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 #include <fcntl.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <sys/ioctl.h>
  15
  16 #include "test_util.h"
  17 #include "kvm_util.h"
  18 #include "processor.h"
  19 #include "vmx.h"
  20
  21 static void guest_code(void)
  22 {
  23 }
  24
  25 static bool smt_possible(void)
  26 {
  27         char buf[16];
  28         FILE *f;
  29         bool res = true;
  30
  31         f = fopen("/sys/devices/system/cpu/smt/control", "r");
  32         if (f) {
  33                 if (fread(buf, sizeof(*buf), sizeof(buf), f) > 0) {
  34                         if (!strncmp(buf, "forceoff", 8) ||
  35                             !strncmp(buf, "notsupported", 12))
  36                                 res = false;
  37                 }
  38                 fclose(f);
  39         }
  40
  41         return res;
  42 }
  43
  44 static void test_hv_cpuid(const struct kvm_cpuid2 *hv_cpuid_entries,
  45                           bool evmcs_expected)
  46 {
  47         int i;
  48         int nent_expected = 10;
  49         u32 test_val;
  50
  51         TEST_ASSERT(hv_cpuid_entries->nent == nent_expected,
  52                     "KVM_GET_SUPPORTED_HV_CPUID should return %d entries"
  53                     " (returned %d)",
  54                     nent_expected, hv_cpuid_entries->nent);
  55
  56         for (i = 0; i < hv_cpuid_entries->nent; i++) {
  57                 const struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];
  58
  59                 TEST_ASSERT((entry->function >= 0x40000000) &&
  60                             (entry->function <= 0x40000082),
  61                             "function %x is our of supported range",
  62                             entry->function);
  63
  64                 TEST_ASSERT(entry->index == 0,
  65                             ".index field should be zero");
  66
  67                 TEST_ASSERT(entry->flags == 0,
  68                             ".flags field should be zero");
  69
  70                 TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
  71                             !entry->padding[2], "padding should be zero");
  72
  73                 switch (entry->function) {
  74                 case 0x40000000:
  75                         test_val = 0x40000082;
  76
  77                         TEST_ASSERT(entry->eax == test_val,
  78                                     "Wrong max leaf report in 0x40000000.EAX: %x"
  79                                     " (evmcs=%d)",
  80                                     entry->eax, evmcs_expected
  81                                 );
  82                         break;
  83                 case 0x40000004:
  84                         test_val = entry->eax & (1UL << 18);
  85
  86                         TEST_ASSERT(!!test_val == !smt_possible(),
  87                                     "NoNonArchitecturalCoreSharing bit"
  88                                     " doesn't reflect SMT setting");
  89                         break;
  90                 case 0x4000000A:
  91                         TEST_ASSERT(entry->eax & (1UL << 19),
  92                                     "Enlightened MSR-Bitmap should always be supported"
  93                                     " 0x40000000.EAX: %x", entry->eax);
  94                         if (evmcs_expected)
  95                                 TEST_ASSERT((entry->eax & 0xffff) == 0x101,
  96                                     "Supported Enlightened VMCS version range is supposed to be 1:1"
  97                                     " 0x40000000.EAX: %x", entry->eax);
  98
  99                         break;
 100                 default:
 101                         break;
 102
 103                 }
 104                 /*
 105                  * If needed for debug:
 106                  * fprintf(stdout,
 107                  *      "CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
 108                  *      entry->function, entry->eax, entry->ebx, entry->ecx,
 109                  *      entry->edx);
 110                  */
 111         }
 112 }
 113
 114 void test_hv_cpuid_e2big(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
 115 {
 116         static struct kvm_cpuid2 cpuid = {.nent = 0};
 117         int ret;
 118
 119         if (vcpu)
 120                 ret = __vcpu_ioctl(vcpu, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
 121         else
 122                 ret = __kvm_ioctl(vm->kvm_fd, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
 123
 124         TEST_ASSERT(ret == -1 && errno == E2BIG,
 125                     "%s KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
 126                     " it should have: %d %d", !vcpu ? "KVM" : "vCPU", ret, errno);
 127 }
 128
 129 int main(int argc, char *argv[])
 130 {
 131         struct kvm_vm *vm;
 132         const struct kvm_cpuid2 *hv_cpuid_entries;
 133         struct kvm_vcpu *vcpu;
 134
 135         TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));
 136
 137         vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 138
 139         /* Test vCPU ioctl version */
 140         test_hv_cpuid_e2big(vm, vcpu);
 141
 142         hv_cpuid_entries = vcpu_get_supported_hv_cpuid(vcpu);
 143         test_hv_cpuid(hv_cpuid_entries, false);
 144         free((void *)hv_cpuid_entries);
 145
 146         if (!kvm_cpu_has(X86_FEATURE_VMX) ||
 147             !kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 148                 print_skip("Enlightened VMCS is unsupported");
 149                 goto do_sys;
 150         }
 151         vcpu_enable_evmcs(vcpu);
 152         hv_cpuid_entries = vcpu_get_supported_hv_cpuid(vcpu);
 153         test_hv_cpuid(hv_cpuid_entries, true);
 154         free((void *)hv_cpuid_entries);
 155
 156 do_sys:
 157         /* Test system ioctl version */
 158         if (!kvm_has_cap(KVM_CAP_SYS_HYPERV_CPUID)) {
 159                 print_skip("KVM_CAP_SYS_HYPERV_CPUID not supported");
 160                 goto out;
 161         }
 162
 163         test_hv_cpuid_e2big(vm, NULL);
 164
 165         hv_cpuid_entries = kvm_get_supported_hv_cpuid();
 166         test_hv_cpuid(hv_cpuid_entries, kvm_cpu_has(X86_FEATURE_VMX));
 167
 168 out:
 169         kvm_vm_free(vm);
 170
 171         return 0;
 172 }