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TOMOYO Linux Cross Reference
Linux/arch/x86/kvm/cpuid.c

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  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 <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 
 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 
 49 bool kvm_mpx_supported(void)
 50 {
 51         return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
 52                  && kvm_x86_ops->mpx_supported());
 53 }
 54 EXPORT_SYMBOL_GPL(kvm_mpx_supported);
 55 
 56 u64 kvm_supported_xcr0(void)
 57 {
 58         u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
 59 
 60         if (!kvm_mpx_supported())
 61                 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
 62 
 63         return xcr0;
 64 }
 65 
 66 #define F(x) bit(X86_FEATURE_##x)
 67 
 68 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
 69 {
 70         struct kvm_cpuid_entry2 *best;
 71         struct kvm_lapic *apic = vcpu->arch.apic;
 72 
 73         best = kvm_find_cpuid_entry(vcpu, 1, 0);
 74         if (!best)
 75                 return 0;
 76 
 77         /* Update OSXSAVE bit */
 78         if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
 79                 best->ecx &= ~F(OSXSAVE);
 80                 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
 81                         best->ecx |= F(OSXSAVE);
 82         }
 83 
 84         if (apic) {
 85                 if (best->ecx & F(TSC_DEADLINE_TIMER))
 86                         apic->lapic_timer.timer_mode_mask = 3 << 17;
 87                 else
 88                         apic->lapic_timer.timer_mode_mask = 1 << 17;
 89         }
 90 
 91         best = kvm_find_cpuid_entry(vcpu, 7, 0);
 92         if (best) {
 93                 /* Update OSPKE bit */
 94                 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
 95                         best->ecx &= ~F(OSPKE);
 96                         if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
 97                                 best->ecx |= F(OSPKE);
 98                 }
 99         }
100 
101         best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
102         if (!best) {
103                 vcpu->arch.guest_supported_xcr0 = 0;
104                 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
105         } else {
106                 vcpu->arch.guest_supported_xcr0 =
107                         (best->eax | ((u64)best->edx << 32)) &
108                         kvm_supported_xcr0();
109                 vcpu->arch.guest_xstate_size = best->ebx =
110                         xstate_required_size(vcpu->arch.xcr0, false);
111         }
112 
113         best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
114         if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
115                 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
116 
117         if (use_eager_fpu())
118                 kvm_x86_ops->fpu_activate(vcpu);
119 
120         /*
121          * The existing code assumes virtual address is 48-bit in the canonical
122          * address checks; exit if it is ever changed.
123          */
124         best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
125         if (best && ((best->eax & 0xff00) >> 8) != 48 &&
126                 ((best->eax & 0xff00) >> 8) != 0)
127                 return -EINVAL;
128 
129         /* Update physical-address width */
130         vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
131 
132         kvm_pmu_refresh(vcpu);
133         return 0;
134 }
135 
136 static int is_efer_nx(void)
137 {
138         unsigned long long efer = 0;
139 
140         rdmsrl_safe(MSR_EFER, &efer);
141         return efer & EFER_NX;
142 }
143 
144 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
145 {
146         int i;
147         struct kvm_cpuid_entry2 *e, *entry;
148 
149         entry = NULL;
150         for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
151                 e = &vcpu->arch.cpuid_entries[i];
152                 if (e->function == 0x80000001) {
153                         entry = e;
154                         break;
155                 }
156         }
157         if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
158                 entry->edx &= ~F(NX);
159                 printk(KERN_INFO "kvm: guest NX capability removed\n");
160         }
161 }
162 
163 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
164 {
165         struct kvm_cpuid_entry2 *best;
166 
167         best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
168         if (!best || best->eax < 0x80000008)
169                 goto not_found;
170         best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
171         if (best)
172                 return best->eax & 0xff;
173 not_found:
174         return 36;
175 }
176 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
177 
178 /* when an old userspace process fills a new kernel module */
179 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
180                              struct kvm_cpuid *cpuid,
181                              struct kvm_cpuid_entry __user *entries)
182 {
183         int r, i;
184         struct kvm_cpuid_entry *cpuid_entries = NULL;
185 
186         r = -E2BIG;
187         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
188                 goto out;
189         r = -ENOMEM;
190         if (cpuid->nent) {
191                 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
192                                         cpuid->nent);
193                 if (!cpuid_entries)
194                         goto out;
195                 r = -EFAULT;
196                 if (copy_from_user(cpuid_entries, entries,
197                                    cpuid->nent * sizeof(struct kvm_cpuid_entry)))
198                         goto out;
199         }
200         for (i = 0; i < cpuid->nent; i++) {
201                 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
202                 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
203                 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
204                 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
205                 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
206                 vcpu->arch.cpuid_entries[i].index = 0;
207                 vcpu->arch.cpuid_entries[i].flags = 0;
208                 vcpu->arch.cpuid_entries[i].padding[0] = 0;
209                 vcpu->arch.cpuid_entries[i].padding[1] = 0;
210                 vcpu->arch.cpuid_entries[i].padding[2] = 0;
211         }
212         vcpu->arch.cpuid_nent = cpuid->nent;
213         cpuid_fix_nx_cap(vcpu);
214         kvm_apic_set_version(vcpu);
215         kvm_x86_ops->cpuid_update(vcpu);
216         r = kvm_update_cpuid(vcpu);
217 
218 out:
219         vfree(cpuid_entries);
220         return r;
221 }
222 
223 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
224                               struct kvm_cpuid2 *cpuid,
225                               struct kvm_cpuid_entry2 __user *entries)
226 {
227         int r;
228 
229         r = -E2BIG;
230         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
231                 goto out;
232         r = -EFAULT;
233         if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
234                            cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
235                 goto out;
236         vcpu->arch.cpuid_nent = cpuid->nent;
237         kvm_apic_set_version(vcpu);
238         kvm_x86_ops->cpuid_update(vcpu);
239         r = kvm_update_cpuid(vcpu);
240 out:
241         return r;
242 }
243 
244 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
245                               struct kvm_cpuid2 *cpuid,
246                               struct kvm_cpuid_entry2 __user *entries)
247 {
248         int r;
249 
250         r = -E2BIG;
251         if (cpuid->nent < vcpu->arch.cpuid_nent)
252                 goto out;
253         r = -EFAULT;
254         if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
255                          vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
256                 goto out;
257         return 0;
258 
259 out:
260         cpuid->nent = vcpu->arch.cpuid_nent;
261         return r;
262 }
263 
264 static void cpuid_mask(u32 *word, int wordnum)
265 {
266         *word &= boot_cpu_data.x86_capability[wordnum];
267 }
268 
269 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
270                            u32 index)
271 {
272         entry->function = function;
273         entry->index = index;
274         cpuid_count(entry->function, entry->index,
275                     &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
276         entry->flags = 0;
277 }
278 
279 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
280                                    u32 func, u32 index, int *nent, int maxnent)
281 {
282         switch (func) {
283         case 0:
284                 entry->eax = 1;         /* only one leaf currently */
285                 ++*nent;
286                 break;
287         case 1:
288                 entry->ecx = F(MOVBE);
289                 ++*nent;
290                 break;
291         default:
292                 break;
293         }
294 
295         entry->function = func;
296         entry->index = index;
297 
298         return 0;
299 }
300 
301 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
302                                  u32 index, int *nent, int maxnent)
303 {
304         int r;
305         unsigned f_nx = is_efer_nx() ? F(NX) : 0;
306 #ifdef CONFIG_X86_64
307         unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
308                                 ? F(GBPAGES) : 0;
309         unsigned f_lm = F(LM);
310 #else
311         unsigned f_gbpages = 0;
312         unsigned f_lm = 0;
313 #endif
314         unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
315         unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
316         unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
317         unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
318 
319         /* cpuid 1.edx */
320         const u32 kvm_cpuid_1_edx_x86_features =
321                 F(FPU) | F(VME) | F(DE) | F(PSE) |
322                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
323                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
324                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
325                 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
326                 0 /* Reserved, DS, ACPI */ | F(MMX) |
327                 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
328                 0 /* HTT, TM, Reserved, PBE */;
329         /* cpuid 0x80000001.edx */
330         const u32 kvm_cpuid_8000_0001_edx_x86_features =
331                 F(FPU) | F(VME) | F(DE) | F(PSE) |
332                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
333                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
334                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
335                 F(PAT) | F(PSE36) | 0 /* Reserved */ |
336                 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
337                 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
338                 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
339         /* cpuid 1.ecx */
340         const u32 kvm_cpuid_1_ecx_x86_features =
341                 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
342                  * but *not* advertised to guests via CPUID ! */
343                 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
344                 0 /* DS-CPL, VMX, SMX, EST */ |
345                 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
346                 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
347                 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
348                 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
349                 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
350                 F(F16C) | F(RDRAND);
351         /* cpuid 0x80000001.ecx */
352         const u32 kvm_cpuid_8000_0001_ecx_x86_features =
353                 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
354                 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
355                 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
356                 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
357 
358         /* cpuid 0xC0000001.edx */
359         const u32 kvm_cpuid_C000_0001_edx_x86_features =
360                 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
361                 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
362                 F(PMM) | F(PMM_EN);
363 
364         /* cpuid 7.0.ebx */
365         const u32 kvm_cpuid_7_0_ebx_x86_features =
366                 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
367                 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
368                 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
369                 F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB);
370 
371         /* cpuid 0xD.1.eax */
372         const u32 kvm_cpuid_D_1_eax_x86_features =
373                 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
374 
375         /* cpuid 7.0.ecx*/
376         const u32 kvm_cpuid_7_0_ecx_x86_features = F(PKU) | 0 /*OSPKE*/;
377 
378         /* all calls to cpuid_count() should be made on the same cpu */
379         get_cpu();
380 
381         r = -E2BIG;
382 
383         if (*nent >= maxnent)
384                 goto out;
385 
386         do_cpuid_1_ent(entry, function, index);
387         ++*nent;
388 
389         switch (function) {
390         case 0:
391                 entry->eax = min(entry->eax, (u32)0xd);
392                 break;
393         case 1:
394                 entry->edx &= kvm_cpuid_1_edx_x86_features;
395                 cpuid_mask(&entry->edx, CPUID_1_EDX);
396                 entry->ecx &= kvm_cpuid_1_ecx_x86_features;
397                 cpuid_mask(&entry->ecx, CPUID_1_ECX);
398                 /* we support x2apic emulation even if host does not support
399                  * it since we emulate x2apic in software */
400                 entry->ecx |= F(X2APIC);
401                 break;
402         /* function 2 entries are STATEFUL. That is, repeated cpuid commands
403          * may return different values. This forces us to get_cpu() before
404          * issuing the first command, and also to emulate this annoying behavior
405          * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
406         case 2: {
407                 int t, times = entry->eax & 0xff;
408 
409                 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
410                 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
411                 for (t = 1; t < times; ++t) {
412                         if (*nent >= maxnent)
413                                 goto out;
414 
415                         do_cpuid_1_ent(&entry[t], function, 0);
416                         entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
417                         ++*nent;
418                 }
419                 break;
420         }
421         /* function 4 has additional index. */
422         case 4: {
423                 int i, cache_type;
424 
425                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
426                 /* read more entries until cache_type is zero */
427                 for (i = 1; ; ++i) {
428                         if (*nent >= maxnent)
429                                 goto out;
430 
431                         cache_type = entry[i - 1].eax & 0x1f;
432                         if (!cache_type)
433                                 break;
434                         do_cpuid_1_ent(&entry[i], function, i);
435                         entry[i].flags |=
436                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
437                         ++*nent;
438                 }
439                 break;
440         }
441         case 6: /* Thermal management */
442                 entry->eax = 0x4; /* allow ARAT */
443                 entry->ebx = 0;
444                 entry->ecx = 0;
445                 entry->edx = 0;
446                 break;
447         case 7: {
448                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
449                 /* Mask ebx against host capability word 9 */
450                 if (index == 0) {
451                         entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
452                         cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
453                         // TSC_ADJUST is emulated
454                         entry->ebx |= F(TSC_ADJUST);
455                         entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
456                         cpuid_mask(&entry->ecx, CPUID_7_ECX);
457                         /* PKU is not yet implemented for shadow paging. */
458                         if (!tdp_enabled)
459                                 entry->ecx &= ~F(PKU);
460                 } else {
461                         entry->ebx = 0;
462                         entry->ecx = 0;
463                 }
464                 entry->eax = 0;
465                 entry->edx = 0;
466                 break;
467         }
468         case 9:
469                 break;
470         case 0xa: { /* Architectural Performance Monitoring */
471                 struct x86_pmu_capability cap;
472                 union cpuid10_eax eax;
473                 union cpuid10_edx edx;
474 
475                 perf_get_x86_pmu_capability(&cap);
476 
477                 /*
478                  * Only support guest architectural pmu on a host
479                  * with architectural pmu.
480                  */
481                 if (!cap.version)
482                         memset(&cap, 0, sizeof(cap));
483 
484                 eax.split.version_id = min(cap.version, 2);
485                 eax.split.num_counters = cap.num_counters_gp;
486                 eax.split.bit_width = cap.bit_width_gp;
487                 eax.split.mask_length = cap.events_mask_len;
488 
489                 edx.split.num_counters_fixed = cap.num_counters_fixed;
490                 edx.split.bit_width_fixed = cap.bit_width_fixed;
491                 edx.split.reserved = 0;
492 
493                 entry->eax = eax.full;
494                 entry->ebx = cap.events_mask;
495                 entry->ecx = 0;
496                 entry->edx = edx.full;
497                 break;
498         }
499         /* function 0xb has additional index. */
500         case 0xb: {
501                 int i, level_type;
502 
503                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
504                 /* read more entries until level_type is zero */
505                 for (i = 1; ; ++i) {
506                         if (*nent >= maxnent)
507                                 goto out;
508 
509                         level_type = entry[i - 1].ecx & 0xff00;
510                         if (!level_type)
511                                 break;
512                         do_cpuid_1_ent(&entry[i], function, i);
513                         entry[i].flags |=
514                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
515                         ++*nent;
516                 }
517                 break;
518         }
519         case 0xd: {
520                 int idx, i;
521                 u64 supported = kvm_supported_xcr0();
522 
523                 entry->eax &= supported;
524                 entry->ebx = xstate_required_size(supported, false);
525                 entry->ecx = entry->ebx;
526                 entry->edx &= supported >> 32;
527                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
528                 if (!supported)
529                         break;
530 
531                 for (idx = 1, i = 1; idx < 64; ++idx) {
532                         u64 mask = ((u64)1 << idx);
533                         if (*nent >= maxnent)
534                                 goto out;
535 
536                         do_cpuid_1_ent(&entry[i], function, idx);
537                         if (idx == 1) {
538                                 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
539                                 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
540                                 entry[i].ebx = 0;
541                                 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
542                                         entry[i].ebx =
543                                                 xstate_required_size(supported,
544                                                                      true);
545                         } else {
546                                 if (entry[i].eax == 0 || !(supported & mask))
547                                         continue;
548                                 if (WARN_ON_ONCE(entry[i].ecx & 1))
549                                         continue;
550                         }
551                         entry[i].ecx = 0;
552                         entry[i].edx = 0;
553                         entry[i].flags |=
554                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
555                         ++*nent;
556                         ++i;
557                 }
558                 break;
559         }
560         case KVM_CPUID_SIGNATURE: {
561                 static const char signature[12] = "KVMKVMKVM\0\0";
562                 const u32 *sigptr = (const u32 *)signature;
563                 entry->eax = KVM_CPUID_FEATURES;
564                 entry->ebx = sigptr[0];
565                 entry->ecx = sigptr[1];
566                 entry->edx = sigptr[2];
567                 break;
568         }
569         case KVM_CPUID_FEATURES:
570                 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
571                              (1 << KVM_FEATURE_NOP_IO_DELAY) |
572                              (1 << KVM_FEATURE_CLOCKSOURCE2) |
573                              (1 << KVM_FEATURE_ASYNC_PF) |
574                              (1 << KVM_FEATURE_PV_EOI) |
575                              (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
576                              (1 << KVM_FEATURE_PV_UNHALT);
577 
578                 if (sched_info_on())
579                         entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
580 
581                 entry->ebx = 0;
582                 entry->ecx = 0;
583                 entry->edx = 0;
584                 break;
585         case 0x80000000:
586                 entry->eax = min(entry->eax, 0x8000001a);
587                 break;
588         case 0x80000001:
589                 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
590                 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
591                 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
592                 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
593                 break;
594         case 0x80000007: /* Advanced power management */
595                 /* invariant TSC is CPUID.80000007H:EDX[8] */
596                 entry->edx &= (1 << 8);
597                 /* mask against host */
598                 entry->edx &= boot_cpu_data.x86_power;
599                 entry->eax = entry->ebx = entry->ecx = 0;
600                 break;
601         case 0x80000008: {
602                 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
603                 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
604                 unsigned phys_as = entry->eax & 0xff;
605 
606                 if (!g_phys_as)
607                         g_phys_as = phys_as;
608                 entry->eax = g_phys_as | (virt_as << 8);
609                 entry->ebx = entry->edx = 0;
610                 break;
611         }
612         case 0x80000019:
613                 entry->ecx = entry->edx = 0;
614                 break;
615         case 0x8000001a:
616                 break;
617         case 0x8000001d:
618                 break;
619         /*Add support for Centaur's CPUID instruction*/
620         case 0xC0000000:
621                 /*Just support up to 0xC0000004 now*/
622                 entry->eax = min(entry->eax, 0xC0000004);
623                 break;
624         case 0xC0000001:
625                 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
626                 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
627                 break;
628         case 3: /* Processor serial number */
629         case 5: /* MONITOR/MWAIT */
630         case 0xC0000002:
631         case 0xC0000003:
632         case 0xC0000004:
633         default:
634                 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
635                 break;
636         }
637 
638         kvm_x86_ops->set_supported_cpuid(function, entry);
639 
640         r = 0;
641 
642 out:
643         put_cpu();
644 
645         return r;
646 }
647 
648 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
649                         u32 idx, int *nent, int maxnent, unsigned int type)
650 {
651         if (type == KVM_GET_EMULATED_CPUID)
652                 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
653 
654         return __do_cpuid_ent(entry, func, idx, nent, maxnent);
655 }
656 
657 #undef F
658 
659 struct kvm_cpuid_param {
660         u32 func;
661         u32 idx;
662         bool has_leaf_count;
663         bool (*qualifier)(const struct kvm_cpuid_param *param);
664 };
665 
666 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
667 {
668         return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
669 }
670 
671 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
672                                  __u32 num_entries, unsigned int ioctl_type)
673 {
674         int i;
675         __u32 pad[3];
676 
677         if (ioctl_type != KVM_GET_EMULATED_CPUID)
678                 return false;
679 
680         /*
681          * We want to make sure that ->padding is being passed clean from
682          * userspace in case we want to use it for something in the future.
683          *
684          * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
685          * have to give ourselves satisfied only with the emulated side. /me
686          * sheds a tear.
687          */
688         for (i = 0; i < num_entries; i++) {
689                 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
690                         return true;
691 
692                 if (pad[0] || pad[1] || pad[2])
693                         return true;
694         }
695         return false;
696 }
697 
698 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
699                             struct kvm_cpuid_entry2 __user *entries,
700                             unsigned int type)
701 {
702         struct kvm_cpuid_entry2 *cpuid_entries;
703         int limit, nent = 0, r = -E2BIG, i;
704         u32 func;
705         static const struct kvm_cpuid_param param[] = {
706                 { .func = 0, .has_leaf_count = true },
707                 { .func = 0x80000000, .has_leaf_count = true },
708                 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
709                 { .func = KVM_CPUID_SIGNATURE },
710                 { .func = KVM_CPUID_FEATURES },
711         };
712 
713         if (cpuid->nent < 1)
714                 goto out;
715         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
716                 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
717 
718         if (sanity_check_entries(entries, cpuid->nent, type))
719                 return -EINVAL;
720 
721         r = -ENOMEM;
722         cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
723         if (!cpuid_entries)
724                 goto out;
725 
726         r = 0;
727         for (i = 0; i < ARRAY_SIZE(param); i++) {
728                 const struct kvm_cpuid_param *ent = &param[i];
729 
730                 if (ent->qualifier && !ent->qualifier(ent))
731                         continue;
732 
733                 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
734                                 &nent, cpuid->nent, type);
735 
736                 if (r)
737                         goto out_free;
738 
739                 if (!ent->has_leaf_count)
740                         continue;
741 
742                 limit = cpuid_entries[nent - 1].eax;
743                 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
744                         r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
745                                      &nent, cpuid->nent, type);
746 
747                 if (r)
748                         goto out_free;
749         }
750 
751         r = -EFAULT;
752         if (copy_to_user(entries, cpuid_entries,
753                          nent * sizeof(struct kvm_cpuid_entry2)))
754                 goto out_free;
755         cpuid->nent = nent;
756         r = 0;
757 
758 out_free:
759         vfree(cpuid_entries);
760 out:
761         return r;
762 }
763 
764 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
765 {
766         struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
767         int j, nent = vcpu->arch.cpuid_nent;
768 
769         e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
770         /* when no next entry is found, the current entry[i] is reselected */
771         for (j = i + 1; ; j = (j + 1) % nent) {
772                 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
773                 if (ej->function == e->function) {
774                         ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
775                         return j;
776                 }
777         }
778         return 0; /* silence gcc, even though control never reaches here */
779 }
780 
781 /* find an entry with matching function, matching index (if needed), and that
782  * should be read next (if it's stateful) */
783 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
784         u32 function, u32 index)
785 {
786         if (e->function != function)
787                 return 0;
788         if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
789                 return 0;
790         if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
791             !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
792                 return 0;
793         return 1;
794 }
795 
796 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
797                                               u32 function, u32 index)
798 {
799         int i;
800         struct kvm_cpuid_entry2 *best = NULL;
801 
802         for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
803                 struct kvm_cpuid_entry2 *e;
804 
805                 e = &vcpu->arch.cpuid_entries[i];
806                 if (is_matching_cpuid_entry(e, function, index)) {
807                         if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
808                                 move_to_next_stateful_cpuid_entry(vcpu, i);
809                         best = e;
810                         break;
811                 }
812         }
813         return best;
814 }
815 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
816 
817 /*
818  * If no match is found, check whether we exceed the vCPU's limit
819  * and return the content of the highest valid _standard_ leaf instead.
820  * This is to satisfy the CPUID specification.
821  */
822 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
823                                                   u32 function, u32 index)
824 {
825         struct kvm_cpuid_entry2 *maxlevel;
826 
827         maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
828         if (!maxlevel || maxlevel->eax >= function)
829                 return NULL;
830         if (function & 0x80000000) {
831                 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
832                 if (!maxlevel)
833                         return NULL;
834         }
835         return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
836 }
837 
838 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
839 {
840         u32 function = *eax, index = *ecx;
841         struct kvm_cpuid_entry2 *best;
842 
843         best = kvm_find_cpuid_entry(vcpu, function, index);
844 
845         if (!best)
846                 best = check_cpuid_limit(vcpu, function, index);
847 
848         /*
849          * Perfmon not yet supported for L2 guest.
850          */
851         if (is_guest_mode(vcpu) && function == 0xa)
852                 best = NULL;
853 
854         if (best) {
855                 *eax = best->eax;
856                 *ebx = best->ebx;
857                 *ecx = best->ecx;
858                 *edx = best->edx;
859         } else
860                 *eax = *ebx = *ecx = *edx = 0;
861         trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
862 }
863 EXPORT_SYMBOL_GPL(kvm_cpuid);
864 
865 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
866 {
867         u32 function, eax, ebx, ecx, edx;
868 
869         function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
870         ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
871         kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
872         kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
873         kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
874         kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
875         kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
876         kvm_x86_ops->skip_emulated_instruction(vcpu);
877 }
878 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
879 

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