On 08/21/2017 09:33 AM, Juergen Gross wrote:

On 06/08/17 18:44, Mikko Rapeli wrote:

quoted

Both are needed to compile <xen/gntdev.h> in userspace. Fixes these
userspace compile errors:

xen/gntdev.h:151:4: error: unknown type name ‘grant_ref_t’
    grant_ref_t ref;
    ^
xen/gntdev.h:153:4: error: unknown type name ‘domid_t’
    domid_t domid;
    ^

Signed-off-by: Mikko Rapeli <redacted>
Cc: Boris Ostrovsky <redacted>
Cc: Juergen Gross <jgross-IBi9RG/b67k@public.gmane.org>
Cc: xen-devel-GuqFBffKawtpuQazS67q72D2FQJk+8+b@public.gmane.org
---
 include/uapi/xen/gntdev.h           | 6 ++++++
 include/xen/interface/grant_table.h | 6 +-----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/uapi/xen/gntdev.h b/include/uapi/xen/gntdev.h
index d0661977667e..f208706b07c9 100644
--- a/include/uapi/xen/gntdev.h
+++ b/include/uapi/xen/gntdev.h

@@ -34,6 +34,12 @@
 #define __LINUX_PUBLIC_GNTDEV_H__
 
 #include <linux/types.h>
+#include <xen/privcmd.h>
+
+/*
+ * Reference to a grant entry in a specified domain's grant table.
+ */
+typedef __u32 grant_ref_t;
 
 struct ioctl_gntdev_grant_ref {
 	/* The domain ID of the grant to be mapped. */

diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h
index 7fb7112d667c..29b3724aec2c 100644
--- a/include/xen/interface/grant_table.h
+++ b/include/xen/interface/grant_table.h

@@ -29,6 +29,7 @@
 #define __XEN_PUBLIC_GRANT_TABLE_H__
 
 #include <xen/interface/xen.h>
+#include <uapi/xen/gntdev.h> /* for grant_ref_t */

Hmm, I really don't like this. We import the Xen headers from the Xen
source repository. The Xen specific types shouldn't be taken from
non-Xen headers.

quoted

 
 /***********************************
  * GRANT TABLE REPRESENTATION

@@ -85,11 +86,6 @@
  */
 
 /*
- * Reference to a grant entry in a specified domain's grant table.
- */
-typedef uint32_t grant_ref_t;
-
-/*
  * A grant table comprises a packed array of grant entries in one or more
  * page frames shared between Xen and a guest.
  * [XEN]: This field is written by Xen and read by the sharing guest.

I'd rather use __u32 instead of grant_ref_t in the uapi headers.

Boris, what do you think?

I agree that including a non-Xen file into include/xen/interface is not
especially desirable.

Can we ifdef __KERNEL__grant_ref_t usage in uapi header, with else
clause using __u32? And maybe stick BUILD_BUG_ON somewhere to check that
sizes are still the same ?

-boris

-boris