// 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"
#include "vmx.h"

#define VCPU_ID 0

static void guest_code(void)
{
}

static bool smt_possible(void)
{
        char buf[16];
        FILE *f;
        bool res = true;

        f = fopen("/sys/devices/system/cpu/smt/control", "r");
        if (f) {
                if (fread(buf, sizeof(*buf), sizeof(buf), f) > 0) {
                        if (!strncmp(buf, "forceoff", 8) ||
                            !strncmp(buf, "notsupported", 12))
                                res = false;
                }
                fclose(f);
        }

        return res;
}

static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
                          bool evmcs_enabled)
{
        int i;
        int nent = 9;
        u32 test_val;

        if (evmcs_enabled)
                nent += 1; /* 0x4000000A */

        TEST_ASSERT(hv_cpuid_entries->nent == nent,
                    "KVM_GET_SUPPORTED_HV_CPUID should return %d entries"
                    " with evmcs=%d (returned %d)",
                    nent, evmcs_enabled, 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 <= 0x40000082),
                            "function %x is our of supported range",
                            entry->function);

                TEST_ASSERT(evmcs_enabled || (entry->function != 0x4000000A),
                            "0x4000000A leaf should not be reported");

                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], "padding should be zero");

                switch (entry->function) {
                case 0x40000000:
                        test_val = 0x40000082;

                        TEST_ASSERT(entry->eax == test_val,
                                    "Wrong max leaf report in 0x40000000.EAX: %x"
                                    " (evmcs=%d)",
                                    entry->eax, evmcs_enabled
                                );
                        break;
                case 0x40000004:
                        test_val = entry->eax & (1UL << 18);

                        TEST_ASSERT(!!test_val == !smt_possible(),
                                    "NoNonArchitecturalCoreSharing bit"
                                    " doesn't reflect SMT setting");
                        break;
                }

                /*
                 * 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;

        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, stage;
        struct kvm_cpuid2 *hv_cpuid_entries;
        bool evmcs_enabled;

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

        rv = kvm_check_cap(KVM_CAP_HYPERV_CPUID);
        if (!rv) {
                print_skip("KVM_CAP_HYPERV_CPUID not supported");
                exit(KSFT_SKIP);
        }

        for (stage = 0; stage < 3; stage++) {
                evmcs_enabled = false;

                vm = vm_create_default(VCPU_ID, 0, guest_code);
                switch (stage) {
                case 0:
                        test_hv_cpuid_e2big(vm);
                        continue;
                case 1:
                        break;
                case 2:
                        if (!nested_vmx_supported() ||
                            !kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
                                print_skip("Enlightened VMCS is unsupported");
                                continue;
                        }
                        vcpu_enable_evmcs(vm, VCPU_ID);
                        evmcs_enabled = true;
                        break;
                }

                hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
                test_hv_cpuid(hv_cpuid_entries, evmcs_enabled);
                free(hv_cpuid_entries);
                kvm_vm_free(vm);
        }

        return 0;
}