If you actually set it to a relative path, the qemu build breaks.
So this commented-out rune (an example) should arrange to be absolute.
Reported-by: M A Young <m.a.young@durham.ac.uk>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
# Specify which qemu-dm to use. This may be `ioemu' to use the old
# Mercurial in-tree version, or a local directory, or a git URL.
-# CONFIG_QEMU ?= ../qemu-xen.git
+# CONFIG_QEMU ?= $(XEN_ROOT)/../qemu-xen.git
CONFIG_QEMU ?= $(QEMU_REMOTE)
QEMU_TAG := xen-4.1.0-rc1