Archipelago » qemu

/*

 * QEMU System Emulator block driver

 *

 * Copyright (c) 2003 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#ifndef BLOCK_INT_H

#define BLOCK_INT_H

#include "block/block.h"

#include "qemu/option.h"

#include "qemu/queue.h"

#include "block/coroutine.h"

#include "qemu/timer.h"

#include "qapi-types.h"

#include "qapi/qmp/qerror.h"

#include "monitor/monitor.h"

#include "qemu/hbitmap.h"

#include "block/snapshot.h"

#include "qemu/main-loop.h"

#include "qemu/throttle.h"

#define BLOCK_FLAG_ENCRYPT          1

#define BLOCK_FLAG_COMPAT6          4

#define BLOCK_FLAG_LAZY_REFCOUNTS   8

#define BLOCK_OPT_SIZE              "size"

#define BLOCK_OPT_ENCRYPT           "encryption"

#define BLOCK_OPT_COMPAT6           "compat6"

#define BLOCK_OPT_BACKING_FILE      "backing_file"

#define BLOCK_OPT_BACKING_FMT       "backing_fmt"

#define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"

#define BLOCK_OPT_TABLE_SIZE        "table_size"

#define BLOCK_OPT_PREALLOC          "preallocation"

#define BLOCK_OPT_SUBFMT            "subformat"

#define BLOCK_OPT_COMPAT_LEVEL      "compat"

#define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"

#define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"

#define BLOCK_OPT_REDUNDANCY        "redundancy"

typedef struct BdrvTrackedRequest {

    BlockDriverState *bs;

    int64_t sector_num;

    int nb_sectors;

    bool is_write;

    QLIST_ENTRY(BdrvTrackedRequest) list;

    Coroutine *co; /* owner, used for deadlock detection */

    CoQueue wait_queue; /* coroutines blocked on this request */

} BdrvTrackedRequest;

struct BlockDriver {

    const char *format_name;

    int instance_size;

    /* this table of boolean contains authorizations for the block operations */

    bool authorizations[BS_AUTHORIZATION_COUNT];

    /* for snapshots complex block filter like Quorum can implement the

     * following recursive callback instead of BS_IS_A_FILTER.

     * It's purpose is to recurse on the filter children while calling

     * bdrv_recurse_is_first_non_filter on them.

     * For a sample implementation look in the future Quorum block filter.

     */

    bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,

                                             BlockDriverState *candidate);

    int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);

    int (*bdrv_probe_device)(const char *filename);

    /* Any driver implementing this callback is expected to be able to handle

     * NULL file names in its .bdrv_open() implementation */

    void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);

    /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have

     * this field set to true, except ones that are defined only by their

     * child's bs.

     * An example of the last type will be the quorum block driver.

     */

    bool bdrv_needs_filename;

    /* For handling image reopen for split or non-split files */

    int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,

                               BlockReopenQueue *queue, Error **errp);

    void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);

    void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);

    int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,

                     Error **errp);

    int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,

                          Error **errp);

    int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,

                     uint8_t *buf, int nb_sectors);

    int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,

                      const uint8_t *buf, int nb_sectors);

    void (*bdrv_close)(BlockDriverState *bs);

    void (*bdrv_rebind)(BlockDriverState *bs);

    int (*bdrv_create)(const char *filename, QEMUOptionParameter *options,

                       Error **errp);

    int (*bdrv_set_key)(BlockDriverState *bs, const char *key);

    int (*bdrv_make_empty)(BlockDriverState *bs);

    /* aio */

    BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque);

    BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque);

    BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,

        BlockDriverCompletionFunc *cb, void *opaque);

    BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,

        int64_t sector_num, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque);

    int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,

        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);

    int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,

        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);

    /*

     * Efficiently zero a region of the disk image.  Typically an image format

     * would use a compact metadata representation to implement this.  This

     * function pointer may be NULL and .bdrv_co_writev() will be called

     * instead.

     */

    int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,

        int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);

    int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,

        int64_t sector_num, int nb_sectors);

    int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,

        int64_t sector_num, int nb_sectors, int *pnum);

    /*

     * Invalidate any cached meta-data.

     */

    void (*bdrv_invalidate_cache)(BlockDriverState *bs);

    /*

     * Flushes all data that was already written to the OS all the way down to

     * the disk (for example raw-posix calls fsync()).

     */

    int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);

    /*

     * Flushes all internal caches to the OS. The data may still sit in a

     * writeback cache of the host OS, but it will survive a crash of the qemu

     * process.

     */

    int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);

    const char *protocol_name;

    int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);

    int64_t (*bdrv_getlength)(BlockDriverState *bs);

    bool has_variable_length;

    int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);

    int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,

                                 const uint8_t *buf, int nb_sectors);

    int (*bdrv_snapshot_create)(BlockDriverState *bs,

                                QEMUSnapshotInfo *sn_info);

    int (*bdrv_snapshot_goto)(BlockDriverState *bs,

                              const char *snapshot_id);

    int (*bdrv_snapshot_delete)(BlockDriverState *bs,

                                const char *snapshot_id,

                                const char *name,

                                Error **errp);

    int (*bdrv_snapshot_list)(BlockDriverState *bs,

                              QEMUSnapshotInfo **psn_info);

    int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,

                                  const char *snapshot_id,

                                  const char *name,

                                  Error **errp);

    int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);

    ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);

    int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,

                             int64_t pos);

    int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,

                             int64_t pos, int size);

    int (*bdrv_change_backing_file)(BlockDriverState *bs,

        const char *backing_file, const char *backing_fmt);

    /* removable device specific */

    int (*bdrv_is_inserted)(BlockDriverState *bs);

    int (*bdrv_media_changed)(BlockDriverState *bs);

    void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);

    void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);

    /* to control generic scsi devices */

    int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);

    BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,

        unsigned long int req, void *buf,

        BlockDriverCompletionFunc *cb, void *opaque);

    /* List of options for creating images, terminated by name == NULL */

    QEMUOptionParameter *create_options;

    /*

     * Returns 0 for completed check, -errno for internal errors.

     * The check results are stored in result.

     */

    int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,

        BdrvCheckMode fix);

    int (*bdrv_amend_options)(BlockDriverState *bs,

        QEMUOptionParameter *options);

    void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);

    /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */

    int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,

        const char *tag);

    int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,

        const char *tag);

    int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);

    bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);

    /*

     * Returns 1 if newly created images are guaranteed to contain only

     * zeros, 0 otherwise.

     */

    int (*bdrv_has_zero_init)(BlockDriverState *bs);

    QLIST_ENTRY(BlockDriver) list;

};

typedef struct BlockLimits {

    /* maximum number of sectors that can be discarded at once */

    int max_discard;

    /* optimal alignment for discard requests in sectors */

    int64_t discard_alignment;

    /* maximum number of sectors that can zeroized at once */

    int max_write_zeroes;

    /* optimal alignment for write zeroes requests in sectors */

    int64_t write_zeroes_alignment;

    /* optimal transfer length in sectors */

    int opt_transfer_length;

} BlockLimits;

/*

 * Note: the function bdrv_append() copies and swaps contents of

 * BlockDriverStates, so if you add new fields to this struct, please

 * inspect bdrv_append() to determine if the new fields need to be

 * copied as well.

 */

struct BlockDriverState {

    int64_t total_sectors; /* if we are reading a disk image, give its

                              size in sectors */

    int read_only; /* if true, the media is read only */

    int open_flags; /* flags used to open the file, re-used for re-open */

    int encrypted; /* if true, the media is encrypted */

    int valid_key; /* if true, a valid encryption key has been set */

    int sg;        /* if true, the device is a /dev/sg* */

    int copy_on_read; /* if true, copy read backing sectors into image

                         note this is a reference count */

    BlockDriver *drv; /* NULL means no media */

    void *opaque;

    void *dev;                  /* attached device model, if any */

    /* TODO change to DeviceState when all users are qdevified */

    const BlockDevOps *dev_ops;

    void *dev_opaque;

    char filename[1024];

    char backing_file[1024]; /* if non zero, the image is a diff of

                                this file image */

    char backing_format[16]; /* if non-zero and backing_file exists */

    int is_temporary;

    BlockDriverState *backing_hd;

    BlockDriverState *file;

    NotifierList close_notifiers;

    /* Callback before write request is processed */

    NotifierWithReturnList before_write_notifiers;

    /* number of in-flight copy-on-read requests */

    unsigned int copy_on_read_in_flight;

    /* I/O throttling */

    ThrottleState throttle_state;

    CoQueue      throttled_reqs[2];

    bool         io_limits_enabled;

    /* I/O stats (display with "info blockstats"). */

    uint64_t nr_bytes[BDRV_MAX_IOTYPE];

    uint64_t nr_ops[BDRV_MAX_IOTYPE];

    uint64_t total_time_ns[BDRV_MAX_IOTYPE];

    uint64_t wr_highest_sector;

    /* I/O Limits */

    BlockLimits bl;

    /* Whether the disk can expand beyond total_sectors */

    int growable;

    /* Whether produces zeros when read beyond eof */

    bool zero_beyond_eof;

    /* the memory alignment required for the buffers handled by this driver */

    int buffer_alignment;

    /* do we need to tell the quest if we have a volatile write cache? */

    int enable_write_cache;

    /* NOTE: the following infos are only hints for real hardware

       drivers. They are not used by the block driver */

    BlockdevOnError on_read_error, on_write_error;

    bool iostatus_enabled;

    BlockDeviceIoStatus iostatus;

    /* the following member gives a name to every node on the bs graph. */

    char node_name[32];

    /* element of the list of named nodes building the graph */

    QTAILQ_ENTRY(BlockDriverState) node_list;

    /* Device name is the name associated with the "drive" the guest sees */

    char device_name[32];

    /* element of the list of "drives" the guest sees */

    QTAILQ_ENTRY(BlockDriverState) device_list;

    QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;

    int refcnt;

    int in_use; /* users other than guest access, eg. block migration */

    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;

    /* long-running background operation */

    BlockJob *job;

    QDict *options;

};

int get_tmp_filename(char *filename, int size);

void bdrv_set_io_limits(BlockDriverState *bs,

                        ThrottleConfig *cfg);

/**

 * bdrv_add_before_write_notifier:

 *

 * Register a callback that is invoked before write requests are processed but

 * after any throttling or waiting for overlapping requests.

 */

void bdrv_add_before_write_notifier(BlockDriverState *bs,

                                    NotifierWithReturn *notifier);

/**

 * bdrv_get_aio_context:

 *

 * Returns: the currently bound #AioContext

 */

AioContext *bdrv_get_aio_context(BlockDriverState *bs);

#ifdef _WIN32

int is_windows_drive(const char *filename);

#endif

void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,

                               enum MonitorEvent ev,

                               BlockErrorAction action, bool is_read);

/**

 * stream_start:

 * @bs: Block device to operate on.

 * @base: Block device that will become the new base, or %NULL to

 * flatten the whole backing file chain onto @bs.

 * @base_id: The file name that will be written to @bs as the new

 * backing file if the job completes.  Ignored if @base is %NULL.

 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.

 * @on_error: The action to take upon error.

 * @cb: Completion function for the job.

 * @opaque: Opaque pointer value passed to @cb.

 * @errp: Error object.

 *

 * Start a streaming operation on @bs.  Clusters that are unallocated

 * in @bs, but allocated in any image between @base and @bs (both

 * exclusive) will be written to @bs.  At the end of a successful

 * streaming job, the backing file of @bs will be changed to

 * @base_id in the written image and to @base in the live BlockDriverState.

 */

void stream_start(BlockDriverState *bs, BlockDriverState *base,

                  const char *base_id, int64_t speed, BlockdevOnError on_error,

                  BlockDriverCompletionFunc *cb,

                  void *opaque, Error **errp);

/**

 * commit_start:

 * @bs: Active block device.

 * @top: Top block device to be committed.

 * @base: Block device that will be written into, and become the new top.

 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.

 * @on_error: The action to take upon error.

 * @cb: Completion function for the job.

 * @opaque: Opaque pointer value passed to @cb.

 * @errp: Error object.

 *

 */

void commit_start(BlockDriverState *bs, BlockDriverState *base,

                 BlockDriverState *top, int64_t speed,

                 BlockdevOnError on_error, BlockDriverCompletionFunc *cb,

                 void *opaque, Error **errp);

/**

 * commit_active_start:

 * @bs: Active block device to be committed.

 * @base: Block device that will be written into, and become the new top.

 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.

 * @on_error: The action to take upon error.

 * @cb: Completion function for the job.

 * @opaque: Opaque pointer value passed to @cb.

 * @errp: Error object.

 *

 */

void commit_active_start(BlockDriverState *bs, BlockDriverState *base,

                         int64_t speed,

                         BlockdevOnError on_error,

                         BlockDriverCompletionFunc *cb,

                         void *opaque, Error **errp);

/*

 * mirror_start:

 * @bs: Block device to operate on.

 * @target: Block device to write to.

 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.

 * @granularity: The chosen granularity for the dirty bitmap.

 * @buf_size: The amount of data that can be in flight at one time.

 * @mode: Whether to collapse all images in the chain to the target.

 * @on_source_error: The action to take upon error reading from the source.

 * @on_target_error: The action to take upon error writing to the target.

 * @cb: Completion function for the job.

 * @opaque: Opaque pointer value passed to @cb.

 * @errp: Error object.

 *

 * Start a mirroring operation on @bs.  Clusters that are allocated

 * in @bs will be written to @bs until the job is cancelled or

 * manually completed.  At the end of a successful mirroring job,

 * @bs will be switched to read from @target.

 */

void mirror_start(BlockDriverState *bs, BlockDriverState *target,

                  int64_t speed, int64_t granularity, int64_t buf_size,

                  MirrorSyncMode mode, BlockdevOnError on_source_error,

                  BlockdevOnError on_target_error,

                  BlockDriverCompletionFunc *cb,

                  void *opaque, Error **errp);

/*

 * backup_start:

 * @bs: Block device to operate on.

 * @target: Block device to write to.

 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.

 * @sync_mode: What parts of the disk image should be copied to the destination.

 * @on_source_error: The action to take upon error reading from the source.

 * @on_target_error: The action to take upon error writing to the target.

 * @cb: Completion function for the job.

 * @opaque: Opaque pointer value passed to @cb.

 *

 * Start a backup operation on @bs.  Clusters in @bs are written to @target

 * until the job is cancelled or manually completed.

 */

void backup_start(BlockDriverState *bs, BlockDriverState *target,

                  int64_t speed, MirrorSyncMode sync_mode,

                  BlockdevOnError on_source_error,

                  BlockdevOnError on_target_error,

                  BlockDriverCompletionFunc *cb, void *opaque,

                  Error **errp);

#endif /* BLOCK_INT_H */