Initial import of abandoned HQEMU version 2.5.2HEADmaster

12 files changed, 3022 insertions, 0 deletions

diff --git a/src/include/block/accounting.h b/src/include/block/accounting.h
new file mode 100644
index 0000000..0f46cb4
--- /dev/null
+++ b/src/include/block/accounting.h
@@ -0,0 +1,85 @@
+/*
+ * QEMU System Emulator block accounting
+ *
+ * Copyright (c) 2011 Christoph Hellwig
+ * Copyright (c) 2015 Igalia, S.L.
+ *
+ * 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_ACCOUNTING_H
+#define BLOCK_ACCOUNTING_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "qemu/typedefs.h"
+#include "qemu/timed-average.h"
+
+typedef struct BlockAcctTimedStats BlockAcctTimedStats;
+
+enum BlockAcctType {
+    BLOCK_ACCT_READ,
+    BLOCK_ACCT_WRITE,
+    BLOCK_ACCT_FLUSH,
+    BLOCK_MAX_IOTYPE,
+};
+
+struct BlockAcctTimedStats {
+    TimedAverage latency[BLOCK_MAX_IOTYPE];
+    unsigned interval_length; /* in seconds */
+    QSLIST_ENTRY(BlockAcctTimedStats) entries;
+};
+
+typedef struct BlockAcctStats {
+    uint64_t nr_bytes[BLOCK_MAX_IOTYPE];
+    uint64_t nr_ops[BLOCK_MAX_IOTYPE];
+    uint64_t invalid_ops[BLOCK_MAX_IOTYPE];
+    uint64_t failed_ops[BLOCK_MAX_IOTYPE];
+    uint64_t total_time_ns[BLOCK_MAX_IOTYPE];
+    uint64_t merged[BLOCK_MAX_IOTYPE];
+    int64_t last_access_time_ns;
+    QSLIST_HEAD(, BlockAcctTimedStats) intervals;
+    bool account_invalid;
+    bool account_failed;
+} BlockAcctStats;
+
+typedef struct BlockAcctCookie {
+    int64_t bytes;
+    int64_t start_time_ns;
+    enum BlockAcctType type;
+} BlockAcctCookie;
+
+void block_acct_init(BlockAcctStats *stats, bool account_invalid,
+                     bool account_failed);
+void block_acct_cleanup(BlockAcctStats *stats);
+void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length);
+BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
+                                              BlockAcctTimedStats *s);
+void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
+                      int64_t bytes, enum BlockAcctType type);
+void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie);
+void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie);
+void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type);
+void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
+                           int num_requests);
+int64_t block_acct_idle_time_ns(BlockAcctStats *stats);
+double block_acct_queue_depth(BlockAcctTimedStats *stats,
+                              enum BlockAcctType type);
+
+#endif
diff --git a/src/include/block/aio.h b/src/include/block/aio.h
new file mode 100644
index 0000000..e086e3b
--- /dev/null
+++ b/src/include/block/aio.h
@@ -0,0 +1,445 @@
+/*
+ * QEMU aio implementation
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_AIO_H
+#define QEMU_AIO_H
+
+#include "qemu/typedefs.h"
+#include "qemu-common.h"
+#include "qemu/queue.h"
+#include "qemu/event_notifier.h"
+#include "qemu/thread.h"
+#include "qemu/rfifolock.h"
+#include "qemu/timer.h"
+
+typedef struct BlockAIOCB BlockAIOCB;
+typedef void BlockCompletionFunc(void *opaque, int ret);
+
+typedef struct AIOCBInfo {
+    void (*cancel_async)(BlockAIOCB *acb);
+    AioContext *(*get_aio_context)(BlockAIOCB *acb);
+    size_t aiocb_size;
+} AIOCBInfo;
+
+struct BlockAIOCB {
+    const AIOCBInfo *aiocb_info;
+    BlockDriverState *bs;
+    BlockCompletionFunc *cb;
+    void *opaque;
+    int refcnt;
+};
+
+void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs,
+                   BlockCompletionFunc *cb, void *opaque);
+void qemu_aio_unref(void *p);
+void qemu_aio_ref(void *p);
+
+typedef struct AioHandler AioHandler;
+typedef void QEMUBHFunc(void *opaque);
+typedef void IOHandler(void *opaque);
+
+struct AioContext {
+    GSource source;
+
+    /* Protects all fields from multi-threaded access */
+    RFifoLock lock;
+
+    /* The list of registered AIO handlers */
+    QLIST_HEAD(, AioHandler) aio_handlers;
+
+    /* This is a simple lock used to protect the aio_handlers list.
+     * Specifically, it's used to ensure that no callbacks are removed while
+     * we're walking and dispatching callbacks.
+     */
+    int walking_handlers;
+
+    /* Used to avoid unnecessary event_notifier_set calls in aio_notify;
+     * accessed with atomic primitives.  If this field is 0, everything
+     * (file descriptors, bottom halves, timers) will be re-evaluated
+     * before the next blocking poll(), thus the event_notifier_set call
+     * can be skipped.  If it is non-zero, you may need to wake up a
+     * concurrent aio_poll or the glib main event loop, making
+     * event_notifier_set necessary.
+     *
+     * Bit 0 is reserved for GSource usage of the AioContext, and is 1
+     * between a call to aio_ctx_check and the next call to aio_ctx_dispatch.
+     * Bits 1-31 simply count the number of active calls to aio_poll
+     * that are in the prepare or poll phase.
+     *
+     * The GSource and aio_poll must use a different mechanism because
+     * there is no certainty that a call to GSource's prepare callback
+     * (via g_main_context_prepare) is indeed followed by check and
+     * dispatch.  It's not clear whether this would be a bug, but let's
+     * play safe and allow it---it will just cause extra calls to
+     * event_notifier_set until the next call to dispatch.
+     *
+     * Instead, the aio_poll calls include both the prepare and the
+     * dispatch phase, hence a simple counter is enough for them.
+     */
+    uint32_t notify_me;
+
+    /* lock to protect between bh's adders and deleter */
+    QemuMutex bh_lock;
+
+    /* Anchor of the list of Bottom Halves belonging to the context */
+    struct QEMUBH *first_bh;
+
+    /* A simple lock used to protect the first_bh list, and ensure that
+     * no callbacks are removed while we're walking and dispatching callbacks.
+     */
+    int walking_bh;
+
+    /* Used by aio_notify.
+     *
+     * "notified" is used to avoid expensive event_notifier_test_and_clear
+     * calls.  When it is clear, the EventNotifier is clear, or one thread
+     * is going to clear "notified" before processing more events.  False
+     * positives are possible, i.e. "notified" could be set even though the
+     * EventNotifier is clear.
+     *
+     * Note that event_notifier_set *cannot* be optimized the same way.  For
+     * more information on the problem that would result, see "#ifdef BUG2"
+     * in the docs/aio_notify_accept.promela formal model.
+     */
+    bool notified;
+    EventNotifier notifier;
+
+    /* Scheduling this BH forces the event loop it iterate */
+    QEMUBH *notify_dummy_bh;
+
+    /* Thread pool for performing work and receiving completion callbacks */
+    struct ThreadPool *thread_pool;
+
+    /* TimerLists for calling timers - one per clock type */
+    QEMUTimerListGroup tlg;
+
+    int external_disable_cnt;
+
+    /* epoll(7) state used when built with CONFIG_EPOLL */
+    int epollfd;
+    bool epoll_enabled;
+    bool epoll_available;
+};
+
+/**
+ * aio_context_new: Allocate a new AioContext.
+ *
+ * AioContext provide a mini event-loop that can be waited on synchronously.
+ * They also provide bottom halves, a service to execute a piece of code
+ * as soon as possible.
+ */
+AioContext *aio_context_new(Error **errp);
+
+/**
+ * aio_context_ref:
+ * @ctx: The AioContext to operate on.
+ *
+ * Add a reference to an AioContext.
+ */
+void aio_context_ref(AioContext *ctx);
+
+/**
+ * aio_context_unref:
+ * @ctx: The AioContext to operate on.
+ *
+ * Drop a reference to an AioContext.
+ */
+void aio_context_unref(AioContext *ctx);
+
+/* Take ownership of the AioContext.  If the AioContext will be shared between
+ * threads, and a thread does not want to be interrupted, it will have to
+ * take ownership around calls to aio_poll().  Otherwise, aio_poll()
+ * automatically takes care of calling aio_context_acquire and
+ * aio_context_release.
+ *
+ * Access to timers and BHs from a thread that has not acquired AioContext
+ * is possible.  Access to callbacks for now must be done while the AioContext
+ * is owned by the thread (FIXME).
+ */
+void aio_context_acquire(AioContext *ctx);
+
+/* Relinquish ownership of the AioContext. */
+void aio_context_release(AioContext *ctx);
+
+/**
+ * aio_bh_new: Allocate a new bottom half structure.
+ *
+ * Bottom halves are lightweight callbacks whose invocation is guaranteed
+ * to be wait-free, thread-safe and signal-safe.  The #QEMUBH structure
+ * is opaque and must be allocated prior to its use.
+ */
+QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque);
+
+/**
+ * aio_notify: Force processing of pending events.
+ *
+ * Similar to signaling a condition variable, aio_notify forces
+ * aio_wait to exit, so that the next call will re-examine pending events.
+ * The caller of aio_notify will usually call aio_wait again very soon,
+ * or go through another iteration of the GLib main loop.  Hence, aio_notify
+ * also has the side effect of recalculating the sets of file descriptors
+ * that the main loop waits for.
+ *
+ * Calling aio_notify is rarely necessary, because for example scheduling
+ * a bottom half calls it already.
+ */
+void aio_notify(AioContext *ctx);
+
+/**
+ * aio_notify_accept: Acknowledge receiving an aio_notify.
+ *
+ * aio_notify() uses an EventNotifier in order to wake up a sleeping
+ * aio_poll() or g_main_context_iteration().  Calls to aio_notify() are
+ * usually rare, but the AioContext has to clear the EventNotifier on
+ * every aio_poll() or g_main_context_iteration() in order to avoid
+ * busy waiting.  This event_notifier_test_and_clear() cannot be done
+ * using the usual aio_context_set_event_notifier(), because it must
+ * be done before processing all events (file descriptors, bottom halves,
+ * timers).
+ *
+ * aio_notify_accept() is an optimized event_notifier_test_and_clear()
+ * that is specific to an AioContext's notifier; it is used internally
+ * to clear the EventNotifier only if aio_notify() had been called.
+ */
+void aio_notify_accept(AioContext *ctx);
+
+/**
+ * aio_bh_call: Executes callback function of the specified BH.
+ */
+void aio_bh_call(QEMUBH *bh);
+
+/**
+ * aio_bh_poll: Poll bottom halves for an AioContext.
+ *
+ * These are internal functions used by the QEMU main loop.
+ * And notice that multiple occurrences of aio_bh_poll cannot
+ * be called concurrently
+ */
+int aio_bh_poll(AioContext *ctx);
+
+/**
+ * qemu_bh_schedule: Schedule a bottom half.
+ *
+ * Scheduling a bottom half interrupts the main loop and causes the
+ * execution of the callback that was passed to qemu_bh_new.
+ *
+ * Bottom halves that are scheduled from a bottom half handler are instantly
+ * invoked.  This can create an infinite loop if a bottom half handler
+ * schedules itself.
+ *
+ * @bh: The bottom half to be scheduled.
+ */
+void qemu_bh_schedule(QEMUBH *bh);
+
+/**
+ * qemu_bh_cancel: Cancel execution of a bottom half.
+ *
+ * Canceling execution of a bottom half undoes the effect of calls to
+ * qemu_bh_schedule without freeing its resources yet.  While cancellation
+ * itself is also wait-free and thread-safe, it can of course race with the
+ * loop that executes bottom halves unless you are holding the iothread
+ * mutex.  This makes it mostly useless if you are not holding the mutex.
+ *
+ * @bh: The bottom half to be canceled.
+ */
+void qemu_bh_cancel(QEMUBH *bh);
+
+/**
+ *qemu_bh_delete: Cancel execution of a bottom half and free its resources.
+ *
+ * Deleting a bottom half frees the memory that was allocated for it by
+ * qemu_bh_new.  It also implies canceling the bottom half if it was
+ * scheduled.
+ * This func is async. The bottom half will do the delete action at the finial
+ * end.
+ *
+ * @bh: The bottom half to be deleted.
+ */
+void qemu_bh_delete(QEMUBH *bh);
+
+/* Return whether there are any pending callbacks from the GSource
+ * attached to the AioContext, before g_poll is invoked.
+ *
+ * This is used internally in the implementation of the GSource.
+ */
+bool aio_prepare(AioContext *ctx);
+
+/* Return whether there are any pending callbacks from the GSource
+ * attached to the AioContext, after g_poll is invoked.
+ *
+ * This is used internally in the implementation of the GSource.
+ */
+bool aio_pending(AioContext *ctx);
+
+/* Dispatch any pending callbacks from the GSource attached to the AioContext.
+ *
+ * This is used internally in the implementation of the GSource.
+ */
+bool aio_dispatch(AioContext *ctx);
+
+/* Progress in completing AIO work to occur.  This can issue new pending
+ * aio as a result of executing I/O completion or bh callbacks.
+ *
+ * Return whether any progress was made by executing AIO or bottom half
+ * handlers.  If @blocking == true, this should always be true except
+ * if someone called aio_notify.
+ *
+ * If there are no pending bottom halves, but there are pending AIO
+ * operations, it may not be possible to make any progress without
+ * blocking.  If @blocking is true, this function will wait until one
+ * or more AIO events have completed, to ensure something has moved
+ * before returning.
+ */
+bool aio_poll(AioContext *ctx, bool blocking);
+
+/* Register a file descriptor and associated callbacks.  Behaves very similarly
+ * to qemu_set_fd_handler.  Unlike qemu_set_fd_handler, these callbacks will
+ * be invoked when using aio_poll().
+ *
+ * Code that invokes AIO completion functions should rely on this function
+ * instead of qemu_set_fd_handler[2].
+ */
+void aio_set_fd_handler(AioContext *ctx,
+                        int fd,
+                        bool is_external,
+                        IOHandler *io_read,
+                        IOHandler *io_write,
+                        void *opaque);
+
+/* Register an event notifier and associated callbacks.  Behaves very similarly
+ * to event_notifier_set_handler.  Unlike event_notifier_set_handler, these callbacks
+ * will be invoked when using aio_poll().
+ *
+ * Code that invokes AIO completion functions should rely on this function
+ * instead of event_notifier_set_handler.
+ */
+void aio_set_event_notifier(AioContext *ctx,
+                            EventNotifier *notifier,
+                            bool is_external,
+                            EventNotifierHandler *io_read);
+
+/* Return a GSource that lets the main loop poll the file descriptors attached
+ * to this AioContext.
+ */
+GSource *aio_get_g_source(AioContext *ctx);
+
+/* Return the ThreadPool bound to this AioContext */
+struct ThreadPool *aio_get_thread_pool(AioContext *ctx);
+
+/**
+ * aio_timer_new:
+ * @ctx: the aio context
+ * @type: the clock type
+ * @scale: the scale
+ * @cb: the callback to call on timer expiry
+ * @opaque: the opaque pointer to pass to the callback
+ *
+ * Allocate a new timer attached to the context @ctx.
+ * The function is responsible for memory allocation.
+ *
+ * The preferred interface is aio_timer_init. Use that
+ * unless you really need dynamic memory allocation.
+ *
+ * Returns: a pointer to the new timer
+ */
+static inline QEMUTimer *aio_timer_new(AioContext *ctx, QEMUClockType type,
+                                       int scale,
+                                       QEMUTimerCB *cb, void *opaque)
+{
+    return timer_new_tl(ctx->tlg.tl[type], scale, cb, opaque);
+}
+
+/**
+ * aio_timer_init:
+ * @ctx: the aio context
+ * @ts: the timer
+ * @type: the clock type
+ * @scale: the scale
+ * @cb: the callback to call on timer expiry
+ * @opaque: the opaque pointer to pass to the callback
+ *
+ * Initialise a new timer attached to the context @ctx.
+ * The caller is responsible for memory allocation.
+ */
+static inline void aio_timer_init(AioContext *ctx,
+                                  QEMUTimer *ts, QEMUClockType type,
+                                  int scale,
+                                  QEMUTimerCB *cb, void *opaque)
+{
+    timer_init_tl(ts, ctx->tlg.tl[type], scale, cb, opaque);
+}
+
+/**
+ * aio_compute_timeout:
+ * @ctx: the aio context
+ *
+ * Compute the timeout that a blocking aio_poll should use.
+ */
+int64_t aio_compute_timeout(AioContext *ctx);
+
+/**
+ * aio_disable_external:
+ * @ctx: the aio context
+ *
+ * Disable the further processing of external clients.
+ */
+static inline void aio_disable_external(AioContext *ctx)
+{
+    atomic_inc(&ctx->external_disable_cnt);
+}
+
+/**
+ * aio_enable_external:
+ * @ctx: the aio context
+ *
+ * Enable the processing of external clients.
+ */
+static inline void aio_enable_external(AioContext *ctx)
+{
+    assert(ctx->external_disable_cnt > 0);
+    atomic_dec(&ctx->external_disable_cnt);
+}
+
+/**
+ * aio_external_disabled:
+ * @ctx: the aio context
+ *
+ * Return true if the external clients are disabled.
+ */
+static inline bool aio_external_disabled(AioContext *ctx)
+{
+    return atomic_read(&ctx->external_disable_cnt);
+}
+
+/**
+ * aio_node_check:
+ * @ctx: the aio context
+ * @is_external: Whether or not the checked node is an external event source.
+ *
+ * Check if the node's is_external flag is okay to be polled by the ctx at this
+ * moment. True means green light.
+ */
+static inline bool aio_node_check(AioContext *ctx, bool is_external)
+{
+    return !is_external || !atomic_read(&ctx->external_disable_cnt);
+}
+
+/**
+ * aio_context_setup:
+ * @ctx: the aio context
+ *
+ * Initialize the aio context.
+ */
+void aio_context_setup(AioContext *ctx, Error **errp);
+
+#endif
diff --git a/src/include/block/block.h b/src/include/block/block.h
new file mode 100644
index 0000000..d83d420
--- /dev/null
+++ b/src/include/block/block.h
@@ -0,0 +1,641 @@
+#ifndef BLOCK_H
+#define BLOCK_H
+
+#include "block/aio.h"
+#include "qemu-common.h"
+#include "qemu/option.h"
+#include "qemu/coroutine.h"
+#include "block/accounting.h"
+#include "qapi/qmp/qobject.h"
+#include "qapi-types.h"
+
+/* block.c */
+typedef struct BlockDriver BlockDriver;
+typedef struct BlockJob BlockJob;
+typedef struct BdrvChild BdrvChild;
+typedef struct BdrvChildRole BdrvChildRole;
+typedef struct BlockJobTxn BlockJobTxn;
+
+typedef struct BlockDriverInfo {
+    /* in bytes, 0 if irrelevant */
+    int cluster_size;
+    /* offset at which the VM state can be saved (0 if not possible) */
+    int64_t vm_state_offset;
+    bool is_dirty;
+    /*
+     * True if unallocated blocks read back as zeroes. This is equivalent
+     * to the LBPRZ flag in the SCSI logical block provisioning page.
+     */
+    bool unallocated_blocks_are_zero;
+    /*
+     * True if the driver can optimize writing zeroes by unmapping
+     * sectors. This is equivalent to the BLKDISCARDZEROES ioctl in Linux
+     * with the difference that in qemu a discard is allowed to silently
+     * fail. Therefore we have to use bdrv_write_zeroes with the
+     * BDRV_REQ_MAY_UNMAP flag for an optimized zero write with unmapping.
+     * After this call the driver has to guarantee that the contents read
+     * back as zero. It is additionally required that the block device is
+     * opened with BDRV_O_UNMAP flag for this to work.
+     */
+    bool can_write_zeroes_with_unmap;
+    /*
+     * True if this block driver only supports compressed writes
+     */
+    bool needs_compressed_writes;
+} BlockDriverInfo;
+
+typedef struct BlockFragInfo {
+    uint64_t allocated_clusters;
+    uint64_t total_clusters;
+    uint64_t fragmented_clusters;
+    uint64_t compressed_clusters;
+} BlockFragInfo;
+
+typedef enum {
+    BDRV_REQ_COPY_ON_READ       = 0x1,
+    BDRV_REQ_ZERO_WRITE         = 0x2,
+    /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
+     * is allowed to optimize a write zeroes request by unmapping (discarding)
+     * blocks if it is guaranteed that the result will read back as
+     * zeroes. The flag is only passed to the driver if the block device is
+     * opened with BDRV_O_UNMAP.
+     */
+    BDRV_REQ_MAY_UNMAP          = 0x4,
+    BDRV_REQ_NO_SERIALISING     = 0x8,
+} BdrvRequestFlags;
+
+typedef struct BlockSizes {
+    uint32_t phys;
+    uint32_t log;
+} BlockSizes;
+
+typedef struct HDGeometry {
+    uint32_t heads;
+    uint32_t sectors;
+    uint32_t cylinders;
+} HDGeometry;
+
+#define BDRV_O_RDWR        0x0002
+#define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
+#define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
+#define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
+#define BDRV_O_CACHE_WB    0x0040 /* use write-back caching */
+#define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
+#define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
+#define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
+#define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
+#define BDRV_O_INCOMING    0x0800  /* consistency hint for incoming migration */
+#define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
+#define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
+#define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
+#define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
+                                      select an appropriate protocol driver,
+                                      ignoring the format layer */
+
+#define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
+
+
+/* Option names of options parsed by the block layer */
+
+#define BDRV_OPT_CACHE_WB       "cache.writeback"
+#define BDRV_OPT_CACHE_DIRECT   "cache.direct"
+#define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
+
+
+#define BDRV_SECTOR_BITS   9
+#define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
+#define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
+
+#define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
+                                     INT_MAX >> BDRV_SECTOR_BITS)
+
+/*
+ * Allocation status flags
+ * BDRV_BLOCK_DATA: data is read from bs->file or another file
+ * BDRV_BLOCK_ZERO: sectors read as zero
+ * BDRV_BLOCK_OFFSET_VALID: sector stored in bs->file as raw data
+ * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
+ *                       layer (as opposed to the backing file)
+ * BDRV_BLOCK_RAW: used internally to indicate that the request
+ *                 was answered by the raw driver and that one
+ *                 should look in bs->file directly.
+ *
+ * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
+ * bs->file where sector data can be read from as raw data.
+ *
+ * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
+ *
+ * DATA ZERO OFFSET_VALID
+ *  t    t        t       sectors read as zero, bs->file is zero at offset
+ *  t    f        t       sectors read as valid from bs->file at offset
+ *  f    t        t       sectors preallocated, read as zero, bs->file not
+ *                        necessarily zero at offset
+ *  f    f        t       sectors preallocated but read from backing_hd,
+ *                        bs->file contains garbage at offset
+ *  t    t        f       sectors preallocated, read as zero, unknown offset
+ *  t    f        f       sectors read from unknown file or offset
+ *  f    t        f       not allocated or unknown offset, read as zero
+ *  f    f        f       not allocated or unknown offset, read from backing_hd
+ */
+#define BDRV_BLOCK_DATA         0x01
+#define BDRV_BLOCK_ZERO         0x02
+#define BDRV_BLOCK_OFFSET_VALID 0x04
+#define BDRV_BLOCK_RAW          0x08
+#define BDRV_BLOCK_ALLOCATED    0x10
+#define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
+
+typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
+
+typedef struct BDRVReopenState {
+    BlockDriverState *bs;
+    int flags;
+    QDict *options;
+    void *opaque;
+} BDRVReopenState;
+
+/*
+ * Block operation types
+ */
+typedef enum BlockOpType {
+    BLOCK_OP_TYPE_BACKUP_SOURCE,
+    BLOCK_OP_TYPE_BACKUP_TARGET,
+    BLOCK_OP_TYPE_CHANGE,
+    BLOCK_OP_TYPE_COMMIT_SOURCE,
+    BLOCK_OP_TYPE_COMMIT_TARGET,
+    BLOCK_OP_TYPE_DATAPLANE,
+    BLOCK_OP_TYPE_DRIVE_DEL,
+    BLOCK_OP_TYPE_EJECT,
+    BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
+    BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
+    BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
+    BLOCK_OP_TYPE_MIRROR,
+    BLOCK_OP_TYPE_RESIZE,
+    BLOCK_OP_TYPE_STREAM,
+    BLOCK_OP_TYPE_REPLACE,
+    BLOCK_OP_TYPE_MAX,
+} BlockOpType;
+
+void bdrv_info_print(Monitor *mon, const QObject *data);
+void bdrv_info(Monitor *mon, QObject **ret_data);
+void bdrv_stats_print(Monitor *mon, const QObject *data);
+void bdrv_info_stats(Monitor *mon, QObject **ret_data);
+
+/* disk I/O throttling */
+void bdrv_io_limits_enable(BlockDriverState *bs, const char *group);
+void bdrv_io_limits_disable(BlockDriverState *bs);
+void bdrv_io_limits_update_group(BlockDriverState *bs, const char *group);
+
+void bdrv_init(void);
+void bdrv_init_with_whitelist(void);
+BlockDriver *bdrv_find_protocol(const char *filename,
+                                bool allow_protocol_prefix,
+                                Error **errp);
+BlockDriver *bdrv_find_format(const char *format_name);
+int bdrv_create(BlockDriver *drv, const char* filename,
+                QemuOpts *opts, Error **errp);
+int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
+BlockDriverState *bdrv_new_root(void);
+BlockDriverState *bdrv_new(void);
+void bdrv_device_remove(BlockDriverState *bs);
+void bdrv_make_anon(BlockDriverState *bs);
+void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old);
+void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
+void bdrv_replace_in_backing_chain(BlockDriverState *old,
+                                   BlockDriverState *new);
+
+int bdrv_parse_cache_flags(const char *mode, int *flags);
+int bdrv_parse_discard_flags(const char *mode, int *flags);
+BdrvChild *bdrv_open_child(const char *filename,
+                           QDict *options, const char *bdref_key,
+                           BlockDriverState* parent,
+                           const BdrvChildRole *child_role,
+                           bool allow_none, Error **errp);
+void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
+int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp);
+int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp);
+int bdrv_open(BlockDriverState **pbs, const char *filename,
+              const char *reference, QDict *options, int flags, Error **errp);
+BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
+                                    BlockDriverState *bs,
+                                    QDict *options, int flags);
+int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
+int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
+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);
+void bdrv_close(BlockDriverState *bs);
+void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify);
+int bdrv_read(BlockDriverState *bs, int64_t sector_num,
+              uint8_t *buf, int nb_sectors);
+int bdrv_read_unthrottled(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);
+int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
+               int nb_sectors, BdrvRequestFlags flags);
+BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, int64_t sector_num,
+                                  int nb_sectors, BdrvRequestFlags flags,
+                                  BlockCompletionFunc *cb, void *opaque);
+int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags);
+int bdrv_pread(BlockDriverState *bs, int64_t offset,
+               void *buf, int count);
+int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
+                const void *buf, int count);
+int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
+int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
+    const void *buf, int count);
+int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
+    int nb_sectors, QEMUIOVector *qiov);
+int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
+    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
+int coroutine_fn bdrv_co_readv_no_serialising(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.  Note that this is a regular
+ * I/O request like read or write and should have a reasonable size.  This
+ * function is not suitable for zeroing the entire image in a single request
+ * because it may allocate memory for the entire region.
+ */
+int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
+    int nb_sectors, BdrvRequestFlags flags);
+BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
+    const char *backing_file);
+int bdrv_get_backing_file_depth(BlockDriverState *bs);
+void bdrv_refresh_filename(BlockDriverState *bs);
+int bdrv_truncate(BlockDriverState *bs, int64_t offset);
+int64_t bdrv_nb_sectors(BlockDriverState *bs);
+int64_t bdrv_getlength(BlockDriverState *bs);
+int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
+void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
+void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
+int bdrv_commit(BlockDriverState *bs);
+int bdrv_commit_all(void);
+int bdrv_change_backing_file(BlockDriverState *bs,
+    const char *backing_file, const char *backing_fmt);
+void bdrv_register(BlockDriver *bdrv);
+int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
+                           BlockDriverState *base,
+                           const char *backing_file_str);
+BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
+                                    BlockDriverState *bs);
+BlockDriverState *bdrv_find_base(BlockDriverState *bs);
+
+
+typedef struct BdrvCheckResult {
+    int corruptions;
+    int leaks;
+    int check_errors;
+    int corruptions_fixed;
+    int leaks_fixed;
+    int64_t image_end_offset;
+    BlockFragInfo bfi;
+} BdrvCheckResult;
+
+typedef enum {
+    BDRV_FIX_LEAKS    = 1,
+    BDRV_FIX_ERRORS   = 2,
+} BdrvCheckMode;
+
+int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
+
+/* The units of offset and total_work_size may be chosen arbitrarily by the
+ * block driver; total_work_size may change during the course of the amendment
+ * operation */
+typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
+                                      int64_t total_work_size);
+int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
+                       BlockDriverAmendStatusCB *status_cb);
+
+/* external snapshots */
+bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
+                                      BlockDriverState *candidate);
+bool bdrv_is_first_non_filter(BlockDriverState *candidate);
+
+/* check if a named node can be replaced when doing drive-mirror */
+BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
+                                        const char *node_name, Error **errp);
+
+/* async block I/O */
+typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector,
+                                     int sector_num);
+BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
+                           QEMUIOVector *iov, int nb_sectors,
+                           BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
+                            QEMUIOVector *iov, int nb_sectors,
+                            BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
+                           BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
+                             int64_t sector_num, int nb_sectors,
+                             BlockCompletionFunc *cb, void *opaque);
+void bdrv_aio_cancel(BlockAIOCB *acb);
+void bdrv_aio_cancel_async(BlockAIOCB *acb);
+
+typedef struct BlockRequest {
+    /* Fields to be filled by multiwrite caller */
+    union {
+        struct {
+            int64_t sector;
+            int nb_sectors;
+            int flags;
+            QEMUIOVector *qiov;
+        };
+        struct {
+            int req;
+            void *buf;
+        };
+    };
+    BlockCompletionFunc *cb;
+    void *opaque;
+
+    /* Filled by multiwrite implementation */
+    int error;
+} BlockRequest;
+
+int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs,
+    int num_reqs);
+
+/* sg packet commands */
+int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
+BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
+        unsigned long int req, void *buf,
+        BlockCompletionFunc *cb, void *opaque);
+
+/* Invalidate any cached metadata used by image formats */
+void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
+void bdrv_invalidate_cache_all(Error **errp);
+
+/* Ensure contents are flushed to disk.  */
+int bdrv_flush(BlockDriverState *bs);
+int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
+int bdrv_flush_all(void);
+void bdrv_close_all(void);
+void bdrv_drain(BlockDriverState *bs);
+void bdrv_drain_all(void);
+
+int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
+int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
+int bdrv_has_zero_init_1(BlockDriverState *bs);
+int bdrv_has_zero_init(BlockDriverState *bs);
+bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
+bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
+int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
+                              int nb_sectors, int *pnum);
+int64_t bdrv_get_block_status_above(BlockDriverState *bs,
+                                    BlockDriverState *base,
+                                    int64_t sector_num,
+                                    int nb_sectors, int *pnum);
+int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
+                      int *pnum);
+int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
+                            int64_t sector_num, int nb_sectors, int *pnum);
+
+int bdrv_is_read_only(BlockDriverState *bs);
+int bdrv_is_sg(BlockDriverState *bs);
+int bdrv_enable_write_cache(BlockDriverState *bs);
+void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce);
+bool bdrv_is_inserted(BlockDriverState *bs);
+int bdrv_media_changed(BlockDriverState *bs);
+void bdrv_lock_medium(BlockDriverState *bs, bool locked);
+void bdrv_eject(BlockDriverState *bs, bool eject_flag);
+const char *bdrv_get_format_name(BlockDriverState *bs);
+BlockDriverState *bdrv_find_node(const char *node_name);
+BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
+BlockDriverState *bdrv_lookup_bs(const char *device,
+                                 const char *node_name,
+                                 Error **errp);
+bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
+BlockDriverState *bdrv_next_node(BlockDriverState *bs);
+BlockDriverState *bdrv_next(BlockDriverState *bs);
+int bdrv_is_encrypted(BlockDriverState *bs);
+int bdrv_key_required(BlockDriverState *bs);
+int bdrv_set_key(BlockDriverState *bs, const char *key);
+void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
+int bdrv_query_missing_keys(void);
+void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
+                         void *opaque);
+const char *bdrv_get_node_name(const BlockDriverState *bs);
+const char *bdrv_get_device_name(const BlockDriverState *bs);
+const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
+int bdrv_get_flags(BlockDriverState *bs);
+int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
+                          const uint8_t *buf, int nb_sectors);
+int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
+ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
+void bdrv_round_to_clusters(BlockDriverState *bs,
+                            int64_t sector_num, int nb_sectors,
+                            int64_t *cluster_sector_num,
+                            int *cluster_nb_sectors);
+
+const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
+void bdrv_get_backing_filename(BlockDriverState *bs,
+                               char *filename, int filename_size);
+void bdrv_get_full_backing_filename(BlockDriverState *bs,
+                                    char *dest, size_t sz, Error **errp);
+void bdrv_get_full_backing_filename_from_filename(const char *backed,
+                                                  const char *backing,
+                                                  char *dest, size_t sz,
+                                                  Error **errp);
+int bdrv_is_snapshot(BlockDriverState *bs);
+
+int path_has_protocol(const char *path);
+int path_is_absolute(const char *path);
+void path_combine(char *dest, int dest_size,
+                  const char *base_path,
+                  const char *filename);
+
+int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
+int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
+                      int64_t pos, int size);
+
+int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
+                      int64_t pos, int size);
+
+void bdrv_img_create(const char *filename, const char *fmt,
+                     const char *base_filename, const char *base_fmt,
+                     char *options, uint64_t img_size, int flags,
+                     Error **errp, bool quiet);
+
+/* Returns the alignment in bytes that is required so that no bounce buffer
+ * is required throughout the stack */
+size_t bdrv_min_mem_align(BlockDriverState *bs);
+/* Returns optimal alignment in bytes for bounce buffer */
+size_t bdrv_opt_mem_align(BlockDriverState *bs);
+void *qemu_blockalign(BlockDriverState *bs, size_t size);
+void *qemu_blockalign0(BlockDriverState *bs, size_t size);
+void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
+void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
+bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
+
+struct HBitmapIter;
+typedef struct BdrvDirtyBitmap BdrvDirtyBitmap;
+BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
+                                          uint32_t granularity,
+                                          const char *name,
+                                          Error **errp);
+int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
+                                       BdrvDirtyBitmap *bitmap,
+                                       Error **errp);
+BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
+                                            BdrvDirtyBitmap *bitmap,
+                                            Error **errp);
+BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
+                                           BdrvDirtyBitmap *bitmap,
+                                           Error **errp);
+BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
+                                        const char *name);
+void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap);
+void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
+void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
+void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
+BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
+uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs);
+uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap);
+bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap);
+bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap);
+DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap);
+int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector);
+void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                           int64_t cur_sector, int nr_sectors);
+void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                             int64_t cur_sector, int nr_sectors);
+void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, struct HBitmapIter *hbi);
+void bdrv_set_dirty_iter(struct HBitmapIter *hbi, int64_t offset);
+int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
+
+void bdrv_enable_copy_on_read(BlockDriverState *bs);
+void bdrv_disable_copy_on_read(BlockDriverState *bs);
+
+void bdrv_ref(BlockDriverState *bs);
+void bdrv_unref(BlockDriverState *bs);
+void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
+
+bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
+void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
+void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
+void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
+void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
+bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
+
+typedef enum {
+    BLKDBG_L1_UPDATE,
+
+    BLKDBG_L1_GROW_ALLOC_TABLE,
+    BLKDBG_L1_GROW_WRITE_TABLE,
+    BLKDBG_L1_GROW_ACTIVATE_TABLE,
+
+    BLKDBG_L2_LOAD,
+    BLKDBG_L2_UPDATE,
+    BLKDBG_L2_UPDATE_COMPRESSED,
+    BLKDBG_L2_ALLOC_COW_READ,
+    BLKDBG_L2_ALLOC_WRITE,
+
+    BLKDBG_READ_AIO,
+    BLKDBG_READ_BACKING_AIO,
+    BLKDBG_READ_COMPRESSED,
+
+    BLKDBG_WRITE_AIO,
+    BLKDBG_WRITE_COMPRESSED,
+
+    BLKDBG_VMSTATE_LOAD,
+    BLKDBG_VMSTATE_SAVE,
+
+    BLKDBG_COW_READ,
+    BLKDBG_COW_WRITE,
+
+    BLKDBG_REFTABLE_LOAD,
+    BLKDBG_REFTABLE_GROW,
+    BLKDBG_REFTABLE_UPDATE,
+
+    BLKDBG_REFBLOCK_LOAD,
+    BLKDBG_REFBLOCK_UPDATE,
+    BLKDBG_REFBLOCK_UPDATE_PART,
+    BLKDBG_REFBLOCK_ALLOC,
+    BLKDBG_REFBLOCK_ALLOC_HOOKUP,
+    BLKDBG_REFBLOCK_ALLOC_WRITE,
+    BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS,
+    BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE,
+    BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE,
+
+    BLKDBG_CLUSTER_ALLOC,
+    BLKDBG_CLUSTER_ALLOC_BYTES,
+    BLKDBG_CLUSTER_FREE,
+
+    BLKDBG_FLUSH_TO_OS,
+    BLKDBG_FLUSH_TO_DISK,
+
+    BLKDBG_PWRITEV_RMW_HEAD,
+    BLKDBG_PWRITEV_RMW_AFTER_HEAD,
+    BLKDBG_PWRITEV_RMW_TAIL,
+    BLKDBG_PWRITEV_RMW_AFTER_TAIL,
+    BLKDBG_PWRITEV,
+    BLKDBG_PWRITEV_ZERO,
+    BLKDBG_PWRITEV_DONE,
+
+    BLKDBG_EMPTY_IMAGE_PREPARE,
+
+    BLKDBG_EVENT_MAX,
+} BlkDebugEvent;
+
+#define BLKDBG_EVENT(child, evt) \
+    do { \
+        if (child) { \
+            bdrv_debug_event(child->bs, evt); \
+        } \
+    } while (0)
+
+void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event);
+
+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);
+
+/**
+ * bdrv_get_aio_context:
+ *
+ * Returns: the currently bound #AioContext
+ */
+AioContext *bdrv_get_aio_context(BlockDriverState *bs);
+
+/**
+ * bdrv_set_aio_context:
+ *
+ * Changes the #AioContext used for fd handlers, timers, and BHs by this
+ * BlockDriverState and all its children.
+ *
+ * This function must be called with iothread lock held.
+ */
+void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
+int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
+int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
+
+void bdrv_io_plug(BlockDriverState *bs);
+void bdrv_io_unplug(BlockDriverState *bs);
+void bdrv_flush_io_queue(BlockDriverState *bs);
+
+/**
+ * bdrv_drained_begin:
+ *
+ * Begin a quiesced section for exclusive access to the BDS, by disabling
+ * external request sources including NBD server and device model. Note that
+ * this doesn't block timers or coroutines from submitting more requests, which
+ * means block_job_pause is still necessary.
+ *
+ * This function can be recursive.
+ */
+void bdrv_drained_begin(BlockDriverState *bs);
+
+/**
+ * bdrv_drained_end:
+ *
+ * End a quiescent section started by bdrv_drained_begin().
+ */
+void bdrv_drained_end(BlockDriverState *bs);
+
+#endif
diff --git a/src/include/block/block_int.h b/src/include/block/block_int.h
new file mode 100644
index 0000000..7029d41
--- /dev/null
+++ b/src/include/block/block_int.h
@@ -0,0 +1,701 @@
+/*
+ * 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/accounting.h"
+#include "block/block.h"
+#include "block/throttle-groups.h"
+#include "qemu/option.h"
+#include "qemu/queue.h"
+#include "qemu/coroutine.h"
+#include "qemu/timer.h"
+#include "qapi-types.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"
+#define BLOCK_OPT_NOCOW             "nocow"
+#define BLOCK_OPT_OBJECT_SIZE       "object_size"
+#define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
+
+#define BLOCK_PROBE_BUF_SIZE        512
+
+enum BdrvTrackedRequestType {
+    BDRV_TRACKED_READ,
+    BDRV_TRACKED_WRITE,
+    BDRV_TRACKED_FLUSH,
+    BDRV_TRACKED_IOCTL,
+    BDRV_TRACKED_DISCARD,
+};
+
+typedef struct BdrvTrackedRequest {
+    BlockDriverState *bs;
+    int64_t offset;
+    unsigned int bytes;
+    enum BdrvTrackedRequestType type;
+
+    bool serialising;
+    int64_t overlap_offset;
+    unsigned int overlap_bytes;
+
+    QLIST_ENTRY(BdrvTrackedRequest) list;
+    Coroutine *co; /* owner, used for deadlock detection */
+    CoQueue wait_queue; /* coroutines blocked on this request */
+
+    struct BdrvTrackedRequest *waiting_for;
+} BdrvTrackedRequest;
+
+struct BlockDriver {
+    const char *format_name;
+    int instance_size;
+
+    /* set to true if the BlockDriver is a block filter */
+    bool is_filter;
+    /* for snapshots block filter like Quorum can implement the
+     * following recursive callback.
+     * 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;
+
+    /* Set if a driver can support backing files */
+    bool supports_backing;
+
+    /* 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);
+    int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
+    int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
+    int (*bdrv_make_empty)(BlockDriverState *bs);
+
+    void (*bdrv_refresh_filename)(BlockDriverState *bs);
+
+    /* aio */
+    BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+        BlockCompletionFunc *cb, void *opaque);
+    BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+        BlockCompletionFunc *cb, void *opaque);
+    BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
+        BlockCompletionFunc *cb, void *opaque);
+    BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
+        int64_t sector_num, int nb_sectors,
+        BlockCompletionFunc *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, Error **errp);
+
+    /*
+     * 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 */
+    bool (*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 */
+    BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
+        unsigned long int req, void *buf,
+        BlockCompletionFunc *cb, void *opaque);
+
+    /* List of options for creating images, terminated by name == NULL */
+    QemuOptsList *create_opts;
+
+    /*
+     * 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, QemuOpts *opts,
+                              BlockDriverAmendStatusCB *status_cb);
+
+    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);
+
+    void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
+
+    /*
+     * Returns 1 if newly created images are guaranteed to contain only
+     * zeros, 0 otherwise.
+     */
+    int (*bdrv_has_zero_init)(BlockDriverState *bs);
+
+    /* Remove fd handlers, timers, and other event loop callbacks so the event
+     * loop is no longer in use.  Called with no in-flight requests and in
+     * depth-first traversal order with parents before child nodes.
+     */
+    void (*bdrv_detach_aio_context)(BlockDriverState *bs);
+
+    /* Add fd handlers, timers, and other event loop callbacks so I/O requests
+     * can be processed again.  Called with no in-flight requests and in
+     * depth-first traversal order with child nodes before parent nodes.
+     */
+    void (*bdrv_attach_aio_context)(BlockDriverState *bs,
+                                    AioContext *new_context);
+
+    /* io queue for linux-aio */
+    void (*bdrv_io_plug)(BlockDriverState *bs);
+    void (*bdrv_io_unplug)(BlockDriverState *bs);
+    void (*bdrv_flush_io_queue)(BlockDriverState *bs);
+
+    /**
+     * Try to get @bs's logical and physical block size.
+     * On success, store them in @bsz and return zero.
+     * On failure, return negative errno.
+     */
+    int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
+    /**
+     * Try to get @bs's geometry (cyls, heads, sectors)
+     * On success, store them in @geo and return 0.
+     * On failure return -errno.
+     * Only drivers that want to override guest geometry implement this
+     * callback; see hd_geometry_guess().
+     */
+    int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
+
+    /**
+     * Drain and stop any internal sources of requests in the driver, and
+     * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
+     */
+    void (*bdrv_drain)(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;
+
+    /* maximal transfer length in sectors */
+    int max_transfer_length;
+
+    /* memory alignment so that no bounce buffer is needed */
+    size_t min_mem_alignment;
+
+    /* memory alignment for bounce buffer */
+    size_t opt_mem_alignment;
+} BlockLimits;
+
+typedef struct BdrvOpBlocker BdrvOpBlocker;
+
+typedef struct BdrvAioNotifier {
+    void (*attached_aio_context)(AioContext *new_context, void *opaque);
+    void (*detach_aio_context)(void *opaque);
+
+    void *opaque;
+
+    QLIST_ENTRY(BdrvAioNotifier) list;
+} BdrvAioNotifier;
+
+struct BdrvChildRole {
+    int (*inherit_flags)(int parent_flags);
+};
+
+extern const BdrvChildRole child_file;
+extern const BdrvChildRole child_format;
+
+struct BdrvChild {
+    BlockDriverState *bs;
+    const BdrvChildRole *role;
+    QLIST_ENTRY(BdrvChild) next;
+    QLIST_ENTRY(BdrvChild) next_parent;
+};
+
+/*
+ * 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 */
+    bool probed;
+
+    BlockDriver *drv; /* NULL means no media */
+    void *opaque;
+
+    BlockBackend *blk;          /* owning backend, if any */
+
+    AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
+    /* long-running tasks intended to always use the same AioContext as this
+     * BDS may register themselves in this list to be notified of changes
+     * regarding this BDS's context */
+    QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
+
+    char filename[PATH_MAX];
+    char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
+                                    this file image */
+    char backing_format[16]; /* if non-zero and backing_file exists */
+
+    QDict *full_open_options;
+    char exact_filename[PATH_MAX];
+
+    BdrvChild *backing;
+    BdrvChild *file;
+
+    NotifierList close_notifiers;
+
+    /* Callback before write request is processed */
+    NotifierWithReturnList before_write_notifiers;
+
+    /* number of in-flight serialising requests */
+    unsigned int serialising_in_flight;
+
+    /* I/O throttling.
+     * throttle_state tells us if this BDS has I/O limits configured.
+     * io_limits_enabled tells us if they are currently being
+     * enforced, but it can be temporarily set to false */
+    CoQueue      throttled_reqs[2];
+    bool         io_limits_enabled;
+    /* The following fields are protected by the ThrottleGroup lock.
+     * See the ThrottleGroup documentation for details. */
+    ThrottleState *throttle_state;
+    ThrottleTimers throttle_timers;
+    unsigned       pending_reqs[2];
+    QLIST_ENTRY(BlockDriverState) round_robin;
+
+    /* Offset after the highest byte written to */
+    uint64_t wr_highest_offset;
+
+    /* I/O Limits */
+    BlockLimits bl;
+
+    /* Whether produces zeros when read beyond eof */
+    bool zero_beyond_eof;
+
+    /* Alignment requirement for offset/length of I/O requests */
+    unsigned int request_alignment;
+
+    /* do we need to tell the quest if we have a volatile write cache? */
+    int enable_write_cache;
+
+    /* 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;
+    /* element of the list of "drives" the guest sees */
+    QTAILQ_ENTRY(BlockDriverState) device_list;
+    QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
+    int refcnt;
+
+    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
+
+    /* operation blockers */
+    QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
+
+    /* long-running background operation */
+    BlockJob *job;
+
+    /* The node that this node inherited default options from (and a reopen on
+     * which can affect this node by changing these defaults). This is always a
+     * parent node of this node. */
+    BlockDriverState *inherits_from;
+    QLIST_HEAD(, BdrvChild) children;
+    QLIST_HEAD(, BdrvChild) parents;
+
+    QDict *options;
+    BlockdevDetectZeroesOptions detect_zeroes;
+
+    /* The error object in use for blocking operations on backing_hd */
+    Error *backing_blocker;
+
+    /* threshold limit for writes, in bytes. "High water mark". */
+    uint64_t write_threshold_offset;
+    NotifierWithReturn write_threshold_notifier;
+
+    int quiesce_counter;
+};
+
+struct BlockBackendRootState {
+    int open_flags;
+    bool read_only;
+    BlockdevDetectZeroesOptions detect_zeroes;
+
+    char *throttle_group;
+    ThrottleState *throttle_state;
+};
+
+static inline BlockDriverState *backing_bs(BlockDriverState *bs)
+{
+    return bs->backing ? bs->backing->bs : NULL;
+}
+
+
+/* Essential block drivers which must always be statically linked into qemu, and
+ * which therefore can be accessed without using bdrv_find_format() */
+extern BlockDriver bdrv_file;
+extern BlockDriver bdrv_raw;
+extern BlockDriver bdrv_qcow2;
+
+extern QTAILQ_HEAD(BdrvStates, BlockDriverState) bdrv_states;
+
+/**
+ * bdrv_setup_io_funcs:
+ *
+ * Prepare a #BlockDriver for I/O request processing by populating
+ * unimplemented coroutine and AIO interfaces with generic wrapper functions
+ * that fall back to implemented interfaces.
+ */
+void bdrv_setup_io_funcs(BlockDriver *bdrv);
+
+int get_tmp_filename(char *filename, int size);
+BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
+                            const char *filename);
+
+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_detach_aio_context:
+ *
+ * May be called from .bdrv_detach_aio_context() to detach children from the
+ * current #AioContext.  This is only needed by block drivers that manage their
+ * own children.  Both ->file and ->backing are automatically handled and
+ * block drivers should not call this function on them explicitly.
+ */
+void bdrv_detach_aio_context(BlockDriverState *bs);
+
+/**
+ * bdrv_attach_aio_context:
+ *
+ * May be called from .bdrv_attach_aio_context() to attach children to the new
+ * #AioContext.  This is only needed by block drivers that manage their own
+ * children.  Both ->file and ->backing are automatically handled and block
+ * drivers should not call this function on them explicitly.
+ */
+void bdrv_attach_aio_context(BlockDriverState *bs,
+                             AioContext *new_context);
+
+/**
+ * bdrv_add_aio_context_notifier:
+ *
+ * If a long-running job intends to be always run in the same AioContext as a
+ * certain BDS, it may use this function to be notified of changes regarding the
+ * association of the BDS to an AioContext.
+ *
+ * attached_aio_context() is called after the target BDS has been attached to a
+ * new AioContext; detach_aio_context() is called before the target BDS is being
+ * detached from its old AioContext.
+ */
+void bdrv_add_aio_context_notifier(BlockDriverState *bs,
+        void (*attached_aio_context)(AioContext *new_context, void *opaque),
+        void (*detach_aio_context)(void *opaque), void *opaque);
+
+/**
+ * bdrv_remove_aio_context_notifier:
+ *
+ * Unsubscribe of change notifications regarding the BDS's AioContext. The
+ * parameters given here have to be the same as those given to
+ * bdrv_add_aio_context_notifier().
+ */
+void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
+                                      void (*aio_context_attached)(AioContext *,
+                                                                   void *),
+                                      void (*aio_context_detached)(void *),
+                                      void *opaque);
+
+#ifdef _WIN32
+int is_windows_drive(const char *filename);
+#endif
+
+/**
+ * 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,
+                  BlockCompletionFunc *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.
+ * @backing_file_str: String to use as the backing file in @top's overlay
+ * @errp: Error object.
+ *
+ */
+void commit_start(BlockDriverState *bs, BlockDriverState *base,
+                 BlockDriverState *top, int64_t speed,
+                 BlockdevOnError on_error, BlockCompletionFunc *cb,
+                 void *opaque, const char *backing_file_str, 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,
+                         BlockCompletionFunc *cb,
+                         void *opaque, Error **errp);
+/*
+ * mirror_start:
+ * @bs: Block device to operate on.
+ * @target: Block device to write to.
+ * @replaces: Block graph node name to replace once the mirror is done. Can
+ *            only be used when full mirroring is selected.
+ * @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.
+ * @unmap: Whether to unmap target where source sectors only contain zeroes.
+ * @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,
+                  const char *replaces,
+                  int64_t speed, uint32_t granularity, int64_t buf_size,
+                  MirrorSyncMode mode, BlockdevOnError on_source_error,
+                  BlockdevOnError on_target_error,
+                  bool unmap,
+                  BlockCompletionFunc *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.
+ * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
+ * @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.
+ * @txn: Transaction that this job is part of (may be NULL).
+ *
+ * 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,
+                  BdrvDirtyBitmap *sync_bitmap,
+                  BlockdevOnError on_source_error,
+                  BlockdevOnError on_target_error,
+                  BlockCompletionFunc *cb, void *opaque,
+                  BlockJobTxn *txn, Error **errp);
+
+void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
+
+void blk_dev_change_media_cb(BlockBackend *blk, bool load);
+bool blk_dev_has_removable_media(BlockBackend *blk);
+bool blk_dev_has_tray(BlockBackend *blk);
+void blk_dev_eject_request(BlockBackend *blk, bool force);
+bool blk_dev_is_tray_open(BlockBackend *blk);
+bool blk_dev_is_medium_locked(BlockBackend *blk);
+void blk_dev_resize_cb(BlockBackend *blk);
+
+void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
+bool bdrv_requests_pending(BlockDriverState *bs);
+
+void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
+void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
+
+#endif /* BLOCK_INT_H */
diff --git a/src/include/block/blockjob.h b/src/include/block/blockjob.h
new file mode 100644
index 0000000..d84ccd8
--- /dev/null
+++ b/src/include/block/blockjob.h
@@ -0,0 +1,446 @@
+/*
+ * Declarations for long-running block device operations
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012 Red Hat, Inc.
+ *
+ * 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 BLOCKJOB_H
+#define BLOCKJOB_H 1
+
+#include "block/block.h"
+
+/**
+ * BlockJobDriver:
+ *
+ * A class type for block job driver.
+ */
+typedef struct BlockJobDriver {
+    /** Derived BlockJob struct size */
+    size_t instance_size;
+
+    /** String describing the operation, part of query-block-jobs QMP API */
+    BlockJobType job_type;
+
+    /** Optional callback for job types that support setting a speed limit */
+    void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
+
+    /** Optional callback for job types that need to forward I/O status reset */
+    void (*iostatus_reset)(BlockJob *job);
+
+    /**
+     * Optional callback for job types whose completion must be triggered
+     * manually.
+     */
+    void (*complete)(BlockJob *job, Error **errp);
+
+    /**
+     * If the callback is not NULL, it will be invoked when all the jobs
+     * belonging to the same transaction complete; or upon this job's
+     * completion if it is not in a transaction. Skipped if NULL.
+     *
+     * All jobs will complete with a call to either .commit() or .abort() but
+     * never both.
+     */
+    void (*commit)(BlockJob *job);
+
+    /**
+     * If the callback is not NULL, it will be invoked when any job in the
+     * same transaction fails; or upon this job's failure (due to error or
+     * cancellation) if it is not in a transaction. Skipped if NULL.
+     *
+     * All jobs will complete with a call to either .commit() or .abort() but
+     * never both.
+     */
+    void (*abort)(BlockJob *job);
+} BlockJobDriver;
+
+/**
+ * BlockJob:
+ *
+ * Long-running operation on a BlockDriverState.
+ */
+struct BlockJob {
+    /** The job type, including the job vtable.  */
+    const BlockJobDriver *driver;
+
+    /** The block device on which the job is operating.  */
+    BlockDriverState *bs;
+
+    /**
+     * The ID of the block job. Currently the BlockBackend name of the BDS
+     * owning the job at the time when the job is started.
+     *
+     * TODO Decouple block job IDs from BlockBackend names
+     */
+    char *id;
+
+    /**
+     * The coroutine that executes the job.  If not NULL, it is
+     * reentered when busy is false and the job is cancelled.
+     */
+    Coroutine *co;
+
+    /**
+     * Set to true if the job should cancel itself.  The flag must
+     * always be tested just before toggling the busy flag from false
+     * to true.  After a job has been cancelled, it should only yield
+     * if #aio_poll will ("sooner or later") reenter the coroutine.
+     */
+    bool cancelled;
+
+    /**
+     * Counter for pause request. If non-zero, the block job is either paused,
+     * or if busy == true will pause itself as soon as possible.
+     */
+    int pause_count;
+
+    /**
+     * Set to true if the job is paused by user.  Can be unpaused with the
+     * block-job-resume QMP command.
+     */
+    bool user_paused;
+
+    /**
+     * Set to false by the job while it is in a quiescent state, where
+     * no I/O is pending and the job has yielded on any condition
+     * that is not detected by #aio_poll, such as a timer.
+     */
+    bool busy;
+
+    /**
+     * Set to true when the job is ready to be completed.
+     */
+    bool ready;
+
+    /** Status that is published by the query-block-jobs QMP API */
+    BlockDeviceIoStatus iostatus;
+
+    /** Offset that is published by the query-block-jobs QMP API */
+    int64_t offset;
+
+    /** Length that is published by the query-block-jobs QMP API */
+    int64_t len;
+
+    /** Speed that was set with @block_job_set_speed.  */
+    int64_t speed;
+
+    /** The completion function that will be called when the job completes.  */
+    BlockCompletionFunc *cb;
+
+    /** Block other operations when block job is running */
+    Error *blocker;
+
+    /** The opaque value that is passed to the completion function.  */
+    void *opaque;
+
+    /** Reference count of the block job */
+    int refcnt;
+
+    /* True if this job has reported completion by calling block_job_completed.
+     */
+    bool completed;
+
+    /* ret code passed to block_job_completed.
+     */
+    int ret;
+
+    /** Non-NULL if this job is part of a transaction */
+    BlockJobTxn *txn;
+    QLIST_ENTRY(BlockJob) txn_list;
+};
+
+/**
+ * block_job_create:
+ * @job_type: The class object for the newly-created job.
+ * @bs: The block
+ * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @cb: Completion function for the job.
+ * @opaque: Opaque pointer value passed to @cb.
+ * @errp: Error object.
+ *
+ * Create a new long-running block device job and return it.  The job
+ * will call @cb asynchronously when the job completes.  Note that
+ * @bs may have been closed at the time the @cb it is called.  If
+ * this is the case, the job may be reported as either cancelled or
+ * completed.
+ *
+ * This function is not part of the public job interface; it should be
+ * called from a wrapper that is specific to the job type.
+ */
+void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
+                       int64_t speed, BlockCompletionFunc *cb,
+                       void *opaque, Error **errp);
+
+/**
+ * block_job_sleep_ns:
+ * @job: The job that calls the function.
+ * @clock: The clock to sleep on.
+ * @ns: How many nanoseconds to stop for.
+ *
+ * Put the job to sleep (assuming that it wasn't canceled) for @ns
+ * nanoseconds.  Canceling the job will interrupt the wait immediately.
+ */
+void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
+
+/**
+ * block_job_yield:
+ * @job: The job that calls the function.
+ *
+ * Yield the block job coroutine.
+ */
+void block_job_yield(BlockJob *job);
+
+/**
+ * block_job_ref:
+ * @bs: The block device.
+ *
+ * Grab a reference to the block job. Should be paired with block_job_unref.
+ */
+void block_job_ref(BlockJob *job);
+
+/**
+ * block_job_unref:
+ * @bs: The block device.
+ *
+ * Release reference to the block job and release resources if it is the last
+ * reference.
+ */
+void block_job_unref(BlockJob *job);
+
+/**
+ * block_job_completed:
+ * @job: The job being completed.
+ * @ret: The status code.
+ *
+ * Call the completion function that was registered at creation time, and
+ * free @job.
+ */
+void block_job_completed(BlockJob *job, int ret);
+
+/**
+ * block_job_set_speed:
+ * @job: The job to set the speed for.
+ * @speed: The new value
+ * @errp: Error object.
+ *
+ * Set a rate-limiting parameter for the job; the actual meaning may
+ * vary depending on the job type.
+ */
+void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
+
+/**
+ * block_job_cancel:
+ * @job: The job to be canceled.
+ *
+ * Asynchronously cancel the specified job.
+ */
+void block_job_cancel(BlockJob *job);
+
+/**
+ * block_job_complete:
+ * @job: The job to be completed.
+ * @errp: Error object.
+ *
+ * Asynchronously complete the specified job.
+ */
+void block_job_complete(BlockJob *job, Error **errp);
+
+/**
+ * block_job_is_cancelled:
+ * @job: The job being queried.
+ *
+ * Returns whether the job is scheduled for cancellation.
+ */
+bool block_job_is_cancelled(BlockJob *job);
+
+/**
+ * block_job_query:
+ * @job: The job to get information about.
+ *
+ * Return information about a job.
+ */
+BlockJobInfo *block_job_query(BlockJob *job);
+
+/**
+ * block_job_pause:
+ * @job: The job to be paused.
+ *
+ * Asynchronously pause the specified job.
+ */
+void block_job_pause(BlockJob *job);
+
+/**
+ * block_job_resume:
+ * @job: The job to be resumed.
+ *
+ * Resume the specified job.  Must be paired with a preceding block_job_pause.
+ */
+void block_job_resume(BlockJob *job);
+
+/**
+ * block_job_enter:
+ * @job: The job to enter.
+ *
+ * Continue the specified job by entering the coroutine.
+ */
+void block_job_enter(BlockJob *job);
+
+/**
+ * block_job_event_cancelled:
+ * @job: The job whose information is requested.
+ *
+ * Send a BLOCK_JOB_CANCELLED event for the specified job.
+ */
+void block_job_event_cancelled(BlockJob *job);
+
+/**
+ * block_job_ready:
+ * @job: The job which is now ready to complete.
+ * @msg: Error message. Only present on failure.
+ *
+ * Send a BLOCK_JOB_COMPLETED event for the specified job.
+ */
+void block_job_event_completed(BlockJob *job, const char *msg);
+
+/**
+ * block_job_ready:
+ * @job: The job which is now ready to complete.
+ *
+ * Send a BLOCK_JOB_READY event for the specified job.
+ */
+void block_job_event_ready(BlockJob *job);
+
+/**
+ * block_job_is_paused:
+ * @job: The job being queried.
+ *
+ * Returns whether the job is currently paused, or will pause
+ * as soon as it reaches a sleeping point.
+ */
+bool block_job_is_paused(BlockJob *job);
+
+/**
+ * block_job_cancel_sync:
+ * @job: The job to be canceled.
+ *
+ * Synchronously cancel the job.  The completion callback is called
+ * before the function returns.  The job may actually complete
+ * instead of canceling itself; the circumstances under which this
+ * happens depend on the kind of job that is active.
+ *
+ * Returns the return value from the job if the job actually completed
+ * during the call, or -ECANCELED if it was canceled.
+ */
+int block_job_cancel_sync(BlockJob *job);
+
+/**
+ * block_job_complete_sync:
+ * @job: The job to be completed.
+ * @errp: Error object which may be set by block_job_complete(); this is not
+ *        necessarily set on every error, the job return value has to be
+ *        checked as well.
+ *
+ * Synchronously complete the job.  The completion callback is called before the
+ * function returns, unless it is NULL (which is permissible when using this
+ * function).
+ *
+ * Returns the return value from the job.
+ */
+int block_job_complete_sync(BlockJob *job, Error **errp);
+
+/**
+ * block_job_iostatus_reset:
+ * @job: The job whose I/O status should be reset.
+ *
+ * Reset I/O status on @job and on BlockDriverState objects it uses,
+ * other than job->bs.
+ */
+void block_job_iostatus_reset(BlockJob *job);
+
+/**
+ * block_job_error_action:
+ * @job: The job to signal an error for.
+ * @bs: The block device on which to set an I/O error.
+ * @on_err: The error action setting.
+ * @is_read: Whether the operation was a read.
+ * @error: The error that was reported.
+ *
+ * Report an I/O error for a block job and possibly stop the VM.  Return the
+ * action that was selected based on @on_err and @error.
+ */
+BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
+                                        BlockdevOnError on_err,
+                                        int is_read, int error);
+
+typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque);
+
+/**
+ * block_job_defer_to_main_loop:
+ * @job: The job
+ * @fn: The function to run in the main loop
+ * @opaque: The opaque value that is passed to @fn
+ *
+ * Execute a given function in the main loop with the BlockDriverState
+ * AioContext acquired.  Block jobs must call bdrv_unref(), bdrv_close(), and
+ * anything that uses bdrv_drain_all() in the main loop.
+ *
+ * The @job AioContext is held while @fn executes.
+ */
+void block_job_defer_to_main_loop(BlockJob *job,
+                                  BlockJobDeferToMainLoopFn *fn,
+                                  void *opaque);
+
+/**
+ * block_job_txn_new:
+ *
+ * Allocate and return a new block job transaction.  Jobs can be added to the
+ * transaction using block_job_txn_add_job().
+ *
+ * The transaction is automatically freed when the last job completes or is
+ * cancelled.
+ *
+ * All jobs in the transaction either complete successfully or fail/cancel as a
+ * group.  Jobs wait for each other before completing.  Cancelling one job
+ * cancels all jobs in the transaction.
+ */
+BlockJobTxn *block_job_txn_new(void);
+
+/**
+ * block_job_txn_unref:
+ *
+ * Release a reference that was previously acquired with block_job_txn_add_job
+ * or block_job_txn_new. If it's the last reference to the object, it will be
+ * freed.
+ */
+void block_job_txn_unref(BlockJobTxn *txn);
+
+/**
+ * block_job_txn_add_job:
+ * @txn: The transaction (may be NULL)
+ * @job: Job to add to the transaction
+ *
+ * Add @job to the transaction.  The @job must not already be in a transaction.
+ * The caller must call either block_job_txn_unref() or block_job_completed()
+ * to release the reference that is automatically grabbed here.
+ */
+void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job);
+
+#endif
diff --git a/src/include/block/nbd.h b/src/include/block/nbd.h
new file mode 100644
index 0000000..65f409d
--- /dev/null
+++ b/src/include/block/nbd.h
@@ -0,0 +1,106 @@
+/*
+ *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
+ *
+ *  Network Block Device
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NBD_H
+#define NBD_H
+
+#include <sys/types.h>
+
+#include "qemu-common.h"
+#include "qemu/option.h"
+
+struct nbd_request {
+    uint32_t magic;
+    uint32_t type;
+    uint64_t handle;
+    uint64_t from;
+    uint32_t len;
+} QEMU_PACKED;
+
+struct nbd_reply {
+    uint32_t magic;
+    uint32_t error;
+    uint64_t handle;
+} QEMU_PACKED;
+
+#define NBD_FLAG_HAS_FLAGS      (1 << 0)        /* Flags are there */
+#define NBD_FLAG_READ_ONLY      (1 << 1)        /* Device is read-only */
+#define NBD_FLAG_SEND_FLUSH     (1 << 2)        /* Send FLUSH */
+#define NBD_FLAG_SEND_FUA       (1 << 3)        /* Send FUA (Force Unit Access) */
+#define NBD_FLAG_ROTATIONAL     (1 << 4)        /* Use elevator algorithm - rotational media */
+#define NBD_FLAG_SEND_TRIM      (1 << 5)        /* Send TRIM (discard) */
+
+/* New-style global flags. */
+#define NBD_FLAG_FIXED_NEWSTYLE     (1 << 0)    /* Fixed newstyle protocol. */
+
+/* New-style client flags. */
+#define NBD_FLAG_C_FIXED_NEWSTYLE   (1 << 0)    /* Fixed newstyle protocol. */
+
+/* Reply types. */
+#define NBD_REP_ACK             (1)             /* Data sending finished. */
+#define NBD_REP_SERVER          (2)             /* Export description. */
+#define NBD_REP_ERR_UNSUP       ((UINT32_C(1) << 31) | 1) /* Unknown option. */
+#define NBD_REP_ERR_INVALID     ((UINT32_C(1) << 31) | 3) /* Invalid length. */
+
+#define NBD_CMD_MASK_COMMAND	0x0000ffff
+#define NBD_CMD_FLAG_FUA	(1 << 16)
+
+enum {
+    NBD_CMD_READ = 0,
+    NBD_CMD_WRITE = 1,
+    NBD_CMD_DISC = 2,
+    NBD_CMD_FLUSH = 3,
+    NBD_CMD_TRIM = 4
+};
+
+#define NBD_DEFAULT_PORT	10809
+
+/* Maximum size of a single READ/WRITE data buffer */
+#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
+
+ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
+int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
+                          off_t *size, Error **errp);
+int nbd_init(int fd, int csock, uint32_t flags, off_t size);
+ssize_t nbd_send_request(int csock, struct nbd_request *request);
+ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply);
+int nbd_client(int fd);
+int nbd_disconnect(int fd);
+
+typedef struct NBDExport NBDExport;
+typedef struct NBDClient NBDClient;
+
+NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size,
+                          uint32_t nbdflags, void (*close)(NBDExport *),
+                          Error **errp);
+void nbd_export_close(NBDExport *exp);
+void nbd_export_get(NBDExport *exp);
+void nbd_export_put(NBDExport *exp);
+
+BlockBackend *nbd_export_get_blockdev(NBDExport *exp);
+
+NBDExport *nbd_export_find(const char *name);
+void nbd_export_set_name(NBDExport *exp, const char *name);
+void nbd_export_close_all(void);
+
+NBDClient *nbd_client_new(NBDExport *exp, int csock,
+                          void (*close)(NBDClient *));
+void nbd_client_get(NBDClient *client);
+void nbd_client_put(NBDClient *client);
+
+#endif
diff --git a/src/include/block/qapi.h b/src/include/block/qapi.h
new file mode 100644
index 0000000..327549d
--- /dev/null
+++ b/src/include/block/qapi.h
@@ -0,0 +1,46 @@
+/*
+ * Block layer qmp and info dump related functions
+ *
+ * Copyright (c) 2003-2008 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_QAPI_H
+#define BLOCK_QAPI_H
+
+#include "qapi-types.h"
+#include "block/block.h"
+#include "block/snapshot.h"
+
+BlockDeviceInfo *bdrv_block_device_info(BlockDriverState *bs, Error **errp);
+int bdrv_query_snapshot_info_list(BlockDriverState *bs,
+                                  SnapshotInfoList **p_list,
+                                  Error **errp);
+void bdrv_query_image_info(BlockDriverState *bs,
+                           ImageInfo **p_info,
+                           Error **errp);
+
+void bdrv_snapshot_dump(fprintf_function func_fprintf, void *f,
+                        QEMUSnapshotInfo *sn);
+void bdrv_image_info_specific_dump(fprintf_function func_fprintf, void *f,
+                                   ImageInfoSpecific *info_spec);
+void bdrv_image_info_dump(fprintf_function func_fprintf, void *f,
+                          ImageInfo *info);
+#endif
diff --git a/src/include/block/scsi.h b/src/include/block/scsi.h
new file mode 100644
index 0000000..a311341
--- /dev/null
+++ b/src/include/block/scsi.h
@@ -0,0 +1,309 @@
+/* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * This header file contains public constants and structures used by
+ * the scsi code for linux.
+ */
+#ifndef HW_SCSI_DEFS_H
+#define HW_SCSI_DEFS_H 1
+
+/*
+ *      SCSI opcodes
+ */
+
+#define TEST_UNIT_READY       0x00
+#define REWIND                0x01
+#define REQUEST_SENSE         0x03
+#define FORMAT_UNIT           0x04
+#define READ_BLOCK_LIMITS     0x05
+#define INITIALIZE_ELEMENT_STATUS 0x07
+#define REASSIGN_BLOCKS       0x07
+#define READ_6                0x08
+#define WRITE_6               0x0a
+#define SET_CAPACITY          0x0b
+#define READ_REVERSE          0x0f
+#define WRITE_FILEMARKS       0x10
+#define SPACE                 0x11
+#define INQUIRY               0x12
+#define RECOVER_BUFFERED_DATA 0x14
+#define MODE_SELECT           0x15
+#define RESERVE               0x16
+#define RELEASE               0x17
+#define COPY                  0x18
+#define ERASE                 0x19
+#define MODE_SENSE            0x1a
+#define LOAD_UNLOAD           0x1b
+#define START_STOP            0x1b
+#define RECEIVE_DIAGNOSTIC    0x1c
+#define SEND_DIAGNOSTIC       0x1d
+#define ALLOW_MEDIUM_REMOVAL  0x1e
+#define READ_CAPACITY_10      0x25
+#define READ_10               0x28
+#define WRITE_10              0x2a
+#define SEEK_10               0x2b
+#define LOCATE_10             0x2b
+#define POSITION_TO_ELEMENT   0x2b
+#define WRITE_VERIFY_10       0x2e
+#define VERIFY_10             0x2f
+#define SEARCH_HIGH           0x30
+#define SEARCH_EQUAL          0x31
+#define SEARCH_LOW            0x32
+#define SET_LIMITS            0x33
+#define PRE_FETCH             0x34
+#define READ_POSITION         0x34
+#define SYNCHRONIZE_CACHE     0x35
+#define LOCK_UNLOCK_CACHE     0x36
+#define INITIALIZE_ELEMENT_STATUS_WITH_RANGE 0x37
+#define READ_DEFECT_DATA      0x37
+#define MEDIUM_SCAN           0x38
+#define COMPARE               0x39
+#define COPY_VERIFY           0x3a
+#define WRITE_BUFFER          0x3b
+#define READ_BUFFER           0x3c
+#define UPDATE_BLOCK          0x3d
+#define READ_LONG_10          0x3e
+#define WRITE_LONG_10         0x3f
+#define CHANGE_DEFINITION     0x40
+#define WRITE_SAME_10         0x41
+#define UNMAP                 0x42
+#define READ_TOC              0x43
+#define REPORT_DENSITY_SUPPORT 0x44
+#define GET_CONFIGURATION     0x46
+#define SANITIZE              0x48
+#define GET_EVENT_STATUS_NOTIFICATION 0x4a
+#define LOG_SELECT            0x4c
+#define LOG_SENSE             0x4d
+#define READ_DISC_INFORMATION 0x51
+#define RESERVE_TRACK         0x53
+#define MODE_SELECT_10        0x55
+#define RESERVE_10            0x56
+#define RELEASE_10            0x57
+#define MODE_SENSE_10         0x5a
+#define SEND_CUE_SHEET        0x5d
+#define PERSISTENT_RESERVE_IN 0x5e
+#define PERSISTENT_RESERVE_OUT 0x5f
+#define VARLENGTH_CDB         0x7f
+#define WRITE_FILEMARKS_16    0x80
+#define READ_REVERSE_16       0x81
+#define ALLOW_OVERWRITE       0x82
+#define EXTENDED_COPY         0x83
+#define ATA_PASSTHROUGH_16    0x85
+#define ACCESS_CONTROL_IN     0x86
+#define ACCESS_CONTROL_OUT    0x87
+#define READ_16               0x88
+#define COMPARE_AND_WRITE     0x89
+#define WRITE_16              0x8a
+#define WRITE_VERIFY_16       0x8e
+#define VERIFY_16             0x8f
+#define PRE_FETCH_16          0x90
+#define SPACE_16              0x91
+#define SYNCHRONIZE_CACHE_16  0x91
+#define LOCATE_16             0x92
+#define WRITE_SAME_16         0x93
+#define ERASE_16              0x93
+#define SERVICE_ACTION_IN_16  0x9e
+#define WRITE_LONG_16         0x9f
+#define REPORT_LUNS           0xa0
+#define ATA_PASSTHROUGH_12    0xa1
+#define MAINTENANCE_IN        0xa3
+#define MAINTENANCE_OUT       0xa4
+#define MOVE_MEDIUM           0xa5
+#define EXCHANGE_MEDIUM       0xa6
+#define SET_READ_AHEAD        0xa7
+#define READ_12               0xa8
+#define WRITE_12              0xaa
+#define SERVICE_ACTION_IN_12  0xab
+#define ERASE_12              0xac
+#define READ_DVD_STRUCTURE    0xad
+#define WRITE_VERIFY_12       0xae
+#define VERIFY_12             0xaf
+#define SEARCH_HIGH_12        0xb0
+#define SEARCH_EQUAL_12       0xb1
+#define SEARCH_LOW_12         0xb2
+#define READ_ELEMENT_STATUS   0xb8
+#define SEND_VOLUME_TAG       0xb6
+#define READ_DEFECT_DATA_12   0xb7
+#define SET_CD_SPEED          0xbb
+#define MECHANISM_STATUS      0xbd
+#define READ_CD               0xbe
+#define SEND_DVD_STRUCTURE    0xbf
+
+const char *scsi_command_name(uint8_t cmd);
+
+/*
+ * SERVICE ACTION IN subcodes
+ */
+#define SAI_READ_CAPACITY_16  0x10
+
+/*
+ * READ POSITION service action codes
+ */
+#define SHORT_FORM_BLOCK_ID  0x00
+#define SHORT_FORM_VENDOR_SPECIFIC 0x01
+#define LONG_FORM            0x06
+#define EXTENDED_FORM        0x08
+
+/*
+ *  SAM Status codes
+ */
+
+#define GOOD                 0x00
+#define CHECK_CONDITION      0x02
+#define CONDITION_GOOD       0x04
+#define BUSY                 0x08
+#define INTERMEDIATE_GOOD    0x10
+#define INTERMEDIATE_C_GOOD  0x14
+#define RESERVATION_CONFLICT 0x18
+#define COMMAND_TERMINATED   0x22
+#define TASK_SET_FULL        0x28
+#define ACA_ACTIVE           0x30
+#define TASK_ABORTED         0x40
+
+#define STATUS_MASK          0x3e
+
+/*
+ *  SENSE KEYS
+ */
+
+#define NO_SENSE            0x00
+#define RECOVERED_ERROR     0x01
+#define NOT_READY           0x02
+#define MEDIUM_ERROR        0x03
+#define HARDWARE_ERROR      0x04
+#define ILLEGAL_REQUEST     0x05
+#define UNIT_ATTENTION      0x06
+#define DATA_PROTECT        0x07
+#define BLANK_CHECK         0x08
+#define COPY_ABORTED        0x0a
+#define ABORTED_COMMAND     0x0b
+#define VOLUME_OVERFLOW     0x0d
+#define MISCOMPARE          0x0e
+
+
+/*
+ *  DEVICE TYPES
+ */
+
+#define TYPE_DISK           0x00
+#define TYPE_TAPE           0x01
+#define TYPE_PRINTER        0x02
+#define TYPE_PROCESSOR      0x03    /* HP scanners use this */
+#define TYPE_WORM           0x04    /* Treated as ROM by our system */
+#define TYPE_ROM            0x05
+#define TYPE_SCANNER        0x06
+#define TYPE_MOD            0x07    /* Magneto-optical disk -
+				     * - treated as TYPE_DISK */
+#define TYPE_MEDIUM_CHANGER 0x08
+#define TYPE_STORAGE_ARRAY  0x0c    /* Storage array device */
+#define TYPE_ENCLOSURE      0x0d    /* Enclosure Services Device */
+#define TYPE_RBC            0x0e    /* Simplified Direct-Access Device */
+#define TYPE_OSD            0x11    /* Object-storage Device */
+#define TYPE_WLUN           0x1e    /* Well known LUN */
+#define TYPE_NOT_PRESENT    0x1f
+#define TYPE_INACTIVE       0x20
+#define TYPE_NO_LUN         0x7f
+
+/* Mode page codes for mode sense/set */
+#define MODE_PAGE_R_W_ERROR                   0x01
+#define MODE_PAGE_HD_GEOMETRY                 0x04
+#define MODE_PAGE_FLEXIBLE_DISK_GEOMETRY      0x05
+#define MODE_PAGE_CACHING                     0x08
+#define MODE_PAGE_AUDIO_CTL                   0x0e
+#define MODE_PAGE_POWER                       0x1a
+#define MODE_PAGE_FAULT_FAIL                  0x1c
+#define MODE_PAGE_TO_PROTECT                  0x1d
+#define MODE_PAGE_CAPABILITIES                0x2a
+#define MODE_PAGE_ALLS                        0x3f
+/* Not in Mt. Fuji, but in ATAPI 2.6 -- deprecated now in favor
+ * of MODE_PAGE_SENSE_POWER */
+#define MODE_PAGE_CDROM                       0x0d
+
+/* Event notification classes for GET EVENT STATUS NOTIFICATION */
+#define GESN_NO_EVENTS                0
+#define GESN_OPERATIONAL_CHANGE       1
+#define GESN_POWER_MANAGEMENT         2
+#define GESN_EXTERNAL_REQUEST         3
+#define GESN_MEDIA                    4
+#define GESN_MULTIPLE_HOSTS           5
+#define GESN_DEVICE_BUSY              6
+
+/* Event codes for MEDIA event status notification */
+#define MEC_NO_CHANGE                 0
+#define MEC_EJECT_REQUESTED           1
+#define MEC_NEW_MEDIA                 2
+#define MEC_MEDIA_REMOVAL             3 /* only for media changers */
+#define MEC_MEDIA_CHANGED             4 /* only for media changers */
+#define MEC_BG_FORMAT_COMPLETED       5 /* MRW or DVD+RW b/g format completed */
+#define MEC_BG_FORMAT_RESTARTED       6 /* MRW or DVD+RW b/g format restarted */
+
+#define MS_TRAY_OPEN                  1
+#define MS_MEDIA_PRESENT              2
+
+/*
+ * Based on values from <linux/cdrom.h> but extending CD_MINS
+ * to the maximum common size allowed by the Orange's Book ATIP
+ *
+ * 90 and 99 min CDs are also available but using them as the
+ * upper limit reduces the effectiveness of the heuristic to
+ * detect DVDs burned to less than 25% of their maximum capacity
+ */
+
+/* Some generally useful CD-ROM information */
+#define CD_MINS                       80 /* max. minutes per CD */
+#define CD_SECS                       60 /* seconds per minute */
+#define CD_FRAMES                     75 /* frames per second */
+#define CD_FRAMESIZE                2048 /* bytes per frame, "cooked" mode */
+#define CD_MAX_BYTES       (CD_MINS * CD_SECS * CD_FRAMES * CD_FRAMESIZE)
+#define CD_MAX_SECTORS     (CD_MAX_BYTES / 512)
+
+/*
+ * The MMC values are not IDE specific and might need to be moved
+ * to a common header if they are also needed for the SCSI emulation
+ */
+
+/* Profile list from MMC-6 revision 1 table 91 */
+#define MMC_PROFILE_NONE                0x0000
+#define MMC_PROFILE_CD_ROM              0x0008
+#define MMC_PROFILE_CD_R                0x0009
+#define MMC_PROFILE_CD_RW               0x000A
+#define MMC_PROFILE_DVD_ROM             0x0010
+#define MMC_PROFILE_DVD_R_SR            0x0011
+#define MMC_PROFILE_DVD_RAM             0x0012
+#define MMC_PROFILE_DVD_RW_RO           0x0013
+#define MMC_PROFILE_DVD_RW_SR           0x0014
+#define MMC_PROFILE_DVD_R_DL_SR         0x0015
+#define MMC_PROFILE_DVD_R_DL_JR         0x0016
+#define MMC_PROFILE_DVD_RW_DL           0x0017
+#define MMC_PROFILE_DVD_DDR             0x0018
+#define MMC_PROFILE_DVD_PLUS_RW         0x001A
+#define MMC_PROFILE_DVD_PLUS_R          0x001B
+#define MMC_PROFILE_DVD_PLUS_RW_DL      0x002A
+#define MMC_PROFILE_DVD_PLUS_R_DL       0x002B
+#define MMC_PROFILE_BD_ROM              0x0040
+#define MMC_PROFILE_BD_R_SRM            0x0041
+#define MMC_PROFILE_BD_R_RRM            0x0042
+#define MMC_PROFILE_BD_RE               0x0043
+#define MMC_PROFILE_HDDVD_ROM           0x0050
+#define MMC_PROFILE_HDDVD_R             0x0051
+#define MMC_PROFILE_HDDVD_RAM           0x0052
+#define MMC_PROFILE_HDDVD_RW            0x0053
+#define MMC_PROFILE_HDDVD_R_DL          0x0058
+#define MMC_PROFILE_HDDVD_RW_DL         0x005A
+#define MMC_PROFILE_INVALID             0xFFFF
+
+#endif
diff --git a/src/include/block/snapshot.h b/src/include/block/snapshot.h
new file mode 100644
index 0000000..c6910da6
--- /dev/null
+++ b/src/include/block/snapshot.h
@@ -0,0 +1,96 @@
+/*
+ * Block layer snapshot related functions
+ *
+ * Copyright (c) 2003-2008 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 SNAPSHOT_H
+#define SNAPSHOT_H
+
+#include "qemu-common.h"
+#include "qapi/error.h"
+#include "qemu/option.h"
+
+
+#define SNAPSHOT_OPT_BASE       "snapshot."
+#define SNAPSHOT_OPT_ID         "snapshot.id"
+#define SNAPSHOT_OPT_NAME       "snapshot.name"
+
+extern QemuOptsList internal_snapshot_opts;
+
+typedef struct QEMUSnapshotInfo {
+    char id_str[128]; /* unique snapshot id */
+    /* the following fields are informative. They are not needed for
+       the consistency of the snapshot */
+    char name[256]; /* user chosen name */
+    uint64_t vm_state_size; /* VM state info size */
+    uint32_t date_sec; /* UTC date of the snapshot */
+    uint32_t date_nsec;
+    uint64_t vm_clock_nsec; /* VM clock relative to boot */
+} QEMUSnapshotInfo;
+
+int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
+                       const char *name);
+bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs,
+                                       const char *id,
+                                       const char *name,
+                                       QEMUSnapshotInfo *sn_info,
+                                       Error **errp);
+int bdrv_can_snapshot(BlockDriverState *bs);
+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_delete_by_id_or_name(BlockDriverState *bs,
+                                       const char *id_or_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_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
+                                         const char *id_or_name,
+                                         Error **errp);
+
+
+/* Group operations. All block drivers are involved.
+ * These functions will properly handle dataplane (take aio_context_acquire
+ * when appropriate for appropriate block drivers */
+
+bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs);
+int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bsd_bs,
+                             Error **err);
+int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bsd_bs);
+int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs);
+int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
+                             BlockDriverState *vm_state_bs,
+                             uint64_t vm_state_size,
+                             BlockDriverState **first_bad_bs);
+
+BlockDriverState *bdrv_all_find_vmstate_bs(void);
+
+#endif
diff --git a/src/include/block/thread-pool.h b/src/include/block/thread-pool.h
new file mode 100644
index 0000000..42eb5e8
--- /dev/null
+++ b/src/include/block/thread-pool.h
@@ -0,0 +1,37 @@
+/*
+ * QEMU block layer thread pool
+ *
+ * Copyright IBM, Corp. 2008
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *  Paolo Bonzini     <pbonzini@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#ifndef QEMU_THREAD_POOL_H
+#define QEMU_THREAD_POOL_H 1
+
+#include "block/block.h"
+
+typedef int ThreadPoolFunc(void *opaque);
+
+typedef struct ThreadPool ThreadPool;
+
+ThreadPool *thread_pool_new(struct AioContext *ctx);
+void thread_pool_free(ThreadPool *pool);
+
+BlockAIOCB *thread_pool_submit_aio(ThreadPool *pool,
+        ThreadPoolFunc *func, void *arg,
+        BlockCompletionFunc *cb, void *opaque);
+int coroutine_fn thread_pool_submit_co(ThreadPool *pool,
+        ThreadPoolFunc *func, void *arg);
+void thread_pool_submit(ThreadPool *pool, ThreadPoolFunc *func, void *arg);
+
+#endif
diff --git a/src/include/block/throttle-groups.h b/src/include/block/throttle-groups.h
new file mode 100644
index 0000000..aba28f3
--- /dev/null
+++ b/src/include/block/throttle-groups.h
@@ -0,0 +1,46 @@
+/*
+ * QEMU block throttling group infrastructure
+ *
+ * Copyright (C) Nodalink, EURL. 2014
+ * Copyright (C) Igalia, S.L. 2015
+ *
+ * Authors:
+ *   Benoît Canet <benoit.canet@nodalink.com>
+ *   Alberto Garcia <berto@igalia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef THROTTLE_GROUPS_H
+#define THROTTLE_GROUPS_H
+
+#include "qemu/throttle.h"
+#include "block/block_int.h"
+
+const char *throttle_group_get_name(BlockDriverState *bs);
+
+ThrottleState *throttle_group_incref(const char *name);
+void throttle_group_unref(ThrottleState *ts);
+
+void throttle_group_config(BlockDriverState *bs, ThrottleConfig *cfg);
+void throttle_group_get_config(BlockDriverState *bs, ThrottleConfig *cfg);
+
+void throttle_group_register_bs(BlockDriverState *bs, const char *groupname);
+void throttle_group_unregister_bs(BlockDriverState *bs);
+
+void coroutine_fn throttle_group_co_io_limits_intercept(BlockDriverState *bs,
+                                                        unsigned int bytes,
+                                                        bool is_write);
+
+#endif
diff --git a/src/include/block/write-threshold.h b/src/include/block/write-threshold.h
new file mode 100644
index 0000000..f1b899c
--- /dev/null
+++ b/src/include/block/write-threshold.h
@@ -0,0 +1,64 @@
+/*
+ * QEMU System Emulator block write threshold notification
+ *
+ * Copyright Red Hat, Inc. 2014
+ *
+ * Authors:
+ *  Francesco Romani <fromani@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+#ifndef BLOCK_WRITE_THRESHOLD_H
+#define BLOCK_WRITE_THRESHOLD_H
+
+#include <stdint.h>
+
+#include "qemu/typedefs.h"
+#include "qemu-common.h"
+
+/*
+ * bdrv_write_threshold_set:
+ *
+ * Set the write threshold for block devices, in bytes.
+ * Notify when a write exceeds the threshold, meaning the device
+ * is becoming full, so it can be transparently resized.
+ * To be used with thin-provisioned block devices.
+ *
+ * Use threshold_bytes == 0 to disable.
+ */
+void bdrv_write_threshold_set(BlockDriverState *bs, uint64_t threshold_bytes);
+
+/*
+ * bdrv_write_threshold_get
+ *
+ * Get the configured write threshold, in bytes.
+ * Zero means no threshold configured.
+ */
+uint64_t bdrv_write_threshold_get(const BlockDriverState *bs);
+
+/*
+ * bdrv_write_threshold_is_set
+ *
+ * Tell if a write threshold is set for a given BDS.
+ */
+bool bdrv_write_threshold_is_set(const BlockDriverState *bs);
+
+/*
+ * bdrv_write_threshold_exceeded
+ *
+ * Return the extent of a write request that exceeded the threshold,
+ * or zero if the request is below the threshold.
+ * Return zero also if the threshold was not set.
+ *
+ * NOTE: here we assume the following holds for each request this code
+ * deals with:
+ *
+ * assert((req->offset + req->bytes) <= UINT64_MAX)
+ *
+ * Please not there is *not* an actual C assert().
+ */
+uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs,
+                                       const BdrvTrackedRequest *req);
+
+#endif