// SPDX-License-Identifier: GPL-2.0-only
/*
 * hello_el2 - Basic KVM selftest for VM running at EL2 with E2H=RES1
 *
 * Copyright 2025 Google LLC
 */
#include "kvm_util.h"
#include "processor.h"
#include "test_util.h"
#include "ucall.h"

#include <asm/sysreg.h>

static void guest_code(void)
{
        u64 mmfr0 = read_sysreg_s(SYS_ID_AA64MMFR0_EL1);
        u64 mmfr1 = read_sysreg_s(SYS_ID_AA64MMFR1_EL1);
        u64 mmfr4 = read_sysreg_s(SYS_ID_AA64MMFR4_EL1);
        u8 e2h0 = SYS_FIELD_GET(ID_AA64MMFR4_EL1, E2H0, mmfr4);

        GUEST_ASSERT_EQ(get_current_el(), 2);
        GUEST_ASSERT(read_sysreg(hcr_el2) & HCR_EL2_E2H);
        GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR1_EL1, VH, mmfr1),
                        ID_AA64MMFR1_EL1_VH_IMP);

        /*
         * Traps of the complete ID register space are IMPDEF without FEAT_FGT,
         * which is really annoying to deal with in KVM describing E2H as RES1.
         *
         * If the implementation doesn't honor the trap then expect the register
         * to return all zeros.
         */
        if (e2h0 == ID_AA64MMFR4_EL1_E2H0_IMP)
                GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR0_EL1, FGT, mmfr0),
                                ID_AA64MMFR0_EL1_FGT_NI);
        else
                GUEST_ASSERT_EQ(e2h0, ID_AA64MMFR4_EL1_E2H0_NI_NV1);

        GUEST_DONE();
}

int main(void)
{
        struct kvm_vcpu_init init;
        struct kvm_vcpu *vcpu;
        struct kvm_vm *vm;
        struct ucall uc;

        TEST_REQUIRE(kvm_check_cap(KVM_CAP_ARM_EL2));

        vm = vm_create(1);

        kvm_get_default_vcpu_target(vm, &init);
        init.features[0] |= BIT(KVM_ARM_VCPU_HAS_EL2);
        vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code);
        kvm_arch_vm_finalize_vcpus(vm);

        vcpu_run(vcpu);
        switch (get_ucall(vcpu, &uc)) {
        case UCALL_DONE:
                break;
        case UCALL_ABORT:
                REPORT_GUEST_ASSERT(uc);
                break;
        default:
                TEST_FAIL("Unhandled ucall: %ld\n", uc.cmd);
        }

        kvm_vm_free(vm);
        return 0;
}