[PATCH V6 24/24] xen/ioreq: Make the IOREQ feature selectable on Arm

[Oleksandr Tyshchenko <olekstysh@xxxxxxxxx>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

The purpose of this patch is to add a possibility for user
to be able to select IOREQ support on Arm (which is disabled
by default) with retaining the current behaviour on x86
(is selected by HVM and it's prompt is not visible).

Also make the IOREQ be depended on CONFIG_EXPERT on Arm since
it is considered as Technological Preview feature.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

---
Please note, this is a split/cleanup/hardening of Julien's PoC:
"Add support for Guest IO forwarding to a device emulator"

Changes V5 -> V6:
   - new patch
---
---
 xen/common/Kconfig | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index fa049a6..225e57b 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -137,7 +137,13 @@ config HYPFS_CONFIG
          want to hide the .config contents from dom0.
 
 config IOREQ_SERVER
-       bool
+       bool "IOREQ support (EXPERT)" if EXPERT && !X86
+       default X86
+       depends on HVM
+       ---help---
+         Enables generic mechanism for providing emulated devices to the 
guests.
+
+         If unsure, say Y.
 
 config KEXEC
        bool "kexec support"
-- 
2.7.4