Add specialized block driver scsi generic API (Avi Kivity)

When a scsi device is backed by a scsi generic device instead of an
ordinary host block device, the block API is abused in a couple of annoying
ways:

 - nb_sectors is negative, and specifies a byte count instead of a sector count
 - offset is ignored, since scsi-generic is essentially a packet protocol

This overloading makes hacking the block layer difficult.  Remove it by
introducing a new explicit API for scsi-generic devices.  The new API
is still backed by the old implementation, but at least the users are
insulated.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6822 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 22 insertions, 0 deletions

diff --git a/block.c b/block.c
index 1ef4ae5f3e..39b27b2702 100644
--- a/block.c
+++ b/block.c
@@ -1675,3 +1675,25 @@ int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
         return drv->bdrv_ioctl(bs, req, buf);
     return -ENOTSUP;
 }
+
+int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count)
+{
+    return bdrv_pwrite(bs, -1, buf, count);
+}
+
+int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count)
+{
+    return bdrv_pread(bs, -1, buf, count);
+}
+
+BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count,
+                                   BlockDriverCompletionFunc *cb, void *opaque)
+{
+    return bdrv_aio_read(bs, 0, buf, -(int64_t)count, cb, opaque);
+}
+
+BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count,
+                                    BlockDriverCompletionFunc *cb, void *opaque)
+{
+    return bdrv_aio_write(bs, 0, buf, -(int64_t)count, cb, opaque);
+}