xref: /freebsd/sys/amd64/vmm/intel/vmcs.c (revision 97cb52fa9aefd90fad38790fded50905aeeb9b9e)
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 "opt_ddb.h"
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/pcpu.h>
39 
40 #include <vm/vm.h>
41 #include <vm/pmap.h>
42 
43 #include <machine/segments.h>
44 #include <machine/vmm.h>
45 #include "vmm_host.h"
46 #include "vmx_cpufunc.h"
47 #include "vmcs.h"
48 #include "ept.h"
49 #include "vmx.h"
50 
51 #ifdef DDB
52 #include <ddb/ddb.h>
53 #endif
54 
55 static uint64_t
56 vmcs_fix_regval(uint32_t encoding, uint64_t val)
57 {
58 
59 	switch (encoding) {
60 	case VMCS_GUEST_CR0:
61 		val = vmx_fix_cr0(val);
62 		break;
63 	case VMCS_GUEST_CR4:
64 		val = vmx_fix_cr4(val);
65 		break;
66 	default:
67 		break;
68 	}
69 	return (val);
70 }
71 
72 static uint32_t
73 vmcs_field_encoding(int ident)
74 {
75 	switch (ident) {
76 	case VM_REG_GUEST_CR0:
77 		return (VMCS_GUEST_CR0);
78 	case VM_REG_GUEST_CR3:
79 		return (VMCS_GUEST_CR3);
80 	case VM_REG_GUEST_CR4:
81 		return (VMCS_GUEST_CR4);
82 	case VM_REG_GUEST_DR7:
83 		return (VMCS_GUEST_DR7);
84 	case VM_REG_GUEST_RSP:
85 		return (VMCS_GUEST_RSP);
86 	case VM_REG_GUEST_RIP:
87 		return (VMCS_GUEST_RIP);
88 	case VM_REG_GUEST_RFLAGS:
89 		return (VMCS_GUEST_RFLAGS);
90 	case VM_REG_GUEST_ES:
91 		return (VMCS_GUEST_ES_SELECTOR);
92 	case VM_REG_GUEST_CS:
93 		return (VMCS_GUEST_CS_SELECTOR);
94 	case VM_REG_GUEST_SS:
95 		return (VMCS_GUEST_SS_SELECTOR);
96 	case VM_REG_GUEST_DS:
97 		return (VMCS_GUEST_DS_SELECTOR);
98 	case VM_REG_GUEST_FS:
99 		return (VMCS_GUEST_FS_SELECTOR);
100 	case VM_REG_GUEST_GS:
101 		return (VMCS_GUEST_GS_SELECTOR);
102 	case VM_REG_GUEST_TR:
103 		return (VMCS_GUEST_TR_SELECTOR);
104 	case VM_REG_GUEST_LDTR:
105 		return (VMCS_GUEST_LDTR_SELECTOR);
106 	case VM_REG_GUEST_EFER:
107 		return (VMCS_GUEST_IA32_EFER);
108 	case VM_REG_GUEST_PDPTE0:
109 		return (VMCS_GUEST_PDPTE0);
110 	case VM_REG_GUEST_PDPTE1:
111 		return (VMCS_GUEST_PDPTE1);
112 	case VM_REG_GUEST_PDPTE2:
113 		return (VMCS_GUEST_PDPTE2);
114 	case VM_REG_GUEST_PDPTE3:
115 		return (VMCS_GUEST_PDPTE3);
116 	default:
117 		return (-1);
118 	}
119 
120 }
121 
122 static int
123 vmcs_seg_desc_encoding(int seg, uint32_t *base, uint32_t *lim, uint32_t *acc)
124 {
125 
126 	switch (seg) {
127 	case VM_REG_GUEST_ES:
128 		*base = VMCS_GUEST_ES_BASE;
129 		*lim = VMCS_GUEST_ES_LIMIT;
130 		*acc = VMCS_GUEST_ES_ACCESS_RIGHTS;
131 		break;
132 	case VM_REG_GUEST_CS:
133 		*base = VMCS_GUEST_CS_BASE;
134 		*lim = VMCS_GUEST_CS_LIMIT;
135 		*acc = VMCS_GUEST_CS_ACCESS_RIGHTS;
136 		break;
137 	case VM_REG_GUEST_SS:
138 		*base = VMCS_GUEST_SS_BASE;
139 		*lim = VMCS_GUEST_SS_LIMIT;
140 		*acc = VMCS_GUEST_SS_ACCESS_RIGHTS;
141 		break;
142 	case VM_REG_GUEST_DS:
143 		*base = VMCS_GUEST_DS_BASE;
144 		*lim = VMCS_GUEST_DS_LIMIT;
145 		*acc = VMCS_GUEST_DS_ACCESS_RIGHTS;
146 		break;
147 	case VM_REG_GUEST_FS:
148 		*base = VMCS_GUEST_FS_BASE;
149 		*lim = VMCS_GUEST_FS_LIMIT;
150 		*acc = VMCS_GUEST_FS_ACCESS_RIGHTS;
151 		break;
152 	case VM_REG_GUEST_GS:
153 		*base = VMCS_GUEST_GS_BASE;
154 		*lim = VMCS_GUEST_GS_LIMIT;
155 		*acc = VMCS_GUEST_GS_ACCESS_RIGHTS;
156 		break;
157 	case VM_REG_GUEST_TR:
158 		*base = VMCS_GUEST_TR_BASE;
159 		*lim = VMCS_GUEST_TR_LIMIT;
160 		*acc = VMCS_GUEST_TR_ACCESS_RIGHTS;
161 		break;
162 	case VM_REG_GUEST_LDTR:
163 		*base = VMCS_GUEST_LDTR_BASE;
164 		*lim = VMCS_GUEST_LDTR_LIMIT;
165 		*acc = VMCS_GUEST_LDTR_ACCESS_RIGHTS;
166 		break;
167 	case VM_REG_GUEST_IDTR:
168 		*base = VMCS_GUEST_IDTR_BASE;
169 		*lim = VMCS_GUEST_IDTR_LIMIT;
170 		*acc = VMCS_INVALID_ENCODING;
171 		break;
172 	case VM_REG_GUEST_GDTR:
173 		*base = VMCS_GUEST_GDTR_BASE;
174 		*lim = VMCS_GUEST_GDTR_LIMIT;
175 		*acc = VMCS_INVALID_ENCODING;
176 		break;
177 	default:
178 		return (EINVAL);
179 	}
180 
181 	return (0);
182 }
183 
184 int
185 vmcs_getreg(struct vmcs *vmcs, int running, int ident, uint64_t *retval)
186 {
187 	int error;
188 	uint32_t encoding;
189 
190 	/*
191 	 * If we need to get at vmx-specific state in the VMCS we can bypass
192 	 * the translation of 'ident' to 'encoding' by simply setting the
193 	 * sign bit. As it so happens the upper 16 bits are reserved (i.e
194 	 * set to 0) in the encodings for the VMCS so we are free to use the
195 	 * sign bit.
196 	 */
197 	if (ident < 0)
198 		encoding = ident & 0x7fffffff;
199 	else
200 		encoding = vmcs_field_encoding(ident);
201 
202 	if (encoding == (uint32_t)-1)
203 		return (EINVAL);
204 
205 	if (!running)
206 		VMPTRLD(vmcs);
207 
208 	error = vmread(encoding, retval);
209 
210 	if (!running)
211 		VMCLEAR(vmcs);
212 
213 	return (error);
214 }
215 
216 int
217 vmcs_setreg(struct vmcs *vmcs, int running, int ident, uint64_t val)
218 {
219 	int error;
220 	uint32_t encoding;
221 
222 	if (ident < 0)
223 		encoding = ident & 0x7fffffff;
224 	else
225 		encoding = vmcs_field_encoding(ident);
226 
227 	if (encoding == (uint32_t)-1)
228 		return (EINVAL);
229 
230 	val = vmcs_fix_regval(encoding, val);
231 
232 	if (!running)
233 		VMPTRLD(vmcs);
234 
235 	error = vmwrite(encoding, val);
236 
237 	if (!running)
238 		VMCLEAR(vmcs);
239 
240 	return (error);
241 }
242 
243 int
244 vmcs_setdesc(struct vmcs *vmcs, int running, int seg, struct seg_desc *desc)
245 {
246 	int error;
247 	uint32_t base, limit, access;
248 
249 	error = vmcs_seg_desc_encoding(seg, &base, &limit, &access);
250 	if (error != 0)
251 		panic("vmcs_setdesc: invalid segment register %d", seg);
252 
253 	if (!running)
254 		VMPTRLD(vmcs);
255 	if ((error = vmwrite(base, desc->base)) != 0)
256 		goto done;
257 
258 	if ((error = vmwrite(limit, desc->limit)) != 0)
259 		goto done;
260 
261 	if (access != VMCS_INVALID_ENCODING) {
262 		if ((error = vmwrite(access, desc->access)) != 0)
263 			goto done;
264 	}
265 done:
266 	if (!running)
267 		VMCLEAR(vmcs);
268 	return (error);
269 }
270 
271 int
272 vmcs_getdesc(struct vmcs *vmcs, int running, int seg, struct seg_desc *desc)
273 {
274 	int error;
275 	uint32_t base, limit, access;
276 	uint64_t u64;
277 
278 	error = vmcs_seg_desc_encoding(seg, &base, &limit, &access);
279 	if (error != 0)
280 		panic("vmcs_getdesc: invalid segment register %d", seg);
281 
282 	if (!running)
283 		VMPTRLD(vmcs);
284 	if ((error = vmread(base, &u64)) != 0)
285 		goto done;
286 	desc->base = u64;
287 
288 	if ((error = vmread(limit, &u64)) != 0)
289 		goto done;
290 	desc->limit = u64;
291 
292 	if (access != VMCS_INVALID_ENCODING) {
293 		if ((error = vmread(access, &u64)) != 0)
294 			goto done;
295 		desc->access = u64;
296 	}
297 done:
298 	if (!running)
299 		VMCLEAR(vmcs);
300 	return (error);
301 }
302 
303 int
304 vmcs_set_msr_save(struct vmcs *vmcs, u_long g_area, u_int g_count)
305 {
306 	int error;
307 
308 	VMPTRLD(vmcs);
309 
310 	/*
311 	 * Guest MSRs are saved in the VM-exit MSR-store area.
312 	 * Guest MSRs are loaded from the VM-entry MSR-load area.
313 	 * Both areas point to the same location in memory.
314 	 */
315 	if ((error = vmwrite(VMCS_EXIT_MSR_STORE, g_area)) != 0)
316 		goto done;
317 	if ((error = vmwrite(VMCS_EXIT_MSR_STORE_COUNT, g_count)) != 0)
318 		goto done;
319 
320 	if ((error = vmwrite(VMCS_ENTRY_MSR_LOAD, g_area)) != 0)
321 		goto done;
322 	if ((error = vmwrite(VMCS_ENTRY_MSR_LOAD_COUNT, g_count)) != 0)
323 		goto done;
324 
325 	error = 0;
326 done:
327 	VMCLEAR(vmcs);
328 	return (error);
329 }
330 
331 int
332 vmcs_init(struct vmcs *vmcs)
333 {
334 	int error, codesel, datasel, tsssel;
335 	u_long cr0, cr4, efer;
336 	uint64_t pat, fsbase, idtrbase;
337 
338 	codesel = vmm_get_host_codesel();
339 	datasel = vmm_get_host_datasel();
340 	tsssel = vmm_get_host_tsssel();
341 
342 	/*
343 	 * Make sure we have a "current" VMCS to work with.
344 	 */
345 	VMPTRLD(vmcs);
346 
347 	/* Host state */
348 
349 	/* Initialize host IA32_PAT MSR */
350 	pat = vmm_get_host_pat();
351 	if ((error = vmwrite(VMCS_HOST_IA32_PAT, pat)) != 0)
352 		goto done;
353 
354 	/* Load the IA32_EFER MSR */
355 	efer = vmm_get_host_efer();
356 	if ((error = vmwrite(VMCS_HOST_IA32_EFER, efer)) != 0)
357 		goto done;
358 
359 	/* Load the control registers */
360 
361 	cr0 = vmm_get_host_cr0();
362 	if ((error = vmwrite(VMCS_HOST_CR0, cr0)) != 0)
363 		goto done;
364 
365 	cr4 = vmm_get_host_cr4() | CR4_VMXE;
366 	if ((error = vmwrite(VMCS_HOST_CR4, cr4)) != 0)
367 		goto done;
368 
369 	/* Load the segment selectors */
370 	if ((error = vmwrite(VMCS_HOST_ES_SELECTOR, datasel)) != 0)
371 		goto done;
372 
373 	if ((error = vmwrite(VMCS_HOST_CS_SELECTOR, codesel)) != 0)
374 		goto done;
375 
376 	if ((error = vmwrite(VMCS_HOST_SS_SELECTOR, datasel)) != 0)
377 		goto done;
378 
379 	if ((error = vmwrite(VMCS_HOST_DS_SELECTOR, datasel)) != 0)
380 		goto done;
381 
382 	if ((error = vmwrite(VMCS_HOST_FS_SELECTOR, datasel)) != 0)
383 		goto done;
384 
385 	if ((error = vmwrite(VMCS_HOST_GS_SELECTOR, datasel)) != 0)
386 		goto done;
387 
388 	if ((error = vmwrite(VMCS_HOST_TR_SELECTOR, tsssel)) != 0)
389 		goto done;
390 
391 	/*
392 	 * Load the Base-Address for %fs and idtr.
393 	 *
394 	 * Note that we exclude %gs, tss and gdtr here because their base
395 	 * address is pcpu specific.
396 	 */
397 	fsbase = vmm_get_host_fsbase();
398 	if ((error = vmwrite(VMCS_HOST_FS_BASE, fsbase)) != 0)
399 		goto done;
400 
401 	idtrbase = vmm_get_host_idtrbase();
402 	if ((error = vmwrite(VMCS_HOST_IDTR_BASE, idtrbase)) != 0)
403 		goto done;
404 
405 	/* instruction pointer */
406 	if ((error = vmwrite(VMCS_HOST_RIP, (u_long)vmx_exit_guest)) != 0)
407 		goto done;
408 
409 	/* link pointer */
410 	if ((error = vmwrite(VMCS_LINK_POINTER, ~0)) != 0)
411 		goto done;
412 done:
413 	VMCLEAR(vmcs);
414 	return (error);
415 }
416 
417 #ifdef DDB
418 extern int vmxon_enabled[];
419 
420 DB_SHOW_COMMAND(vmcs, db_show_vmcs)
421 {
422 	uint64_t cur_vmcs, val;
423 	uint32_t exit;
424 
425 	if (!vmxon_enabled[curcpu]) {
426 		db_printf("VMX not enabled\n");
427 		return;
428 	}
429 
430 	if (have_addr) {
431 		db_printf("Only current VMCS supported\n");
432 		return;
433 	}
434 
435 	vmptrst(&cur_vmcs);
436 	if (cur_vmcs == VMCS_INITIAL) {
437 		db_printf("No current VM context\n");
438 		return;
439 	}
440 	db_printf("VMCS: %jx\n", cur_vmcs);
441 	db_printf("VPID: %lu\n", vmcs_read(VMCS_VPID));
442 	db_printf("Activity: ");
443 	val = vmcs_read(VMCS_GUEST_ACTIVITY);
444 	switch (val) {
445 	case 0:
446 		db_printf("Active");
447 		break;
448 	case 1:
449 		db_printf("HLT");
450 		break;
451 	case 2:
452 		db_printf("Shutdown");
453 		break;
454 	case 3:
455 		db_printf("Wait for SIPI");
456 		break;
457 	default:
458 		db_printf("Unknown: %#lx", val);
459 	}
460 	db_printf("\n");
461 	exit = vmcs_read(VMCS_EXIT_REASON);
462 	if (exit & 0x80000000)
463 		db_printf("Entry Failure Reason: %u\n", exit & 0xffff);
464 	else
465 		db_printf("Exit Reason: %u\n", exit & 0xffff);
466 	db_printf("Qualification: %#lx\n", vmcs_exit_qualification());
467 	db_printf("Guest Linear Address: %#lx\n",
468 	    vmcs_read(VMCS_GUEST_LINEAR_ADDRESS));
469 	switch (exit & 0x8000ffff) {
470 	case EXIT_REASON_EXCEPTION:
471 	case EXIT_REASON_EXT_INTR:
472 		val = vmcs_read(VMCS_EXIT_INTR_INFO);
473 		db_printf("Interrupt Type: ");
474 		switch (val >> 8 & 0x7) {
475 		case 0:
476 			db_printf("external");
477 			break;
478 		case 2:
479 			db_printf("NMI");
480 			break;
481 		case 3:
482 			db_printf("HW exception");
483 			break;
484 		case 4:
485 			db_printf("SW exception");
486 			break;
487 		default:
488 			db_printf("?? %lu", val >> 8 & 0x7);
489 			break;
490 		}
491 		db_printf("  Vector: %lu", val & 0xff);
492 		if (val & 0x800)
493 			db_printf("  Error Code: %lx",
494 			    vmcs_read(VMCS_EXIT_INTR_ERRCODE));
495 		db_printf("\n");
496 		break;
497 	case EXIT_REASON_EPT_FAULT:
498 	case EXIT_REASON_EPT_MISCONFIG:
499 		db_printf("Guest Physical Address: %#lx\n",
500 		    vmcs_read(VMCS_GUEST_PHYSICAL_ADDRESS));
501 		break;
502 	}
503 	db_printf("VM-instruction error: %#lx\n", vmcs_instruction_error());
504 }
505 #endif
506