modules: add and migrate to the Xen module

Currently, the MIT-licensed Xen public headers were incorporated
under the `include/zephyr/xen/public`.

However, the recent policy is to not include sources other than
Apache-2 in the main tree, so we will externalize them.

File differences:

The repository contains the RELEASE-4.17.0 file,
which is close to the version before the migration,
but there are some differences in `arch-arm.h`,
due to the following two commits.
These are considered to need to be incorporated,
so they have been changed from the pre-migration version.

- arm64: Change type of hsr, cpsr, spsr_el1 to uint64_t
  xen-project/xen@918b8842
- xen/arm: set CPSR Z bit when creating aarch32 guests
  xen-project/xen@0e03ff97

Also, in the pre-migration version,

```
DEFINE_XEN_GUEST_HANDLE(uint8_t);
```

was added.
But this can be handled by the line

```
__DEFINE_XEN_GUEST_HANDLE(uint8, uint8_t);
```

So the differences related to this are not applied
and left the code from `RELEASE-4.17.0`.

Also, visibility was controlled with `CONFIG_XEN_DOM0`,
but this is not necessarily required, so it has been omitted.

Configuration behavior change:

The behavior of CONFIG_XEN_INTERFACE_VERSION has been changed
so that if 0 is set,
the LATEST version defined in the header will be used.
The default value has also been changed to 0.

Accordingly, we have updated the path and reviewed the location of
the config items.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>

Author: soburi

MAINTAINERS.yml

@@ -2379,6 +2379,7 @@ Xen Platform:
     - soc/xen/
     - boards/xen/
     - dts/bindings/xen/
+    - modules/xen/
   labels:
     - "area: Xen Platform"
 

arch/arm64/core/Kconfig

@@ -216,8 +216,6 @@ config ARMV8_A
 	  so that it can support some features included in the AArch64 state.
 	  It supports the T32 and A32 instruction sets.
 
-rsource "xen/Kconfig"
-
 endif # CPU_CORTEX_A
 
 if CPU_AARCH64_CORTEX_R

arch/arm64/core/xen/enlighten.c

@@ -7,8 +7,8 @@
 #include <zephyr/arch/arm64/hypercall.h>
 #include <zephyr/xen/events.h>
 #include <zephyr/xen/generic.h>
-#include <zephyr/xen/public/xen.h>
-#include <zephyr/xen/public/memory.h>
+#include <xen/public/xen.h>
+#include <xen/public/memory.h>
 
 #include <zephyr/device.h>
 #include <zephyr/init.h>

arch/arm64/core/xen/hypercall.S

@@ -5,8 +5,8 @@
 
 #include <zephyr/toolchain.h>
 #include <zephyr/linker/sections.h>
-#include <zephyr/xen/public/arch-arm.h>
-#include <zephyr/xen/public/xen.h>
+#include <xen/public/arch-arm.h>
+#include <xen/public/xen.h>
 
 #define HYPERCALL(hypercall)			\
 GTEXT(HYPERVISOR_##hypercall);			\

drivers/serial/uart_hvc_xen.c

@@ -9,9 +9,9 @@
 #include <zephyr/xen/events.h>
 #include <zephyr/xen/generic.h>
 #include <zephyr/xen/hvm.h>
-#include <zephyr/xen/public/io/console.h>
-#include <zephyr/xen/public/sched.h>
-#include <zephyr/xen/public/xen.h>
+#include <xen/public/io/console.h>
+#include <xen/public/sched.h>
+#include <xen/public/xen.h>
 
 #include <zephyr/device.h>
 #include <zephyr/init.h>

drivers/serial/uart_hvc_xen_consoleio.c

@@ -10,7 +10,7 @@
  */
 
 #include <zephyr/arch/arm64/hypercall.h>
-#include <zephyr/xen/public/xen.h>
+#include <xen/public/xen.h>
 
 #include <zephyr/device.h>
 #include <zephyr/drivers/uart.h>

drivers/xen/dom0/domctl.c

@@ -7,8 +7,8 @@
 #include <zephyr/arch/arm64/hypercall.h>
 #include <zephyr/xen/dom0/domctl.h>
 #include <zephyr/xen/generic.h>
-#include <zephyr/xen/public/domctl.h>
-#include <zephyr/xen/public/xen.h>
+#include <xen/public/domctl.h>
+#include <xen/public/xen.h>
 
 #include <zephyr/init.h>
 #include <zephyr/kernel.h>

drivers/xen/events.c

@@ -6,8 +6,8 @@
  */
 
 #include <zephyr/arch/arm64/hypercall.h>
-#include <zephyr/xen/public/xen.h>
-#include <zephyr/xen/public/event_channel.h>
+#include <xen/public/xen.h>
+#include <xen/public/event_channel.h>
 #include <zephyr/xen/events.h>
 #include <zephyr/sys/barrier.h>
 

drivers/xen/gnttab.c

@@ -20,9 +20,9 @@
 #include <zephyr/arch/arm64/hypercall.h>
 #include <zephyr/xen/generic.h>
 #include <zephyr/xen/gnttab.h>
-#include <zephyr/xen/public/grant_table.h>
-#include <zephyr/xen/public/memory.h>
-#include <zephyr/xen/public/xen.h>
+#include <xen/public/grant_table.h>
+#include <xen/public/memory.h>
+#include <xen/public/xen.h>
 #include <zephyr/sys/barrier.h>
 
 #include <zephyr/init.h>

drivers/xen/hvm.c

@@ -6,8 +6,8 @@
 
 #include <zephyr/arch/arm64/hypercall.h>
 #include <zephyr/xen/hvm.h>
-#include <zephyr/xen/public/hvm/hvm_op.h>
-#include <zephyr/xen/public/hvm/params.h>
+#include <xen/public/hvm/hvm_op.h>
+#include <xen/public/hvm/params.h>
 
 #include <zephyr/kernel.h>