vmcs.c revision 260531 
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: head/sys/amd64/vmm/intel/vmcs.c 260531 2014-01-11 03:14:05Z neel $
27 */
28
29#include "opt_ddb.h"
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/sys/amd64/vmm/intel/vmcs.c 260531 2014-01-11 03:14:05Z neel $");
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
53static uint64_t
54vmcs_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
70static uint32_t
71vmcs_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
112static int
113vmcs_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
174int
175vmcs_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
206int
207vmcs_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
233int
234vmcs_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	}
254done:
255	VMCLEAR(vmcs);
256	return (error);
257}
258
259int
260vmcs_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	}
284done:
285	VMCLEAR(vmcs);
286	return (error);
287}
288
289int
290vmcs_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;
312done:
313	VMCLEAR(vmcs);
314	return (error);
315}
316
317int
318vmcs_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;
416done:
417	VMCLEAR(vmcs);
418	return (error);
419}
420
421#ifdef DDB
422extern int vmxon_enabled[];
423
424DB_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