tools/kvm/cpuid.c

   1 #include "kvm/kvm-cpu.h"
   2
   3 #include "kvm/kvm.h"
   4 #include "kvm/util.h"
   5
   6 #include <sys/ioctl.h>
   7 #include <stdlib.h>
   8 #include <assert.h>
   9
  10 #define CPUID_FUNC_PERFMON              0x0A
  11
  12 #define MAX_KVM_CPUID_ENTRIES           100
  13
  14 static void filter_cpuid(struct kvm_cpuid2 *kvm_cpuid)
  15 {
  16         unsigned int i;
  17
  18         /*
  19          * Filter CPUID functions that are not supported by the hypervisor.
  20          */
  21         for (i = 0; i < kvm_cpuid->nent; i++) {
  22                 struct kvm_cpuid_entry2 *entry = &kvm_cpuid->entries[i];
  23
  24                 switch (entry->function) {
  25                 case CPUID_FUNC_PERFMON:
  26                         entry->eax      = 0x00; /* disable it */
  27                         break;
  28                 default:
  29                         /* Keep the CPUID function as -is */
  30                         break;
  31                 };
  32         }
  33 }
  34
  35 void kvm_cpu__setup_cpuid(struct kvm_cpu *vcpu)
  36 {
  37         struct kvm_cpuid2 *kvm_cpuid;
  38
  39         kvm_cpuid = calloc(1, sizeof(*kvm_cpuid) + MAX_KVM_CPUID_ENTRIES * sizeof(*kvm_cpuid->entries));
  40
  41         kvm_cpuid->nent = MAX_KVM_CPUID_ENTRIES;
  42         if (ioctl(vcpu->kvm->sys_fd, KVM_GET_SUPPORTED_CPUID, kvm_cpuid) < 0)
  43                 die_perror("KVM_GET_SUPPORTED_CPUID failed");
  44
  45         filter_cpuid(kvm_cpuid);
  46
  47         if (ioctl(vcpu->vcpu_fd, KVM_SET_CPUID2, kvm_cpuid) < 0)
  48                 die_perror("KVM_SET_CPUID2 failed");
  49
  50         free(kvm_cpuid);
  51 }