/*
 * QEMU KVM support
 *
 * Copyright IBM, Corp. 2008
 *           Red Hat, Inc. 2008
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *  Glauber Costa     <gcosta@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 *
 */

#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "sysemu/kvm.h"
#include "sysemu/kvm_int.h"
#include "sysemu/runstate.h"
#include "sysemu/cpus.h"
#include "qemu/guest-random.h"
#include "qapi/error.h"

#include <linux/kvm.h>
#include "kvm-cpus.h"

static void *kvm_vcpu_thread_fn(void *arg)
{
    CPUState *cpu = arg;
    int r;

    rcu_register_thread();

    qemu_mutex_lock_iothread();
    qemu_thread_get_self(cpu->thread);
    cpu->thread_id = qemu_get_thread_id();
    cpu->neg.can_do_io = true;
    current_cpu = cpu;

    r = kvm_init_vcpu(cpu, &error_fatal);
    kvm_init_cpu_signals(cpu);

    /* signal CPU creation */
    cpu_thread_signal_created(cpu);
    qemu_guest_random_seed_thread_part2(cpu->random_seed);

    do {
        if (cpu_can_run(cpu)) {
            r = kvm_cpu_exec(cpu);
            if (r == EXCP_DEBUG) {
                cpu_handle_guest_debug(cpu);
            }
        }
        qemu_wait_io_event(cpu);
    } while (!cpu->unplug || cpu_can_run(cpu));

    kvm_destroy_vcpu(cpu);
    cpu_thread_signal_destroyed(cpu);
    qemu_mutex_unlock_iothread();
    rcu_unregister_thread();
    return NULL;
}

static void kvm_start_vcpu_thread(CPUState *cpu)
{
    char thread_name[VCPU_THREAD_NAME_SIZE];

    cpu->thread = g_malloc0(sizeof(QemuThread));
    cpu->halt_cond = g_malloc0(sizeof(QemuCond));
    qemu_cond_init(cpu->halt_cond);
    snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/KVM",
             cpu->cpu_index);
    qemu_thread_create(cpu->thread, thread_name, kvm_vcpu_thread_fn,
                       cpu, QEMU_THREAD_JOINABLE);
}

static bool kvm_vcpu_thread_is_idle(CPUState *cpu)
{
    return !kvm_halt_in_kernel();
}

static bool kvm_cpus_are_resettable(void)
{
    return !kvm_enabled() || kvm_cpu_check_are_resettable();
}

#ifdef KVM_CAP_SET_GUEST_DEBUG
static int kvm_update_guest_debug_ops(CPUState *cpu)
{
    return kvm_update_guest_debug(cpu, 0);
}
#endif

static void kvm_accel_ops_class_init(ObjectClass *oc, void *data)
{
    AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);

    ops->create_vcpu_thread = kvm_start_vcpu_thread;
    ops->cpu_thread_is_idle = kvm_vcpu_thread_is_idle;
    ops->cpus_are_resettable = kvm_cpus_are_resettable;
    ops->synchronize_post_reset = kvm_cpu_synchronize_post_reset;
    ops->synchronize_post_init = kvm_cpu_synchronize_post_init;
    ops->synchronize_state = kvm_cpu_synchronize_state;
    ops->synchronize_pre_loadvm = kvm_cpu_synchronize_pre_loadvm;

#ifdef KVM_CAP_SET_GUEST_DEBUG
    ops->update_guest_debug = kvm_update_guest_debug_ops;
    ops->supports_guest_debug = kvm_supports_guest_debug;
    ops->insert_breakpoint = kvm_insert_breakpoint;
    ops->remove_breakpoint = kvm_remove_breakpoint;
    ops->remove_all_breakpoints = kvm_remove_all_breakpoints;
#endif
}

static const TypeInfo kvm_accel_ops_type = {
    .name = ACCEL_OPS_NAME("kvm"),

    .parent = TYPE_ACCEL_OPS,
    .class_init = kvm_accel_ops_class_init,
    .abstract = true,
};

static void kvm_accel_ops_register_types(void)
{
    type_register_static(&kvm_accel_ops_type);
}
type_init(kvm_accel_ops_register_types);