// 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"

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;

        /* Read kvm stats header */
        header = malloc(sizeof(*header));
        TEST_ASSERT(header, "Allocate memory for stats header");

        ret = read(stats_fd, header, sizeof(*header));
        TEST_ASSERT(ret == sizeof(*header), "Read stats header");
        size_desc = sizeof(*stats_desc) + header->name_size;

        /* Read kvm stats id string */
        id = malloc(header->name_size);
        TEST_ASSERT(id, "Allocate memory for id string");
        ret = read(stats_fd, id, header->name_size);
        TEST_ASSERT(ret == header->name_size, "Read id string");

        /* 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) {
                printf("No KVM stats defined!");
                return;
        }
        /* Check overlap */
        TEST_ASSERT(header->desc_offset > 0 && header->data_offset > 0
                        && header->desc_offset >= sizeof(*header)
                        && 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");

        /* Allocate memory for stats descriptors */
        stats_desc = calloc(header->num_desc, size_desc);
        TEST_ASSERT(stats_desc, "Allocate memory for stats descriptors");
        /* Read kvm stats descriptors */
        ret = pread(stats_fd, stats_desc,
                        size_desc * header->num_desc, header->desc_offset);
        TEST_ASSERT(ret == size_desc * header->num_desc,
                        "Read KVM stats descriptors");

        /* Sanity check for fields in descriptors */
        for (i = 0; i < header->num_desc; ++i) {
                pdesc = (void *)stats_desc + i * size_desc;
                /* Check type,unit,base boundaries */
                TEST_ASSERT((pdesc->flags & KVM_STATS_TYPE_MASK)
                                <= KVM_STATS_TYPE_MAX, "Unknown KVM stats type");
                TEST_ASSERT((pdesc->flags & KVM_STATS_UNIT_MASK)
                                <= KVM_STATS_UNIT_MAX, "Unknown KVM stats unit");
                TEST_ASSERT((pdesc->flags & KVM_STATS_BASE_MASK)
                                <= KVM_STATS_BASE_MAX, "Unknown KVM stats 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
                 */
                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 unit");
                        break;
                case KVM_STATS_UNIT_SECONDS:
                        TEST_ASSERT(pdesc->exponent <= 0,
                                        "Unsupported KVM stats unit");
                        break;
                }
                /* Check name string */
                TEST_ASSERT(strlen(pdesc->name) < header->name_size,
                                "KVM stats name(%s) too long", pdesc->name);
                /* Check size field, which should not be zero */
                TEST_ASSERT(pdesc->size, "KVM descriptor(%s) with size of 0",
                                pdesc->name);
                size_data += pdesc->size * sizeof(*stats_data);
        }
        /* Check overlap */
        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");
        /* Check stats offset */
        for (i = 0; i < header->num_desc; ++i) {
                pdesc = (void *)stats_desc + i * size_desc;
                TEST_ASSERT(pdesc->offset < size_data,
                        "Invalid offset (%u) for stats: %s",
                        pdesc->offset, pdesc->name);
        }

        /* 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 */
        size_data = 0;
        for (i = 0; i < header->num_desc; ++i) {
                pdesc = (void *)stats_desc + i * size_desc;
                ret = pread(stats_fd, stats_data,
                                pdesc->size * sizeof(*stats_data),
                                header->data_offset + size_data);
                TEST_ASSERT(ret == pdesc->size * sizeof(*stats_data),
                                "Read data of KVM stats: %s", pdesc->name);
                size_data += pdesc->size * sizeof(*stats_data);
        }

        free(stats_data);
        free(stats_desc);
        free(id);
        free(header);
}


static void vm_stats_test(struct kvm_vm *vm)
{
        int stats_fd;

        /* Get fd for VM stats */
        stats_fd = vm_get_stats_fd(vm);
        TEST_ASSERT(stats_fd >= 0, "Get VM stats fd");

        stats_test(stats_fd);
        close(stats_fd);
        TEST_ASSERT(fcntl(stats_fd, F_GETFD) == -1, "Stats fd not freed");
}

static void vcpu_stats_test(struct kvm_vm *vm, int vcpu_id)
{
        int stats_fd;

        /* Get fd for VCPU stats */
        stats_fd = vcpu_get_stats_fd(vm, vcpu_id);
        TEST_ASSERT(stats_fd >= 0, "Get VCPU stats fd");

        stats_test(stats_fd);
        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 i, j;
        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;
        }

        /* Check the extension for binary stats */
        if (kvm_check_cap(KVM_CAP_BINARY_STATS_FD) <= 0) {
                print_skip("Binary form statistics interface is not supported");
                exit(KSFT_SKIP);
        }

        /* Create VMs and VCPUs */
        vms = malloc(sizeof(vms[0]) * max_vm);
        TEST_ASSERT(vms, "Allocate memory for storing VM pointers");
        for (i = 0; i < max_vm; ++i) {
                vms[i] = vm_create(VM_MODE_DEFAULT,
                                DEFAULT_GUEST_PHY_PAGES, O_RDWR);
                for (j = 0; j < max_vcpu; ++j)
                        vm_vcpu_add(vms[i], j);
        }

        /* Check stats read for every VM and VCPU */
        for (i = 0; i < max_vm; ++i) {
                vm_stats_test(vms[i]);
                for (j = 0; j < max_vcpu; ++j)
                        vcpu_stats_test(vms[i], j);
        }

        for (i = 0; i < max_vm; ++i)
                kvm_vm_free(vms[i]);
        free(vms);
        return 0;
}