[Xen-devel] [PATCH 3/4] xen/public: Don't expose XEN_GUEST_HANDLE_PARAM outside of the hypervisor

[Julien Grall <julien.grall@xxxxxxxxxx>]

A XEN_GUEST_HANDLE_PARAM is used to represent a guest pointer passed as
an hypercall register. It will always be the size of a native register.

This is only used in Xen for type-safety, the guest will directly pass a
pointer in the hypercall parameter.

Note that for ARM we only hide XEN_GUEST_HANDLE_PARAM. The type
__guest_handle_param_* is still exposed because it would result to
duplicating the macro to create the type. I find this solution more
difficult to read.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>

---

Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Keir Fraser <keir@xxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
---
 xen/include/public/arch-arm.h     | 4 ++++
 xen/include/public/arch-x86/xen.h | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index 477254f..b278bc0 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -188,7 +188,11 @@
 #define DEFINE_XEN_GUEST_HANDLE(name)   __DEFINE_XEN_GUEST_HANDLE(name, name)
 #define __XEN_GUEST_HANDLE(name)        __guest_handle_ ## name
 #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
+
+#ifdef __XEN__ /* Internal only, should never be exposed to the guest */
 #define XEN_GUEST_HANDLE_PARAM(name)    __guest_handle_param_ ## name
+#endif
+
 #define set_xen_guest_handle_raw(hnd, val)                  \
     do {                                                    \
         typeof(&(hnd)) _sxghr_tmp = &(hnd);                 \
diff --git a/xen/include/public/arch-x86/xen.h 
b/xen/include/public/arch-x86/xen.h
index 5187560..8036b3c 100644
--- a/xen/include/public/arch-x86/xen.h
+++ b/xen/include/public/arch-x86/xen.h
@@ -52,7 +52,11 @@
 #define DEFINE_XEN_GUEST_HANDLE(name)   __DEFINE_XEN_GUEST_HANDLE(name, name)
 #define __XEN_GUEST_HANDLE(name)        __guest_handle_ ## name
 #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
+
+#ifdef __XEN__ /* Internal only, should never be exposed to the guest */
 #define XEN_GUEST_HANDLE_PARAM(name)    XEN_GUEST_HANDLE(name)
+#endif
+
 #define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = val; } while (0)
 #define set_xen_guest_handle(hnd, val) set_xen_guest_handle_raw(hnd, val)
 
-- 
2.1.4


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