xen: add virtual network device driver

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

Signed-off-by: Jeremy Fitzhardinge <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
Acked-by: Jeff Garzik <[email protected]>
Cc: Ian Pratt <[email protected]>
Cc: Christian Limpach <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Keir Fraser <[email protected]>
Cc: [email protected]

drivers/net/Kconfig

@@ -2486,6 +2486,18 @@ source "drivers/atm/Kconfig"
 
 source "drivers/s390/net/Kconfig"
 
+config XEN_NETDEV_FRONTEND
+	tristate "Xen network device frontend driver"
+	depends on XEN
+	default y
+	help
+	  The network device frontend driver allows the kernel to
+	  access network devices exported exported by a virtual
+	  machine containing a physical network device driver. The
+	  frontend driver is intended for unprivileged guest domains;
+	  if you are compiling a kernel for a Xen guest, you almost
+	  certainly want to enable this.
+
 config ISERIES_VETH
 	tristate "iSeries Virtual Ethernet driver support"
 	depends on PPC_ISERIES

drivers/net/Makefile

@@ -127,6 +127,8 @@ obj-$(CONFIG_PPPOL2TP) += pppox.o pppol2tp.o
 obj-$(CONFIG_SLIP) += slip.o
 obj-$(CONFIG_SLHC) += slhc.o
 
+obj-$(CONFIG_XEN_NETDEV_FRONTEND) += xen-netfront.o
+
 obj-$(CONFIG_DUMMY) += dummy.o
 obj-$(CONFIG_IFB) += ifb.o
 obj-$(CONFIG_MACVLAN) += macvlan.o