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, 3 insertions, 10 deletions

diff --git a/block_int.h b/block_int.h
index 8b4c5fe5fc..b45bde04d4 100644
--- a/block_int.h
+++ b/block_int.h
@@ -86,16 +86,9 @@ struct BlockDriver {
 
     /* to control generic scsi devices */
     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
-    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);
+    BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
+        unsigned long int req, void *buf,
+        BlockDriverCompletionFunc *cb, void *opaque);
 
     AIOPool aio_pool;
     struct BlockDriver *next;