// SPDX-License-Identifier: GPL-2.0-only
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
#include "vmx.h"

#include <string.h>
#include <sys/ioctl.h>

#include "kselftest.h"

#define ARBITRARY_IO_PORT 0x2000

static struct kvm_vm *vm;

static void l2_guest_code(void)
{
        /*
         * Generate an exit to L0 userspace, i.e. main(), via I/O to an
         * arbitrary port.
         */
        asm volatile("inb %%dx, %%al"
                     : : [port] "d" (ARBITRARY_IO_PORT) : "rax");
}

static void l1_guest_code(struct vmx_pages *vmx_pages)
{
#define L2_GUEST_STACK_SIZE 64
        unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];

        GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
        GUEST_ASSERT(load_vmcs(vmx_pages));

        /* Prepare the VMCS for L2 execution. */
        prepare_vmcs(vmx_pages, l2_guest_code,
                     &l2_guest_stack[L2_GUEST_STACK_SIZE]);

        /*
         * L2 must be run without unrestricted guest, verify that the selftests
         * library hasn't enabled it.  Because KVM selftests jump directly to
         * 64-bit mode, unrestricted guest support isn't required.
         */
        GUEST_ASSERT(!(vmreadz(CPU_BASED_VM_EXEC_CONTROL) & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) ||
                     !(vmreadz(SECONDARY_VM_EXEC_CONTROL) & SECONDARY_EXEC_UNRESTRICTED_GUEST));

        GUEST_ASSERT(!vmlaunch());

        /* L2 should triple fault after main() stuffs invalid guest state. */
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_TRIPLE_FAULT);
        GUEST_DONE();
}

int main(int argc, char *argv[])
{
        vm_vaddr_t vmx_pages_gva;
        struct kvm_sregs sregs;
        struct kvm_vcpu *vcpu;
        struct kvm_run *run;
        struct ucall uc;

        TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));

        vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);

        /* Allocate VMX pages and shared descriptors (vmx_pages). */
        vcpu_alloc_vmx(vm, &vmx_pages_gva);
        vcpu_args_set(vcpu, 1, vmx_pages_gva);

        vcpu_run(vcpu);

        run = vcpu->run;

        /*
         * The first exit to L0 userspace should be an I/O access from L2.
         * Running L1 should launch L2 without triggering an exit to userspace.
         */
        TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

        TEST_ASSERT(run->io.port == ARBITRARY_IO_PORT,
                    "Expected IN from port %d from L2, got port %d",
                    ARBITRARY_IO_PORT, run->io.port);

        /*
         * Stuff invalid guest state for L2 by making TR unusuable.  The next
         * KVM_RUN should induce a TRIPLE_FAULT in L2 as KVM doesn't support
         * emulating invalid guest state for L2.
         */
        memset(&sregs, 0, sizeof(sregs));
        vcpu_sregs_get(vcpu, &sregs);
        sregs.tr.unusable = 1;
        vcpu_sregs_set(vcpu, &sregs);

        vcpu_run(vcpu);

        switch (get_ucall(vcpu, &uc)) {
        case UCALL_DONE:
                break;
        case UCALL_ABORT:
                REPORT_GUEST_ASSERT(uc);
        default:
                TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
        }
}