From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 20 Sep 2012 11:31:19 +0000 (+0200)
Subject: introduce guest_handle_for_field()
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~7871
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=bb544585137259545d4adc9afe6eed8dc7c7376d;p=xen.git

introduce guest_handle_for_field()

This helper turns a field of a GUEST_HANDLE in a GUEST_HANDLE.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---

diff --git a/xen/include/asm-x86/guest_access.h b/xen/include/asm-x86/guest_access.h
index 2b429c225f..e3ac1d6fa8 100644
--- a/xen/include/asm-x86/guest_access.h
+++ b/xen/include/asm-x86/guest_access.h
@@ -51,6 +51,9 @@
     (XEN_GUEST_HANDLE(type)) { _x };            \
 })
 
+#define guest_handle_for_field(hnd, type, fld)          \
+    ((XEN_GUEST_HANDLE(type)) { &(hnd).p->fld })
+
 #define guest_handle_from_ptr(ptr, type)        \
     ((XEN_GUEST_HANDLE(type)) { (type *)ptr })
 #define const_guest_handle_from_ptr(ptr, type)  \