/*
 * Hyper-V guest/hypervisor interaction
 *
 * Copyright (c) 2015-2018 Virtuozzo International GmbH.
 *
 * 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/main-loop.h"
#include "sysemu/kvm.h"
#include "hw/hyperv/hyperv.h"

struct HvSintRoute {
    uint32_t sint;
    CPUState *cs;
    int gsi;
    EventNotifier sint_set_notifier;
    EventNotifier sint_ack_notifier;
    HvSintAckClb sint_ack_clb;
    void *sint_ack_clb_data;
    unsigned refcount;
};

static CPUState *hyperv_find_vcpu(uint32_t vp_index)
{
    CPUState *cs = qemu_get_cpu(vp_index);
    assert(hyperv_vp_index(cs) == vp_index);
    return cs;
}

static void kvm_hv_sint_ack_handler(EventNotifier *notifier)
{
    HvSintRoute *sint_route = container_of(notifier, HvSintRoute,
                                           sint_ack_notifier);
    event_notifier_test_and_clear(notifier);
    sint_route->sint_ack_clb(sint_route->sint_ack_clb_data);
}

HvSintRoute *hyperv_sint_route_new(uint32_t vp_index, uint32_t sint,
                                   HvSintAckClb sint_ack_clb,
                                   void *sint_ack_clb_data)
{
    HvSintRoute *sint_route;
    EventNotifier *ack_notifier;
    int r, gsi;
    CPUState *cs;

    cs = hyperv_find_vcpu(vp_index);
    if (!cs) {
        return NULL;
    }

    sint_route = g_new0(HvSintRoute, 1);
    r = event_notifier_init(&sint_route->sint_set_notifier, false);
    if (r) {
        goto err;
    }

    ack_notifier = sint_ack_clb ? &sint_route->sint_ack_notifier : NULL;
    if (ack_notifier) {
        r = event_notifier_init(ack_notifier, false);
        if (r) {
            goto err_sint_set_notifier;
        }

        event_notifier_set_handler(ack_notifier, kvm_hv_sint_ack_handler);
    }

    gsi = kvm_irqchip_add_hv_sint_route(kvm_state, vp_index, sint);
    if (gsi < 0) {
        goto err_gsi;
    }

    r = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state,
                                           &sint_route->sint_set_notifier,
                                           ack_notifier, gsi);
    if (r) {
        goto err_irqfd;
    }
    sint_route->gsi = gsi;
    sint_route->sint_ack_clb = sint_ack_clb;
    sint_route->sint_ack_clb_data = sint_ack_clb_data;
    sint_route->cs = cs;
    sint_route->sint = sint;
    sint_route->refcount = 1;

    return sint_route;

err_irqfd:
    kvm_irqchip_release_virq(kvm_state, gsi);
err_gsi:
    if (ack_notifier) {
        event_notifier_set_handler(ack_notifier, NULL);
        event_notifier_cleanup(ack_notifier);
    }
err_sint_set_notifier:
    event_notifier_cleanup(&sint_route->sint_set_notifier);
err:
    g_free(sint_route);

    return NULL;
}

void hyperv_sint_route_ref(HvSintRoute *sint_route)
{
    sint_route->refcount++;
}

void hyperv_sint_route_unref(HvSintRoute *sint_route)
{
    if (!sint_route) {
        return;
    }

    assert(sint_route->refcount > 0);

    if (--sint_route->refcount) {
        return;
    }

    kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
                                          &sint_route->sint_set_notifier,
                                          sint_route->gsi);
    kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
    if (sint_route->sint_ack_clb) {
        event_notifier_set_handler(&sint_route->sint_ack_notifier, NULL);
        event_notifier_cleanup(&sint_route->sint_ack_notifier);
    }
    event_notifier_cleanup(&sint_route->sint_set_notifier);
    g_free(sint_route);
}

int hyperv_sint_route_set_sint(HvSintRoute *sint_route)
{
    return event_notifier_set(&sint_route->sint_set_notifier);
}