net: qemu: Allow SLIP or normal ethernet connectivity

Introduce new Kconfig option for selecting either slip or ethernet
connectivity to host.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

boards/x86/qemu_x86/board.cmake

@@ -13,7 +13,6 @@ set(QEMU_FLAGS_${ARCH}
   -nographic
   -vga none
   -display none
-  -net none
   -no-acpi
   -machine type=pc-0.14
   )

cmake/app/boilerplate.cmake

@@ -327,6 +327,28 @@ message(STATUS "Cache files will be written to: ${USER_CACHE_DIR}")
 
 include(${BOARD_DIR}/board.cmake OPTIONAL)
 
+# If we are using a suitable ethernet driver inside qemu, then these options
+# must be set, otherwise a zephyr instance cannot receive any network packets.
+# The Qemu supported ethernet driver should define CONFIG_ETH_NIC_MODEL
+# string that tells what nic model Qemu should use.
+if(CONFIG_QEMU_TARGET)
+  if(CONFIG_NET_QEMU_ETHERNET)
+    if(CONFIG_ETH_NIC_MODEL)
+      list(APPEND QEMU_FLAGS_${ARCH}
+	-nic tap,model=${CONFIG_ETH_NIC_MODEL},script=no,downscript=no,ifname=zeth
+	)
+    else()
+      message(FATAL_ERROR
+	"No Qemu ethernet driver configured!
+Enable Qemu supported ethernet driver like e1000 at drivers/ethernet")
+    endif()
+  else()
+    list(APPEND QEMU_FLAGS_${ARCH}
+      -net none
+      )
+  endif()
+endif()
+
 zephyr_library_named(app)
 
 add_subdirectory(${ZEPHYR_BASE} ${__build_dir})

cmake/emu/qemu.cmake

@@ -72,8 +72,10 @@ endif()
 # pass data between them. The QEMU flags are not set for standalone
 # tests defined by CONFIG_NET_TEST.
 if(CONFIG_NETWORKING)
-  if(CONFIG_NET_SLIP_TAP)
-    set(QEMU_NET_STACK 1)
+  if(CONFIG_NET_QEMU_SLIP)
+    if(CONFIG_NET_SLIP_TAP)
+      set(QEMU_NET_STACK 1)
+    endif()
   endif()
 endif()
 

drivers/ethernet/Kconfig.e1000

@@ -12,3 +12,12 @@ menuconfig ETH_E1000
 	depends on NET_L2_ETHERNET && PCI_ENUMERATION
 	help
 	  Enable Intel(R) PRO/1000 Gigabit Ethernet driver.
+
+# Hidden option
+config ETH_NIC_MODEL
+	string
+	default "e1000"
+	depends on ETH_E1000
+	help
+	  Tells what Qemu network model to use. This value is given as
+	  a parameter to -nic qemu command line option.

drivers/net/Kconfig

@@ -35,6 +35,7 @@
 #
 menuconfig SLIP
 	bool "SLIP driver"
+	depends on (!QEMU_TARGET || NET_QEMU_SLIP)
 	select UART_PIPE
 	select UART_INTERRUPT_DRIVEN
 

subsys/net/ip/Kconfig

@@ -20,6 +20,28 @@ config NET_RAW_MODE
 
 if !NET_RAW_MODE
 
+choice
+	prompt "Qemu networking"
+	default NET_QEMU_SLIP
+	depends on QEMU_TARGET
+	help
+	  Can be used to select how the network connectivity is established
+	  from inside qemu to host system. This can be done either via
+	  serial connection (SLIP) or via Qemu ethernet driver.
+
+config NET_QEMU_SLIP
+	bool "SLIP"
+	help
+	  Connect to host or to another Qemu via SLIP.
+
+config NET_QEMU_ETHERNET
+	bool "Ethernet"
+	help
+	  Connect to host system via Qemu ethernet driver support. One such
+	  driver that Zephyr supports is Intel e1000 ethernet driver.
+
+endchoice
+
 config NET_INIT_PRIO
 	int
 	default 90
@@ -355,6 +377,7 @@ config NET_TEST
 
 config NET_SLIP_TAP
 	bool "TAP SLIP driver"
+	depends on NET_QEMU_SLIP
 	select SLIP
 	select UART_PIPE
 	select UART_INTERRUPT_DRIVEN