lguest: add iomem region, where guest page faults get sent to userspace.

This lets us implement PCI.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/tools/lguest/lguest.c b/tools/lguest/lguest.c
index 485fe13..02f3539 100644
--- a/tools/lguest/lguest.c
+++ b/tools/lguest/lguest.c
@@ -548,7 +548,8 @@
 {
 	unsigned long args[] = { LHREQ_INITIALIZE,
 				 (unsigned long)guest_base,
-				 guest_limit / getpagesize(), start };
+				 guest_limit / getpagesize(), start,
+				 guest_limit / getpagesize() };
 	verbose("Guest: %p - %p (%#lx)\n",
 		guest_base, guest_base + guest_limit, guest_limit);
 	lguest_fd = open_or_die("/dev/lguest", O_RDWR);