1 /*
2 * Kernel-based Virtual Machine driver for Linux
3 * cpuid support routines
4 *
5 * derived from arch/x86/kvm/x86.c
6 *
7 * Copyright 2011 Red Hat, Inc. and/or its affiliates.
8 * Copyright IBM Corporation, 2008
9 *
10 * This work is licensed under the terms of the GNU GPL, version 2. See
11 * the COPYING file in the top-level directory.
12 *
13 */
14
15 #include <linux/kvm_host.h>
16 #include <linux/module.h>
17 #include <linux/vmalloc.h>
18 #include <linux/uaccess.h>
19 #include <asm/fpu/internal.h> /* For use_eager_fpu. Ugh! */
20 #include <asm/user.h>
21 #include <asm/fpu/xstate.h>
22 #include "cpuid.h"
23 #include "lapic.h"
24 #include "mmu.h"
25 #include "trace.h"
26 #include "pmu.h"
27
xstate_required_size(u64 xstate_bv,bool compacted)28 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
29 {
30 int feature_bit = 0;
31 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
32
33 xstate_bv &= XFEATURE_MASK_EXTEND;
34 while (xstate_bv) {
35 if (xstate_bv & 0x1) {
36 u32 eax, ebx, ecx, edx, offset;
37 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
38 offset = compacted ? ret : ebx;
39 ret = max(ret, offset + eax);
40 }
41
42 xstate_bv >>= 1;
43 feature_bit++;
44 }
45
46 return ret;
47 }
48
kvm_supported_xcr0(void)49 u64 kvm_supported_xcr0(void)
50 {
51 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
52
53 if (!kvm_x86_ops->mpx_supported())
54 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
55
56 return xcr0;
57 }
58
59 #define F(x) bit(X86_FEATURE_##x)
60
kvm_update_cpuid(struct kvm_vcpu * vcpu)61 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
62 {
63 struct kvm_cpuid_entry2 *best;
64 struct kvm_lapic *apic = vcpu->arch.apic;
65
66 best = kvm_find_cpuid_entry(vcpu, 1, 0);
67 if (!best)
68 return 0;
69
70 /* Update OSXSAVE bit */
71 if (cpu_has_xsave && best->function == 0x1) {
72 best->ecx &= ~F(OSXSAVE);
73 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
74 best->ecx |= F(OSXSAVE);
75 }
76
77 if (apic) {
78 if (best->ecx & F(TSC_DEADLINE_TIMER))
79 apic->lapic_timer.timer_mode_mask = 3 << 17;
80 else
81 apic->lapic_timer.timer_mode_mask = 1 << 17;
82 }
83
84 best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
85 if (!best) {
86 vcpu->arch.guest_supported_xcr0 = 0;
87 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
88 } else {
89 vcpu->arch.guest_supported_xcr0 =
90 (best->eax | ((u64)best->edx << 32)) &
91 kvm_supported_xcr0();
92 vcpu->arch.guest_xstate_size = best->ebx =
93 xstate_required_size(vcpu->arch.xcr0, false);
94 }
95
96 best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
97 if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
98 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
99
100 vcpu->arch.eager_fpu = use_eager_fpu() || guest_cpuid_has_mpx(vcpu);
101 if (vcpu->arch.eager_fpu)
102 kvm_x86_ops->fpu_activate(vcpu);
103
104 /*
105 * The existing code assumes virtual address is 48-bit in the canonical
106 * address checks; exit if it is ever changed.
107 */
108 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
109 if (best && ((best->eax & 0xff00) >> 8) != 48 &&
110 ((best->eax & 0xff00) >> 8) != 0)
111 return -EINVAL;
112
113 /* Update physical-address width */
114 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
115
116 kvm_pmu_refresh(vcpu);
117 return 0;
118 }
119
is_efer_nx(void)120 static int is_efer_nx(void)
121 {
122 unsigned long long efer = 0;
123
124 rdmsrl_safe(MSR_EFER, &efer);
125 return efer & EFER_NX;
126 }
127
cpuid_fix_nx_cap(struct kvm_vcpu * vcpu)128 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
129 {
130 int i;
131 struct kvm_cpuid_entry2 *e, *entry;
132
133 entry = NULL;
134 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
135 e = &vcpu->arch.cpuid_entries[i];
136 if (e->function == 0x80000001) {
137 entry = e;
138 break;
139 }
140 }
141 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
142 entry->edx &= ~F(NX);
143 printk(KERN_INFO "kvm: guest NX capability removed\n");
144 }
145 }
146
cpuid_query_maxphyaddr(struct kvm_vcpu * vcpu)147 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
148 {
149 struct kvm_cpuid_entry2 *best;
150
151 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
152 if (!best || best->eax < 0x80000008)
153 goto not_found;
154 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
155 if (best)
156 return best->eax & 0xff;
157 not_found:
158 return 36;
159 }
160 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
161
162 /* when an old userspace process fills a new kernel module */
kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu * vcpu,struct kvm_cpuid * cpuid,struct kvm_cpuid_entry __user * entries)163 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
164 struct kvm_cpuid *cpuid,
165 struct kvm_cpuid_entry __user *entries)
166 {
167 int r, i;
168 struct kvm_cpuid_entry *cpuid_entries;
169
170 r = -E2BIG;
171 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
172 goto out;
173 r = -ENOMEM;
174 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
175 if (!cpuid_entries)
176 goto out;
177 r = -EFAULT;
178 if (copy_from_user(cpuid_entries, entries,
179 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
180 goto out_free;
181 for (i = 0; i < cpuid->nent; i++) {
182 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
183 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
184 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
185 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
186 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
187 vcpu->arch.cpuid_entries[i].index = 0;
188 vcpu->arch.cpuid_entries[i].flags = 0;
189 vcpu->arch.cpuid_entries[i].padding[0] = 0;
190 vcpu->arch.cpuid_entries[i].padding[1] = 0;
191 vcpu->arch.cpuid_entries[i].padding[2] = 0;
192 }
193 vcpu->arch.cpuid_nent = cpuid->nent;
194 cpuid_fix_nx_cap(vcpu);
195 kvm_apic_set_version(vcpu);
196 kvm_x86_ops->cpuid_update(vcpu);
197 r = kvm_update_cpuid(vcpu);
198
199 out_free:
200 vfree(cpuid_entries);
201 out:
202 return r;
203 }
204
kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu * vcpu,struct kvm_cpuid2 * cpuid,struct kvm_cpuid_entry2 __user * entries)205 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
206 struct kvm_cpuid2 *cpuid,
207 struct kvm_cpuid_entry2 __user *entries)
208 {
209 int r;
210
211 r = -E2BIG;
212 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
213 goto out;
214 r = -EFAULT;
215 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
216 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
217 goto out;
218 vcpu->arch.cpuid_nent = cpuid->nent;
219 kvm_apic_set_version(vcpu);
220 kvm_x86_ops->cpuid_update(vcpu);
221 r = kvm_update_cpuid(vcpu);
222 out:
223 return r;
224 }
225
kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu * vcpu,struct kvm_cpuid2 * cpuid,struct kvm_cpuid_entry2 __user * entries)226 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
227 struct kvm_cpuid2 *cpuid,
228 struct kvm_cpuid_entry2 __user *entries)
229 {
230 int r;
231
232 r = -E2BIG;
233 if (cpuid->nent < vcpu->arch.cpuid_nent)
234 goto out;
235 r = -EFAULT;
236 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
237 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
238 goto out;
239 return 0;
240
241 out:
242 cpuid->nent = vcpu->arch.cpuid_nent;
243 return r;
244 }
245
cpuid_mask(u32 * word,int wordnum)246 static void cpuid_mask(u32 *word, int wordnum)
247 {
248 *word &= boot_cpu_data.x86_capability[wordnum];
249 }
250
do_cpuid_1_ent(struct kvm_cpuid_entry2 * entry,u32 function,u32 index)251 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
252 u32 index)
253 {
254 entry->function = function;
255 entry->index = index;
256 cpuid_count(entry->function, entry->index,
257 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
258 entry->flags = 0;
259 }
260
__do_cpuid_ent_emulated(struct kvm_cpuid_entry2 * entry,u32 func,u32 index,int * nent,int maxnent)261 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
262 u32 func, u32 index, int *nent, int maxnent)
263 {
264 switch (func) {
265 case 0:
266 entry->eax = 1; /* only one leaf currently */
267 ++*nent;
268 break;
269 case 1:
270 entry->ecx = F(MOVBE);
271 ++*nent;
272 break;
273 default:
274 break;
275 }
276
277 entry->function = func;
278 entry->index = index;
279
280 return 0;
281 }
282
__do_cpuid_ent(struct kvm_cpuid_entry2 * entry,u32 function,u32 index,int * nent,int maxnent)283 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
284 u32 index, int *nent, int maxnent)
285 {
286 int r;
287 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
288 #ifdef CONFIG_X86_64
289 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
290 ? F(GBPAGES) : 0;
291 unsigned f_lm = F(LM);
292 #else
293 unsigned f_gbpages = 0;
294 unsigned f_lm = 0;
295 #endif
296 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
297 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
298 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0;
299 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
300
301 /* cpuid 1.edx */
302 const u32 kvm_supported_word0_x86_features =
303 F(FPU) | F(VME) | F(DE) | F(PSE) |
304 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
305 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
306 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
307 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
308 0 /* Reserved, DS, ACPI */ | F(MMX) |
309 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
310 0 /* HTT, TM, Reserved, PBE */;
311 /* cpuid 0x80000001.edx */
312 const u32 kvm_supported_word1_x86_features =
313 F(FPU) | F(VME) | F(DE) | F(PSE) |
314 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
315 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
316 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
317 F(PAT) | F(PSE36) | 0 /* Reserved */ |
318 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
319 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
320 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
321 /* cpuid 1.ecx */
322 const u32 kvm_supported_word4_x86_features =
323 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
324 * but *not* advertised to guests via CPUID ! */
325 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
326 0 /* DS-CPL, VMX, SMX, EST */ |
327 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
328 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
329 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
330 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
331 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
332 F(F16C) | F(RDRAND);
333 /* cpuid 0x80000001.ecx */
334 const u32 kvm_supported_word6_x86_features =
335 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
336 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
337 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
338 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
339
340 /* cpuid 0xC0000001.edx */
341 const u32 kvm_supported_word5_x86_features =
342 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
343 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
344 F(PMM) | F(PMM_EN);
345
346 /* cpuid 7.0.ebx */
347 const u32 kvm_supported_word9_x86_features =
348 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
349 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
350 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
351 F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(PCOMMIT);
352
353 /* cpuid 0xD.1.eax */
354 const u32 kvm_supported_word10_x86_features =
355 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
356
357 /* all calls to cpuid_count() should be made on the same cpu */
358 get_cpu();
359
360 r = -E2BIG;
361
362 if (*nent >= maxnent)
363 goto out;
364
365 do_cpuid_1_ent(entry, function, index);
366 ++*nent;
367
368 switch (function) {
369 case 0:
370 entry->eax = min(entry->eax, (u32)0xd);
371 break;
372 case 1:
373 entry->edx &= kvm_supported_word0_x86_features;
374 cpuid_mask(&entry->edx, 0);
375 entry->ecx &= kvm_supported_word4_x86_features;
376 cpuid_mask(&entry->ecx, 4);
377 /* we support x2apic emulation even if host does not support
378 * it since we emulate x2apic in software */
379 entry->ecx |= F(X2APIC);
380 break;
381 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
382 * may return different values. This forces us to get_cpu() before
383 * issuing the first command, and also to emulate this annoying behavior
384 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
385 case 2: {
386 int t, times = entry->eax & 0xff;
387
388 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
389 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
390 for (t = 1; t < times; ++t) {
391 if (*nent >= maxnent)
392 goto out;
393
394 do_cpuid_1_ent(&entry[t], function, 0);
395 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
396 ++*nent;
397 }
398 break;
399 }
400 /* function 4 has additional index. */
401 case 4: {
402 int i, cache_type;
403
404 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
405 /* read more entries until cache_type is zero */
406 for (i = 1; ; ++i) {
407 if (*nent >= maxnent)
408 goto out;
409
410 cache_type = entry[i - 1].eax & 0x1f;
411 if (!cache_type)
412 break;
413 do_cpuid_1_ent(&entry[i], function, i);
414 entry[i].flags |=
415 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
416 ++*nent;
417 }
418 break;
419 }
420 case 6: /* Thermal management */
421 entry->eax = 0x4; /* allow ARAT */
422 entry->ebx = 0;
423 entry->ecx = 0;
424 entry->edx = 0;
425 break;
426 case 7: {
427 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
428 /* Mask ebx against host capability word 9 */
429 if (index == 0) {
430 entry->ebx &= kvm_supported_word9_x86_features;
431 cpuid_mask(&entry->ebx, 9);
432 // TSC_ADJUST is emulated
433 entry->ebx |= F(TSC_ADJUST);
434 } else
435 entry->ebx = 0;
436 entry->eax = 0;
437 entry->ecx = 0;
438 entry->edx = 0;
439 break;
440 }
441 case 9:
442 break;
443 case 0xa: { /* Architectural Performance Monitoring */
444 struct x86_pmu_capability cap;
445 union cpuid10_eax eax;
446 union cpuid10_edx edx;
447
448 perf_get_x86_pmu_capability(&cap);
449
450 /*
451 * Only support guest architectural pmu on a host
452 * with architectural pmu.
453 */
454 if (!cap.version)
455 memset(&cap, 0, sizeof(cap));
456
457 eax.split.version_id = min(cap.version, 2);
458 eax.split.num_counters = cap.num_counters_gp;
459 eax.split.bit_width = cap.bit_width_gp;
460 eax.split.mask_length = cap.events_mask_len;
461
462 edx.split.num_counters_fixed = cap.num_counters_fixed;
463 edx.split.bit_width_fixed = cap.bit_width_fixed;
464 edx.split.reserved = 0;
465
466 entry->eax = eax.full;
467 entry->ebx = cap.events_mask;
468 entry->ecx = 0;
469 entry->edx = edx.full;
470 break;
471 }
472 /* function 0xb has additional index. */
473 case 0xb: {
474 int i, level_type;
475
476 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
477 /* read more entries until level_type is zero */
478 for (i = 1; ; ++i) {
479 if (*nent >= maxnent)
480 goto out;
481
482 level_type = entry[i - 1].ecx & 0xff00;
483 if (!level_type)
484 break;
485 do_cpuid_1_ent(&entry[i], function, i);
486 entry[i].flags |=
487 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
488 ++*nent;
489 }
490 break;
491 }
492 case 0xd: {
493 int idx, i;
494 u64 supported = kvm_supported_xcr0();
495
496 entry->eax &= supported;
497 entry->ebx = xstate_required_size(supported, false);
498 entry->ecx = entry->ebx;
499 entry->edx &= supported >> 32;
500 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
501 if (!supported)
502 break;
503
504 for (idx = 1, i = 1; idx < 64; ++idx) {
505 u64 mask = ((u64)1 << idx);
506 if (*nent >= maxnent)
507 goto out;
508
509 do_cpuid_1_ent(&entry[i], function, idx);
510 if (idx == 1) {
511 entry[i].eax &= kvm_supported_word10_x86_features;
512 cpuid_mask(&entry[i].eax, 10);
513 entry[i].ebx = 0;
514 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
515 entry[i].ebx =
516 xstate_required_size(supported,
517 true);
518 } else {
519 if (entry[i].eax == 0 || !(supported & mask))
520 continue;
521 if (WARN_ON_ONCE(entry[i].ecx & 1))
522 continue;
523 }
524 entry[i].ecx = 0;
525 entry[i].edx = 0;
526 entry[i].flags |=
527 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
528 ++*nent;
529 ++i;
530 }
531 break;
532 }
533 case KVM_CPUID_SIGNATURE: {
534 static const char signature[12] = "KVMKVMKVM\0\0";
535 const u32 *sigptr = (const u32 *)signature;
536 entry->eax = KVM_CPUID_FEATURES;
537 entry->ebx = sigptr[0];
538 entry->ecx = sigptr[1];
539 entry->edx = sigptr[2];
540 break;
541 }
542 case KVM_CPUID_FEATURES:
543 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
544 (1 << KVM_FEATURE_NOP_IO_DELAY) |
545 (1 << KVM_FEATURE_CLOCKSOURCE2) |
546 (1 << KVM_FEATURE_ASYNC_PF) |
547 (1 << KVM_FEATURE_PV_EOI) |
548 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
549 (1 << KVM_FEATURE_PV_UNHALT);
550
551 if (sched_info_on())
552 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
553
554 entry->ebx = 0;
555 entry->ecx = 0;
556 entry->edx = 0;
557 break;
558 case 0x80000000:
559 entry->eax = min(entry->eax, 0x8000001a);
560 break;
561 case 0x80000001:
562 entry->edx &= kvm_supported_word1_x86_features;
563 cpuid_mask(&entry->edx, 1);
564 entry->ecx &= kvm_supported_word6_x86_features;
565 cpuid_mask(&entry->ecx, 6);
566 break;
567 case 0x80000007: /* Advanced power management */
568 /* invariant TSC is CPUID.80000007H:EDX[8] */
569 entry->edx &= (1 << 8);
570 /* mask against host */
571 entry->edx &= boot_cpu_data.x86_power;
572 entry->eax = entry->ebx = entry->ecx = 0;
573 break;
574 case 0x80000008: {
575 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
576 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
577 unsigned phys_as = entry->eax & 0xff;
578
579 if (!g_phys_as)
580 g_phys_as = phys_as;
581 entry->eax = g_phys_as | (virt_as << 8);
582 entry->ebx = entry->edx = 0;
583 break;
584 }
585 case 0x80000019:
586 entry->ecx = entry->edx = 0;
587 break;
588 case 0x8000001a:
589 break;
590 case 0x8000001d:
591 break;
592 /*Add support for Centaur's CPUID instruction*/
593 case 0xC0000000:
594 /*Just support up to 0xC0000004 now*/
595 entry->eax = min(entry->eax, 0xC0000004);
596 break;
597 case 0xC0000001:
598 entry->edx &= kvm_supported_word5_x86_features;
599 cpuid_mask(&entry->edx, 5);
600 break;
601 case 3: /* Processor serial number */
602 case 5: /* MONITOR/MWAIT */
603 case 0xC0000002:
604 case 0xC0000003:
605 case 0xC0000004:
606 default:
607 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
608 break;
609 }
610
611 kvm_x86_ops->set_supported_cpuid(function, entry);
612
613 r = 0;
614
615 out:
616 put_cpu();
617
618 return r;
619 }
620
do_cpuid_ent(struct kvm_cpuid_entry2 * entry,u32 func,u32 idx,int * nent,int maxnent,unsigned int type)621 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
622 u32 idx, int *nent, int maxnent, unsigned int type)
623 {
624 if (type == KVM_GET_EMULATED_CPUID)
625 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
626
627 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
628 }
629
630 #undef F
631
632 struct kvm_cpuid_param {
633 u32 func;
634 u32 idx;
635 bool has_leaf_count;
636 bool (*qualifier)(const struct kvm_cpuid_param *param);
637 };
638
is_centaur_cpu(const struct kvm_cpuid_param * param)639 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
640 {
641 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
642 }
643
sanity_check_entries(struct kvm_cpuid_entry2 __user * entries,__u32 num_entries,unsigned int ioctl_type)644 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
645 __u32 num_entries, unsigned int ioctl_type)
646 {
647 int i;
648 __u32 pad[3];
649
650 if (ioctl_type != KVM_GET_EMULATED_CPUID)
651 return false;
652
653 /*
654 * We want to make sure that ->padding is being passed clean from
655 * userspace in case we want to use it for something in the future.
656 *
657 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
658 * have to give ourselves satisfied only with the emulated side. /me
659 * sheds a tear.
660 */
661 for (i = 0; i < num_entries; i++) {
662 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
663 return true;
664
665 if (pad[0] || pad[1] || pad[2])
666 return true;
667 }
668 return false;
669 }
670
kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 * cpuid,struct kvm_cpuid_entry2 __user * entries,unsigned int type)671 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
672 struct kvm_cpuid_entry2 __user *entries,
673 unsigned int type)
674 {
675 struct kvm_cpuid_entry2 *cpuid_entries;
676 int limit, nent = 0, r = -E2BIG, i;
677 u32 func;
678 static const struct kvm_cpuid_param param[] = {
679 { .func = 0, .has_leaf_count = true },
680 { .func = 0x80000000, .has_leaf_count = true },
681 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
682 { .func = KVM_CPUID_SIGNATURE },
683 { .func = KVM_CPUID_FEATURES },
684 };
685
686 if (cpuid->nent < 1)
687 goto out;
688 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
689 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
690
691 if (sanity_check_entries(entries, cpuid->nent, type))
692 return -EINVAL;
693
694 r = -ENOMEM;
695 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
696 if (!cpuid_entries)
697 goto out;
698
699 r = 0;
700 for (i = 0; i < ARRAY_SIZE(param); i++) {
701 const struct kvm_cpuid_param *ent = ¶m[i];
702
703 if (ent->qualifier && !ent->qualifier(ent))
704 continue;
705
706 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
707 &nent, cpuid->nent, type);
708
709 if (r)
710 goto out_free;
711
712 if (!ent->has_leaf_count)
713 continue;
714
715 limit = cpuid_entries[nent - 1].eax;
716 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
717 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
718 &nent, cpuid->nent, type);
719
720 if (r)
721 goto out_free;
722 }
723
724 r = -EFAULT;
725 if (copy_to_user(entries, cpuid_entries,
726 nent * sizeof(struct kvm_cpuid_entry2)))
727 goto out_free;
728 cpuid->nent = nent;
729 r = 0;
730
731 out_free:
732 vfree(cpuid_entries);
733 out:
734 return r;
735 }
736
move_to_next_stateful_cpuid_entry(struct kvm_vcpu * vcpu,int i)737 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
738 {
739 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
740 int j, nent = vcpu->arch.cpuid_nent;
741
742 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
743 /* when no next entry is found, the current entry[i] is reselected */
744 for (j = i + 1; ; j = (j + 1) % nent) {
745 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
746 if (ej->function == e->function) {
747 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
748 return j;
749 }
750 }
751 return 0; /* silence gcc, even though control never reaches here */
752 }
753
754 /* find an entry with matching function, matching index (if needed), and that
755 * should be read next (if it's stateful) */
is_matching_cpuid_entry(struct kvm_cpuid_entry2 * e,u32 function,u32 index)756 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
757 u32 function, u32 index)
758 {
759 if (e->function != function)
760 return 0;
761 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
762 return 0;
763 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
764 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
765 return 0;
766 return 1;
767 }
768
kvm_find_cpuid_entry(struct kvm_vcpu * vcpu,u32 function,u32 index)769 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
770 u32 function, u32 index)
771 {
772 int i;
773 struct kvm_cpuid_entry2 *best = NULL;
774
775 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
776 struct kvm_cpuid_entry2 *e;
777
778 e = &vcpu->arch.cpuid_entries[i];
779 if (is_matching_cpuid_entry(e, function, index)) {
780 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
781 move_to_next_stateful_cpuid_entry(vcpu, i);
782 best = e;
783 break;
784 }
785 }
786 return best;
787 }
788 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
789
790 /*
791 * If no match is found, check whether we exceed the vCPU's limit
792 * and return the content of the highest valid _standard_ leaf instead.
793 * This is to satisfy the CPUID specification.
794 */
check_cpuid_limit(struct kvm_vcpu * vcpu,u32 function,u32 index)795 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
796 u32 function, u32 index)
797 {
798 struct kvm_cpuid_entry2 *maxlevel;
799
800 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
801 if (!maxlevel || maxlevel->eax >= function)
802 return NULL;
803 if (function & 0x80000000) {
804 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
805 if (!maxlevel)
806 return NULL;
807 }
808 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
809 }
810
kvm_cpuid(struct kvm_vcpu * vcpu,u32 * eax,u32 * ebx,u32 * ecx,u32 * edx)811 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
812 {
813 u32 function = *eax, index = *ecx;
814 struct kvm_cpuid_entry2 *best;
815
816 best = kvm_find_cpuid_entry(vcpu, function, index);
817
818 if (!best)
819 best = check_cpuid_limit(vcpu, function, index);
820
821 /*
822 * Perfmon not yet supported for L2 guest.
823 */
824 if (is_guest_mode(vcpu) && function == 0xa)
825 best = NULL;
826
827 if (best) {
828 *eax = best->eax;
829 *ebx = best->ebx;
830 *ecx = best->ecx;
831 *edx = best->edx;
832 } else
833 *eax = *ebx = *ecx = *edx = 0;
834 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
835 }
836 EXPORT_SYMBOL_GPL(kvm_cpuid);
837
kvm_emulate_cpuid(struct kvm_vcpu * vcpu)838 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
839 {
840 u32 function, eax, ebx, ecx, edx;
841
842 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
843 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
844 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
845 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
846 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
847 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
848 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
849 kvm_x86_ops->skip_emulated_instruction(vcpu);
850 }
851 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
852