nvme-loop: add a NVMe loopback host driver

Christoph Hellwig · axboe · commit 3a85a5de29ea · 2016-07-05T11:30:36.000-06:00
This patch implements adds nvme-loop which allows to access local devices
exported as NVMe over Fabrics namespaces. This module can be useful for
easy evaluation, testing and also feature experimentation.

To createa nvme-loop device you need to configure the NVMe target to
export a loop port (see the nvmetcli documentaton for that) and then
connect to it using

	nvme connect-all -t loop

which requires the very latest nvme-cli version with Fabrics support.

Signed-off-by: Jay Freyensee &lt;james.p.freyensee@intel.com&gt;
Signed-off-by: Ming Lin &lt;ming.l@ssi.samsung.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
@@ -13,4 +13,14 @@ config NVME_TARGET
 	  To configure the NVMe target you probably want to use the nvmetcli
 	  tool from http://git.infradead.org/users/hch/nvmetcli.git.
 
+config NVME_TARGET_LOOP
+	tristate "NVMe loopback device support"
+	depends on BLK_DEV_NVME
+	select NVME_TARGET
+	select NVME_FABRICS
+	select SG_POOL
+	help
+	  This enables the NVMe loopback device support, which can be useful
+	  to test NVMe host and target side features.
+
 	  If unsure, say N.
diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
@@ -1,5 +1,7 @@
 
 obj-$(CONFIG_NVME_TARGET)		+= nvmet.o
+obj-$(CONFIG_NVME_TARGET_LOOP)		+= nvme-loop.o
 
 nvmet-y		+= core.o configfs.o admin-cmd.o io-cmd.o fabrics-cmd.o \
 			discovery.o
+nvme-loop-y	+= loop.o
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
