LXR linux/tools/testing/selftests/kvm/x86_64/hyperv

   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
  25static void guest_code(void)
  26{
  27}
  28
  29static int smt_possible(void)
  30{
  31        char buf[16];
  32        FILE *f;
  33        bool res = 1;
  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 = 0;
  41                }
  42                fclose(f);
  43        }
  44
  45        return res;
  46}
  47
  48static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
  49                          int evmcs_enabled)
  50{
  51        int i;
  52
  53        if (!evmcs_enabled)
  54                TEST_ASSERT(hv_cpuid_entries->nent == 6,
  55                            "KVM_GET_SUPPORTED_HV_CPUID should return 6 entries"
  56                            " when Enlightened VMCS is disabled (returned %d)",
  57                            hv_cpuid_entries->nent);
  58        else
  59                TEST_ASSERT(hv_cpuid_entries->nent == 7,
  60                            "KVM_GET_SUPPORTED_HV_CPUID should return 7 entries"
  61                            " when Enlightened VMCS is enabled (returned %d)",
  62                            hv_cpuid_entries->nent);
  63
  64        for (i = 0; i < hv_cpuid_entries->nent; i++) {
  65                struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];
  66
  67                TEST_ASSERT((entry->function >= 0x40000000) &&
  68                            (entry->function <= 0x4000000A),
  69                            "function %lx is our of supported range",
  70                            entry->function);
  71
  72                TEST_ASSERT(entry->index == 0,
  73                            ".index field should be zero");
  74
  75                TEST_ASSERT(entry->flags == 0,
  76                            ".flags field should be zero");
  77
  78                TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
  79                            !entry->padding[2], "padding should be zero");
  80
  81                if (entry->function == 0x40000004) {
  82                        int nononarchcs = !!(entry->eax & (1UL << 18));
  83
  84                        TEST_ASSERT(nononarchcs == !smt_possible(),
  85                                    "NoNonArchitecturalCoreSharing bit"
  86                                    " doesn't reflect SMT setting");
  87                }
  88
  89                /*
  90                 * If needed for debug:
  91                 * fprintf(stdout,
  92                 *      "CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
  93                 *      entry->function, entry->eax, entry->ebx, entry->ecx,
  94                 *      entry->edx);
  95                 */
  96        }
  97
  98}
  99
 100void test_hv_cpuid_e2big(struct kvm_vm *vm)
 101{
 102        static struct kvm_cpuid2 cpuid = {.nent = 0};
 103        int ret;
 104
 105        ret = _vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
 106
 107        TEST_ASSERT(ret == -1 && errno == E2BIG,
 108                    "KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
 109                    " it should have: %d %d", ret, errno);
 110}
 111
 112
 113struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(struct kvm_vm *vm)
 114{
 115        int nent = 20; /* should be enough */
 116        static struct kvm_cpuid2 *cpuid;
 117
 118        cpuid = malloc(sizeof(*cpuid) + nent * sizeof(struct kvm_cpuid_entry2));
 119
 120        if (!cpuid) {
 121                perror("malloc");
 122                abort();
 123        }
 124
 125        cpuid->nent = nent;
 126
 127        vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, cpuid);
 128
 129        return cpuid;
 130}
 131
 132
 133int main(int argc, char *argv[])
 134{
 135        struct kvm_vm *vm;
 136        int rv;
 137        struct kvm_cpuid2 *hv_cpuid_entries;
 138
 139        /* Tell stdout not to buffer its content */
 140        setbuf(stdout, NULL);
 141
 142        rv = kvm_check_cap(KVM_CAP_HYPERV_CPUID);
 143        if (!rv) {
 144                fprintf(stderr,
 145                        "KVM_CAP_HYPERV_CPUID not supported, skip test\n");
 146                exit(KSFT_SKIP);
 147        }
 148
 149        /* Create VM */
 150        vm = vm_create_default(VCPU_ID, 0, guest_code);
 151
 152        test_hv_cpuid_e2big(vm);
 153
 154        hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
 155        if (!hv_cpuid_entries)
 156                return 1;
 157
 158        test_hv_cpuid(hv_cpuid_entries, 0);
 159
 160        free(hv_cpuid_entries);
 161
 162        if (!kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 163                fprintf(stderr,
 164                        "Enlightened VMCS is unsupported, skip related test\n");
 165                goto vm_free;
 166        }
 167
 168        vcpu_enable_evmcs(vm, VCPU_ID);
 169
 170        hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
 171        if (!hv_cpuid_entries)
 172                return 1;
 173
 174        test_hv_cpuid(hv_cpuid_entries, 1);
 175
 176        free(hv_cpuid_entries);
 177
 178vm_free:
 179        kvm_vm_free(vm);
 180
 181        return 0;
 182}
 183