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/export.h>
17 #include <linux/vmalloc.h>
18 #include <linux/uaccess.h>
19 #include <linux/sched/stat.h>
20
21 #include <asm/processor.h>
22 #include <asm/user.h>
23 #include <asm/fpu/xstate.h>
24 #include "cpuid.h"
25 #include "lapic.h"
26 #include "mmu.h"
27 #include "trace.h"
28 #include "pmu.h"
29
xstate_required_size(u64 xstate_bv,bool compacted)30 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
31 {
32 int feature_bit = 0;
33 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
34
35 xstate_bv &= XFEATURE_MASK_EXTEND;
36 while (xstate_bv) {
37 if (xstate_bv & 0x1) {
38 u32 eax, ebx, ecx, edx, offset;
39 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
40 offset = compacted ? ret : ebx;
41 ret = max(ret, offset + eax);
42 }
43
44 xstate_bv >>= 1;
45 feature_bit++;
46 }
47
48 return ret;
49 }
50
kvm_mpx_supported(void)51 bool kvm_mpx_supported(void)
52 {
53 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
54 && kvm_x86_ops->mpx_supported());
55 }
56 EXPORT_SYMBOL_GPL(kvm_mpx_supported);
57
kvm_supported_xcr0(void)58 u64 kvm_supported_xcr0(void)
59 {
60 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
61
62 if (!kvm_mpx_supported())
63 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
64
65 return xcr0;
66 }
67
68 #define F(x) bit(X86_FEATURE_##x)
69
70 /* For scattered features from cpufeatures.h; we currently expose none */
71 #define KF(x) bit(KVM_CPUID_BIT_##x)
72
kvm_update_cpuid(struct kvm_vcpu * vcpu)73 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
74 {
75 struct kvm_cpuid_entry2 *best;
76 struct kvm_lapic *apic = vcpu->arch.apic;
77
78 best = kvm_find_cpuid_entry(vcpu, 1, 0);
79 if (!best)
80 return 0;
81
82 /* Update OSXSAVE bit */
83 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
84 best->ecx &= ~F(OSXSAVE);
85 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
86 best->ecx |= F(OSXSAVE);
87 }
88
89 best->edx &= ~F(APIC);
90 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)
91 best->edx |= F(APIC);
92
93 if (apic) {
94 if (best->ecx & F(TSC_DEADLINE_TIMER))
95 apic->lapic_timer.timer_mode_mask = 3 << 17;
96 else
97 apic->lapic_timer.timer_mode_mask = 1 << 17;
98 }
99
100 best = kvm_find_cpuid_entry(vcpu, 7, 0);
101 if (best) {
102 /* Update OSPKE bit */
103 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
104 best->ecx &= ~F(OSPKE);
105 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
106 best->ecx |= F(OSPKE);
107 }
108 }
109
110 best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
111 if (!best) {
112 vcpu->arch.guest_supported_xcr0 = 0;
113 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
114 } else {
115 vcpu->arch.guest_supported_xcr0 =
116 (best->eax | ((u64)best->edx << 32)) &
117 kvm_supported_xcr0();
118 vcpu->arch.guest_xstate_size = best->ebx =
119 xstate_required_size(vcpu->arch.xcr0, false);
120 }
121
122 best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
123 if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
124 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
125
126 /*
127 * The existing code assumes virtual address is 48-bit or 57-bit in the
128 * canonical address checks; exit if it is ever changed.
129 */
130 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
131 if (best) {
132 int vaddr_bits = (best->eax & 0xff00) >> 8;
133
134 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
135 return -EINVAL;
136 }
137
138 /* Update physical-address width */
139 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
140 kvm_mmu_reset_context(vcpu);
141
142 kvm_pmu_refresh(vcpu);
143 return 0;
144 }
145
is_efer_nx(void)146 static int is_efer_nx(void)
147 {
148 unsigned long long efer = 0;
149
150 rdmsrl_safe(MSR_EFER, &efer);
151 return efer & EFER_NX;
152 }
153
cpuid_fix_nx_cap(struct kvm_vcpu * vcpu)154 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
155 {
156 int i;
157 struct kvm_cpuid_entry2 *e, *entry;
158
159 entry = NULL;
160 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
161 e = &vcpu->arch.cpuid_entries[i];
162 if (e->function == 0x80000001) {
163 entry = e;
164 break;
165 }
166 }
167 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
168 entry->edx &= ~F(NX);
169 printk(KERN_INFO "kvm: guest NX capability removed\n");
170 }
171 }
172
cpuid_query_maxphyaddr(struct kvm_vcpu * vcpu)173 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
174 {
175 struct kvm_cpuid_entry2 *best;
176
177 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
178 if (!best || best->eax < 0x80000008)
179 goto not_found;
180 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
181 if (best)
182 return best->eax & 0xff;
183 not_found:
184 return 36;
185 }
186 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
187
188 /* 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)189 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
190 struct kvm_cpuid *cpuid,
191 struct kvm_cpuid_entry __user *entries)
192 {
193 int r, i;
194 struct kvm_cpuid_entry *cpuid_entries = NULL;
195
196 r = -E2BIG;
197 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
198 goto out;
199 r = -ENOMEM;
200 if (cpuid->nent) {
201 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
202 cpuid->nent);
203 if (!cpuid_entries)
204 goto out;
205 r = -EFAULT;
206 if (copy_from_user(cpuid_entries, entries,
207 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
208 goto out;
209 }
210 for (i = 0; i < cpuid->nent; i++) {
211 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
212 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
213 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
214 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
215 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
216 vcpu->arch.cpuid_entries[i].index = 0;
217 vcpu->arch.cpuid_entries[i].flags = 0;
218 vcpu->arch.cpuid_entries[i].padding[0] = 0;
219 vcpu->arch.cpuid_entries[i].padding[1] = 0;
220 vcpu->arch.cpuid_entries[i].padding[2] = 0;
221 }
222 vcpu->arch.cpuid_nent = cpuid->nent;
223 cpuid_fix_nx_cap(vcpu);
224 kvm_apic_set_version(vcpu);
225 kvm_x86_ops->cpuid_update(vcpu);
226 r = kvm_update_cpuid(vcpu);
227
228 out:
229 vfree(cpuid_entries);
230 return r;
231 }
232
kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu * vcpu,struct kvm_cpuid2 * cpuid,struct kvm_cpuid_entry2 __user * entries)233 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
234 struct kvm_cpuid2 *cpuid,
235 struct kvm_cpuid_entry2 __user *entries)
236 {
237 int r;
238
239 r = -E2BIG;
240 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
241 goto out;
242 r = -EFAULT;
243 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
244 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
245 goto out;
246 vcpu->arch.cpuid_nent = cpuid->nent;
247 kvm_apic_set_version(vcpu);
248 kvm_x86_ops->cpuid_update(vcpu);
249 r = kvm_update_cpuid(vcpu);
250 out:
251 return r;
252 }
253
kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu * vcpu,struct kvm_cpuid2 * cpuid,struct kvm_cpuid_entry2 __user * entries)254 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
255 struct kvm_cpuid2 *cpuid,
256 struct kvm_cpuid_entry2 __user *entries)
257 {
258 int r;
259
260 r = -E2BIG;
261 if (cpuid->nent < vcpu->arch.cpuid_nent)
262 goto out;
263 r = -EFAULT;
264 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
265 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
266 goto out;
267 return 0;
268
269 out:
270 cpuid->nent = vcpu->arch.cpuid_nent;
271 return r;
272 }
273
cpuid_mask(u32 * word,int wordnum)274 static void cpuid_mask(u32 *word, int wordnum)
275 {
276 *word &= boot_cpu_data.x86_capability[wordnum];
277 }
278
do_cpuid_1_ent(struct kvm_cpuid_entry2 * entry,u32 function,u32 index)279 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
280 u32 index)
281 {
282 entry->function = function;
283 entry->index = index;
284 cpuid_count(entry->function, entry->index,
285 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
286 entry->flags = 0;
287 }
288
__do_cpuid_ent_emulated(struct kvm_cpuid_entry2 * entry,u32 func,u32 index,int * nent,int maxnent)289 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
290 u32 func, u32 index, int *nent, int maxnent)
291 {
292 switch (func) {
293 case 0:
294 entry->eax = 7;
295 ++*nent;
296 break;
297 case 1:
298 entry->ecx = F(MOVBE);
299 ++*nent;
300 break;
301 case 7:
302 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
303 if (index == 0)
304 entry->ecx = F(RDPID);
305 ++*nent;
306 default:
307 break;
308 }
309
310 entry->function = func;
311 entry->index = index;
312
313 return 0;
314 }
315
__do_cpuid_ent(struct kvm_cpuid_entry2 * entry,u32 function,u32 index,int * nent,int maxnent)316 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
317 u32 index, int *nent, int maxnent)
318 {
319 int r;
320 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
321 #ifdef CONFIG_X86_64
322 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
323 ? F(GBPAGES) : 0;
324 unsigned f_lm = F(LM);
325 #else
326 unsigned f_gbpages = 0;
327 unsigned f_lm = 0;
328 #endif
329 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
330 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
331 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
332 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
333
334 /* cpuid 1.edx */
335 const u32 kvm_cpuid_1_edx_x86_features =
336 F(FPU) | F(VME) | F(DE) | F(PSE) |
337 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
338 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
339 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
340 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
341 0 /* Reserved, DS, ACPI */ | F(MMX) |
342 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
343 0 /* HTT, TM, Reserved, PBE */;
344 /* cpuid 0x80000001.edx */
345 const u32 kvm_cpuid_8000_0001_edx_x86_features =
346 F(FPU) | F(VME) | F(DE) | F(PSE) |
347 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
348 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
349 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
350 F(PAT) | F(PSE36) | 0 /* Reserved */ |
351 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
352 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
353 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
354 /* cpuid 1.ecx */
355 const u32 kvm_cpuid_1_ecx_x86_features =
356 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
357 * but *not* advertised to guests via CPUID ! */
358 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
359 0 /* DS-CPL, VMX, SMX, EST */ |
360 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
361 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
362 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
363 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
364 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
365 F(F16C) | F(RDRAND);
366 /* cpuid 0x80000001.ecx */
367 const u32 kvm_cpuid_8000_0001_ecx_x86_features =
368 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
369 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
370 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
371 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
372
373 /* cpuid 0x80000008.ebx */
374 const u32 kvm_cpuid_8000_0008_ebx_x86_features =
375 F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
376 F(AMD_SSB_NO) | F(AMD_STIBP);
377
378 /* cpuid 0xC0000001.edx */
379 const u32 kvm_cpuid_C000_0001_edx_x86_features =
380 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
381 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
382 F(PMM) | F(PMM_EN);
383
384 /* cpuid 7.0.ebx */
385 const u32 kvm_cpuid_7_0_ebx_x86_features =
386 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
387 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
388 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
389 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
390 F(SHA_NI) | F(AVX512BW) | F(AVX512VL);
391
392 /* cpuid 0xD.1.eax */
393 const u32 kvm_cpuid_D_1_eax_x86_features =
394 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
395
396 /* cpuid 7.0.ecx*/
397 const u32 kvm_cpuid_7_0_ecx_x86_features =
398 F(AVX512VBMI) | F(LA57) | F(PKU) |
399 0 /*OSPKE*/ | F(AVX512_VPOPCNTDQ);
400
401 /* cpuid 7.0.edx*/
402 const u32 kvm_cpuid_7_0_edx_x86_features =
403 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
404 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
405 F(MD_CLEAR);
406
407 /* all calls to cpuid_count() should be made on the same cpu */
408 get_cpu();
409
410 r = -E2BIG;
411
412 if (WARN_ON(*nent >= maxnent))
413 goto out;
414
415 do_cpuid_1_ent(entry, function, index);
416 ++*nent;
417
418 switch (function) {
419 case 0:
420 entry->eax = min(entry->eax, (u32)0xd);
421 break;
422 case 1:
423 entry->edx &= kvm_cpuid_1_edx_x86_features;
424 cpuid_mask(&entry->edx, CPUID_1_EDX);
425 entry->ecx &= kvm_cpuid_1_ecx_x86_features;
426 cpuid_mask(&entry->ecx, CPUID_1_ECX);
427 /* we support x2apic emulation even if host does not support
428 * it since we emulate x2apic in software */
429 entry->ecx |= F(X2APIC);
430 break;
431 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
432 * may return different values. This forces us to get_cpu() before
433 * issuing the first command, and also to emulate this annoying behavior
434 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
435 case 2: {
436 int t, times = entry->eax & 0xff;
437
438 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
439 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
440 for (t = 1; t < times; ++t) {
441 if (*nent >= maxnent)
442 goto out;
443
444 do_cpuid_1_ent(&entry[t], function, 0);
445 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
446 ++*nent;
447 }
448 break;
449 }
450 /* function 4 has additional index. */
451 case 4: {
452 int i, cache_type;
453
454 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
455 /* read more entries until cache_type is zero */
456 for (i = 1; ; ++i) {
457 if (*nent >= maxnent)
458 goto out;
459
460 cache_type = entry[i - 1].eax & 0x1f;
461 if (!cache_type)
462 break;
463 do_cpuid_1_ent(&entry[i], function, i);
464 entry[i].flags |=
465 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
466 ++*nent;
467 }
468 break;
469 }
470 case 6: /* Thermal management */
471 entry->eax = 0x4; /* allow ARAT */
472 entry->ebx = 0;
473 entry->ecx = 0;
474 entry->edx = 0;
475 break;
476 case 7: {
477 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
478 /* Mask ebx against host capability word 9 */
479 if (index == 0) {
480 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
481 cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
482 // TSC_ADJUST is emulated
483 entry->ebx |= F(TSC_ADJUST);
484 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
485 cpuid_mask(&entry->ecx, CPUID_7_ECX);
486 /* PKU is not yet implemented for shadow paging. */
487 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
488 entry->ecx &= ~F(PKU);
489
490 entry->edx &= kvm_cpuid_7_0_edx_x86_features;
491 cpuid_mask(&entry->edx, CPUID_7_EDX);
492 if (boot_cpu_has(X86_FEATURE_IBPB) &&
493 boot_cpu_has(X86_FEATURE_IBRS))
494 entry->edx |= F(SPEC_CTRL);
495 if (boot_cpu_has(X86_FEATURE_STIBP))
496 entry->edx |= F(INTEL_STIBP);
497 if (boot_cpu_has(X86_FEATURE_SSBD))
498 entry->edx |= F(SPEC_CTRL_SSBD);
499 /*
500 * We emulate ARCH_CAPABILITIES in software even
501 * if the host doesn't support it.
502 */
503 entry->edx |= F(ARCH_CAPABILITIES);
504 } else {
505 entry->ebx = 0;
506 entry->ecx = 0;
507 entry->edx = 0;
508 }
509 entry->eax = 0;
510 break;
511 }
512 case 9:
513 break;
514 case 0xa: { /* Architectural Performance Monitoring */
515 struct x86_pmu_capability cap;
516 union cpuid10_eax eax;
517 union cpuid10_edx edx;
518
519 perf_get_x86_pmu_capability(&cap);
520
521 /*
522 * Only support guest architectural pmu on a host
523 * with architectural pmu.
524 */
525 if (!cap.version)
526 memset(&cap, 0, sizeof(cap));
527
528 eax.split.version_id = min(cap.version, 2);
529 eax.split.num_counters = cap.num_counters_gp;
530 eax.split.bit_width = cap.bit_width_gp;
531 eax.split.mask_length = cap.events_mask_len;
532
533 edx.split.num_counters_fixed = cap.num_counters_fixed;
534 edx.split.bit_width_fixed = cap.bit_width_fixed;
535 edx.split.reserved = 0;
536
537 entry->eax = eax.full;
538 entry->ebx = cap.events_mask;
539 entry->ecx = 0;
540 entry->edx = edx.full;
541 break;
542 }
543 /* function 0xb has additional index. */
544 case 0xb: {
545 int i, level_type;
546
547 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
548 /* read more entries until level_type is zero */
549 for (i = 1; ; ++i) {
550 if (*nent >= maxnent)
551 goto out;
552
553 level_type = entry[i - 1].ecx & 0xff00;
554 if (!level_type)
555 break;
556 do_cpuid_1_ent(&entry[i], function, i);
557 entry[i].flags |=
558 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
559 ++*nent;
560 }
561 break;
562 }
563 case 0xd: {
564 int idx, i;
565 u64 supported = kvm_supported_xcr0();
566
567 entry->eax &= supported;
568 entry->ebx = xstate_required_size(supported, false);
569 entry->ecx = entry->ebx;
570 entry->edx &= supported >> 32;
571 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
572 if (!supported)
573 break;
574
575 for (idx = 1, i = 1; idx < 64; ++idx) {
576 u64 mask = ((u64)1 << idx);
577 if (*nent >= maxnent)
578 goto out;
579
580 do_cpuid_1_ent(&entry[i], function, idx);
581 if (idx == 1) {
582 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
583 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
584 entry[i].ebx = 0;
585 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
586 entry[i].ebx =
587 xstate_required_size(supported,
588 true);
589 } else {
590 if (entry[i].eax == 0 || !(supported & mask))
591 continue;
592 if (WARN_ON_ONCE(entry[i].ecx & 1))
593 continue;
594 }
595 entry[i].ecx = 0;
596 entry[i].edx = 0;
597 entry[i].flags |=
598 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
599 ++*nent;
600 ++i;
601 }
602 break;
603 }
604 case KVM_CPUID_SIGNATURE: {
605 static const char signature[12] = "KVMKVMKVM\0\0";
606 const u32 *sigptr = (const u32 *)signature;
607 entry->eax = KVM_CPUID_FEATURES;
608 entry->ebx = sigptr[0];
609 entry->ecx = sigptr[1];
610 entry->edx = sigptr[2];
611 break;
612 }
613 case KVM_CPUID_FEATURES:
614 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
615 (1 << KVM_FEATURE_NOP_IO_DELAY) |
616 (1 << KVM_FEATURE_CLOCKSOURCE2) |
617 (1 << KVM_FEATURE_ASYNC_PF) |
618 (1 << KVM_FEATURE_PV_EOI) |
619 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
620 (1 << KVM_FEATURE_PV_UNHALT) |
621 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT);
622
623 if (sched_info_on())
624 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
625
626 entry->ebx = 0;
627 entry->ecx = 0;
628 entry->edx = 0;
629 break;
630 case 0x80000000:
631 entry->eax = min(entry->eax, 0x8000001a);
632 break;
633 case 0x80000001:
634 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
635 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
636 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
637 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
638 break;
639 case 0x80000007: /* Advanced power management */
640 /* invariant TSC is CPUID.80000007H:EDX[8] */
641 entry->edx &= (1 << 8);
642 /* mask against host */
643 entry->edx &= boot_cpu_data.x86_power;
644 entry->eax = entry->ebx = entry->ecx = 0;
645 break;
646 case 0x80000008: {
647 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
648 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
649 unsigned phys_as = entry->eax & 0xff;
650
651 if (!g_phys_as)
652 g_phys_as = phys_as;
653 entry->eax = g_phys_as | (virt_as << 8);
654 entry->edx = 0;
655 /*
656 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
657 * hardware cpuid
658 */
659 if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
660 entry->ebx |= F(AMD_IBPB);
661 if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
662 entry->ebx |= F(AMD_IBRS);
663 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
664 entry->ebx |= F(VIRT_SSBD);
665 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
666 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
667 /*
668 * The preference is to use SPEC CTRL MSR instead of the
669 * VIRT_SPEC MSR.
670 */
671 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) &&
672 !boot_cpu_has(X86_FEATURE_AMD_SSBD))
673 entry->ebx |= F(VIRT_SSBD);
674 break;
675 }
676 case 0x80000019:
677 entry->ecx = entry->edx = 0;
678 break;
679 case 0x8000001a:
680 break;
681 case 0x8000001d:
682 break;
683 /*Add support for Centaur's CPUID instruction*/
684 case 0xC0000000:
685 /*Just support up to 0xC0000004 now*/
686 entry->eax = min(entry->eax, 0xC0000004);
687 break;
688 case 0xC0000001:
689 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
690 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
691 break;
692 case 3: /* Processor serial number */
693 case 5: /* MONITOR/MWAIT */
694 case 0xC0000002:
695 case 0xC0000003:
696 case 0xC0000004:
697 default:
698 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
699 break;
700 }
701
702 kvm_x86_ops->set_supported_cpuid(function, entry);
703
704 r = 0;
705
706 out:
707 put_cpu();
708
709 return r;
710 }
711
do_cpuid_ent(struct kvm_cpuid_entry2 * entry,u32 func,u32 idx,int * nent,int maxnent,unsigned int type)712 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
713 u32 idx, int *nent, int maxnent, unsigned int type)
714 {
715 if (*nent >= maxnent)
716 return -E2BIG;
717
718 if (type == KVM_GET_EMULATED_CPUID)
719 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
720
721 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
722 }
723
724 #undef F
725
726 struct kvm_cpuid_param {
727 u32 func;
728 u32 idx;
729 bool has_leaf_count;
730 bool (*qualifier)(const struct kvm_cpuid_param *param);
731 };
732
is_centaur_cpu(const struct kvm_cpuid_param * param)733 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
734 {
735 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
736 }
737
sanity_check_entries(struct kvm_cpuid_entry2 __user * entries,__u32 num_entries,unsigned int ioctl_type)738 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
739 __u32 num_entries, unsigned int ioctl_type)
740 {
741 int i;
742 __u32 pad[3];
743
744 if (ioctl_type != KVM_GET_EMULATED_CPUID)
745 return false;
746
747 /*
748 * We want to make sure that ->padding is being passed clean from
749 * userspace in case we want to use it for something in the future.
750 *
751 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
752 * have to give ourselves satisfied only with the emulated side. /me
753 * sheds a tear.
754 */
755 for (i = 0; i < num_entries; i++) {
756 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
757 return true;
758
759 if (pad[0] || pad[1] || pad[2])
760 return true;
761 }
762 return false;
763 }
764
kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 * cpuid,struct kvm_cpuid_entry2 __user * entries,unsigned int type)765 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
766 struct kvm_cpuid_entry2 __user *entries,
767 unsigned int type)
768 {
769 struct kvm_cpuid_entry2 *cpuid_entries;
770 int limit, nent = 0, r = -E2BIG, i;
771 u32 func;
772 static const struct kvm_cpuid_param param[] = {
773 { .func = 0, .has_leaf_count = true },
774 { .func = 0x80000000, .has_leaf_count = true },
775 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
776 { .func = KVM_CPUID_SIGNATURE },
777 { .func = KVM_CPUID_FEATURES },
778 };
779
780 if (cpuid->nent < 1)
781 goto out;
782 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
783 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
784
785 if (sanity_check_entries(entries, cpuid->nent, type))
786 return -EINVAL;
787
788 r = -ENOMEM;
789 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
790 if (!cpuid_entries)
791 goto out;
792
793 r = 0;
794 for (i = 0; i < ARRAY_SIZE(param); i++) {
795 const struct kvm_cpuid_param *ent = ¶m[i];
796
797 if (ent->qualifier && !ent->qualifier(ent))
798 continue;
799
800 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
801 &nent, cpuid->nent, type);
802
803 if (r)
804 goto out_free;
805
806 if (!ent->has_leaf_count)
807 continue;
808
809 limit = cpuid_entries[nent - 1].eax;
810 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
811 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
812 &nent, cpuid->nent, type);
813
814 if (r)
815 goto out_free;
816 }
817
818 r = -EFAULT;
819 if (copy_to_user(entries, cpuid_entries,
820 nent * sizeof(struct kvm_cpuid_entry2)))
821 goto out_free;
822 cpuid->nent = nent;
823 r = 0;
824
825 out_free:
826 vfree(cpuid_entries);
827 out:
828 return r;
829 }
830
move_to_next_stateful_cpuid_entry(struct kvm_vcpu * vcpu,int i)831 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
832 {
833 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
834 struct kvm_cpuid_entry2 *ej;
835 int j = i;
836 int nent = vcpu->arch.cpuid_nent;
837
838 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
839 /* when no next entry is found, the current entry[i] is reselected */
840 do {
841 j = (j + 1) % nent;
842 ej = &vcpu->arch.cpuid_entries[j];
843 } while (ej->function != e->function);
844
845 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
846
847 return j;
848 }
849
850 /* find an entry with matching function, matching index (if needed), and that
851 * should be read next (if it's stateful) */
is_matching_cpuid_entry(struct kvm_cpuid_entry2 * e,u32 function,u32 index)852 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
853 u32 function, u32 index)
854 {
855 if (e->function != function)
856 return 0;
857 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
858 return 0;
859 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
860 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
861 return 0;
862 return 1;
863 }
864
kvm_find_cpuid_entry(struct kvm_vcpu * vcpu,u32 function,u32 index)865 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
866 u32 function, u32 index)
867 {
868 int i;
869 struct kvm_cpuid_entry2 *best = NULL;
870
871 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
872 struct kvm_cpuid_entry2 *e;
873
874 e = &vcpu->arch.cpuid_entries[i];
875 if (is_matching_cpuid_entry(e, function, index)) {
876 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
877 move_to_next_stateful_cpuid_entry(vcpu, i);
878 best = e;
879 break;
880 }
881 }
882 return best;
883 }
884 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
885
886 /*
887 * If no match is found, check whether we exceed the vCPU's limit
888 * and return the content of the highest valid _standard_ leaf instead.
889 * This is to satisfy the CPUID specification.
890 */
check_cpuid_limit(struct kvm_vcpu * vcpu,u32 function,u32 index)891 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
892 u32 function, u32 index)
893 {
894 struct kvm_cpuid_entry2 *maxlevel;
895
896 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
897 if (!maxlevel || maxlevel->eax >= function)
898 return NULL;
899 if (function & 0x80000000) {
900 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
901 if (!maxlevel)
902 return NULL;
903 }
904 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
905 }
906
kvm_cpuid(struct kvm_vcpu * vcpu,u32 * eax,u32 * ebx,u32 * ecx,u32 * edx,bool check_limit)907 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
908 u32 *ecx, u32 *edx, bool check_limit)
909 {
910 u32 function = *eax, index = *ecx;
911 struct kvm_cpuid_entry2 *best;
912 bool entry_found = true;
913
914 best = kvm_find_cpuid_entry(vcpu, function, index);
915
916 if (!best) {
917 entry_found = false;
918 if (!check_limit)
919 goto out;
920
921 best = check_cpuid_limit(vcpu, function, index);
922 }
923
924 out:
925 if (best) {
926 *eax = best->eax;
927 *ebx = best->ebx;
928 *ecx = best->ecx;
929 *edx = best->edx;
930 } else
931 *eax = *ebx = *ecx = *edx = 0;
932 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
933 return entry_found;
934 }
935 EXPORT_SYMBOL_GPL(kvm_cpuid);
936
kvm_emulate_cpuid(struct kvm_vcpu * vcpu)937 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
938 {
939 u32 eax, ebx, ecx, edx;
940
941 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
942 return 1;
943
944 eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
945 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
946 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
947 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
948 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
949 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
950 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
951 return kvm_skip_emulated_instruction(vcpu);
952 }
953 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
954