Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

Block pull request

# gpg: Signature made Fri 06 Jun 2014 17:08:50 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/block-pull-request: (42 commits)
  qapi: Extract qapi/block.json definitions
  qapi: Extract qapi/block-core.json definitions
  qapi: create two block related json modules
  qapi: Extract qapi/common.json definitions
  sheepdog: reload only header in a case of live snapshot
  sheepdog: fix vdi object update after live snapshot
  rbd: Fix leaks in rbd_start_aio() error path
  qemu-img: Document check exit codes
  block: fix wrong order in live block migration setup
  blockdev: acquire AioContext in block_set_io_throttle
  throttle: add detach/attach test case
  throttle: add throttle_detach/attach_aio_context()
  dataplane: Support VIRTIO_BLK_T_SCSI_CMD
  virtio-blk: Factor out virtio_blk_handle_scsi_req from virtio_blk_handle_scsi
  virtio-blk: Allow config-wce in dataplane
  block: Move declaration of bdrv_get_aio_context to block.h
  raw-posix: drop raw_get_aio_fd() since it is no longer used
  dataplane: implement async flush
  dataplane: delete IOQueue since it is no longer used
  dataplane: use the QEMU block layer for I/O
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

include/block/block.h

@@ -481,15 +481,6 @@ 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);
 
-#ifdef CONFIG_LINUX_AIO
-int raw_get_aio_fd(BlockDriverState *bs);
-#else
-static inline int raw_get_aio_fd(BlockDriverState *bs)
-{
-    return -ENOTSUP;
-}
-#endif
-
 enum BlockAcctType {
     BDRV_ACCT_READ,
     BDRV_ACCT_WRITE,
@@ -574,4 +565,22 @@ 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 from the old #AioContext or with a lock held so
+ * the old #AioContext is not executing.
+ */
+void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
+
 #endif

include/block/block_int.h

@@ -247,6 +247,19 @@ struct BlockDriver {
      */
     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);
+
     QLIST_ENTRY(BlockDriver) list;
 };
 
@@ -297,6 +310,8 @@ struct BlockDriverState {
     const BlockDevOps *dev_ops;
     void *dev_opaque;
 
+    AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
+
     char filename[1024];
     char backing_file[1024]; /* if non zero, the image is a diff of
                                 this file image */
@@ -390,11 +405,25 @@ void bdrv_add_before_write_notifier(BlockDriverState *bs,
                                     NotifierWithReturn *notifier);
 
 /**
- * bdrv_get_aio_context:
+ * bdrv_detach_aio_context:
  *
- * Returns: the currently bound #AioContext
+ * 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_hd are automatically handled and
+ * block drivers should not call this function on them explicitly.
  */
-AioContext *bdrv_get_aio_context(BlockDriverState *bs);
+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_hd are automatically handled and block
+ * drivers should not call this function on them explicitly.
+ */
+void bdrv_attach_aio_context(BlockDriverState *bs,
+                             AioContext *new_context);
 
 #ifdef _WIN32
 int is_windows_drive(const char *filename);

include/hw/virtio/virtio-blk.h

@@ -155,4 +155,7 @@ typedef struct VirtIOBlock {
 
 void virtio_blk_set_conf(DeviceState *dev, VirtIOBlkConf *blk);
 
+int virtio_blk_handle_scsi_req(VirtIOBlock *blk,
+                               VirtQueueElement *elem);
+
 #endif

include/qemu/throttle.h

@@ -67,6 +67,11 @@ typedef struct ThrottleState {
     int64_t previous_leak;    /* timestamp of the last leak done */
     QEMUTimer * timers[2];    /* timers used to do the throttling */
     QEMUClockType clock_type; /* the clock used */
+
+    /* Callbacks */
+    QEMUTimerCB *read_timer_cb;
+    QEMUTimerCB *write_timer_cb;
+    void *timer_opaque;
 } ThrottleState;
 
 /* operations on single leaky buckets */
@@ -82,6 +87,7 @@ bool throttle_compute_timer(ThrottleState *ts,
 
 /* init/destroy cycle */
 void throttle_init(ThrottleState *ts,
+                   AioContext *aio_context,
                    QEMUClockType clock_type,
                    void (read_timer)(void *),
                    void (write_timer)(void *),
@@ -89,6 +95,10 @@ void throttle_init(ThrottleState *ts,
 
 void throttle_destroy(ThrottleState *ts);
 
+void throttle_detach_aio_context(ThrottleState *ts);
+
+void throttle_attach_aio_context(ThrottleState *ts, AioContext *new_context);
+
 bool throttle_have_timer(ThrottleState *ts);
 
 /* configuration */