cmake: Adds the necessary flags support for Qemu ivshmem feature

Depending whether doorbell or plain versions are enabled, it will set
the right flags to qemu.

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>

boards/Kconfig

@@ -44,6 +44,15 @@ config QEMU_ICOUNT_SHIFT
 	  The virtual CPU will execute one instruction every 2^N nanoseconds
 	  of virtual time, where N is the value provided here.
 
+config QEMU_IVSHMEM_PLAIN_MEM_SIZE
+	int "QEMU ivshmem-plain shared memory size in mega-bytes"
+	default 1
+	depends on QEMU_TARGET && IVSHMEM && !IVSHMEM_DOORBELL
+	help
+	  This sets the size of the shared memory when using ivshmem-plain
+	  device in Qemu. Note that it's in mega-bytes, so 1 means 1M for Qemu
+	  etc..
+
 # There might not be any board options, hence the optional source
 osource "$(BOARD_DIR)/Kconfig"
 endmenu

cmake/emu/qemu.cmake

@@ -285,6 +285,20 @@ if(CONFIG_X86_64)
     )
 endif()
 
+if(CONFIG_IVSHMEM)
+  if(CONFIG_IVSHMEM_DOORBELL)
+    list(APPEND QEMU_FLAGS
+      -device ivshmem-doorbell,vectors=${CONFIG_IVSHMEM_MSI_X_VECTORS},chardev=ivshmem
+      -chardev socket,path=/tmp/ivshmem_socket,id=ivshmem
+    )
+  else()
+    list(APPEND QEMU_FLAGS
+      -device ivshmem-plain,memdev=hostmem
+      -object memory-backend-file,size=${CONFIG_QEMU_IVSHMEM_PLAIN_MEM_SIZE}M,share,mem-path=/dev/shm/ivshmem,id=hostmem
+    )
+  endif()
+endif()
+
 if(NOT QEMU_PIPE)
   set(QEMU_PIPE_COMMENT "\nTo exit from QEMU enter: 'CTRL+a, x'\n")
 endif()