xen: add virtual block device driver.

The block device frontend driver allows the kernel to access block
devices exported exported by a virtual machine containing a physical
block device driver.

Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Greg KH <greg@kroah.com>
Cc: Jens Axboe <axboe@kernel.dk>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 8f65b88cf711..a4a311992408 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -427,4 +427,13 @@ config XILINX_SYSACE
         help
           Include support for the Xilinx SystemACE CompactFlash interface
 
+config XEN_BLKDEV_FRONTEND
+        tristate "Xen virtual block device support"
+        depends on XEN
+        default y
+        help
+          This driver implements the front-end of the Xen virtual
+          block device driver.  It communicates with a back-end driver
+          in another domain which drives the actual block device.
+
 endif # BLK_DEV