// Copyright 2022 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.
library fuchsia.virtualization;

/// A `MemController` controls a guest's virtio-mem
@discoverable
closed protocol MemController {
    /// Get the configured region size, usable region size, plugged size and requestd size
    ///
    /// block_size is the size and the alignment in bytes of a memory block. Cannot change.
    /// region_size is the size of device-managed memory region in bytes. Cannot change.
    /// usable_region_size is the size of the usable device-managed memory region. Can grow up to
    /// the region_size. Can only shrink due to VIRTIO_MEM_REQ_UNPLUG_ALL requests.
    /// plugged_size is the amount of plugged memory in bytes within the usable device-managed
    /// memory region.
    /// requested_size is the requested amount of plugged memory within the usable device-managed
    /// memory region.
    strict GetMemSize() -> (struct {
        block_size uint64;
        region_size uint64;
        usable_region_size uint64;
        plugged_size uint64;
        requested_size uint64;
    });

    /// Update the requested size to plug or unplug memory
    ///
    /// The driver SHOULD react to resize requests from the device (requested_size in the device
    /// configuration changed) by (un)plugging memory blocks.
    strict RequestSize(struct {
        requested_size uint64;
    });
};