[PATCH v4 04/20] xen: introduce CONFIG_SYSCTL

[Penny Zheng <Penny.Zheng@amd.com>]

From: Stefano Stabellini <stefano.stabellini@amd.com>

We introduce a new Kconfig CONFIG_SYSCTL, which shall only be disabled
on some dom0less systems or PV shim on x86, to reduce Xen footprint.

Making SYSCTL without prompt is transient and it will be fixed in the final
patch. Also, we will also state unsetting SYSCTL in pvshim_defconfig to
explicitly make it unavailable for PV shim in the final patch.

Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
v2 -> v3:
- remove "intend to" in commit message
---
v3 -> v4:
- introduce the option without prompt (simply "defbool y") to eliminate the
need for transient "#ifdef CONFIG_SYSCTL"
- calling out the transient scenario in commit message
---
 xen/common/Kconfig | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 3d66d09397..28e6ac2142 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -579,4 +579,15 @@ config BUDDY_ALLOCATOR_SIZE
 	  Amount of memory reserved for the buddy allocator to serve Xen heap,
 	  working alongside the colored one.
 
+menu "Supported hypercall interfaces"
+	visible if EXPERT
+
+config SYSCTL
+	bool "Enable sysctl hypercall"
+	def_bool y
+	help
+	  This option shall only be disabled on some dom0less systems,
+	  to reduce Xen footprint.
+endmenu
+
 endmenu
-- 
2.34.1