 
212 	if (ident < 0)
213 		encoding = ident & 0x7fffffff;
214 	else
215 		encoding = vmcs_field_encoding(ident);
216 
217 	if (encoding == (uint32_t)-1)
218 		return (EINVAL);
219 
220 	val = vmcs_fix_regval(encoding, val);
221 
222 	if (!running)
223 		VMPTRLD(vmcs);
224 
225 	error = vmwrite(encoding, val);
226 
227 	if (!running)
228 		VMCLEAR(vmcs);
229 
230 	return (error);
231 }
232 
233 int
234 vmcs_setdesc(struct vmcs *vmcs, int seg, struct seg_desc *desc)
235 {
236 	int error;
237 	uint32_t base, limit, access;
238 
239 	error = vmcs_seg_desc_encoding(seg, &base, &limit, &access);
240 	if (error != 0)
241 		panic("vmcs_setdesc: invalid segment register %d", seg);
242 
243 	VMPTRLD(vmcs);
244 	if ((error = vmwrite(base, desc->base)) != 0)
245 		goto done;
246 
247 	if ((error = vmwrite(limit, desc->limit)) != 0)
248 		goto done;
249 
250 	if (access != VMCS_INVALID_ENCODING) {
251 		if ((error = vmwrite(access, desc->access)) != 0)
252 			goto done;
253 	}
254 done:
255 	VMCLEAR(vmcs);
256 	return (error);
257 }
258 
259 int
260 vmcs_getdesc(struct vmcs *vmcs, int seg, struct seg_desc *desc)
261 {
262 	int error;
263 	uint32_t base, limit, access;
264 	uint64_t u64;
265 
266 	error = vmcs_seg_desc_encoding(seg, &base, &limit, &access);
267 	if (error != 0)
268 		panic("vmcs_getdesc: invalid segment register %d", seg);
269 
270 	VMPTRLD(vmcs);
271 	if ((error = vmread(base, &u64)) != 0)
272 		goto done;
273 	desc->base = u64;
274 
275 	if ((error = vmread(limit, &u64)) != 0)
276 		goto done;
277 	desc->limit = u64;
278 
279 	if (access != VMCS_INVALID_ENCODING) {
280 		if ((error = vmread(access, &u64)) != 0)
281 			goto done;
282 		desc->access = u64;
283 	}
284 done:
285 	VMCLEAR(vmcs);
286 	return (error);
287 }
288 
289 int
290 vmcs_set_msr_save(struct vmcs *vmcs, u_long g_area, u_int g_count)
291 {
292 	int error;
293 
294 	VMPTRLD(vmcs);
295 
296 	/*
297 	 * Guest MSRs are saved in the VM-exit MSR-store area.
298 	 * Guest MSRs are loaded from the VM-entry MSR-load area.
299 	 * Both areas point to the same location in memory.
300 	 */
301 	if ((error = vmwrite(VMCS_EXIT_MSR_STORE, g_area)) != 0)
302 		goto done;
303 	if ((error = vmwrite(VMCS_EXIT_MSR_STORE_COUNT, g_count)) != 0)
304 		goto done;
305 
306 	if ((error = vmwrite(VMCS_ENTRY_MSR_LOAD, g_area)) != 0)
307 		goto done;
308 	if ((error = vmwrite(VMCS_ENTRY_MSR_LOAD_COUNT, g_count)) != 0)
309 		goto done;
310 
311 	error = 0;
312 done:
313 	VMCLEAR(vmcs);
314 	return (error);
315 }
316 
317 int
318 vmcs_init(struct vmcs *vmcs)
319 {
320 	int error, codesel, datasel, tsssel;
321 	u_long cr0, cr4, efer;
322 	uint64_t pat, fsbase, idtrbase;
323 	uint32_t exc_bitmap;
324 
325 	codesel = vmm_get_host_codesel();
326 	datasel = vmm_get_host_datasel();
327 	tsssel = vmm_get_host_tsssel();
328 
329 	/*
330 	 * Make sure we have a "current" VMCS to work with.
331 	 */
332 	VMPTRLD(vmcs);
333 
334 	/* Initialize guest IA32_PAT MSR with the default value */
335 	pat = PAT_VALUE(0, PAT_WRITE_BACK)	|
336 	      PAT_VALUE(1, PAT_WRITE_THROUGH)	|
337 	      PAT_VALUE(2, PAT_UNCACHED)	|
338 	      PAT_VALUE(3, PAT_UNCACHEABLE)	|
339 	      PAT_VALUE(4, PAT_WRITE_BACK)	|
340 	      PAT_VALUE(5, PAT_WRITE_THROUGH)	|
341 	      PAT_VALUE(6, PAT_UNCACHED)	|
342 	      PAT_VALUE(7, PAT_UNCACHEABLE);
343 	if ((error = vmwrite(VMCS_GUEST_IA32_PAT, pat)) != 0)
344 		goto done;
345 
346 	/* Host state */
347 
348 	/* Initialize host IA32_PAT MSR */
349 	pat = vmm_get_host_pat();
350 	if ((error = vmwrite(VMCS_HOST_IA32_PAT, pat)) != 0)
351 		goto done;
352 
353 	/* Load the IA32_EFER MSR */
354 	efer = vmm_get_host_efer();
355 	if ((error = vmwrite(VMCS_HOST_IA32_EFER, efer)) != 0)
356 		goto done;
357 
358 	/* Load the control registers */
359 
360 	cr0 = vmm_get_host_cr0();
361 	if ((error = vmwrite(VMCS_HOST_CR0, cr0)) != 0)
362 		goto done;
363 
364 	cr4 = vmm_get_host_cr4() | CR4_VMXE;
365 	if ((error = vmwrite(VMCS_HOST_CR4, cr4)) != 0)
366 		goto done;
367 
368 	/* Load the segment selectors */
369 	if ((error = vmwrite(VMCS_HOST_ES_SELECTOR, datasel)) != 0)
370 		goto done;
371 
372 	if ((error = vmwrite(VMCS_HOST_CS_SELECTOR, codesel)) != 0)
373 		goto done;
374 
375 	if ((error = vmwrite(VMCS_HOST_SS_SELECTOR, datasel)) != 0)
376 		goto done;
377 
378 	if ((error = vmwrite(VMCS_HOST_DS_SELECTOR, datasel)) != 0)
379 		goto done;
380 
381 	if ((error = vmwrite(VMCS_HOST_FS_SELECTOR, datasel)) != 0)
382 		goto done;
383 
384 	if ((error = vmwrite(VMCS_HOST_GS_SELECTOR, datasel)) != 0)
385 		goto done;
386 
387 	if ((error = vmwrite(VMCS_HOST_TR_SELECTOR, tsssel)) != 0)
388 		goto done;
389 
390 	/*
391 	 * Load the Base-Address for %fs and idtr.
392 	 *
393 	 * Note that we exclude %gs, tss and gdtr here because their base
394 	 * address is pcpu specific.
395 	 */
396 	fsbase = vmm_get_host_fsbase();
397 	if ((error = vmwrite(VMCS_HOST_FS_BASE, fsbase)) != 0)
398 		goto done;
399 
400 	idtrbase = vmm_get_host_idtrbase();
401 	if ((error = vmwrite(VMCS_HOST_IDTR_BASE, idtrbase)) != 0)
402 		goto done;
403 
404 	/* instruction pointer */
405 	if ((error = vmwrite(VMCS_HOST_RIP, (u_long)vmx_exit_guest)) != 0)
406 		goto done;
407 
408 	/* exception bitmap */
409 	exc_bitmap = 1 << IDT_MC;
410 	if ((error = vmwrite(VMCS_EXCEPTION_BITMAP, exc_bitmap)) != 0)
411 		goto done;
412 
413 	/* link pointer */
414 	if ((error = vmwrite(VMCS_LINK_POINTER, ~0)) != 0)
415 		goto done;
416 done:
417 	VMCLEAR(vmcs);
418 	return (error);
419 }
420 
421 #ifdef DDB
422 extern int vmxon_enabled[];
423 
424 DB_SHOW_COMMAND(vmcs, db_show_vmcs)
425 {
426 	uint64_t cur_vmcs, val;
427 	uint32_t exit;
428 
429 	if (!vmxon_enabled[curcpu]) {
430 		db_printf("VMX not enabled\n");
431 		return;
432 	}
433 
434 	if (have_addr) {
435 		db_printf("Only current VMCS supported\n");
436 		return;
437 	}
438 
439 	vmptrst(&cur_vmcs);
440 	if (cur_vmcs == VMCS_INITIAL) {
441 		db_printf("No current VM context\n");
442 		return;
443 	}
444 	db_printf("VMCS: %jx\n", cur_vmcs);
445 	db_printf("VPID: %lu\n", vmcs_read(VMCS_VPID));
446 	db_printf("Activity: ");
447 	val = vmcs_read(VMCS_GUEST_ACTIVITY);
448 	switch (val) {
449 	case 0:
450 		db_printf("Active");
451 		break;
452 	case 1:
453 		db_printf("HLT");
454 		break;
455 	case 2:
456 		db_printf("Shutdown");
457 		break;
458 	case 3:
459 		db_printf("Wait for SIPI");
460 		break;
461 	default:
462 		db_printf("Unknown: %#lx", val);
463 	}
464 	db_printf("\n");
465 	exit = vmcs_read(VMCS_EXIT_REASON);
466 	if (exit & 0x80000000)
467 		db_printf("Entry Failure Reason: %u\n", exit & 0xffff);
468 	else
469 		db_printf("Exit Reason: %u\n", exit & 0xffff);
470 	db_printf("Qualification: %#lx\n", vmcs_exit_qualification());
471 	db_printf("Guest Linear Address: %#lx\n",
472 	    vmcs_read(VMCS_GUEST_LINEAR_ADDRESS));
473 	switch (exit & 0x8000ffff) {
474 	case EXIT_REASON_EXCEPTION:
475 	case EXIT_REASON_EXT_INTR:
476 		val = vmcs_read(VMCS_EXIT_INTR_INFO);
477 		db_printf("Interrupt Type: ");
478 		switch (val >> 8 & 0x7) {
479 		case 0:
480 			db_printf("external");
481 			break;
482 		case 2:
483 			db_printf("NMI");
484 			break;
485 		case 3:
486 			db_printf("HW exception");
487 			break;
488 		case 4:
489 			db_printf("SW exception");
490 			break;
491 		default:
492 			db_printf("?? %lu", val >> 8 & 0x7);
493 			break;
494 		}
495 		db_printf("  Vector: %lu", val & 0xff);
496 		if (val & 0x800)
497 			db_printf("  Error Code: %lx",
498 			    vmcs_read(VMCS_EXIT_INTR_ERRCODE));
499 		db_printf("\n");
500 		break;
501 	case EXIT_REASON_EPT_FAULT:
502 	case EXIT_REASON_EPT_MISCONFIG:
503 		db_printf("Guest Physical Address: %#lx\n",
504 		    vmcs_read(VMCS_GUEST_PHYSICAL_ADDRESS));
505 		break;
506 	}
507 	db_printf("VM-instruction error: %#lx\n", vmcs_instruction_error());
508 }
509 #endif
510