bdev_virtio: added --without-virtio configure flag

SPDK can now be compiled without
the virtio driver.

Change-Id: I92999c871d28875d519749a73a7f2230c3881fbe
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/382828
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

CONFIG

@@ -81,5 +81,8 @@ CONFIG_RBD?=n
 # Build vhost library.
 CONFIG_VHOST?=y
 
+# Build vhost initiator (Virtio) driver.
+CONFIG_VIRTIO?=y
+
 # Build with NVML backends
 CONFIG_NVML?=n

configure

@@ -31,6 +31,8 @@ function usage()
 	echo "                           example: /usr/share/dpdk/x86_64-default-linuxapp-gcc"
 	echo " fio                       Required to build fio_plugin."
 	echo "                           example: /usr/src/fio"
+	echo " virtio                    Required to build vhost initiator (Virtio) bdev module."
+	echo "                           No path required."
 	echo " nvml                      Required to build persistent memory bdev."
 	echo "                           example: /usr/share/nvml"
 	echo " rbd                       [disabled]"
@@ -111,6 +113,12 @@ for i in "$@"; do
 		--without-dpdk)
 			CONFIG_DPDK_DIR=
 			;;
+		--with-virtio)
+			CONFIG_VIRTIO=y
+			;;
+		--without-virtio)
+			CONFIG_VIRTIO=n
+			;;
 		--with-nvml)
 			CONFIG_NVML=y
 			;;
@@ -218,6 +226,9 @@ fi
 if [ -n "$CONFIG_DPDK_DIR" ]; then
 	echo "CONFIG_DPDK_DIR?=$CONFIG_DPDK_DIR" >> CONFIG.local
 fi
+if [ -n "$CONFIG_VIRTIO" ]; then
+	echo "CONFIG_VIRTIO?=$CONFIG_VIRTIO" >> CONFIG.local
+fi
 if [ -n "$CONFIG_NVML" ]; then
 	echo "CONFIG_NVML?=$CONFIG_NVML" >> CONFIG.local
 fi

lib/bdev/Makefile

@@ -47,7 +47,8 @@ LIBNAME = bdev
 DIRS-y += error gpt lvol malloc null nvme rpc split
 
 ifeq ($(OS),Linux)
-DIRS-y += aio virtio
+DIRS-y += aio
+DIRS-$(CONFIG_VIRTIO) += virtio
 DIRS-$(CONFIG_NVML) += pmem
 endif