// SPDX-License-Identifier: GPL-2.0-only
/*
* kvm_binary_stats_test
*
* Copyright (C) 2021, Google LLC.
*
* Test the fd-based interface for KVM statistics.
*/
#define _GNU_SOURCE /* for program_invocation_short_name */
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "test_util.h"
#include "kvm_util.h"
#include "asm/kvm.h"
#include "linux/kvm.h"
#include "kselftest.h"
static void stats_test(int stats_fd)
{
ssize_t ret;
int i;
size_t size_desc;
size_t size_data = 0;
struct kvm_stats_header header;
char *id;
struct kvm_stats_desc *stats_desc;
u64 *stats_data;
struct kvm_stats_desc *pdesc;
u32 type, unit, base;
/* Read kvm stats header */
read_stats_header(stats_fd, &header);
size_desc = get_stats_descriptor_size(&header);
/* Read kvm stats id string */
id = malloc(header.name_size);
TEST_ASSERT(id, "Allocate memory for id string");
ret = pread(stats_fd, id, header.name_size, sizeof(header));
TEST_ASSERT(ret == header.name_size,
"Expected header size '%u', read '%lu' bytes",
header.name_size, ret);
/* Check id string, that should start with "kvm" */
TEST_ASSERT(!strncmp(id, "kvm", 3) && strlen(id) < header.name_size,
"Invalid KVM stats type, id: %s", id);
/* Sanity check for other fields in header */
if (header.num_desc == 0) {
ksft_print_msg("No KVM stats defined!\n");
return;
}
/*
* The descriptor and data offsets must be valid, they must not overlap
* the header, and the descriptor and data blocks must not overlap each
* other. Note, the data block is rechecked after its size is known.
*/
TEST_ASSERT(header.desc_offset && header.desc_offset >= sizeof(header) &&
header.data_offset && header.data_offset >= sizeof(header),
"Invalid offset fields in header");
TEST_ASSERT(header.desc_offset > header.data_offset ||
(header.desc_offset + size_desc * header.num_desc <= header.data_offset),
"Descriptor block is overlapped with data block");
/* Read kvm stats descriptors */
stats_desc = read_stats_descriptors(stats_fd, &header);
/* Sanity check for fields in descriptors */
for (i = 0; i < header.num_desc; ++i) {
pdesc = get_stats_descriptor(stats_desc, i, &header);
type = pdesc->flags & KVM_STATS_TYPE_MASK;
unit = pdesc->flags & KVM_STATS_UNIT_MASK;
base = pdesc->flags & KVM_STATS_BASE_MASK;
/* Check name string */
TEST_ASSERT(strlen(pdesc->name) < header.name_size,
"KVM stats name (index: %d) too long", i);
/* Check type,unit,base boundaries */
TEST_ASSERT(type <= KVM_STATS_TYPE_MAX,
"Unknown KVM stats (%s) type: %u", pdesc->name, type);
TEST_ASSERT(unit <= KVM_STATS_UNIT_MAX,
"Unknown KVM stats (%s) unit: %u", pdesc->name, unit);
TEST_ASSERT(base <= KVM_STATS_BASE_MAX,
"Unknown KVM stats (%s) base: %u", pdesc->name, base);
/*
* Check exponent for stats unit
* Exponent for counter should be greater than or equal to 0
* Exponent for unit bytes should be greater than or equal to 0
* Exponent for unit seconds should be less than or equal to 0
* Exponent for unit clock cycles should be greater than or
* equal to 0
* Exponent for unit boolean should be 0
*/
switch (pdesc->flags & KVM_STATS_UNIT_MASK) {
case KVM_STATS_UNIT_NONE:
case KVM_STATS_UNIT_BYTES:
case KVM_STATS_UNIT_CYCLES:
TEST_ASSERT(pdesc->exponent >= 0,
"Unsupported KVM stats (%s) exponent: %i",
pdesc->name, pdesc->exponent);
break;
case KVM_STATS_UNIT_SECONDS:
TEST_ASSERT(pdesc->exponent <= 0,
"Unsupported KVM stats (%s) exponent: %i",
pdesc->name, pdesc->exponent);
break;
case KVM_STATS_UNIT_BOOLEAN:
TEST_ASSERT(pdesc->exponent == 0,
"Unsupported KVM stats (%s) exponent: %d",
pdesc->name, pdesc->exponent);
break;
}
/* Check size field, which should not be zero */
TEST_ASSERT(pdesc->size,
"KVM descriptor(%s) with size of 0", pdesc->name);
/* Check bucket_size field */
switch (pdesc->flags & KVM_STATS_TYPE_MASK) {
case KVM_STATS_TYPE_LINEAR_HIST:
TEST_ASSERT(pdesc->bucket_size,
"Bucket size of Linear Histogram stats (%s) is zero",
pdesc->name);
break;
default:
TEST_ASSERT(!pdesc->bucket_size,
"Bucket size of stats (%s) is not zero",
pdesc->name);
}
size_data = max(size_data, pdesc->offset + pdesc->size * sizeof(*stats_data));
}
/*
* Now that the size of the data block is known, verify the data block
* doesn't overlap the descriptor block.
*/
TEST_ASSERT(header.data_offset >= header.desc_offset ||
header.data_offset + size_data <= header.desc_offset,
"Data block is overlapped with Descriptor block");
/* Check validity of all stats data size */
TEST_ASSERT(size_data >= header.num_desc * sizeof(*stats_data),
"Data size is not correct");
/* Allocate memory for stats data */
stats_data = malloc(size_data);
TEST_ASSERT(stats_data, "Allocate memory for stats data");
/* Read kvm stats data as a bulk */
ret = pread(stats_fd, stats_data, size_data, header.data_offset);
TEST_ASSERT(ret == size_data, "Read KVM stats data");
/* Read kvm stats data one by one */
for (i = 0; i < header.num_desc; ++i) {
pdesc = get_stats_descriptor(stats_desc, i, &header);
read_stat_data(stats_fd, &header, pdesc, stats_data,
pdesc->size);
}
free(stats_data);
free(stats_desc);
free(id);
close(stats_fd);
TEST_ASSERT(fcntl(stats_fd, F_GETFD) == -1, "Stats fd not freed");
}
#define DEFAULT_NUM_VM 4
#define DEFAULT_NUM_VCPU 4
/*
* Usage: kvm_bin_form_stats [#vm] [#vcpu]
* The first parameter #vm set the number of VMs being created.
* The second parameter #vcpu set the number of VCPUs being created.
* By default, DEFAULT_NUM_VM VM and DEFAULT_NUM_VCPU VCPU for the VM would be
* created for testing.
*/
int main(int argc, char *argv[])
{
int vm_stats_fds, *vcpu_stats_fds;
int i, j;
struct kvm_vcpu **vcpus;
struct kvm_vm **vms;
int max_vm = DEFAULT_NUM_VM;
int max_vcpu = DEFAULT_NUM_VCPU;
/* Get the number of VMs and VCPUs that would be created for testing. */
if (argc > 1) {
max_vm = strtol(argv[1], NULL, 0);
if (max_vm <= 0)
max_vm = DEFAULT_NUM_VM;
}
if (argc > 2) {
max_vcpu = strtol(argv[2], NULL, 0);
if (max_vcpu <= 0)
max_vcpu = DEFAULT_NUM_VCPU;
}
ksft_print_header();
/* Check the extension for binary stats */
TEST_REQUIRE(kvm_has_cap(KVM_CAP_BINARY_STATS_FD));
ksft_set_plan(max_vm);
/* Create VMs and VCPUs */
vms = malloc(sizeof(vms[0]) * max_vm);
TEST_ASSERT(vms, "Allocate memory for storing VM pointers");
vcpus = malloc(sizeof(struct kvm_vcpu *) * max_vm * max_vcpu);
TEST_ASSERT(vcpus, "Allocate memory for storing vCPU pointers");
/*
* Not per-VM as the array is populated, used, and invalidated within a
* single for-loop iteration.
*/
vcpu_stats_fds = calloc(max_vm, sizeof(*vcpu_stats_fds));
TEST_ASSERT(vcpu_stats_fds, "Allocate memory for VM stats fds");
for (i = 0; i < max_vm; ++i) {
vms[i] = vm_create_barebones();
for (j = 0; j < max_vcpu; ++j)
vcpus[i * max_vcpu + j] = __vm_vcpu_add(vms[i], j);
}
/*
* Check stats read for every VM and vCPU, with a variety of flavors.
* Note, stats_test() closes the passed in stats fd.
*/
for (i = 0; i < max_vm; ++i) {
/*
* Verify that creating multiple userspace references to a
* single stats file works and doesn't cause explosions.
*/
vm_stats_fds = vm_get_stats_fd(vms[i]);
stats_test(dup(vm_stats_fds));
/* Verify userspace can instantiate multiple stats files. */
stats_test(vm_get_stats_fd(vms[i]));
for (j = 0; j < max_vcpu; ++j) {
vcpu_stats_fds[j] = vcpu_get_stats_fd(vcpus[i * max_vcpu + j]);
stats_test(dup(vcpu_stats_fds[j]));
stats_test(vcpu_get_stats_fd(vcpus[i * max_vcpu + j]));
}
/*
* Close the VM fd and redo the stats tests. KVM should gift a
* reference (to the VM) to each stats fd, i.e. stats should
* still be accessible even after userspace has put its last
* _direct_ reference to the VM.
*/
kvm_vm_free(vms[i]);
stats_test(vm_stats_fds);
for (j = 0; j < max_vcpu; ++j)
stats_test(vcpu_stats_fds[j]);
ksft_test_result_pass("vm%i\n", i);
}
free(vms);
free(vcpus);
free(vcpu_stats_fds);
ksft_finished(); /* Print results and exit() accordingly */
}