linux/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
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   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 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
  48static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
  49                          bool evmcs_expected)
  50{
  51        int i;
  52        int nent_expected = 10;
  53        u32 test_val;
  54
  55        TEST_ASSERT(hv_cpuid_entries->nent == nent_expected,
  56                    "KVM_GET_SUPPORTED_HV_CPUID should return %d entries"
  57                    " (returned %d)",
  58                    nent_expected, hv_cpuid_entries->nent);
  59
  60        for (i = 0; i < hv_cpuid_entries->nent; i++) {
  61                struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];
  62
  63                TEST_ASSERT((entry->function >= 0x40000000) &&
  64                            (entry->function <= 0x40000082),
  65                            "function %x is our of supported range",
  66                            entry->function);
  67
  68                TEST_ASSERT(entry->index == 0,
  69                            ".index field should be zero");
  70
  71                TEST_ASSERT(entry->flags == 0,
  72                            ".flags field should be zero");
  73
  74                TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
  75                            !entry->padding[2], "padding should be zero");
  76
  77                switch (entry->function) {
  78                case 0x40000000:
  79                        test_val = 0x40000082;
  80
  81                        TEST_ASSERT(entry->eax == test_val,
  82                                    "Wrong max leaf report in 0x40000000.EAX: %x"
  83                                    " (evmcs=%d)",
  84                                    entry->eax, evmcs_expected
  85                                );
  86                        break;
  87                case 0x40000004:
  88                        test_val = entry->eax & (1UL << 18);
  89
  90                        TEST_ASSERT(!!test_val == !smt_possible(),
  91                                    "NoNonArchitecturalCoreSharing bit"
  92                                    " doesn't reflect SMT setting");
  93                        break;
  94                case 0x4000000A:
  95                        TEST_ASSERT(entry->eax & (1UL << 19),
  96                                    "Enlightened MSR-Bitmap should always be supported"
  97                                    " 0x40000000.EAX: %x", entry->eax);
  98                        if (evmcs_expected)
  99                                TEST_ASSERT((entry->eax & 0xffff) == 0x101,
 100                                    "Supported Enlightened VMCS version range is supposed to be 1:1"
 101                                    " 0x40000000.EAX: %x", entry->eax);
 102
 103                        break;
 104                default:
 105                        break;
 106
 107                }
 108                /*
 109                 * If needed for debug:
 110                 * fprintf(stdout,
 111                 *      "CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
 112                 *      entry->function, entry->eax, entry->ebx, entry->ecx,
 113                 *      entry->edx);
 114                 */
 115        }
 116}
 117
 118void test_hv_cpuid_e2big(struct kvm_vm *vm, bool system)
 119{
 120        static struct kvm_cpuid2 cpuid = {.nent = 0};
 121        int ret;
 122
 123        if (!system)
 124                ret = _vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
 125        else
 126                ret = _kvm_ioctl(vm, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
 127
 128        TEST_ASSERT(ret == -1 && errno == E2BIG,
 129                    "%s KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
 130                    " it should have: %d %d", system ? "KVM" : "vCPU", ret, errno);
 131}
 132
 133int main(int argc, char *argv[])
 134{
 135        struct kvm_vm *vm;
 136        struct kvm_cpuid2 *hv_cpuid_entries;
 137
 138        /* Tell stdout not to buffer its content */
 139        setbuf(stdout, NULL);
 140
 141        if (!kvm_check_cap(KVM_CAP_HYPERV_CPUID)) {
 142                print_skip("KVM_CAP_HYPERV_CPUID not supported");
 143                exit(KSFT_SKIP);
 144        }
 145
 146        vm = vm_create_default(VCPU_ID, 0, guest_code);
 147
 148        /* Test vCPU ioctl version */
 149        test_hv_cpuid_e2big(vm, false);
 150
 151        hv_cpuid_entries = vcpu_get_supported_hv_cpuid(vm, VCPU_ID);
 152        test_hv_cpuid(hv_cpuid_entries, false);
 153        free(hv_cpuid_entries);
 154
 155        if (!nested_vmx_supported() ||
 156            !kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 157                print_skip("Enlightened VMCS is unsupported");
 158                goto do_sys;
 159        }
 160        vcpu_enable_evmcs(vm, VCPU_ID);
 161        hv_cpuid_entries = vcpu_get_supported_hv_cpuid(vm, VCPU_ID);
 162        test_hv_cpuid(hv_cpuid_entries, true);
 163        free(hv_cpuid_entries);
 164
 165do_sys:
 166        /* Test system ioctl version */
 167        if (!kvm_check_cap(KVM_CAP_SYS_HYPERV_CPUID)) {
 168                print_skip("KVM_CAP_SYS_HYPERV_CPUID not supported");
 169                goto out;
 170        }
 171
 172        test_hv_cpuid_e2big(vm, true);
 173
 174        hv_cpuid_entries = kvm_get_supported_hv_cpuid();
 175        test_hv_cpuid(hv_cpuid_entries, nested_vmx_supported());
 176
 177out:
 178        kvm_vm_free(vm);
 179
 180        return 0;
 181}
 182