libxc: add ability to query OS interface for "fakeness"

i.e. not running on a real hypervisor

Allows users of the library to adjust behaviour. I don't especially
like this violation of the abstraction but both oxenstored and xapi
use this to avoid difficult to simulate operations when running on the
simulator.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson.citrix.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index 18d778bdb1..4827303b73 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -159,6 +159,15 @@ enum xc_open_flags {
  */
 int xc_interface_close(xc_interface *xch);
 
+/**
+ * Query the active OS interface (i.e. that which would be returned by
+ * xc_interface_open) to find out if it is fake (i.e. backends onto
+ * something other than an actual Xen hypervisor).
+ *
+ * @return 0 is "real", >0 if fake, -1 on error.
+ */
+int xc_interface_is_fake(void);
+
 /*
  * HYPERCALL SAFE MEMORY BUFFER
  *