From: David Vrabel <david.vrabel@citrix.com>
Date: Mon, 9 Jun 2014 15:41:10 +0000 (+0100)
Subject: tools/libxc: add DECLARE_HYPERCALL_BUFFER_SHADOW()
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~4879
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=60572c972b8dbfbfff91c3bf0773838381c5a8c4;p=xen.git

tools/libxc: add DECLARE_HYPERCALL_BUFFER_SHADOW()

DECLARE_HYPERCALL_BUFFER_SHADOW() is like DECLARE_HYPERCALL_BUFFER()
except it is backed by an already allocated hypercall buffer.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---

diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index 400f0dfe43..b55d85728c 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -265,6 +265,24 @@ typedef struct xc_hypercall_buffer xc_hypercall_buffer_t;
         HYPERCALL_BUFFER_INIT_NO_BOUNCE                        \
     }
 
+/*
+ * Like DECLARE_HYPERCALL_BUFFER() but using an already allocated
+ * hypercall buffer, _hbuf.
+ *
+ * Useful when a hypercall buffer is passed to a function and access
+ * via the user pointer is required.
+ *
+ * See DECLARE_HYPERCALL_BUFFER_ARGUMENT() if the user pointer is not
+ * required.
+ */
+#define DECLARE_HYPERCALL_BUFFER_SHADOW(_type, _name, _hbuf)   \
+    _type *_name = _hbuf->hbuf;                                \
+    xc_hypercall_buffer_t XC__HYPERCALL_BUFFER_NAME(_name) = { \
+        .hbuf = (void *)-1,                                    \
+        .param_shadow = _hbuf,                                 \
+        HYPERCALL_BUFFER_INIT_NO_BOUNCE                        \
+    }
+
 /*
  * Declare the necessary data structure to allow a hypercall buffer
  * passed as an argument to a function to be used in the normal way.