// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "garnet/lib/machina/virtio_balloon.h"

#include <lib/fxl/logging.h>
#include <lib/svc/cpp/services.h>

namespace machina {

static constexpr char kVirtioBalloonUrl[] = "fuchsia-pkg://fuchsia.com/virtio_balloon#meta/virtio_balloon.cmx";

VirtioBalloon::VirtioBalloon(const PhysMem& phys_mem)
    : VirtioComponentDevice(
          phys_mem, VIRTIO_BALLOON_F_STATS_VQ | VIRTIO_BALLOON_F_DEFLATE_ON_OOM,
          fit::bind_member(this, &VirtioBalloon::ConfigureQueue),
          fit::bind_member(this, &VirtioBalloon::Ready)) {}

zx_status_t VirtioBalloon::AddPublicService(
    component::StartupContext* context) {
  return context->outgoing().AddPublicService(bindings_.GetHandler(this));
}

zx_status_t VirtioBalloon::Start(const zx::guest& guest,
                                 fuchsia::sys::Launcher* launcher,
                                 async_dispatcher_t* dispatcher) {
  component::Services services;
  fuchsia::sys::LaunchInfo launch_info{
      .url = kVirtioBalloonUrl,
      .directory_request = services.NewRequest(),
  };
  launcher->CreateComponent(std::move(launch_info), controller_.NewRequest());
  services.ConnectToService(balloon_.NewRequest());
  services.ConnectToService(stats_.NewRequest());

  fuchsia::guest::device::StartInfo start_info;
  zx_status_t status = PrepStart(guest, dispatcher, &start_info);
  if (status != ZX_OK) {
    return status;
  }
  return balloon_->Start(std::move(start_info));
}

zx_status_t VirtioBalloon::ConfigureQueue(uint16_t queue, uint16_t size,
                                          zx_gpaddr_t desc, zx_gpaddr_t avail,
                                          zx_gpaddr_t used) {
  return balloon_->ConfigureQueue(queue, size, desc, avail, used);
}

zx_status_t VirtioBalloon::Ready(uint32_t negotiated_features) {
  return balloon_->Ready(negotiated_features);
}

void VirtioBalloon::GetNumPages(GetNumPagesCallback callback) {
  uint32_t actual;
  {
    std::lock_guard<std::mutex> lock(device_config_.mutex);
    actual = config_.actual;
  }
  callback(actual);
}

void VirtioBalloon::RequestNumPages(uint32_t num_pages) {
  {
    std::lock_guard<std::mutex> lock(device_config_.mutex);
    config_.num_pages = num_pages;
  }
  // Send a config change interrupt to the guest.
  zx_status_t status =
      Interrupt(VirtioQueue::SET_CONFIG | VirtioQueue::TRY_INTERRUPT);
  if (status != ZX_OK) {
    FXL_LOG(ERROR) << "Failed to generate configuration interrupt " << status;
  }
}

void VirtioBalloon::GetMemStats(GetMemStatsCallback callback) {
  stats_->GetMemStats(std::move(callback));
}

}  // namespace machina