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KVM: selftests: Add hyperv_cpuid test
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Add a simple (and stupid) hyperv_cpuid test: check that we got the
expected number of entries with and without Enlightened VMCS enabled
and that all currently reserved fields are zeroed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Vitaly Kuznetsov authored and Paolo Bonzini committed Dec 14, 2018
1 parent 7e50c42 commit 7edcb73
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1 change: 1 addition & 0 deletions tools/testing/selftests/kvm/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
TEST_GEN_PROGS_x86_64 += x86_64/cr4_cpuid_sync_test
TEST_GEN_PROGS_x86_64 += x86_64/state_test
TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
TEST_GEN_PROGS_x86_64 += dirty_log_test
TEST_GEN_PROGS_x86_64 += clear_dirty_log_test

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157 changes: 157 additions & 0 deletions tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,157 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Test for x86 KVM_CAP_HYPERV_CPUID
*
* Copyright (C) 2018, Red Hat, Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2.
*
*/

#define _GNU_SOURCE /* for program_invocation_short_name */
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>

#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"

#define VCPU_ID 0

static void guest_code(void)
{
}

static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
int evmcs_enabled)
{
int i;

if (!evmcs_enabled)
TEST_ASSERT(hv_cpuid_entries->nent == 6,
"KVM_GET_SUPPORTED_HV_CPUID should return 6 entries"
" when Enlightened VMCS is disabled (returned %d)",
hv_cpuid_entries->nent);
else
TEST_ASSERT(hv_cpuid_entries->nent == 7,
"KVM_GET_SUPPORTED_HV_CPUID should return 7 entries"
" when Enlightened VMCS is enabled (returned %d)",
hv_cpuid_entries->nent);

for (i = 0; i < hv_cpuid_entries->nent; i++) {
struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];

TEST_ASSERT((entry->function >= 0x40000000) &&
(entry->function <= 0x4000000A),
"function %lx is our of supported range",
entry->function);

TEST_ASSERT(entry->index == 0,
".index field should be zero");

TEST_ASSERT(entry->index == 0,
".index field should be zero");

TEST_ASSERT(entry->flags == 0,
".flags field should be zero");

TEST_ASSERT(entry->padding[0] == entry->padding[1]
== entry->padding[2] == 0,
".index field should be zero");

/*
* If needed for debug:
* fprintf(stdout,
* "CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
* entry->function, entry->eax, entry->ebx, entry->ecx,
* entry->edx);
*/
}

}

void test_hv_cpuid_e2big(struct kvm_vm *vm)
{
static struct kvm_cpuid2 cpuid = {.nent = 0};
int ret;

ret = _vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);

TEST_ASSERT(ret == -1 && errno == E2BIG,
"KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
" it should have: %d %d", ret, errno);
}


struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(struct kvm_vm *vm)
{
int nent = 20; /* should be enough */
static struct kvm_cpuid2 *cpuid;
int ret;

cpuid = malloc(sizeof(*cpuid) + nent * sizeof(struct kvm_cpuid_entry2));

if (!cpuid) {
perror("malloc");
abort();
}

cpuid->nent = nent;

vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, cpuid);

return cpuid;
}


int main(int argc, char *argv[])
{
struct kvm_vm *vm;
int rv;
uint16_t evmcs_ver;
struct kvm_cpuid2 *hv_cpuid_entries;
struct kvm_enable_cap enable_evmcs_cap = {
.cap = KVM_CAP_HYPERV_ENLIGHTENED_VMCS,
.args[0] = (unsigned long)&evmcs_ver
};

/* Tell stdout not to buffer its content */
setbuf(stdout, NULL);

rv = kvm_check_cap(KVM_CAP_HYPERV_CPUID);
if (!rv) {
fprintf(stderr,
"KVM_CAP_HYPERV_CPUID not supported, skip test\n");
exit(KSFT_SKIP);
}

/* Create VM */
vm = vm_create_default(VCPU_ID, 0, guest_code);

test_hv_cpuid_e2big(vm);

hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
if (!hv_cpuid_entries)
return 1;

test_hv_cpuid(hv_cpuid_entries, 0);

free(hv_cpuid_entries);

vcpu_ioctl(vm, VCPU_ID, KVM_ENABLE_CAP, &enable_evmcs_cap);

hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
if (!hv_cpuid_entries)
return 1;

test_hv_cpuid(hv_cpuid_entries, 1);

free(hv_cpuid_entries);

kvm_vm_free(vm);

return 0;
}

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