[mirror_qemu.git] / include / sysemu / block-backend-common.h

/*
 * QEMU Block backends
 *
 * Copyright (C) 2014-2016 Red Hat, Inc.
 *
 * Authors:
 *  Markus Armbruster <armbru@redhat.com>,
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.1
 * or later.  See the COPYING.LIB file in the top-level directory.
 */

#ifndef BLOCK_BACKEND_COMMON_H
#define BLOCK_BACKEND_COMMON_H

#include "qemu/iov.h"
#include "block/throttle-groups.h"

/*
 * TODO Have to include block/block.h for a bunch of block layer
 * types.  Unfortunately, this pulls in the whole BlockDriverState
 * API, which we don't want used by many BlockBackend users.  Some of
 * the types belong here, and the rest should be split into a common
 * header and one for the BlockDriverState API.
 */
#include "block/block.h"

/* Callbacks for block device models */
typedef struct BlockDevOps {

    /*
     * Global state (GS) API. These functions run under the BQL.
     *
     * See include/block/block-global-state.h for more information about
     * the GS API.
     */

    /*
     * Runs when virtual media changed (monitor commands eject, change)
     * Argument load is true on load and false on eject.
     * Beware: doesn't run when a host device's physical media
     * changes.  Sure would be useful if it did.
     * Device models with removable media must implement this callback.
     */
    void (*change_media_cb)(void *opaque, bool load, Error **errp);
    /*
     * Runs when an eject request is issued from the monitor, the tray
     * is closed, and the medium is locked.
     * Device models that do not implement is_medium_locked will not need
     * this callback.  Device models that can lock the medium or tray might
     * want to implement the callback and unlock the tray when "force" is
     * true, even if they do not support eject requests.
     */
    void (*eject_request_cb)(void *opaque, bool force);

    /*
     * Is the virtual medium locked into the device?
     * Device models implement this only when device has such a lock.
     */
    bool (*is_medium_locked)(void *opaque);

    /*
     * I/O API functions. These functions are thread-safe.
     *
     * See include/block/block-io.h for more information about
     * the I/O API.
     */

    /*
     * Is the virtual tray open?
     * Device models implement this only when the device has a tray.
     */
    bool (*is_tray_open)(void *opaque);

    /*
     * Runs when the size changed (e.g. monitor command block_resize)
     */
    void (*resize_cb)(void *opaque);
    /*
     * Runs when the backend receives a drain request.
     */
    void (*drained_begin)(void *opaque);
    /*
     * Runs when the backend's last drain request ends.
     */
    void (*drained_end)(void *opaque);
    /*
     * Is the device still busy?
     */
    bool (*drained_poll)(void *opaque);
} BlockDevOps;

/*
 * This struct is embedded in (the private) BlockBackend struct and contains
 * fields that must be public. This is in particular for QLIST_ENTRY() and
 * friends so that BlockBackends can be kept in lists outside block-backend.c
 */
typedef struct BlockBackendPublic {
    ThrottleGroupMember throttle_group_member;
} BlockBackendPublic;

#endif /* BLOCK_BACKEND_COMMON_H */
Commit	Line	Data
a2c4c3b1 EGE	1	/*
	2	* QEMU Block backends
	3	*
	4	* Copyright (C) 2014-2016 Red Hat, Inc.
	5	*
	6	* Authors:
	7	* Markus Armbruster <armbru@redhat.com>,
	8	*
	9	* This work is licensed under the terms of the GNU LGPL, version 2.1
	10	* or later. See the COPYING.LIB file in the top-level directory.
	11	*/
	12
	13	#ifndef BLOCK_BACKEND_COMMON_H
	14	#define BLOCK_BACKEND_COMMON_H
	15
	16	#include "qemu/iov.h"
	17	#include "block/throttle-groups.h"
	18
	19	/*
	20	* TODO Have to include block/block.h for a bunch of block layer
	21	* types. Unfortunately, this pulls in the whole BlockDriverState
	22	* API, which we don't want used by many BlockBackend users. Some of
	23	* the types belong here, and the rest should be split into a common
	24	* header and one for the BlockDriverState API.
	25	*/
	26	#include "block/block.h"
	27
	28	/* Callbacks for block device models */
	29	typedef struct BlockDevOps {
dc2b15ba EGE	30
	31	/*
	32	* Global state (GS) API. These functions run under the BQL.
	33	*
	34	* See include/block/block-global-state.h for more information about
	35	* the GS API.
	36	*/
	37
a2c4c3b1 EGE	38	/*
	39	* Runs when virtual media changed (monitor commands eject, change)
	40	* Argument load is true on load and false on eject.
	41	* Beware: doesn't run when a host device's physical media
	42	* changes. Sure would be useful if it did.
	43	* Device models with removable media must implement this callback.
	44	*/
	45	void (change_media_cb)(void opaque, bool load, Error **errp);
	46	/*
	47	* Runs when an eject request is issued from the monitor, the tray
	48	* is closed, and the medium is locked.
	49	* Device models that do not implement is_medium_locked will not need
	50	* this callback. Device models that can lock the medium or tray might
	51	* want to implement the callback and unlock the tray when "force" is
	52	* true, even if they do not support eject requests.
	53	*/
	54	void (eject_request_cb)(void opaque, bool force);
dc2b15ba	55
a2c4c3b1 EGE	56	/*
	57	* Is the virtual medium locked into the device?
	58	* Device models implement this only when device has such a lock.
	59	*/
	60	bool (is_medium_locked)(void opaque);
dc2b15ba EGE	61
	62	/*
	63	* I/O API functions. These functions are thread-safe.
	64	*
	65	* See include/block/block-io.h for more information about
	66	* the I/O API.
	67	*/
	68
	69	/*
	70	* Is the virtual tray open?
	71	* Device models implement this only when the device has a tray.
	72	*/
	73	bool (is_tray_open)(void opaque);
	74
a2c4c3b1 EGE	75	/*
	76	* Runs when the size changed (e.g. monitor command block_resize)
	77	*/
	78	void (resize_cb)(void opaque);
	79	/*
	80	* Runs when the backend receives a drain request.
	81	*/
	82	void (drained_begin)(void opaque);
	83	/*
	84	* Runs when the backend's last drain request ends.
	85	*/
	86	void (drained_end)(void opaque);
	87	/*
	88	* Is the device still busy?
	89	*/
	90	bool (drained_poll)(void opaque);
	91	} BlockDevOps;
	92
	93	/*
	94	* This struct is embedded in (the private) BlockBackend struct and contains
	95	* fields that must be public. This is in particular for QLIST_ENTRY() and
	96	* friends so that BlockBackends can be kept in lists outside block-backend.c
	97	*/
	98	typedef struct BlockBackendPublic {
	99	ThrottleGroupMember throttle_group_member;
	100	} BlockBackendPublic;
	101
	102	#endif /* BLOCK_BACKEND_COMMON_H */