xenbus: Add support for xenbus backend in stub domain

Add an ioctl to the /dev/xen/xenbus_backend device allowing the xenbus
backend to be started after the kernel has booted. This allows xenstore
to run in a different domain from the dom0.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

2 files changed, 5 insertions, 0 deletions

diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 15f8a00ff003..11e27c3af3cb 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -46,6 +46,8 @@
 
 #include <xen/features.h>
 
+#define GNTTAB_RESERVED_XENSTORE 1
+
 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
 #define NR_GRANT_FRAMES 4
 
diff --git a/include/xen/xenbus_dev.h b/include/xen/xenbus_dev.h
index ac5f0fe47ed9..bbee8c6a349d 100644
--- a/include/xen/xenbus_dev.h
+++ b/include/xen/xenbus_dev.h
@@ -38,4 +38,7 @@
 #define IOCTL_XENBUS_BACKEND_EVTCHN                     \
         _IOC(_IOC_NONE, 'B', 0, 0)
 
+#define IOCTL_XENBUS_BACKEND_SETUP                      \
+        _IOC(_IOC_NONE, 'B', 1, 0)
+
 #endif /* __LINUX_XEN_XENBUS_DEV_H__ */