[PATCH v4 20/20] xen/sysctl: wrap around sysctl hypercall

[Penny Zheng <Penny.Zheng@xxxxxxx>]

From: Stefano Stabellini <sstabellini@xxxxxxxxxx>

Wrap sysctl hypercall def and sysctl.o with CONFIG_SYSCTL, and since
PV_SHIM_EXCLUSIVE needs sorting in the future, we move them out of
PV_SHIM_EXCLUSIVE condition at the same time.

We need to make SYSCTL with prompt back and state unsetting SYSCTL in
pvshim_defconfig to explicitly make it unavailable for PV shim.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
v1 -> v2:
- remove all transient "#ifdef CONFIG_SYSCTL"-s in sysctl.c
---
v2 -> v3:
- move out of CONFIG_PV_SHIM_EXCLUSIVE condition
---
v3 -> v4:
- make SYSCTL with prompt
- state unsetting SYSCTL in pvshim_defconfig
---
 xen/arch/x86/configs/pvshim_defconfig | 1 +
 xen/common/Kconfig                    | 2 +-
 xen/common/Makefile                   | 2 +-
 xen/include/hypercall-defs.c          | 8 ++++++--
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/configs/pvshim_defconfig 
b/xen/arch/x86/configs/pvshim_defconfig
index 6f652e145e..7d0cd45493 100644
--- a/xen/arch/x86/configs/pvshim_defconfig
+++ b/xen/arch/x86/configs/pvshim_defconfig
@@ -31,3 +31,4 @@ CONFIG_EXPERT=y
 # HYPERV_HYPERV_GUEST is not set
 # CONFIG_HVM is not set
 # CONFIG_VGA is not set
+# CONFIG_SYSCTL is not set
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index e3b6fd6ec4..f85593a9db 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -585,7 +585,7 @@ menu "Supported hypercall interfaces"
 
 config SYSCTL
        bool "Enable sysctl hypercall"
-       def_bool y
+       default y
        help
          This option shall only be disabled on some dom0less systems,
          to reduce Xen footprint.
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 98f0873056..15ab048244 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -49,6 +49,7 @@ obj-y += spinlock.o
 obj-$(CONFIG_STACK_PROTECTOR) += stack-protector.o
 obj-y += stop_machine.o
 obj-y += symbols.o
+obj-$(CONFIG_SYSCTL) += sysctl.o
 obj-y += tasklet.o
 obj-y += time.o
 obj-y += timer.o
@@ -70,7 +71,6 @@ obj-$(CONFIG_COMPAT) += $(addprefix compat/,domain.o memory.o 
multicall.o xlat.o
 ifneq ($(CONFIG_PV_SHIM_EXCLUSIVE),y)
 obj-y += domctl.o
 obj-$(CONFIG_VM_EVENT) += monitor.o
-obj-y += sysctl.o
 endif
 
 extra-y := symbols-dummy.o
diff --git a/xen/include/hypercall-defs.c b/xen/include/hypercall-defs.c
index 7720a29ade..c1081d87a2 100644
--- a/xen/include/hypercall-defs.c
+++ b/xen/include/hypercall-defs.c
@@ -194,8 +194,10 @@ kexec_op(unsigned long op, void *uarg)
 #ifdef CONFIG_IOREQ_SERVER
 dm_op(domid_t domid, unsigned int nr_bufs, xen_dm_op_buf_t *bufs)
 #endif
-#ifndef CONFIG_PV_SHIM_EXCLUSIVE
+#ifdef CONFIG_SYSCTL
 sysctl(xen_sysctl_t *u_sysctl)
+#endif
+#ifndef CONFIG_PV_SHIM_EXCLUSIVE
 domctl(xen_domctl_t *u_domctl)
 paging_domctl_cont(xen_domctl_t *u_domctl)
 platform_op(xen_platform_op_t *u_xenpf_op)
@@ -273,8 +275,10 @@ physdev_op                         compat   do       hvm   
   hvm      do_arm
 #ifdef CONFIG_HVM
 hvm_op                             do       do       do       do       do
 #endif
-#ifndef CONFIG_PV_SHIM_EXCLUSIVE
+#ifdef CONFIG_SYSCTL
 sysctl                             do       do       do       do       do
+#endif
+#ifndef CONFIG_PV_SHIM_EXCLUSIVE
 domctl                             do       do       do       do       do
 #endif
 #ifdef CONFIG_KEXEC
-- 
2.34.1