1 /*-
2 * Copyright (c) 2013, Anish Gupta (akgupt3@gmail.com)
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 unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: stable/10/sys/amd64/vmm/amd/svm.c 330069 2018-02-27 14:47:56Z avg $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/smp.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/pcpu.h>
36 #include <sys/proc.h>
37 #include <sys/sysctl.h>
38
39 #include <vm/vm.h>
40 #include <vm/pmap.h>
41
42 #include <machine/cpufunc.h>
43 #include <machine/psl.h>
44 #include <machine/pmap.h>
45 #include <machine/md_var.h>
46 #include <machine/specialreg.h>
47 #include <machine/smp.h>
48 #include <machine/vmm.h>
49 #include <machine/vmm_dev.h>
50 #include <machine/vmm_instruction_emul.h>
51
52 #include "vmm_lapic.h"
53 #include "vmm_stat.h"
54 #include "vmm_ktr.h"
55 #include "vmm_ioport.h"
56 #include "vatpic.h"
57 #include "vlapic.h"
58 #include "vlapic_priv.h"
59
60 #include "x86.h"
61 #include "vmcb.h"
62 #include "svm.h"
63 #include "svm_softc.h"
64 #include "svm_msr.h"
65 #include "npt.h"
66
67 SYSCTL_DECL(_hw_vmm);
68 SYSCTL_NODE(_hw_vmm, OID_AUTO, svm, CTLFLAG_RW, NULL, NULL);
69
70 /*
71 * SVM CPUID function 0x8000_000A, edx bit decoding.
72 */
73 #define AMD_CPUID_SVM_NP BIT(0) /* Nested paging or RVI */
74 #define AMD_CPUID_SVM_LBR BIT(1) /* Last branch virtualization */
75 #define AMD_CPUID_SVM_SVML BIT(2) /* SVM lock */
76 #define AMD_CPUID_SVM_NRIP_SAVE BIT(3) /* Next RIP is saved */
77 #define AMD_CPUID_SVM_TSC_RATE BIT(4) /* TSC rate control. */
78 #define AMD_CPUID_SVM_VMCB_CLEAN BIT(5) /* VMCB state caching */
79 #define AMD_CPUID_SVM_FLUSH_BY_ASID BIT(6) /* Flush by ASID */
80 #define AMD_CPUID_SVM_DECODE_ASSIST BIT(7) /* Decode assist */
81 #define AMD_CPUID_SVM_PAUSE_INC BIT(10) /* Pause intercept filter. */
82 #define AMD_CPUID_SVM_PAUSE_FTH BIT(12) /* Pause filter threshold */
83 #define AMD_CPUID_SVM_AVIC BIT(13) /* AVIC present */
84
85 #define VMCB_CACHE_DEFAULT (VMCB_CACHE_ASID | \
86 VMCB_CACHE_IOPM | \
87 VMCB_CACHE_I | \
88 VMCB_CACHE_TPR | \
89 VMCB_CACHE_CR2 | \
90 VMCB_CACHE_CR | \
91 VMCB_CACHE_DT | \
92 VMCB_CACHE_SEG | \
93 VMCB_CACHE_NP)
94
95 static uint32_t vmcb_clean = VMCB_CACHE_DEFAULT;
96 SYSCTL_INT(_hw_vmm_svm, OID_AUTO, vmcb_clean, CTLFLAG_RDTUN, &vmcb_clean,
97 0, NULL);
98
99 static MALLOC_DEFINE(M_SVM, "svm", "svm");
100 static MALLOC_DEFINE(M_SVM_VLAPIC, "svm-vlapic", "svm-vlapic");
101
102 /* Per-CPU context area. */
103 extern struct pcpu __pcpu[];
104
105 static uint32_t svm_feature = ~0U; /* AMD SVM features. */
106 SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, features, CTLFLAG_RDTUN, &svm_feature, 0,
107 "SVM features advertised by CPUID.8000000AH:EDX");
108
109 static int disable_npf_assist;
110 SYSCTL_INT(_hw_vmm_svm, OID_AUTO, disable_npf_assist, CTLFLAG_RWTUN,
111 &disable_npf_assist, 0, NULL);
112
113 /* Maximum ASIDs supported by the processor */
114 static uint32_t nasid;
115 SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, num_asids, CTLFLAG_RDTUN, &nasid, 0,
116 "Number of ASIDs supported by this processor");
117
118 /* Current ASID generation for each host cpu */
119 static struct asid asid[MAXCPU];
120
121 /*
122 * SVM host state saved area of size 4KB for each core.
123 */
124 static uint8_t hsave[MAXCPU][PAGE_SIZE] __aligned(PAGE_SIZE);
125
126 static VMM_STAT_AMD(VCPU_EXITINTINFO, "VM exits during event delivery");
127 static VMM_STAT_AMD(VCPU_INTINFO_INJECTED, "Events pending at VM entry");
128 static VMM_STAT_AMD(VMEXIT_VINTR, "VM exits due to interrupt window");
129
130 static int svm_setreg(void *arg, int vcpu, int ident, uint64_t val);
131
132 static __inline int
flush_by_asid(void)133 flush_by_asid(void)
134 {
135
136 return (svm_feature & AMD_CPUID_SVM_FLUSH_BY_ASID);
137 }
138
139 static __inline int
decode_assist(void)140 decode_assist(void)
141 {
142
143 return (svm_feature & AMD_CPUID_SVM_DECODE_ASSIST);
144 }
145
146 static void
svm_disable(void * arg __unused)147 svm_disable(void *arg __unused)
148 {
149 uint64_t efer;
150
151 efer = rdmsr(MSR_EFER);
152 efer &= ~EFER_SVM;
153 wrmsr(MSR_EFER, efer);
154 }
155
156 /*
157 * Disable SVM on all CPUs.
158 */
159 static int
svm_cleanup(void)160 svm_cleanup(void)
161 {
162
163 smp_rendezvous(NULL, svm_disable, NULL, NULL);
164 return (0);
165 }
166
167 /*
168 * Verify that all the features required by bhyve are available.
169 */
170 static int
check_svm_features(void)171 check_svm_features(void)
172 {
173 u_int regs[4];
174
175 /* CPUID Fn8000_000A is for SVM */
176 do_cpuid(0x8000000A, regs);
177 svm_feature &= regs[3];
178
179 /*
180 * The number of ASIDs can be configured to be less than what is
181 * supported by the hardware but not more.
182 */
183 if (nasid == 0 || nasid > regs[1])
184 nasid = regs[1];
185 KASSERT(nasid > 1, ("Insufficient ASIDs for guests: %#x", nasid));
186
187 /* bhyve requires the Nested Paging feature */
188 if (!(svm_feature & AMD_CPUID_SVM_NP)) {
189 printf("SVM: Nested Paging feature not available.\n");
190 return (ENXIO);
191 }
192
193 /* bhyve requires the NRIP Save feature */
194 if (!(svm_feature & AMD_CPUID_SVM_NRIP_SAVE)) {
195 printf("SVM: NRIP Save feature not available.\n");
196 return (ENXIO);
197 }
198
199 return (0);
200 }
201
202 static void
svm_enable(void * arg __unused)203 svm_enable(void *arg __unused)
204 {
205 uint64_t efer;
206
207 efer = rdmsr(MSR_EFER);
208 efer |= EFER_SVM;
209 wrmsr(MSR_EFER, efer);
210
211 wrmsr(MSR_VM_HSAVE_PA, vtophys(hsave[curcpu]));
212 }
213
214 /*
215 * Return 1 if SVM is enabled on this processor and 0 otherwise.
216 */
217 static int
svm_available(void)218 svm_available(void)
219 {
220 uint64_t msr;
221
222 /* Section 15.4 Enabling SVM from APM2. */
223 if ((amd_feature2 & AMDID2_SVM) == 0) {
224 printf("SVM: not available.\n");
225 return (0);
226 }
227
228 msr = rdmsr(MSR_VM_CR);
229 if ((msr & VM_CR_SVMDIS) != 0) {
230 printf("SVM: disabled by BIOS.\n");
231 return (0);
232 }
233
234 return (1);
235 }
236
237 static int
svm_init(int ipinum)238 svm_init(int ipinum)
239 {
240 int error, cpu;
241
242 if (!svm_available())
243 return (ENXIO);
244
245 error = check_svm_features();
246 if (error)
247 return (error);
248
249 vmcb_clean &= VMCB_CACHE_DEFAULT;
250
251 for (cpu = 0; cpu < MAXCPU; cpu++) {
252 /*
253 * Initialize the host ASIDs to their "highest" valid values.
254 *
255 * The next ASID allocation will rollover both 'gen' and 'num'
256 * and start off the sequence at {1,1}.
257 */
258 asid[cpu].gen = ~0UL;
259 asid[cpu].num = nasid - 1;
260 }
261
262 svm_msr_init();
263 svm_npt_init(ipinum);
264
265 /* Enable SVM on all CPUs */
266 smp_rendezvous(NULL, svm_enable, NULL, NULL);
267
268 return (0);
269 }
270
271 static void
svm_restore(void)272 svm_restore(void)
273 {
274
275 svm_enable(NULL);
276 }
277
278 /* Pentium compatible MSRs */
279 #define MSR_PENTIUM_START 0
280 #define MSR_PENTIUM_END 0x1FFF
281 /* AMD 6th generation and Intel compatible MSRs */
282 #define MSR_AMD6TH_START 0xC0000000UL
283 #define MSR_AMD6TH_END 0xC0001FFFUL
284 /* AMD 7th and 8th generation compatible MSRs */
285 #define MSR_AMD7TH_START 0xC0010000UL
286 #define MSR_AMD7TH_END 0xC0011FFFUL
287
288 /*
289 * Get the index and bit position for a MSR in permission bitmap.
290 * Two bits are used for each MSR: lower bit for read and higher bit for write.
291 */
292 static int
svm_msr_index(uint64_t msr,int * index,int * bit)293 svm_msr_index(uint64_t msr, int *index, int *bit)
294 {
295 uint32_t base, off;
296
297 *index = -1;
298 *bit = (msr % 4) * 2;
299 base = 0;
300
301 if (msr >= MSR_PENTIUM_START && msr <= MSR_PENTIUM_END) {
302 *index = msr / 4;
303 return (0);
304 }
305
306 base += (MSR_PENTIUM_END - MSR_PENTIUM_START + 1);
307 if (msr >= MSR_AMD6TH_START && msr <= MSR_AMD6TH_END) {
308 off = (msr - MSR_AMD6TH_START);
309 *index = (off + base) / 4;
310 return (0);
311 }
312
313 base += (MSR_AMD6TH_END - MSR_AMD6TH_START + 1);
314 if (msr >= MSR_AMD7TH_START && msr <= MSR_AMD7TH_END) {
315 off = (msr - MSR_AMD7TH_START);
316 *index = (off + base) / 4;
317 return (0);
318 }
319
320 return (EINVAL);
321 }
322
323 /*
324 * Allow vcpu to read or write the 'msr' without trapping into the hypervisor.
325 */
326 static void
svm_msr_perm(uint8_t * perm_bitmap,uint64_t msr,bool read,bool write)327 svm_msr_perm(uint8_t *perm_bitmap, uint64_t msr, bool read, bool write)
328 {
329 int index, bit, error;
330
331 error = svm_msr_index(msr, &index, &bit);
332 KASSERT(error == 0, ("%s: invalid msr %#lx", __func__, msr));
333 KASSERT(index >= 0 && index < SVM_MSR_BITMAP_SIZE,
334 ("%s: invalid index %d for msr %#lx", __func__, index, msr));
335 KASSERT(bit >= 0 && bit <= 6, ("%s: invalid bit position %d "
336 "msr %#lx", __func__, bit, msr));
337
338 if (read)
339 perm_bitmap[index] &= ~(1UL << bit);
340
341 if (write)
342 perm_bitmap[index] &= ~(2UL << bit);
343 }
344
345 static void
svm_msr_rw_ok(uint8_t * perm_bitmap,uint64_t msr)346 svm_msr_rw_ok(uint8_t *perm_bitmap, uint64_t msr)
347 {
348
349 svm_msr_perm(perm_bitmap, msr, true, true);
350 }
351
352 static void
svm_msr_rd_ok(uint8_t * perm_bitmap,uint64_t msr)353 svm_msr_rd_ok(uint8_t *perm_bitmap, uint64_t msr)
354 {
355
356 svm_msr_perm(perm_bitmap, msr, true, false);
357 }
358
359 static __inline int
svm_get_intercept(struct svm_softc * sc,int vcpu,int idx,uint32_t bitmask)360 svm_get_intercept(struct svm_softc *sc, int vcpu, int idx, uint32_t bitmask)
361 {
362 struct vmcb_ctrl *ctrl;
363
364 KASSERT(idx >=0 && idx < 5, ("invalid intercept index %d", idx));
365
366 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
367 return (ctrl->intercept[idx] & bitmask ? 1 : 0);
368 }
369
370 static __inline void
svm_set_intercept(struct svm_softc * sc,int vcpu,int idx,uint32_t bitmask,int enabled)371 svm_set_intercept(struct svm_softc *sc, int vcpu, int idx, uint32_t bitmask,
372 int enabled)
373 {
374 struct vmcb_ctrl *ctrl;
375 uint32_t oldval;
376
377 KASSERT(idx >=0 && idx < 5, ("invalid intercept index %d", idx));
378
379 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
380 oldval = ctrl->intercept[idx];
381
382 if (enabled)
383 ctrl->intercept[idx] |= bitmask;
384 else
385 ctrl->intercept[idx] &= ~bitmask;
386
387 if (ctrl->intercept[idx] != oldval) {
388 svm_set_dirty(sc, vcpu, VMCB_CACHE_I);
389 VCPU_CTR3(sc->vm, vcpu, "intercept[%d] modified "
390 "from %#x to %#x", idx, oldval, ctrl->intercept[idx]);
391 }
392 }
393
394 static __inline void
svm_disable_intercept(struct svm_softc * sc,int vcpu,int off,uint32_t bitmask)395 svm_disable_intercept(struct svm_softc *sc, int vcpu, int off, uint32_t bitmask)
396 {
397
398 svm_set_intercept(sc, vcpu, off, bitmask, 0);
399 }
400
401 static __inline void
svm_enable_intercept(struct svm_softc * sc,int vcpu,int off,uint32_t bitmask)402 svm_enable_intercept(struct svm_softc *sc, int vcpu, int off, uint32_t bitmask)
403 {
404
405 svm_set_intercept(sc, vcpu, off, bitmask, 1);
406 }
407
408 static void
vmcb_init(struct svm_softc * sc,int vcpu,uint64_t iopm_base_pa,uint64_t msrpm_base_pa,uint64_t np_pml4)409 vmcb_init(struct svm_softc *sc, int vcpu, uint64_t iopm_base_pa,
410 uint64_t msrpm_base_pa, uint64_t np_pml4)
411 {
412 struct vmcb_ctrl *ctrl;
413 struct vmcb_state *state;
414 uint32_t mask;
415 int n;
416
417 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
418 state = svm_get_vmcb_state(sc, vcpu);
419
420 ctrl->iopm_base_pa = iopm_base_pa;
421 ctrl->msrpm_base_pa = msrpm_base_pa;
422
423 /* Enable nested paging */
424 ctrl->np_enable = 1;
425 ctrl->n_cr3 = np_pml4;
426
427 /*
428 * Intercept accesses to the control registers that are not shadowed
429 * in the VMCB - i.e. all except cr0, cr2, cr3, cr4 and cr8.
430 */
431 for (n = 0; n < 16; n++) {
432 mask = (BIT(n) << 16) | BIT(n);
433 if (n == 0 || n == 2 || n == 3 || n == 4 || n == 8)
434 svm_disable_intercept(sc, vcpu, VMCB_CR_INTCPT, mask);
435 else
436 svm_enable_intercept(sc, vcpu, VMCB_CR_INTCPT, mask);
437 }
438
439
440 /*
441 * Intercept everything when tracing guest exceptions otherwise
442 * just intercept machine check exception.
443 */
444 if (vcpu_trace_exceptions(sc->vm, vcpu)) {
445 for (n = 0; n < 32; n++) {
446 /*
447 * Skip unimplemented vectors in the exception bitmap.
448 */
449 if (n == 2 || n == 9) {
450 continue;
451 }
452 svm_enable_intercept(sc, vcpu, VMCB_EXC_INTCPT, BIT(n));
453 }
454 } else {
455 svm_enable_intercept(sc, vcpu, VMCB_EXC_INTCPT, BIT(IDT_MC));
456 }
457
458 /* Intercept various events (for e.g. I/O, MSR and CPUID accesses) */
459 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_IO);
460 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_MSR);
461 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_CPUID);
462 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_INTR);
463 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_INIT);
464 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_NMI);
465 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_SMI);
466 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_SHUTDOWN);
467 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
468 VMCB_INTCPT_FERR_FREEZE);
469
470 svm_enable_intercept(sc, vcpu, VMCB_CTRL2_INTCPT, VMCB_INTCPT_MONITOR);
471 svm_enable_intercept(sc, vcpu, VMCB_CTRL2_INTCPT, VMCB_INTCPT_MWAIT);
472
473 /*
474 * From section "Canonicalization and Consistency Checks" in APMv2
475 * the VMRUN intercept bit must be set to pass the consistency check.
476 */
477 svm_enable_intercept(sc, vcpu, VMCB_CTRL2_INTCPT, VMCB_INTCPT_VMRUN);
478
479 /*
480 * The ASID will be set to a non-zero value just before VMRUN.
481 */
482 ctrl->asid = 0;
483
484 /*
485 * Section 15.21.1, Interrupt Masking in EFLAGS
486 * Section 15.21.2, Virtualizing APIC.TPR
487 *
488 * This must be set for %rflag and %cr8 isolation of guest and host.
489 */
490 ctrl->v_intr_masking = 1;
491
492 /* Enable Last Branch Record aka LBR for debugging */
493 ctrl->lbr_virt_en = 1;
494 state->dbgctl = BIT(0);
495
496 /* EFER_SVM must always be set when the guest is executing */
497 state->efer = EFER_SVM;
498
499 /* Set up the PAT to power-on state */
500 state->g_pat = PAT_VALUE(0, PAT_WRITE_BACK) |
501 PAT_VALUE(1, PAT_WRITE_THROUGH) |
502 PAT_VALUE(2, PAT_UNCACHED) |
503 PAT_VALUE(3, PAT_UNCACHEABLE) |
504 PAT_VALUE(4, PAT_WRITE_BACK) |
505 PAT_VALUE(5, PAT_WRITE_THROUGH) |
506 PAT_VALUE(6, PAT_UNCACHED) |
507 PAT_VALUE(7, PAT_UNCACHEABLE);
508 }
509
510 /*
511 * Initialize a virtual machine.
512 */
513 static void *
svm_vminit(struct vm * vm,pmap_t pmap)514 svm_vminit(struct vm *vm, pmap_t pmap)
515 {
516 struct svm_softc *svm_sc;
517 struct svm_vcpu *vcpu;
518 vm_paddr_t msrpm_pa, iopm_pa, pml4_pa;
519 int i;
520
521 svm_sc = malloc(sizeof (*svm_sc), M_SVM, M_WAITOK | M_ZERO);
522 if (((uintptr_t)svm_sc & PAGE_MASK) != 0)
523 panic("malloc of svm_softc not aligned on page boundary");
524
525 svm_sc->msr_bitmap = contigmalloc(SVM_MSR_BITMAP_SIZE, M_SVM,
526 M_WAITOK, 0, ~(vm_paddr_t)0, PAGE_SIZE, 0);
527 if (svm_sc->msr_bitmap == NULL)
528 panic("contigmalloc of SVM MSR bitmap failed");
529 svm_sc->iopm_bitmap = contigmalloc(SVM_IO_BITMAP_SIZE, M_SVM,
530 M_WAITOK, 0, ~(vm_paddr_t)0, PAGE_SIZE, 0);
531 if (svm_sc->iopm_bitmap == NULL)
532 panic("contigmalloc of SVM IO bitmap failed");
533
534 svm_sc->vm = vm;
535 svm_sc->nptp = (vm_offset_t)vtophys(pmap->pm_pml4);
536
537 /*
538 * Intercept read and write accesses to all MSRs.
539 */
540 memset(svm_sc->msr_bitmap, 0xFF, SVM_MSR_BITMAP_SIZE);
541
542 /*
543 * Access to the following MSRs is redirected to the VMCB when the
544 * guest is executing. Therefore it is safe to allow the guest to
545 * read/write these MSRs directly without hypervisor involvement.
546 */
547 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_GSBASE);
548 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_FSBASE);
549 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_KGSBASE);
550
551 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_STAR);
552 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_LSTAR);
553 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_CSTAR);
554 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SF_MASK);
555 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SYSENTER_CS_MSR);
556 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SYSENTER_ESP_MSR);
557 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_SYSENTER_EIP_MSR);
558 svm_msr_rw_ok(svm_sc->msr_bitmap, MSR_PAT);
559
560 svm_msr_rd_ok(svm_sc->msr_bitmap, MSR_TSC);
561
562 /*
563 * Intercept writes to make sure that the EFER_SVM bit is not cleared.
564 */
565 svm_msr_rd_ok(svm_sc->msr_bitmap, MSR_EFER);
566
567 /* Intercept access to all I/O ports. */
568 memset(svm_sc->iopm_bitmap, 0xFF, SVM_IO_BITMAP_SIZE);
569
570 iopm_pa = vtophys(svm_sc->iopm_bitmap);
571 msrpm_pa = vtophys(svm_sc->msr_bitmap);
572 pml4_pa = svm_sc->nptp;
573 for (i = 0; i < VM_MAXCPU; i++) {
574 vcpu = svm_get_vcpu(svm_sc, i);
575 vcpu->nextrip = ~0;
576 vcpu->lastcpu = NOCPU;
577 vcpu->vmcb_pa = vtophys(&vcpu->vmcb);
578 vmcb_init(svm_sc, i, iopm_pa, msrpm_pa, pml4_pa);
579 svm_msr_guest_init(svm_sc, i);
580 }
581 return (svm_sc);
582 }
583
584 /*
585 * Collateral for a generic SVM VM-exit.
586 */
587 static void
vm_exit_svm(struct vm_exit * vme,uint64_t code,uint64_t info1,uint64_t info2)588 vm_exit_svm(struct vm_exit *vme, uint64_t code, uint64_t info1, uint64_t info2)
589 {
590
591 vme->exitcode = VM_EXITCODE_SVM;
592 vme->u.svm.exitcode = code;
593 vme->u.svm.exitinfo1 = info1;
594 vme->u.svm.exitinfo2 = info2;
595 }
596
597 static int
svm_cpl(struct vmcb_state * state)598 svm_cpl(struct vmcb_state *state)
599 {
600
601 /*
602 * From APMv2:
603 * "Retrieve the CPL from the CPL field in the VMCB, not
604 * from any segment DPL"
605 */
606 return (state->cpl);
607 }
608
609 static enum vm_cpu_mode
svm_vcpu_mode(struct vmcb * vmcb)610 svm_vcpu_mode(struct vmcb *vmcb)
611 {
612 struct vmcb_segment seg;
613 struct vmcb_state *state;
614 int error;
615
616 state = &vmcb->state;
617
618 if (state->efer & EFER_LMA) {
619 error = vmcb_seg(vmcb, VM_REG_GUEST_CS, &seg);
620 KASSERT(error == 0, ("%s: vmcb_seg(cs) error %d", __func__,
621 error));
622
623 /*
624 * Section 4.8.1 for APM2, check if Code Segment has
625 * Long attribute set in descriptor.
626 */
627 if (seg.attrib & VMCB_CS_ATTRIB_L)
628 return (CPU_MODE_64BIT);
629 else
630 return (CPU_MODE_COMPATIBILITY);
631 } else if (state->cr0 & CR0_PE) {
632 return (CPU_MODE_PROTECTED);
633 } else {
634 return (CPU_MODE_REAL);
635 }
636 }
637
638 static enum vm_paging_mode
svm_paging_mode(uint64_t cr0,uint64_t cr4,uint64_t efer)639 svm_paging_mode(uint64_t cr0, uint64_t cr4, uint64_t efer)
640 {
641
642 if ((cr0 & CR0_PG) == 0)
643 return (PAGING_MODE_FLAT);
644 if ((cr4 & CR4_PAE) == 0)
645 return (PAGING_MODE_32);
646 if (efer & EFER_LME)
647 return (PAGING_MODE_64);
648 else
649 return (PAGING_MODE_PAE);
650 }
651
652 /*
653 * ins/outs utility routines
654 */
655 static uint64_t
svm_inout_str_index(struct svm_regctx * regs,int in)656 svm_inout_str_index(struct svm_regctx *regs, int in)
657 {
658 uint64_t val;
659
660 val = in ? regs->sctx_rdi : regs->sctx_rsi;
661
662 return (val);
663 }
664
665 static uint64_t
svm_inout_str_count(struct svm_regctx * regs,int rep)666 svm_inout_str_count(struct svm_regctx *regs, int rep)
667 {
668 uint64_t val;
669
670 val = rep ? regs->sctx_rcx : 1;
671
672 return (val);
673 }
674
675 static void
svm_inout_str_seginfo(struct svm_softc * svm_sc,int vcpu,int64_t info1,int in,struct vm_inout_str * vis)676 svm_inout_str_seginfo(struct svm_softc *svm_sc, int vcpu, int64_t info1,
677 int in, struct vm_inout_str *vis)
678 {
679 int error, s;
680
681 if (in) {
682 vis->seg_name = VM_REG_GUEST_ES;
683 } else {
684 /* The segment field has standard encoding */
685 s = (info1 >> 10) & 0x7;
686 vis->seg_name = vm_segment_name(s);
687 }
688
689 error = vmcb_getdesc(svm_sc, vcpu, vis->seg_name, &vis->seg_desc);
690 KASSERT(error == 0, ("%s: svm_getdesc error %d", __func__, error));
691 }
692
693 static int
svm_inout_str_addrsize(uint64_t info1)694 svm_inout_str_addrsize(uint64_t info1)
695 {
696 uint32_t size;
697
698 size = (info1 >> 7) & 0x7;
699 switch (size) {
700 case 1:
701 return (2); /* 16 bit */
702 case 2:
703 return (4); /* 32 bit */
704 case 4:
705 return (8); /* 64 bit */
706 default:
707 panic("%s: invalid size encoding %d", __func__, size);
708 }
709 }
710
711 static void
svm_paging_info(struct vmcb * vmcb,struct vm_guest_paging * paging)712 svm_paging_info(struct vmcb *vmcb, struct vm_guest_paging *paging)
713 {
714 struct vmcb_state *state;
715
716 state = &vmcb->state;
717 paging->cr3 = state->cr3;
718 paging->cpl = svm_cpl(state);
719 paging->cpu_mode = svm_vcpu_mode(vmcb);
720 paging->paging_mode = svm_paging_mode(state->cr0, state->cr4,
721 state->efer);
722 }
723
724 #define UNHANDLED 0
725
726 /*
727 * Handle guest I/O intercept.
728 */
729 static int
svm_handle_io(struct svm_softc * svm_sc,int vcpu,struct vm_exit * vmexit)730 svm_handle_io(struct svm_softc *svm_sc, int vcpu, struct vm_exit *vmexit)
731 {
732 struct vmcb_ctrl *ctrl;
733 struct vmcb_state *state;
734 struct svm_regctx *regs;
735 struct vm_inout_str *vis;
736 uint64_t info1;
737 int inout_string;
738
739 state = svm_get_vmcb_state(svm_sc, vcpu);
740 ctrl = svm_get_vmcb_ctrl(svm_sc, vcpu);
741 regs = svm_get_guest_regctx(svm_sc, vcpu);
742
743 info1 = ctrl->exitinfo1;
744 inout_string = info1 & BIT(2) ? 1 : 0;
745
746 /*
747 * The effective segment number in EXITINFO1[12:10] is populated
748 * only if the processor has the DecodeAssist capability.
749 *
750 * XXX this is not specified explicitly in APMv2 but can be verified
751 * empirically.
752 */
753 if (inout_string && !decode_assist())
754 return (UNHANDLED);
755
756 vmexit->exitcode = VM_EXITCODE_INOUT;
757 vmexit->u.inout.in = (info1 & BIT(0)) ? 1 : 0;
758 vmexit->u.inout.string = inout_string;
759 vmexit->u.inout.rep = (info1 & BIT(3)) ? 1 : 0;
760 vmexit->u.inout.bytes = (info1 >> 4) & 0x7;
761 vmexit->u.inout.port = (uint16_t)(info1 >> 16);
762 vmexit->u.inout.eax = (uint32_t)(state->rax);
763
764 if (inout_string) {
765 vmexit->exitcode = VM_EXITCODE_INOUT_STR;
766 vis = &vmexit->u.inout_str;
767 svm_paging_info(svm_get_vmcb(svm_sc, vcpu), &vis->paging);
768 vis->rflags = state->rflags;
769 vis->cr0 = state->cr0;
770 vis->index = svm_inout_str_index(regs, vmexit->u.inout.in);
771 vis->count = svm_inout_str_count(regs, vmexit->u.inout.rep);
772 vis->addrsize = svm_inout_str_addrsize(info1);
773 svm_inout_str_seginfo(svm_sc, vcpu, info1,
774 vmexit->u.inout.in, vis);
775 }
776
777 return (UNHANDLED);
778 }
779
780 static int
npf_fault_type(uint64_t exitinfo1)781 npf_fault_type(uint64_t exitinfo1)
782 {
783
784 if (exitinfo1 & VMCB_NPF_INFO1_W)
785 return (VM_PROT_WRITE);
786 else if (exitinfo1 & VMCB_NPF_INFO1_ID)
787 return (VM_PROT_EXECUTE);
788 else
789 return (VM_PROT_READ);
790 }
791
792 static bool
svm_npf_emul_fault(uint64_t exitinfo1)793 svm_npf_emul_fault(uint64_t exitinfo1)
794 {
795
796 if (exitinfo1 & VMCB_NPF_INFO1_ID) {
797 return (false);
798 }
799
800 if (exitinfo1 & VMCB_NPF_INFO1_GPT) {
801 return (false);
802 }
803
804 if ((exitinfo1 & VMCB_NPF_INFO1_GPA) == 0) {
805 return (false);
806 }
807
808 return (true);
809 }
810
811 static void
svm_handle_inst_emul(struct vmcb * vmcb,uint64_t gpa,struct vm_exit * vmexit)812 svm_handle_inst_emul(struct vmcb *vmcb, uint64_t gpa, struct vm_exit *vmexit)
813 {
814 struct vm_guest_paging *paging;
815 struct vmcb_segment seg;
816 struct vmcb_ctrl *ctrl;
817 char *inst_bytes;
818 int error, inst_len;
819
820 ctrl = &vmcb->ctrl;
821 paging = &vmexit->u.inst_emul.paging;
822
823 vmexit->exitcode = VM_EXITCODE_INST_EMUL;
824 vmexit->u.inst_emul.gpa = gpa;
825 vmexit->u.inst_emul.gla = VIE_INVALID_GLA;
826 svm_paging_info(vmcb, paging);
827
828 error = vmcb_seg(vmcb, VM_REG_GUEST_CS, &seg);
829 KASSERT(error == 0, ("%s: vmcb_seg(CS) error %d", __func__, error));
830
831 switch(paging->cpu_mode) {
832 case CPU_MODE_REAL:
833 vmexit->u.inst_emul.cs_base = seg.base;
834 vmexit->u.inst_emul.cs_d = 0;
835 break;
836 case CPU_MODE_PROTECTED:
837 case CPU_MODE_COMPATIBILITY:
838 vmexit->u.inst_emul.cs_base = seg.base;
839
840 /*
841 * Section 4.8.1 of APM2, Default Operand Size or D bit.
842 */
843 vmexit->u.inst_emul.cs_d = (seg.attrib & VMCB_CS_ATTRIB_D) ?
844 1 : 0;
845 break;
846 default:
847 vmexit->u.inst_emul.cs_base = 0;
848 vmexit->u.inst_emul.cs_d = 0;
849 break;
850 }
851
852 /*
853 * Copy the instruction bytes into 'vie' if available.
854 */
855 if (decode_assist() && !disable_npf_assist) {
856 inst_len = ctrl->inst_len;
857 inst_bytes = ctrl->inst_bytes;
858 } else {
859 inst_len = 0;
860 inst_bytes = NULL;
861 }
862 vie_init(&vmexit->u.inst_emul.vie, inst_bytes, inst_len);
863 }
864
865 #ifdef KTR
866 static const char *
intrtype_to_str(int intr_type)867 intrtype_to_str(int intr_type)
868 {
869 switch (intr_type) {
870 case VMCB_EVENTINJ_TYPE_INTR:
871 return ("hwintr");
872 case VMCB_EVENTINJ_TYPE_NMI:
873 return ("nmi");
874 case VMCB_EVENTINJ_TYPE_INTn:
875 return ("swintr");
876 case VMCB_EVENTINJ_TYPE_EXCEPTION:
877 return ("exception");
878 default:
879 panic("%s: unknown intr_type %d", __func__, intr_type);
880 }
881 }
882 #endif
883
884 /*
885 * Inject an event to vcpu as described in section 15.20, "Event injection".
886 */
887 static void
svm_eventinject(struct svm_softc * sc,int vcpu,int intr_type,int vector,uint32_t error,bool ec_valid)888 svm_eventinject(struct svm_softc *sc, int vcpu, int intr_type, int vector,
889 uint32_t error, bool ec_valid)
890 {
891 struct vmcb_ctrl *ctrl;
892
893 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
894
895 KASSERT((ctrl->eventinj & VMCB_EVENTINJ_VALID) == 0,
896 ("%s: event already pending %#lx", __func__, ctrl->eventinj));
897
898 KASSERT(vector >=0 && vector <= 255, ("%s: invalid vector %d",
899 __func__, vector));
900
901 switch (intr_type) {
902 case VMCB_EVENTINJ_TYPE_INTR:
903 case VMCB_EVENTINJ_TYPE_NMI:
904 case VMCB_EVENTINJ_TYPE_INTn:
905 break;
906 case VMCB_EVENTINJ_TYPE_EXCEPTION:
907 if (vector >= 0 && vector <= 31 && vector != 2)
908 break;
909 /* FALLTHROUGH */
910 default:
911 panic("%s: invalid intr_type/vector: %d/%d", __func__,
912 intr_type, vector);
913 }
914 ctrl->eventinj = vector | (intr_type << 8) | VMCB_EVENTINJ_VALID;
915 if (ec_valid) {
916 ctrl->eventinj |= VMCB_EVENTINJ_EC_VALID;
917 ctrl->eventinj |= (uint64_t)error << 32;
918 VCPU_CTR3(sc->vm, vcpu, "Injecting %s at vector %d errcode %#x",
919 intrtype_to_str(intr_type), vector, error);
920 } else {
921 VCPU_CTR2(sc->vm, vcpu, "Injecting %s at vector %d",
922 intrtype_to_str(intr_type), vector);
923 }
924 }
925
926 static void
svm_update_virqinfo(struct svm_softc * sc,int vcpu)927 svm_update_virqinfo(struct svm_softc *sc, int vcpu)
928 {
929 struct vm *vm;
930 struct vlapic *vlapic;
931 struct vmcb_ctrl *ctrl;
932
933 vm = sc->vm;
934 vlapic = vm_lapic(vm, vcpu);
935 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
936
937 /* Update %cr8 in the emulated vlapic */
938 vlapic_set_cr8(vlapic, ctrl->v_tpr);
939
940 /* Virtual interrupt injection is not used. */
941 KASSERT(ctrl->v_intr_vector == 0, ("%s: invalid "
942 "v_intr_vector %d", __func__, ctrl->v_intr_vector));
943 }
944
945 static void
svm_save_intinfo(struct svm_softc * svm_sc,int vcpu)946 svm_save_intinfo(struct svm_softc *svm_sc, int vcpu)
947 {
948 struct vmcb_ctrl *ctrl;
949 uint64_t intinfo;
950
951 ctrl = svm_get_vmcb_ctrl(svm_sc, vcpu);
952 intinfo = ctrl->exitintinfo;
953 if (!VMCB_EXITINTINFO_VALID(intinfo))
954 return;
955
956 /*
957 * From APMv2, Section "Intercepts during IDT interrupt delivery"
958 *
959 * If a #VMEXIT happened during event delivery then record the event
960 * that was being delivered.
961 */
962 VCPU_CTR2(svm_sc->vm, vcpu, "SVM:Pending INTINFO(0x%lx), vector=%d.\n",
963 intinfo, VMCB_EXITINTINFO_VECTOR(intinfo));
964 vmm_stat_incr(svm_sc->vm, vcpu, VCPU_EXITINTINFO, 1);
965 vm_exit_intinfo(svm_sc->vm, vcpu, intinfo);
966 }
967
968 #ifdef INVARIANTS
969 static __inline int
vintr_intercept_enabled(struct svm_softc * sc,int vcpu)970 vintr_intercept_enabled(struct svm_softc *sc, int vcpu)
971 {
972
973 return (svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
974 VMCB_INTCPT_VINTR));
975 }
976 #endif
977
978 static __inline void
enable_intr_window_exiting(struct svm_softc * sc,int vcpu)979 enable_intr_window_exiting(struct svm_softc *sc, int vcpu)
980 {
981 struct vmcb_ctrl *ctrl;
982
983 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
984
985 if (ctrl->v_irq && ctrl->v_intr_vector == 0) {
986 KASSERT(ctrl->v_ign_tpr, ("%s: invalid v_ign_tpr", __func__));
987 KASSERT(vintr_intercept_enabled(sc, vcpu),
988 ("%s: vintr intercept should be enabled", __func__));
989 return;
990 }
991
992 VCPU_CTR0(sc->vm, vcpu, "Enable intr window exiting");
993 ctrl->v_irq = 1;
994 ctrl->v_ign_tpr = 1;
995 ctrl->v_intr_vector = 0;
996 svm_set_dirty(sc, vcpu, VMCB_CACHE_TPR);
997 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_VINTR);
998 }
999
1000 static __inline void
disable_intr_window_exiting(struct svm_softc * sc,int vcpu)1001 disable_intr_window_exiting(struct svm_softc *sc, int vcpu)
1002 {
1003 struct vmcb_ctrl *ctrl;
1004
1005 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
1006
1007 if (!ctrl->v_irq && ctrl->v_intr_vector == 0) {
1008 KASSERT(!vintr_intercept_enabled(sc, vcpu),
1009 ("%s: vintr intercept should be disabled", __func__));
1010 return;
1011 }
1012
1013 VCPU_CTR0(sc->vm, vcpu, "Disable intr window exiting");
1014 ctrl->v_irq = 0;
1015 ctrl->v_intr_vector = 0;
1016 svm_set_dirty(sc, vcpu, VMCB_CACHE_TPR);
1017 svm_disable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_VINTR);
1018 }
1019
1020 static int
svm_modify_intr_shadow(struct svm_softc * sc,int vcpu,uint64_t val)1021 svm_modify_intr_shadow(struct svm_softc *sc, int vcpu, uint64_t val)
1022 {
1023 struct vmcb_ctrl *ctrl;
1024 int oldval, newval;
1025
1026 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
1027 oldval = ctrl->intr_shadow;
1028 newval = val ? 1 : 0;
1029 if (newval != oldval) {
1030 ctrl->intr_shadow = newval;
1031 VCPU_CTR1(sc->vm, vcpu, "Setting intr_shadow to %d", newval);
1032 }
1033 return (0);
1034 }
1035
1036 static int
svm_get_intr_shadow(struct svm_softc * sc,int vcpu,uint64_t * val)1037 svm_get_intr_shadow(struct svm_softc *sc, int vcpu, uint64_t *val)
1038 {
1039 struct vmcb_ctrl *ctrl;
1040
1041 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
1042 *val = ctrl->intr_shadow;
1043 return (0);
1044 }
1045
1046 /*
1047 * Once an NMI is injected it blocks delivery of further NMIs until the handler
1048 * executes an IRET. The IRET intercept is enabled when an NMI is injected to
1049 * to track when the vcpu is done handling the NMI.
1050 */
1051 static int
nmi_blocked(struct svm_softc * sc,int vcpu)1052 nmi_blocked(struct svm_softc *sc, int vcpu)
1053 {
1054 int blocked;
1055
1056 blocked = svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
1057 VMCB_INTCPT_IRET);
1058 return (blocked);
1059 }
1060
1061 static void
enable_nmi_blocking(struct svm_softc * sc,int vcpu)1062 enable_nmi_blocking(struct svm_softc *sc, int vcpu)
1063 {
1064
1065 KASSERT(!nmi_blocked(sc, vcpu), ("vNMI already blocked"));
1066 VCPU_CTR0(sc->vm, vcpu, "vNMI blocking enabled");
1067 svm_enable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_IRET);
1068 }
1069
1070 static void
clear_nmi_blocking(struct svm_softc * sc,int vcpu)1071 clear_nmi_blocking(struct svm_softc *sc, int vcpu)
1072 {
1073 int error;
1074
1075 KASSERT(nmi_blocked(sc, vcpu), ("vNMI already unblocked"));
1076 VCPU_CTR0(sc->vm, vcpu, "vNMI blocking cleared");
1077 /*
1078 * When the IRET intercept is cleared the vcpu will attempt to execute
1079 * the "iret" when it runs next. However, it is possible to inject
1080 * another NMI into the vcpu before the "iret" has actually executed.
1081 *
1082 * For e.g. if the "iret" encounters a #NPF when accessing the stack
1083 * it will trap back into the hypervisor. If an NMI is pending for
1084 * the vcpu it will be injected into the guest.
1085 *
1086 * XXX this needs to be fixed
1087 */
1088 svm_disable_intercept(sc, vcpu, VMCB_CTRL1_INTCPT, VMCB_INTCPT_IRET);
1089
1090 /*
1091 * Set 'intr_shadow' to prevent an NMI from being injected on the
1092 * immediate VMRUN.
1093 */
1094 error = svm_modify_intr_shadow(sc, vcpu, 1);
1095 KASSERT(!error, ("%s: error %d setting intr_shadow", __func__, error));
1096 }
1097
1098 #define EFER_MBZ_BITS 0xFFFFFFFFFFFF0200UL
1099
1100 static int
svm_write_efer(struct svm_softc * sc,int vcpu,uint64_t newval,bool * retu)1101 svm_write_efer(struct svm_softc *sc, int vcpu, uint64_t newval, bool *retu)
1102 {
1103 struct vm_exit *vme;
1104 struct vmcb_state *state;
1105 uint64_t changed, lma, oldval;
1106 int error;
1107
1108 state = svm_get_vmcb_state(sc, vcpu);
1109
1110 oldval = state->efer;
1111 VCPU_CTR2(sc->vm, vcpu, "wrmsr(efer) %#lx/%#lx", oldval, newval);
1112
1113 newval &= ~0xFE; /* clear the Read-As-Zero (RAZ) bits */
1114 changed = oldval ^ newval;
1115
1116 if (newval & EFER_MBZ_BITS)
1117 goto gpf;
1118
1119 /* APMv2 Table 14-5 "Long-Mode Consistency Checks" */
1120 if (changed & EFER_LME) {
1121 if (state->cr0 & CR0_PG)
1122 goto gpf;
1123 }
1124
1125 /* EFER.LMA = EFER.LME & CR0.PG */
1126 if ((newval & EFER_LME) != 0 && (state->cr0 & CR0_PG) != 0)
1127 lma = EFER_LMA;
1128 else
1129 lma = 0;
1130
1131 if ((newval & EFER_LMA) != lma)
1132 goto gpf;
1133
1134 if (newval & EFER_NXE) {
1135 if (!vm_cpuid_capability(sc->vm, vcpu, VCC_NO_EXECUTE))
1136 goto gpf;
1137 }
1138
1139 /*
1140 * XXX bhyve does not enforce segment limits in 64-bit mode. Until
1141 * this is fixed flag guest attempt to set EFER_LMSLE as an error.
1142 */
1143 if (newval & EFER_LMSLE) {
1144 vme = vm_exitinfo(sc->vm, vcpu);
1145 vm_exit_svm(vme, VMCB_EXIT_MSR, 1, 0);
1146 *retu = true;
1147 return (0);
1148 }
1149
1150 if (newval & EFER_FFXSR) {
1151 if (!vm_cpuid_capability(sc->vm, vcpu, VCC_FFXSR))
1152 goto gpf;
1153 }
1154
1155 if (newval & EFER_TCE) {
1156 if (!vm_cpuid_capability(sc->vm, vcpu, VCC_TCE))
1157 goto gpf;
1158 }
1159
1160 error = svm_setreg(sc, vcpu, VM_REG_GUEST_EFER, newval);
1161 KASSERT(error == 0, ("%s: error %d updating efer", __func__, error));
1162 return (0);
1163 gpf:
1164 vm_inject_gp(sc->vm, vcpu);
1165 return (0);
1166 }
1167
1168 static int
emulate_wrmsr(struct svm_softc * sc,int vcpu,u_int num,uint64_t val,bool * retu)1169 emulate_wrmsr(struct svm_softc *sc, int vcpu, u_int num, uint64_t val,
1170 bool *retu)
1171 {
1172 int error;
1173
1174 if (lapic_msr(num))
1175 error = lapic_wrmsr(sc->vm, vcpu, num, val, retu);
1176 else if (num == MSR_EFER)
1177 error = svm_write_efer(sc, vcpu, val, retu);
1178 else
1179 error = svm_wrmsr(sc, vcpu, num, val, retu);
1180
1181 return (error);
1182 }
1183
1184 static int
emulate_rdmsr(struct svm_softc * sc,int vcpu,u_int num,bool * retu)1185 emulate_rdmsr(struct svm_softc *sc, int vcpu, u_int num, bool *retu)
1186 {
1187 struct vmcb_state *state;
1188 struct svm_regctx *ctx;
1189 uint64_t result;
1190 int error;
1191
1192 if (lapic_msr(num))
1193 error = lapic_rdmsr(sc->vm, vcpu, num, &result, retu);
1194 else
1195 error = svm_rdmsr(sc, vcpu, num, &result, retu);
1196
1197 if (error == 0) {
1198 state = svm_get_vmcb_state(sc, vcpu);
1199 ctx = svm_get_guest_regctx(sc, vcpu);
1200 state->rax = result & 0xffffffff;
1201 ctx->sctx_rdx = result >> 32;
1202 }
1203
1204 return (error);
1205 }
1206
1207 #ifdef KTR
1208 static const char *
exit_reason_to_str(uint64_t reason)1209 exit_reason_to_str(uint64_t reason)
1210 {
1211 static char reasonbuf[32];
1212
1213 switch (reason) {
1214 case VMCB_EXIT_INVALID:
1215 return ("invalvmcb");
1216 case VMCB_EXIT_SHUTDOWN:
1217 return ("shutdown");
1218 case VMCB_EXIT_NPF:
1219 return ("nptfault");
1220 case VMCB_EXIT_PAUSE:
1221 return ("pause");
1222 case VMCB_EXIT_HLT:
1223 return ("hlt");
1224 case VMCB_EXIT_CPUID:
1225 return ("cpuid");
1226 case VMCB_EXIT_IO:
1227 return ("inout");
1228 case VMCB_EXIT_MC:
1229 return ("mchk");
1230 case VMCB_EXIT_INTR:
1231 return ("extintr");
1232 case VMCB_EXIT_NMI:
1233 return ("nmi");
1234 case VMCB_EXIT_VINTR:
1235 return ("vintr");
1236 case VMCB_EXIT_MSR:
1237 return ("msr");
1238 case VMCB_EXIT_IRET:
1239 return ("iret");
1240 case VMCB_EXIT_MONITOR:
1241 return ("monitor");
1242 case VMCB_EXIT_MWAIT:
1243 return ("mwait");
1244 default:
1245 snprintf(reasonbuf, sizeof(reasonbuf), "%#lx", reason);
1246 return (reasonbuf);
1247 }
1248 }
1249 #endif /* KTR */
1250
1251 /*
1252 * From section "State Saved on Exit" in APMv2: nRIP is saved for all #VMEXITs
1253 * that are due to instruction intercepts as well as MSR and IOIO intercepts
1254 * and exceptions caused by INT3, INTO and BOUND instructions.
1255 *
1256 * Return 1 if the nRIP is valid and 0 otherwise.
1257 */
1258 static int
nrip_valid(uint64_t exitcode)1259 nrip_valid(uint64_t exitcode)
1260 {
1261 switch (exitcode) {
1262 case 0x00 ... 0x0F: /* read of CR0 through CR15 */
1263 case 0x10 ... 0x1F: /* write of CR0 through CR15 */
1264 case 0x20 ... 0x2F: /* read of DR0 through DR15 */
1265 case 0x30 ... 0x3F: /* write of DR0 through DR15 */
1266 case 0x43: /* INT3 */
1267 case 0x44: /* INTO */
1268 case 0x45: /* BOUND */
1269 case 0x65 ... 0x7C: /* VMEXIT_CR0_SEL_WRITE ... VMEXIT_MSR */
1270 case 0x80 ... 0x8D: /* VMEXIT_VMRUN ... VMEXIT_XSETBV */
1271 return (1);
1272 default:
1273 return (0);
1274 }
1275 }
1276
1277 static int
svm_vmexit(struct svm_softc * svm_sc,int vcpu,struct vm_exit * vmexit)1278 svm_vmexit(struct svm_softc *svm_sc, int vcpu, struct vm_exit *vmexit)
1279 {
1280 struct vmcb *vmcb;
1281 struct vmcb_state *state;
1282 struct vmcb_ctrl *ctrl;
1283 struct svm_regctx *ctx;
1284 uint64_t code, info1, info2, val;
1285 uint32_t eax, ecx, edx;
1286 int error, errcode_valid, handled, idtvec, reflect;
1287 bool retu;
1288
1289 ctx = svm_get_guest_regctx(svm_sc, vcpu);
1290 vmcb = svm_get_vmcb(svm_sc, vcpu);
1291 state = &vmcb->state;
1292 ctrl = &vmcb->ctrl;
1293
1294 handled = 0;
1295 code = ctrl->exitcode;
1296 info1 = ctrl->exitinfo1;
1297 info2 = ctrl->exitinfo2;
1298
1299 vmexit->exitcode = VM_EXITCODE_BOGUS;
1300 vmexit->rip = state->rip;
1301 vmexit->inst_length = nrip_valid(code) ? ctrl->nrip - state->rip : 0;
1302
1303 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_COUNT, 1);
1304
1305 /*
1306 * #VMEXIT(INVALID) needs to be handled early because the VMCB is
1307 * in an inconsistent state and can trigger assertions that would
1308 * never happen otherwise.
1309 */
1310 if (code == VMCB_EXIT_INVALID) {
1311 vm_exit_svm(vmexit, code, info1, info2);
1312 return (0);
1313 }
1314
1315 KASSERT((ctrl->eventinj & VMCB_EVENTINJ_VALID) == 0, ("%s: event "
1316 "injection valid bit is set %#lx", __func__, ctrl->eventinj));
1317
1318 KASSERT(vmexit->inst_length >= 0 && vmexit->inst_length <= 15,
1319 ("invalid inst_length %d: code (%#lx), info1 (%#lx), info2 (%#lx)",
1320 vmexit->inst_length, code, info1, info2));
1321
1322 svm_update_virqinfo(svm_sc, vcpu);
1323 svm_save_intinfo(svm_sc, vcpu);
1324
1325 switch (code) {
1326 case VMCB_EXIT_IRET:
1327 /*
1328 * Restart execution at "iret" but with the intercept cleared.
1329 */
1330 vmexit->inst_length = 0;
1331 clear_nmi_blocking(svm_sc, vcpu);
1332 handled = 1;
1333 break;
1334 case VMCB_EXIT_VINTR: /* interrupt window exiting */
1335 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_VINTR, 1);
1336 handled = 1;
1337 break;
1338 case VMCB_EXIT_INTR: /* external interrupt */
1339 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_EXTINT, 1);
1340 handled = 1;
1341 break;
1342 case VMCB_EXIT_NMI: /* external NMI */
1343 handled = 1;
1344 break;
1345 case 0x40 ... 0x5F:
1346 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_EXCEPTION, 1);
1347 reflect = 1;
1348 idtvec = code - 0x40;
1349 switch (idtvec) {
1350 case IDT_MC:
1351 /*
1352 * Call the machine check handler by hand. Also don't
1353 * reflect the machine check back into the guest.
1354 */
1355 reflect = 0;
1356 VCPU_CTR0(svm_sc->vm, vcpu, "Vectoring to MCE handler");
1357 __asm __volatile("int $18");
1358 break;
1359 case IDT_PF:
1360 error = svm_setreg(svm_sc, vcpu, VM_REG_GUEST_CR2,
1361 info2);
1362 KASSERT(error == 0, ("%s: error %d updating cr2",
1363 __func__, error));
1364 /* fallthru */
1365 case IDT_NP:
1366 case IDT_SS:
1367 case IDT_GP:
1368 case IDT_AC:
1369 case IDT_TS:
1370 errcode_valid = 1;
1371 break;
1372
1373 case IDT_DF:
1374 errcode_valid = 1;
1375 info1 = 0;
1376 break;
1377
1378 case IDT_BP:
1379 case IDT_OF:
1380 case IDT_BR:
1381 /*
1382 * The 'nrip' field is populated for INT3, INTO and
1383 * BOUND exceptions and this also implies that
1384 * 'inst_length' is non-zero.
1385 *
1386 * Reset 'inst_length' to zero so the guest %rip at
1387 * event injection is identical to what it was when
1388 * the exception originally happened.
1389 */
1390 VCPU_CTR2(svm_sc->vm, vcpu, "Reset inst_length from %d "
1391 "to zero before injecting exception %d",
1392 vmexit->inst_length, idtvec);
1393 vmexit->inst_length = 0;
1394 /* fallthru */
1395 default:
1396 errcode_valid = 0;
1397 info1 = 0;
1398 break;
1399 }
1400 KASSERT(vmexit->inst_length == 0, ("invalid inst_length (%d) "
1401 "when reflecting exception %d into guest",
1402 vmexit->inst_length, idtvec));
1403
1404 if (reflect) {
1405 /* Reflect the exception back into the guest */
1406 VCPU_CTR2(svm_sc->vm, vcpu, "Reflecting exception "
1407 "%d/%#x into the guest", idtvec, (int)info1);
1408 error = vm_inject_exception(svm_sc->vm, vcpu, idtvec,
1409 errcode_valid, info1, 0);
1410 KASSERT(error == 0, ("%s: vm_inject_exception error %d",
1411 __func__, error));
1412 }
1413 handled = 1;
1414 break;
1415 case VMCB_EXIT_MSR: /* MSR access. */
1416 eax = state->rax;
1417 ecx = ctx->sctx_rcx;
1418 edx = ctx->sctx_rdx;
1419 retu = false;
1420
1421 if (info1) {
1422 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_WRMSR, 1);
1423 val = (uint64_t)edx << 32 | eax;
1424 VCPU_CTR2(svm_sc->vm, vcpu, "wrmsr %#x val %#lx",
1425 ecx, val);
1426 if (emulate_wrmsr(svm_sc, vcpu, ecx, val, &retu)) {
1427 vmexit->exitcode = VM_EXITCODE_WRMSR;
1428 vmexit->u.msr.code = ecx;
1429 vmexit->u.msr.wval = val;
1430 } else if (!retu) {
1431 handled = 1;
1432 } else {
1433 KASSERT(vmexit->exitcode != VM_EXITCODE_BOGUS,
1434 ("emulate_wrmsr retu with bogus exitcode"));
1435 }
1436 } else {
1437 VCPU_CTR1(svm_sc->vm, vcpu, "rdmsr %#x", ecx);
1438 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_RDMSR, 1);
1439 if (emulate_rdmsr(svm_sc, vcpu, ecx, &retu)) {
1440 vmexit->exitcode = VM_EXITCODE_RDMSR;
1441 vmexit->u.msr.code = ecx;
1442 } else if (!retu) {
1443 handled = 1;
1444 } else {
1445 KASSERT(vmexit->exitcode != VM_EXITCODE_BOGUS,
1446 ("emulate_rdmsr retu with bogus exitcode"));
1447 }
1448 }
1449 break;
1450 case VMCB_EXIT_IO:
1451 handled = svm_handle_io(svm_sc, vcpu, vmexit);
1452 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_INOUT, 1);
1453 break;
1454 case VMCB_EXIT_CPUID:
1455 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_CPUID, 1);
1456 handled = x86_emulate_cpuid(svm_sc->vm, vcpu,
1457 (uint32_t *)&state->rax,
1458 (uint32_t *)&ctx->sctx_rbx,
1459 (uint32_t *)&ctx->sctx_rcx,
1460 (uint32_t *)&ctx->sctx_rdx);
1461 break;
1462 case VMCB_EXIT_HLT:
1463 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_HLT, 1);
1464 vmexit->exitcode = VM_EXITCODE_HLT;
1465 vmexit->u.hlt.rflags = state->rflags;
1466 break;
1467 case VMCB_EXIT_PAUSE:
1468 vmexit->exitcode = VM_EXITCODE_PAUSE;
1469 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_PAUSE, 1);
1470 break;
1471 case VMCB_EXIT_NPF:
1472 /* EXITINFO2 contains the faulting guest physical address */
1473 if (info1 & VMCB_NPF_INFO1_RSV) {
1474 VCPU_CTR2(svm_sc->vm, vcpu, "nested page fault with "
1475 "reserved bits set: info1(%#lx) info2(%#lx)",
1476 info1, info2);
1477 } else if (vm_mem_allocated(svm_sc->vm, vcpu, info2)) {
1478 vmexit->exitcode = VM_EXITCODE_PAGING;
1479 vmexit->u.paging.gpa = info2;
1480 vmexit->u.paging.fault_type = npf_fault_type(info1);
1481 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_NESTED_FAULT, 1);
1482 VCPU_CTR3(svm_sc->vm, vcpu, "nested page fault "
1483 "on gpa %#lx/%#lx at rip %#lx",
1484 info2, info1, state->rip);
1485 } else if (svm_npf_emul_fault(info1)) {
1486 svm_handle_inst_emul(vmcb, info2, vmexit);
1487 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_INST_EMUL, 1);
1488 VCPU_CTR3(svm_sc->vm, vcpu, "inst_emul fault "
1489 "for gpa %#lx/%#lx at rip %#lx",
1490 info2, info1, state->rip);
1491 }
1492 break;
1493 case VMCB_EXIT_MONITOR:
1494 vmexit->exitcode = VM_EXITCODE_MONITOR;
1495 break;
1496 case VMCB_EXIT_MWAIT:
1497 vmexit->exitcode = VM_EXITCODE_MWAIT;
1498 break;
1499 default:
1500 vmm_stat_incr(svm_sc->vm, vcpu, VMEXIT_UNKNOWN, 1);
1501 break;
1502 }
1503
1504 VCPU_CTR4(svm_sc->vm, vcpu, "%s %s vmexit at %#lx/%d",
1505 handled ? "handled" : "unhandled", exit_reason_to_str(code),
1506 vmexit->rip, vmexit->inst_length);
1507
1508 if (handled) {
1509 vmexit->rip += vmexit->inst_length;
1510 vmexit->inst_length = 0;
1511 state->rip = vmexit->rip;
1512 } else {
1513 if (vmexit->exitcode == VM_EXITCODE_BOGUS) {
1514 /*
1515 * If this VM exit was not claimed by anybody then
1516 * treat it as a generic SVM exit.
1517 */
1518 vm_exit_svm(vmexit, code, info1, info2);
1519 } else {
1520 /*
1521 * The exitcode and collateral have been populated.
1522 * The VM exit will be processed further in userland.
1523 */
1524 }
1525 }
1526 return (handled);
1527 }
1528
1529 static void
svm_inj_intinfo(struct svm_softc * svm_sc,int vcpu)1530 svm_inj_intinfo(struct svm_softc *svm_sc, int vcpu)
1531 {
1532 uint64_t intinfo;
1533
1534 if (!vm_entry_intinfo(svm_sc->vm, vcpu, &intinfo))
1535 return;
1536
1537 KASSERT(VMCB_EXITINTINFO_VALID(intinfo), ("%s: entry intinfo is not "
1538 "valid: %#lx", __func__, intinfo));
1539
1540 svm_eventinject(svm_sc, vcpu, VMCB_EXITINTINFO_TYPE(intinfo),
1541 VMCB_EXITINTINFO_VECTOR(intinfo),
1542 VMCB_EXITINTINFO_EC(intinfo),
1543 VMCB_EXITINTINFO_EC_VALID(intinfo));
1544 vmm_stat_incr(svm_sc->vm, vcpu, VCPU_INTINFO_INJECTED, 1);
1545 VCPU_CTR1(svm_sc->vm, vcpu, "Injected entry intinfo: %#lx", intinfo);
1546 }
1547
1548 /*
1549 * Inject event to virtual cpu.
1550 */
1551 static void
svm_inj_interrupts(struct svm_softc * sc,int vcpu,struct vlapic * vlapic)1552 svm_inj_interrupts(struct svm_softc *sc, int vcpu, struct vlapic *vlapic)
1553 {
1554 struct vmcb_ctrl *ctrl;
1555 struct vmcb_state *state;
1556 struct svm_vcpu *vcpustate;
1557 uint8_t v_tpr;
1558 int vector, need_intr_window;
1559 int extint_pending;
1560
1561 state = svm_get_vmcb_state(sc, vcpu);
1562 ctrl = svm_get_vmcb_ctrl(sc, vcpu);
1563 vcpustate = svm_get_vcpu(sc, vcpu);
1564
1565 need_intr_window = 0;
1566
1567 if (vcpustate->nextrip != state->rip) {
1568 ctrl->intr_shadow = 0;
1569 VCPU_CTR2(sc->vm, vcpu, "Guest interrupt blocking "
1570 "cleared due to rip change: %#lx/%#lx",
1571 vcpustate->nextrip, state->rip);
1572 }
1573
1574 /*
1575 * Inject pending events or exceptions for this vcpu.
1576 *
1577 * An event might be pending because the previous #VMEXIT happened
1578 * during event delivery (i.e. ctrl->exitintinfo).
1579 *
1580 * An event might also be pending because an exception was injected
1581 * by the hypervisor (e.g. #PF during instruction emulation).
1582 */
1583 svm_inj_intinfo(sc, vcpu);
1584
1585 /* NMI event has priority over interrupts. */
1586 if (vm_nmi_pending(sc->vm, vcpu)) {
1587 if (nmi_blocked(sc, vcpu)) {
1588 /*
1589 * Can't inject another NMI if the guest has not
1590 * yet executed an "iret" after the last NMI.
1591 */
1592 VCPU_CTR0(sc->vm, vcpu, "Cannot inject NMI due "
1593 "to NMI-blocking");
1594 } else if (ctrl->intr_shadow) {
1595 /*
1596 * Can't inject an NMI if the vcpu is in an intr_shadow.
1597 */
1598 VCPU_CTR0(sc->vm, vcpu, "Cannot inject NMI due to "
1599 "interrupt shadow");
1600 need_intr_window = 1;
1601 goto done;
1602 } else if (ctrl->eventinj & VMCB_EVENTINJ_VALID) {
1603 /*
1604 * If there is already an exception/interrupt pending
1605 * then defer the NMI until after that.
1606 */
1607 VCPU_CTR1(sc->vm, vcpu, "Cannot inject NMI due to "
1608 "eventinj %#lx", ctrl->eventinj);
1609
1610 /*
1611 * Use self-IPI to trigger a VM-exit as soon as
1612 * possible after the event injection is completed.
1613 *
1614 * This works only if the external interrupt exiting
1615 * is at a lower priority than the event injection.
1616 *
1617 * Although not explicitly specified in APMv2 the
1618 * relative priorities were verified empirically.
1619 */
1620 ipi_cpu(curcpu, IPI_AST); /* XXX vmm_ipinum? */
1621 } else {
1622 vm_nmi_clear(sc->vm, vcpu);
1623
1624 /* Inject NMI, vector number is not used */
1625 svm_eventinject(sc, vcpu, VMCB_EVENTINJ_TYPE_NMI,
1626 IDT_NMI, 0, false);
1627
1628 /* virtual NMI blocking is now in effect */
1629 enable_nmi_blocking(sc, vcpu);
1630
1631 VCPU_CTR0(sc->vm, vcpu, "Injecting vNMI");
1632 }
1633 }
1634
1635 extint_pending = vm_extint_pending(sc->vm, vcpu);
1636 if (!extint_pending) {
1637 if (!vlapic_pending_intr(vlapic, &vector))
1638 goto done;
1639 KASSERT(vector >= 16 && vector <= 255,
1640 ("invalid vector %d from local APIC", vector));
1641 } else {
1642 /* Ask the legacy pic for a vector to inject */
1643 vatpic_pending_intr(sc->vm, &vector);
1644 KASSERT(vector >= 0 && vector <= 255,
1645 ("invalid vector %d from INTR", vector));
1646 }
1647
1648 /*
1649 * If the guest has disabled interrupts or is in an interrupt shadow
1650 * then we cannot inject the pending interrupt.
1651 */
1652 if ((state->rflags & PSL_I) == 0) {
1653 VCPU_CTR2(sc->vm, vcpu, "Cannot inject vector %d due to "
1654 "rflags %#lx", vector, state->rflags);
1655 need_intr_window = 1;
1656 goto done;
1657 }
1658
1659 if (ctrl->intr_shadow) {
1660 VCPU_CTR1(sc->vm, vcpu, "Cannot inject vector %d due to "
1661 "interrupt shadow", vector);
1662 need_intr_window = 1;
1663 goto done;
1664 }
1665
1666 if (ctrl->eventinj & VMCB_EVENTINJ_VALID) {
1667 VCPU_CTR2(sc->vm, vcpu, "Cannot inject vector %d due to "
1668 "eventinj %#lx", vector, ctrl->eventinj);
1669 need_intr_window = 1;
1670 goto done;
1671 }
1672
1673 svm_eventinject(sc, vcpu, VMCB_EVENTINJ_TYPE_INTR, vector, 0, false);
1674
1675 if (!extint_pending) {
1676 vlapic_intr_accepted(vlapic, vector);
1677 } else {
1678 vm_extint_clear(sc->vm, vcpu);
1679 vatpic_intr_accepted(sc->vm, vector);
1680 }
1681
1682 /*
1683 * Force a VM-exit as soon as the vcpu is ready to accept another
1684 * interrupt. This is done because the PIC might have another vector
1685 * that it wants to inject. Also, if the APIC has a pending interrupt
1686 * that was preempted by the ExtInt then it allows us to inject the
1687 * APIC vector as soon as possible.
1688 */
1689 need_intr_window = 1;
1690 done:
1691 /*
1692 * The guest can modify the TPR by writing to %CR8. In guest mode
1693 * the processor reflects this write to V_TPR without hypervisor
1694 * intervention.
1695 *
1696 * The guest can also modify the TPR by writing to it via the memory
1697 * mapped APIC page. In this case, the write will be emulated by the
1698 * hypervisor. For this reason V_TPR must be updated before every
1699 * VMRUN.
1700 */
1701 v_tpr = vlapic_get_cr8(vlapic);
1702 KASSERT(v_tpr <= 15, ("invalid v_tpr %#x", v_tpr));
1703 if (ctrl->v_tpr != v_tpr) {
1704 VCPU_CTR2(sc->vm, vcpu, "VMCB V_TPR changed from %#x to %#x",
1705 ctrl->v_tpr, v_tpr);
1706 ctrl->v_tpr = v_tpr;
1707 svm_set_dirty(sc, vcpu, VMCB_CACHE_TPR);
1708 }
1709
1710 if (need_intr_window) {
1711 /*
1712 * We use V_IRQ in conjunction with the VINTR intercept to
1713 * trap into the hypervisor as soon as a virtual interrupt
1714 * can be delivered.
1715 *
1716 * Since injected events are not subject to intercept checks
1717 * we need to ensure that the V_IRQ is not actually going to
1718 * be delivered on VM entry. The KASSERT below enforces this.
1719 */
1720 KASSERT((ctrl->eventinj & VMCB_EVENTINJ_VALID) != 0 ||
1721 (state->rflags & PSL_I) == 0 || ctrl->intr_shadow,
1722 ("Bogus intr_window_exiting: eventinj (%#lx), "
1723 "intr_shadow (%u), rflags (%#lx)",
1724 ctrl->eventinj, ctrl->intr_shadow, state->rflags));
1725 enable_intr_window_exiting(sc, vcpu);
1726 } else {
1727 disable_intr_window_exiting(sc, vcpu);
1728 }
1729 }
1730
1731 static __inline void
restore_host_tss(void)1732 restore_host_tss(void)
1733 {
1734 struct system_segment_descriptor *tss_sd;
1735
1736 /*
1737 * The TSS descriptor was in use prior to launching the guest so it
1738 * has been marked busy.
1739 *
1740 * 'ltr' requires the descriptor to be marked available so change the
1741 * type to "64-bit available TSS".
1742 */
1743 tss_sd = PCPU_GET(tss);
1744 tss_sd->sd_type = SDT_SYSTSS;
1745 ltr(GSEL(GPROC0_SEL, SEL_KPL));
1746 }
1747
1748 static void
check_asid(struct svm_softc * sc,int vcpuid,pmap_t pmap,u_int thiscpu)1749 check_asid(struct svm_softc *sc, int vcpuid, pmap_t pmap, u_int thiscpu)
1750 {
1751 struct svm_vcpu *vcpustate;
1752 struct vmcb_ctrl *ctrl;
1753 long eptgen;
1754 bool alloc_asid;
1755
1756 KASSERT(CPU_ISSET(thiscpu, &pmap->pm_active), ("%s: nested pmap not "
1757 "active on cpu %u", __func__, thiscpu));
1758
1759 vcpustate = svm_get_vcpu(sc, vcpuid);
1760 ctrl = svm_get_vmcb_ctrl(sc, vcpuid);
1761
1762 /*
1763 * The TLB entries associated with the vcpu's ASID are not valid
1764 * if either of the following conditions is true:
1765 *
1766 * 1. The vcpu's ASID generation is different than the host cpu's
1767 * ASID generation. This happens when the vcpu migrates to a new
1768 * host cpu. It can also happen when the number of vcpus executing
1769 * on a host cpu is greater than the number of ASIDs available.
1770 *
1771 * 2. The pmap generation number is different than the value cached in
1772 * the 'vcpustate'. This happens when the host invalidates pages
1773 * belonging to the guest.
1774 *
1775 * asidgen eptgen Action
1776 * mismatch mismatch
1777 * 0 0 (a)
1778 * 0 1 (b1) or (b2)
1779 * 1 0 (c)
1780 * 1 1 (d)
1781 *
1782 * (a) There is no mismatch in eptgen or ASID generation and therefore
1783 * no further action is needed.
1784 *
1785 * (b1) If the cpu supports FlushByAsid then the vcpu's ASID is
1786 * retained and the TLB entries associated with this ASID
1787 * are flushed by VMRUN.
1788 *
1789 * (b2) If the cpu does not support FlushByAsid then a new ASID is
1790 * allocated.
1791 *
1792 * (c) A new ASID is allocated.
1793 *
1794 * (d) A new ASID is allocated.
1795 */
1796
1797 alloc_asid = false;
1798 eptgen = pmap->pm_eptgen;
1799 ctrl->tlb_ctrl = VMCB_TLB_FLUSH_NOTHING;
1800
1801 if (vcpustate->asid.gen != asid[thiscpu].gen) {
1802 alloc_asid = true; /* (c) and (d) */
1803 } else if (vcpustate->eptgen != eptgen) {
1804 if (flush_by_asid())
1805 ctrl->tlb_ctrl = VMCB_TLB_FLUSH_GUEST; /* (b1) */
1806 else
1807 alloc_asid = true; /* (b2) */
1808 } else {
1809 /*
1810 * This is the common case (a).
1811 */
1812 KASSERT(!alloc_asid, ("ASID allocation not necessary"));
1813 KASSERT(ctrl->tlb_ctrl == VMCB_TLB_FLUSH_NOTHING,
1814 ("Invalid VMCB tlb_ctrl: %#x", ctrl->tlb_ctrl));
1815 }
1816
1817 if (alloc_asid) {
1818 if (++asid[thiscpu].num >= nasid) {
1819 asid[thiscpu].num = 1;
1820 if (++asid[thiscpu].gen == 0)
1821 asid[thiscpu].gen = 1;
1822 /*
1823 * If this cpu does not support "flush-by-asid"
1824 * then flush the entire TLB on a generation
1825 * bump. Subsequent ASID allocation in this
1826 * generation can be done without a TLB flush.
1827 */
1828 if (!flush_by_asid())
1829 ctrl->tlb_ctrl = VMCB_TLB_FLUSH_ALL;
1830 }
1831 vcpustate->asid.gen = asid[thiscpu].gen;
1832 vcpustate->asid.num = asid[thiscpu].num;
1833
1834 ctrl->asid = vcpustate->asid.num;
1835 svm_set_dirty(sc, vcpuid, VMCB_CACHE_ASID);
1836 /*
1837 * If this cpu supports "flush-by-asid" then the TLB
1838 * was not flushed after the generation bump. The TLB
1839 * is flushed selectively after every new ASID allocation.
1840 */
1841 if (flush_by_asid())
1842 ctrl->tlb_ctrl = VMCB_TLB_FLUSH_GUEST;
1843 }
1844 vcpustate->eptgen = eptgen;
1845
1846 KASSERT(ctrl->asid != 0, ("Guest ASID must be non-zero"));
1847 KASSERT(ctrl->asid == vcpustate->asid.num,
1848 ("ASID mismatch: %u/%u", ctrl->asid, vcpustate->asid.num));
1849 }
1850
1851 static __inline void
disable_gintr(void)1852 disable_gintr(void)
1853 {
1854
1855 __asm __volatile("clgi");
1856 }
1857
1858 static __inline void
enable_gintr(void)1859 enable_gintr(void)
1860 {
1861
1862 __asm __volatile("stgi");
1863 }
1864
1865 /*
1866 * Start vcpu with specified RIP.
1867 */
1868 static int
svm_vmrun(void * arg,int vcpu,register_t rip,pmap_t pmap,struct vm_eventinfo * evinfo)1869 svm_vmrun(void *arg, int vcpu, register_t rip, pmap_t pmap,
1870 struct vm_eventinfo *evinfo)
1871 {
1872 struct svm_regctx *gctx;
1873 struct svm_softc *svm_sc;
1874 struct svm_vcpu *vcpustate;
1875 struct vmcb_state *state;
1876 struct vmcb_ctrl *ctrl;
1877 struct vm_exit *vmexit;
1878 struct vlapic *vlapic;
1879 struct vm *vm;
1880 uint64_t vmcb_pa;
1881 int handled;
1882
1883 svm_sc = arg;
1884 vm = svm_sc->vm;
1885
1886 vcpustate = svm_get_vcpu(svm_sc, vcpu);
1887 state = svm_get_vmcb_state(svm_sc, vcpu);
1888 ctrl = svm_get_vmcb_ctrl(svm_sc, vcpu);
1889 vmexit = vm_exitinfo(vm, vcpu);
1890 vlapic = vm_lapic(vm, vcpu);
1891
1892 gctx = svm_get_guest_regctx(svm_sc, vcpu);
1893 vmcb_pa = svm_sc->vcpu[vcpu].vmcb_pa;
1894
1895 if (vcpustate->lastcpu != curcpu) {
1896 /*
1897 * Force new ASID allocation by invalidating the generation.
1898 */
1899 vcpustate->asid.gen = 0;
1900
1901 /*
1902 * Invalidate the VMCB state cache by marking all fields dirty.
1903 */
1904 svm_set_dirty(svm_sc, vcpu, 0xffffffff);
1905
1906 /*
1907 * XXX
1908 * Setting 'vcpustate->lastcpu' here is bit premature because
1909 * we may return from this function without actually executing
1910 * the VMRUN instruction. This could happen if a rendezvous
1911 * or an AST is pending on the first time through the loop.
1912 *
1913 * This works for now but any new side-effects of vcpu
1914 * migration should take this case into account.
1915 */
1916 vcpustate->lastcpu = curcpu;
1917 vmm_stat_incr(vm, vcpu, VCPU_MIGRATIONS, 1);
1918 }
1919
1920 svm_msr_guest_enter(svm_sc, vcpu);
1921
1922 /* Update Guest RIP */
1923 state->rip = rip;
1924
1925 do {
1926 /*
1927 * Disable global interrupts to guarantee atomicity during
1928 * loading of guest state. This includes not only the state
1929 * loaded by the "vmrun" instruction but also software state
1930 * maintained by the hypervisor: suspended and rendezvous
1931 * state, NPT generation number, vlapic interrupts etc.
1932 */
1933 disable_gintr();
1934
1935 if (vcpu_suspended(evinfo)) {
1936 enable_gintr();
1937 vm_exit_suspended(vm, vcpu, state->rip);
1938 break;
1939 }
1940
1941 if (vcpu_rendezvous_pending(evinfo)) {
1942 enable_gintr();
1943 vm_exit_rendezvous(vm, vcpu, state->rip);
1944 break;
1945 }
1946
1947 if (vcpu_reqidle(evinfo)) {
1948 enable_gintr();
1949 vm_exit_reqidle(vm, vcpu, state->rip);
1950 break;
1951 }
1952
1953 /* We are asked to give the cpu by scheduler. */
1954 if (vcpu_should_yield(vm, vcpu)) {
1955 enable_gintr();
1956 vm_exit_astpending(vm, vcpu, state->rip);
1957 break;
1958 }
1959
1960 svm_inj_interrupts(svm_sc, vcpu, vlapic);
1961
1962 /* Activate the nested pmap on 'curcpu' */
1963 CPU_SET_ATOMIC_ACQ(curcpu, &pmap->pm_active);
1964
1965 /*
1966 * Check the pmap generation and the ASID generation to
1967 * ensure that the vcpu does not use stale TLB mappings.
1968 */
1969 check_asid(svm_sc, vcpu, pmap, curcpu);
1970
1971 ctrl->vmcb_clean = vmcb_clean & ~vcpustate->dirty;
1972 vcpustate->dirty = 0;
1973 VCPU_CTR1(vm, vcpu, "vmcb clean %#x", ctrl->vmcb_clean);
1974
1975 /* Launch Virtual Machine. */
1976 VCPU_CTR1(vm, vcpu, "Resume execution at %#lx", state->rip);
1977 svm_launch(vmcb_pa, gctx, &__pcpu[curcpu]);
1978
1979 CPU_CLR_ATOMIC(curcpu, &pmap->pm_active);
1980
1981 /*
1982 * The host GDTR and IDTR is saved by VMRUN and restored
1983 * automatically on #VMEXIT. However, the host TSS needs
1984 * to be restored explicitly.
1985 */
1986 restore_host_tss();
1987
1988 /* #VMEXIT disables interrupts so re-enable them here. */
1989 enable_gintr();
1990
1991 /* Update 'nextrip' */
1992 vcpustate->nextrip = state->rip;
1993
1994 /* Handle #VMEXIT and if required return to user space. */
1995 handled = svm_vmexit(svm_sc, vcpu, vmexit);
1996 } while (handled);
1997
1998 svm_msr_guest_exit(svm_sc, vcpu);
1999
2000 return (0);
2001 }
2002
2003 static void
svm_vmcleanup(void * arg)2004 svm_vmcleanup(void *arg)
2005 {
2006 struct svm_softc *sc = arg;
2007
2008 contigfree(sc->iopm_bitmap, SVM_IO_BITMAP_SIZE, M_SVM);
2009 contigfree(sc->msr_bitmap, SVM_MSR_BITMAP_SIZE, M_SVM);
2010 free(sc, M_SVM);
2011 }
2012
2013 static register_t *
swctx_regptr(struct svm_regctx * regctx,int reg)2014 swctx_regptr(struct svm_regctx *regctx, int reg)
2015 {
2016
2017 switch (reg) {
2018 case VM_REG_GUEST_RBX:
2019 return (®ctx->sctx_rbx);
2020 case VM_REG_GUEST_RCX:
2021 return (®ctx->sctx_rcx);
2022 case VM_REG_GUEST_RDX:
2023 return (®ctx->sctx_rdx);
2024 case VM_REG_GUEST_RDI:
2025 return (®ctx->sctx_rdi);
2026 case VM_REG_GUEST_RSI:
2027 return (®ctx->sctx_rsi);
2028 case VM_REG_GUEST_RBP:
2029 return (®ctx->sctx_rbp);
2030 case VM_REG_GUEST_R8:
2031 return (®ctx->sctx_r8);
2032 case VM_REG_GUEST_R9:
2033 return (®ctx->sctx_r9);
2034 case VM_REG_GUEST_R10:
2035 return (®ctx->sctx_r10);
2036 case VM_REG_GUEST_R11:
2037 return (®ctx->sctx_r11);
2038 case VM_REG_GUEST_R12:
2039 return (®ctx->sctx_r12);
2040 case VM_REG_GUEST_R13:
2041 return (®ctx->sctx_r13);
2042 case VM_REG_GUEST_R14:
2043 return (®ctx->sctx_r14);
2044 case VM_REG_GUEST_R15:
2045 return (®ctx->sctx_r15);
2046 default:
2047 return (NULL);
2048 }
2049 }
2050
2051 static int
svm_getreg(void * arg,int vcpu,int ident,uint64_t * val)2052 svm_getreg(void *arg, int vcpu, int ident, uint64_t *val)
2053 {
2054 struct svm_softc *svm_sc;
2055 register_t *reg;
2056
2057 svm_sc = arg;
2058
2059 if (ident == VM_REG_GUEST_INTR_SHADOW) {
2060 return (svm_get_intr_shadow(svm_sc, vcpu, val));
2061 }
2062
2063 if (vmcb_read(svm_sc, vcpu, ident, val) == 0) {
2064 return (0);
2065 }
2066
2067 reg = swctx_regptr(svm_get_guest_regctx(svm_sc, vcpu), ident);
2068
2069 if (reg != NULL) {
2070 *val = *reg;
2071 return (0);
2072 }
2073
2074 VCPU_CTR1(svm_sc->vm, vcpu, "svm_getreg: unknown register %#x", ident);
2075 return (EINVAL);
2076 }
2077
2078 static int
svm_setreg(void * arg,int vcpu,int ident,uint64_t val)2079 svm_setreg(void *arg, int vcpu, int ident, uint64_t val)
2080 {
2081 struct svm_softc *svm_sc;
2082 register_t *reg;
2083
2084 svm_sc = arg;
2085
2086 if (ident == VM_REG_GUEST_INTR_SHADOW) {
2087 return (svm_modify_intr_shadow(svm_sc, vcpu, val));
2088 }
2089
2090 if (vmcb_write(svm_sc, vcpu, ident, val) == 0) {
2091 return (0);
2092 }
2093
2094 reg = swctx_regptr(svm_get_guest_regctx(svm_sc, vcpu), ident);
2095
2096 if (reg != NULL) {
2097 *reg = val;
2098 return (0);
2099 }
2100
2101 /*
2102 * XXX deal with CR3 and invalidate TLB entries tagged with the
2103 * vcpu's ASID. This needs to be treated differently depending on
2104 * whether 'running' is true/false.
2105 */
2106
2107 VCPU_CTR1(svm_sc->vm, vcpu, "svm_setreg: unknown register %#x", ident);
2108 return (EINVAL);
2109 }
2110
2111 static int
svm_setcap(void * arg,int vcpu,int type,int val)2112 svm_setcap(void *arg, int vcpu, int type, int val)
2113 {
2114 struct svm_softc *sc;
2115 int error;
2116
2117 sc = arg;
2118 error = 0;
2119 switch (type) {
2120 case VM_CAP_HALT_EXIT:
2121 svm_set_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
2122 VMCB_INTCPT_HLT, val);
2123 break;
2124 case VM_CAP_PAUSE_EXIT:
2125 svm_set_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
2126 VMCB_INTCPT_PAUSE, val);
2127 break;
2128 case VM_CAP_UNRESTRICTED_GUEST:
2129 /* Unrestricted guest execution cannot be disabled in SVM */
2130 if (val == 0)
2131 error = EINVAL;
2132 break;
2133 default:
2134 error = ENOENT;
2135 break;
2136 }
2137 return (error);
2138 }
2139
2140 static int
svm_getcap(void * arg,int vcpu,int type,int * retval)2141 svm_getcap(void *arg, int vcpu, int type, int *retval)
2142 {
2143 struct svm_softc *sc;
2144 int error;
2145
2146 sc = arg;
2147 error = 0;
2148
2149 switch (type) {
2150 case VM_CAP_HALT_EXIT:
2151 *retval = svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
2152 VMCB_INTCPT_HLT);
2153 break;
2154 case VM_CAP_PAUSE_EXIT:
2155 *retval = svm_get_intercept(sc, vcpu, VMCB_CTRL1_INTCPT,
2156 VMCB_INTCPT_PAUSE);
2157 break;
2158 case VM_CAP_UNRESTRICTED_GUEST:
2159 *retval = 1; /* unrestricted guest is always enabled */
2160 break;
2161 default:
2162 error = ENOENT;
2163 break;
2164 }
2165 return (error);
2166 }
2167
2168 static struct vlapic *
svm_vlapic_init(void * arg,int vcpuid)2169 svm_vlapic_init(void *arg, int vcpuid)
2170 {
2171 struct svm_softc *svm_sc;
2172 struct vlapic *vlapic;
2173
2174 svm_sc = arg;
2175 vlapic = malloc(sizeof(struct vlapic), M_SVM_VLAPIC, M_WAITOK | M_ZERO);
2176 vlapic->vm = svm_sc->vm;
2177 vlapic->vcpuid = vcpuid;
2178 vlapic->apic_page = (struct LAPIC *)&svm_sc->apic_page[vcpuid];
2179
2180 vlapic_init(vlapic);
2181
2182 return (vlapic);
2183 }
2184
2185 static void
svm_vlapic_cleanup(void * arg,struct vlapic * vlapic)2186 svm_vlapic_cleanup(void *arg, struct vlapic *vlapic)
2187 {
2188
2189 vlapic_cleanup(vlapic);
2190 free(vlapic, M_SVM_VLAPIC);
2191 }
2192
2193 struct vmm_ops vmm_ops_amd = {
2194 svm_init,
2195 svm_cleanup,
2196 svm_restore,
2197 svm_vminit,
2198 svm_vmrun,
2199 svm_vmcleanup,
2200 svm_getreg,
2201 svm_setreg,
2202 vmcb_getdesc,
2203 vmcb_setdesc,
2204 svm_getcap,
2205 svm_setcap,
2206 svm_npt_alloc,
2207 svm_npt_free,
2208 svm_vlapic_init,
2209 svm_vlapic_cleanup
2210 };
2211