block: explicit I/O accounting

Decouple the I/O accounting from bdrv_aio_readv/writev/flush and
make the hardware models call directly into the accounting helpers.

This means:
 - we do not count internal requests from image formats in addition
   to guest originating I/O
 - we do not double count I/O ops if the device model handles it
   chunk wise
 - we only account I/O once it actuall is done
 - can extent I/O accounting to synchronous or coroutine I/O easily
 - implement I/O latency tracking easily (see the next patch)

I've conveted the existing device model callers to the new model,
device models that are using synchronous I/O and weren't accounted
before haven't been updated yet.  Also scsi hasn't been converted
to the end-to-end accounting as I want to defer that after the pending
scsi layer overhaul.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/hw/ide/ahci.h b/hw/ide/ahci.h
index e456193..832539c 100644
--- a/hw/ide/ahci.h
+++ b/hw/ide/ahci.h
@@ -258,6 +258,7 @@ typedef struct NCQTransferState {
     AHCIDevice *drive;
     BlockDriverAIOCB *aiocb;
     QEMUSGList sglist;
+    BlockAcctCookie acct;
     int is_read;
     uint16_t sector_count;
     uint64_t lba;