tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Test for x86 KVM_CAP_HYPERV_CPUID
   4  *
   5  * Copyright (C) 2018, Red Hat, Inc.
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2.
   8  *
   9  */
  10
  11 #define _GNU_SOURCE /* for program_invocation_short_name */
  12 #include <fcntl.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <sys/ioctl.h>
  17
  18 #include "test_util.h"
  19 #include "kvm_util.h"
  20 #include "processor.h"
  21 #include "vmx.h"
  22
  23 #define VCPU_ID 0
  24
  25 static void guest_code(void)
  26 {
  27 }
  28
  29 static bool smt_possible(void)
  30 {
  31         char buf[16];
  32         FILE *f;
  33         bool res = true;
  34
  35         f = fopen("/sys/devices/system/cpu/smt/control", "r");
  36         if (f) {
  37                 if (fread(buf, sizeof(*buf), sizeof(buf), f) > 0) {
  38                         if (!strncmp(buf, "forceoff", 8) ||
  39                             !strncmp(buf, "notsupported", 12))
  40                                 res = false;
  41                 }
  42                 fclose(f);
  43         }
  44
  45         return res;
  46 }
  47
  48 static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
  49                           bool evmcs_expected)
  50 {
  51         int i;
  52         int nent = 9;
  53         u32 test_val;
  54
  55         if (evmcs_expected)
  56                 nent += 1; /* 0x4000000A */
  57
  58         TEST_ASSERT(hv_cpuid_entries->nent == nent,
  59                     "KVM_GET_SUPPORTED_HV_CPUID should return %d entries"
  60                     " with evmcs=%d (returned %d)",
  61                     nent, evmcs_expected, hv_cpuid_entries->nent);
  62
  63         for (i = 0; i < hv_cpuid_entries->nent; i++) {
  64                 struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];
  65
  66                 TEST_ASSERT((entry->function >= 0x40000000) &&
  67                             (entry->function <= 0x40000082),
  68                             "function %x is our of supported range",
  69                             entry->function);
  70
  71                 TEST_ASSERT(evmcs_expected || (entry->function != 0x4000000A),
  72                             "0x4000000A leaf should not be reported");
  73
  74                 TEST_ASSERT(entry->index == 0,
  75                             ".index field should be zero");
  76
  77                 TEST_ASSERT(entry->flags == 0,
  78                             ".flags field should be zero");
  79
  80                 TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
  81                             !entry->padding[2], "padding should be zero");
  82
  83                 switch (entry->function) {
  84                 case 0x40000000:
  85                         test_val = 0x40000082;
  86
  87                         TEST_ASSERT(entry->eax == test_val,
  88                                     "Wrong max leaf report in 0x40000000.EAX: %x"
  89                                     " (evmcs=%d)",
  90                                     entry->eax, evmcs_expected
  91                                 );
  92                         break;
  93                 case 0x40000004:
  94                         test_val = entry->eax & (1UL << 18);
  95
  96                         TEST_ASSERT(!!test_val == !smt_possible(),
  97                                     "NoNonArchitecturalCoreSharing bit"
  98                                     " doesn't reflect SMT setting");
  99                         break;
 100                 }
 101
 102                 /*
 103                  * If needed for debug:
 104                  * fprintf(stdout,
 105                  *      "CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
 106                  *      entry->function, entry->eax, entry->ebx, entry->ecx,
 107                  *      entry->edx);
 108                  */
 109         }
 110
 111 }
 112
 113 void test_hv_cpuid_e2big(struct kvm_vm *vm, bool system)
 114 {
 115         static struct kvm_cpuid2 cpuid = {.nent = 0};
 116         int ret;
 117
 118         if (!system)
 119                 ret = _vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
 120         else
 121                 ret = _kvm_ioctl(vm, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
 122
 123         TEST_ASSERT(ret == -1 && errno == E2BIG,
 124                     "%s KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
 125                     " it should have: %d %d", system ? "KVM" : "vCPU", ret, errno);
 126 }
 127
 128
 129 struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(struct kvm_vm *vm, bool system)
 130 {
 131         int nent = 20; /* should be enough */
 132         static struct kvm_cpuid2 *cpuid;
 133
 134         cpuid = malloc(sizeof(*cpuid) + nent * sizeof(struct kvm_cpuid_entry2));
 135
 136         if (!cpuid) {
 137                 perror("malloc");
 138                 abort();
 139         }
 140
 141         cpuid->nent = nent;
 142
 143         if (!system)
 144                 vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, cpuid);
 145         else
 146                 kvm_ioctl(vm, KVM_GET_SUPPORTED_HV_CPUID, cpuid);
 147
 148         return cpuid;
 149 }
 150
 151
 152 int main(int argc, char *argv[])
 153 {
 154         struct kvm_vm *vm;
 155         struct kvm_cpuid2 *hv_cpuid_entries;
 156
 157         /* Tell stdout not to buffer its content */
 158         setbuf(stdout, NULL);
 159
 160         if (!kvm_check_cap(KVM_CAP_HYPERV_CPUID)) {
 161                 print_skip("KVM_CAP_HYPERV_CPUID not supported");
 162                 exit(KSFT_SKIP);
 163         }
 164
 165         vm = vm_create_default(VCPU_ID, 0, guest_code);
 166
 167         /* Test vCPU ioctl version */
 168         test_hv_cpuid_e2big(vm, false);
 169
 170         hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm, false);
 171         test_hv_cpuid(hv_cpuid_entries, false);
 172         free(hv_cpuid_entries);
 173
 174         if (!nested_vmx_supported() ||
 175             !kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 176                 print_skip("Enlightened VMCS is unsupported");
 177                 goto do_sys;
 178         }
 179         vcpu_enable_evmcs(vm, VCPU_ID);
 180         hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm, false);
 181         test_hv_cpuid(hv_cpuid_entries, true);
 182         free(hv_cpuid_entries);
 183
 184 do_sys:
 185         /* Test system ioctl version */
 186         if (!kvm_check_cap(KVM_CAP_SYS_HYPERV_CPUID)) {
 187                 print_skip("KVM_CAP_SYS_HYPERV_CPUID not supported");
 188                 goto out;
 189         }
 190
 191         test_hv_cpuid_e2big(vm, true);
 192
 193         hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm, true);
 194         test_hv_cpuid(hv_cpuid_entries, nested_vmx_supported());
 195         free(hv_cpuid_entries);
 196
 197 out:
 198         kvm_vm_free(vm);
 199
 200         return 0;
 201 }