[Qemu-devel] [PATCH] xen: Fix ring.h header

[Anthony PERARD <anthony.perard@citrix.com>]

The xen_[rw]?mb() macros defined in ring.h can't be used and the fact
that there are gated behind __XEN_INTERFACE_VERSION__ means that it
needs to be defined somewhere. QEMU doesn't implement interfaces with
the Xen hypervisor so defining __XEN_INTERFACE_VERSION__ is pointless.
This leads to:
    include/hw/xen/io/ring.h:47:5: error: "__XEN_INTERFACE_VERSION__"
        is not defined, evaluates to 0 [-Werror=undef]

Cleanup ring.h. The xen_*mb() macros are already defined in xenctrl.h
which is included in xen_common.h.

Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---

Notes:
    A similar patch have been sent to the canonical version:
    https://lists.xenproject.org/archives/html/xen-devel/2019-07/msg00370.html

 include/hw/xen/interface/io/ring.h | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/include/hw/xen/interface/io/ring.h b/include/hw/xen/interface/io/ring.h
index 1adacf09f9..704990a2c9 100644
--- a/include/hw/xen/interface/io/ring.h
+++ b/include/hw/xen/interface/io/ring.h
@@ -42,12 +42,6 @@
  * and grant_table.h from the Xen public headers.
  */
 
-#if __XEN_INTERFACE_VERSION__ < 0x00030208
-#define xen_mb()  mb()
-#define xen_rmb() rmb()
-#define xen_wmb() wmb()
-#endif
-
 typedef unsigned int RING_IDX;
 
 /* Round a 32-bit unsigned constant down to the nearest power of two. */
-- 
Anthony PERARD