/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2023 Oxide Computer Company
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <libgen.h>
#include <sys/stat.h>
#include <errno.h>
#include <err.h>
#include <assert.h>
#include <sys/sysmacros.h>
#include <stdbool.h>
#include <pthread.h>
#include <signal.h>

#include <sys/vmm.h>
#include <sys/vmm_dev.h>
#include <sys/vmm_data.h>
#include <vmmapi.h>

#include "common.h"
#include "in_guest.h"

static pthread_t vcpu0_tid;
static bool timed_out = false;

static void *
vcpu0_thread(void *arg)
{
        struct vcpu *vcpu = arg;

        struct vm_entry ventry = { 0 };
        struct vm_exit vexit = { 0 };

        do {
                int err = vm_run(vcpu, &ventry, &vexit);
                if (err != 0) {
                        test_fail_errno(err, "error during vm_run()");
                }
                switch (vexit.exitcode) {
                case VM_EXITCODE_BOGUS:
                        /* We expect a BOGUS exit from the barrier */
                        return (NULL);
                default:
                        test_fail_vmexit(&vexit);
                }
        } while (true);
}

static void
sigalrm_handler(int sig)
{
        (void) pthread_cancel(vcpu0_tid);
        timed_out = true;
}

static void
configure_timeout(void)
{
        struct sigaction sa = {
                .sa_handler = sigalrm_handler,
        };
        struct sigaction old_sa;
        if (sigaction(SIGALRM, &sa, &old_sa) != 0) {
                test_fail_errno(errno,
                    "could not prep signal handling for bad access");
        }

        /* set a simple 1s-in-the-future alarm */
        (void) alarm(1);
}

int
main(int argc, char *argv[])
{
        const char *suite_name = basename(argv[0]);
        struct vmctx *ctx;
        struct vcpu *vcpu;
        int err;

        ctx = test_initialize(suite_name);
        assert(ctx != NULL);

        if ((vcpu = vm_vcpu_open(ctx, 0)) == NULL) {
                test_fail_errno(errno, "Could not open vcpu0");
        }

        /* Activate vcpu0 as if it were running */
        err = vm_activate_cpu(vcpu);
        if (err != 0) {
                test_fail_errno(err, "could not activate vcpu0");
        }

        /*
         * Set unorthodox run-state for vcpu0: wait-for-SIPI
         * This way it will dawdle in the kernel during VM_RUN, despite there
         * being no code to execute.  Normally the emulated APIC would not allow
         * a CPU to SIPI itself, making this state impossible to reach.
         */
        err = vm_set_run_state(vcpu, VRS_INIT, 0);
        if (err != 0) {
                test_fail_errno(err, "could not set vcpu0 run_state");
        }

        /* Get the vCPU thread running (and stuck in the kernel)... */
        if (pthread_create(&vcpu0_tid, NULL, vcpu0_thread, (void *)vcpu) != 0) {
                test_fail_errno(errno, "could not create thread for vcpu0");
        }

        /* configure a timeout in case the barrier failed */
        configure_timeout();

        /* ... then issue our barrier: */
        err = vm_vcpu_barrier(vcpu);
        if (err != 0) {
                test_fail_errno(err, "failed to issue vcpu barrier");
        }

        void *status = NULL;
        if (pthread_join(vcpu0_tid, &status) != 0) {
                test_fail_errno(errno, "could not join thread for vcpu0");
        }

        /* cancel any timeout now that thread was joined */
        (void) alarm(0);

        if (timed_out) {
                test_fail_msg("timed out while waiting for barrier\n");
        }

        test_pass();
}