kvm/x86_64/hyperv_cpuid.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Test for x86 KVM_CAP_HYPERV_CPUID
0004  *
0005  * Copyright (C) 2018, Red Hat, Inc.
0006  *
0007  * This work is licensed under the terms of the GNU GPL, version 2.
0008  *
0009  */
0010
0011 #define _GNU_SOURCE /* for program_invocation_short_name */
0012 #include <fcntl.h>
0013 #include <stdio.h>
0014 #include <stdlib.h>
0015 #include <string.h>
0016 #include <sys/ioctl.h>
0017
0018 #include "test_util.h"
0019 #include "kvm_util.h"
0020 #include "processor.h"
0021 #include "vmx.h"
0022
0023 static void guest_code(void)
0024 {
0025 }
0026
0027 static bool smt_possible(void)
0028 {
0029     char buf[16];
0030     FILE *f;
0031     bool res = true;
0032
0033     f = fopen("/sys/devices/system/cpu/smt/control", "r");
0034     if (f) {
0035         if (fread(buf, sizeof(*buf), sizeof(buf), f) > 0) {
0036             if (!strncmp(buf, "forceoff", 8) ||
0037                 !strncmp(buf, "notsupported", 12))
0038                 res = false;
0039         }
0040         fclose(f);
0041     }
0042
0043     return res;
0044 }
0045
0046 static void test_hv_cpuid(const struct kvm_cpuid2 *hv_cpuid_entries,
0047               bool evmcs_expected)
0048 {
0049     int i;
0050     int nent_expected = 10;
0051     u32 test_val;
0052
0053     TEST_ASSERT(hv_cpuid_entries->nent == nent_expected,
0054             "KVM_GET_SUPPORTED_HV_CPUID should return %d entries"
0055             " (returned %d)",
0056             nent_expected, hv_cpuid_entries->nent);
0057
0058     for (i = 0; i < hv_cpuid_entries->nent; i++) {
0059         const struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];
0060
0061         TEST_ASSERT((entry->function >= 0x40000000) &&
0062                 (entry->function <= 0x40000082),
0063                 "function %x is our of supported range",
0064                 entry->function);
0065
0066         TEST_ASSERT(entry->index == 0,
0067                 ".index field should be zero");
0068
0069         TEST_ASSERT(entry->flags == 0,
0070                 ".flags field should be zero");
0071
0072         TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
0073                 !entry->padding[2], "padding should be zero");
0074
0075         switch (entry->function) {
0076         case 0x40000000:
0077             test_val = 0x40000082;
0078
0079             TEST_ASSERT(entry->eax == test_val,
0080                     "Wrong max leaf report in 0x40000000.EAX: %x"
0081                     " (evmcs=%d)",
0082                     entry->eax, evmcs_expected
0083                 );
0084             break;
0085         case 0x40000004:
0086             test_val = entry->eax & (1UL << 18);
0087
0088             TEST_ASSERT(!!test_val == !smt_possible(),
0089                     "NoNonArchitecturalCoreSharing bit"
0090                     " doesn't reflect SMT setting");
0091             break;
0092         case 0x4000000A:
0093             TEST_ASSERT(entry->eax & (1UL << 19),
0094                     "Enlightened MSR-Bitmap should always be supported"
0095                     " 0x40000000.EAX: %x", entry->eax);
0096             if (evmcs_expected)
0097                 TEST_ASSERT((entry->eax & 0xffff) == 0x101,
0098                     "Supported Enlightened VMCS version range is supposed to be 1:1"
0099                     " 0x40000000.EAX: %x", entry->eax);
0100
0101             break;
0102         default:
0103             break;
0104
0105         }
0106         /*
0107          * If needed for debug:
0108          * fprintf(stdout,
0109          *  "CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
0110          *  entry->function, entry->eax, entry->ebx, entry->ecx,
0111          *  entry->edx);
0112          */
0113     }
0114 }
0115
0116 void test_hv_cpuid_e2big(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
0117 {
0118     static struct kvm_cpuid2 cpuid = {.nent = 0};
0119     int ret;
0120
0121     if (vcpu)
0122         ret = __vcpu_ioctl(vcpu, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
0123     else
0124         ret = __kvm_ioctl(vm->kvm_fd, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
0125
0126     TEST_ASSERT(ret == -1 && errno == E2BIG,
0127             "%s KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
0128             " it should have: %d %d", !vcpu ? "KVM" : "vCPU", ret, errno);
0129 }
0130
0131 int main(int argc, char *argv[])
0132 {
0133     struct kvm_vm *vm;
0134     const struct kvm_cpuid2 *hv_cpuid_entries;
0135     struct kvm_vcpu *vcpu;
0136
0137     /* Tell stdout not to buffer its content */
0138     setbuf(stdout, NULL);
0139
0140     TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));
0141
0142     vm = vm_create_with_one_vcpu(&vcpu, guest_code);
0143
0144     /* Test vCPU ioctl version */
0145     test_hv_cpuid_e2big(vm, vcpu);
0146
0147     hv_cpuid_entries = vcpu_get_supported_hv_cpuid(vcpu);
0148     test_hv_cpuid(hv_cpuid_entries, false);
0149     free((void *)hv_cpuid_entries);
0150
0151     if (!kvm_cpu_has(X86_FEATURE_VMX) ||
0152         !kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
0153         print_skip("Enlightened VMCS is unsupported");
0154         goto do_sys;
0155     }
0156     vcpu_enable_evmcs(vcpu);
0157     hv_cpuid_entries = vcpu_get_supported_hv_cpuid(vcpu);
0158     test_hv_cpuid(hv_cpuid_entries, true);
0159     free((void *)hv_cpuid_entries);
0160
0161 do_sys:
0162     /* Test system ioctl version */
0163     if (!kvm_has_cap(KVM_CAP_SYS_HYPERV_CPUID)) {
0164         print_skip("KVM_CAP_SYS_HYPERV_CPUID not supported");
0165         goto out;
0166     }
0167
0168     test_hv_cpuid_e2big(vm, NULL);
0169
0170     hv_cpuid_entries = kvm_get_supported_hv_cpuid();
0171     test_hv_cpuid(hv_cpuid_entries, kvm_cpu_has(X86_FEATURE_VMX));
0172
0173 out:
0174     kvm_vm_free(vm);
0175
0176     return 0;
0177 }