new scsi-generic abstraction, use SG_IO (Christoph Hellwig)

Okay, I started looking into how to handle scsi-generic I/O in the
new world order.

I think the best is to use the SG_IO ioctl instead of the read/write
interface as that allows us to support scsi passthrough on disk/cdrom
devices, too.  See Hannes patch on the kvm list from August for an
example.

Now that we always do ioctls we don't need another abstraction than
bdrv_ioctl for the synchronous requests for now, and for asynchronous
requests I've added a aio_ioctl abstraction keeping it simple.

Long-term we might want to move the ops to a higher-level abstraction
and let the low-level code fill out the request header, but I'm lazy
enough to leave that to the people trying to support scsi-passthrough
on a non-Linux OS.

Tested lightly by issuing various sg_ commands from sg3-utils in a guest
to a host CDROM device.


Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6895 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 4 insertions, 7 deletions

diff --git a/block.h b/block.h
index b0c63ac588..750816e55d 100644
--- a/block.h
+++ b/block.h
@@ -102,12 +102,10 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
 void bdrv_aio_cancel(BlockDriverAIOCB *acb);
 
 /* sg packet commands */
-int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count);
-int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count);
-BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count,
-                                   BlockDriverCompletionFunc *cb, void *opaque);
-BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count,
-                                    BlockDriverCompletionFunc *cb, void *opaque);
+int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
+BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
+        unsigned long int req, void *buf,
+        BlockDriverCompletionFunc *cb, void *opaque);
 
 /* Ensure contents are flushed to disk.  */
 void bdrv_flush(BlockDriverState *bs);
@@ -169,7 +167,6 @@ int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
 int bdrv_snapshot_list(BlockDriverState *bs,
                        QEMUSnapshotInfo **psn_info);
 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn);
-int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
 
 char *get_human_readable_size(char *buf, int buf_size, int64_t size);
 int path_is_absolute(const char *path);