Index: xen-unstable/tools/blktap/drivers/Makefile
===================================================================
--- xen-unstable.orig/tools/blktap/drivers/Makefile
+++ xen-unstable/tools/blktap/drivers/Makefile
@@ -8,7 +8,6 @@ QCOW_UTIL    = img2qcow qcow2raw qcow-cr
 INST_DIR  = /usr/sbin
 LIBAIO_DIR   = ../../libaio/src
 
-CFLAGS   += -Werror
 CFLAGS   += -Wno-unused
 CFLAGS   += -fno-strict-aliasing
 CFLAGS   += -I $(XEN_LIBXC) -I $(LIBAIO_DIR)
Index: xen-unstable/tools/ioemu/Makefile
===================================================================
--- xen-unstable.orig/tools/ioemu/Makefile
+++ xen-unstable/tools/ioemu/Makefile
@@ -8,7 +8,7 @@ include $(XEN_ROOT)/tools/Rules.mk
 .PHONY: all clean distclean dvi info install install-doc tar tarbin \
 	speed test test2 html dvi info
 
-CFLAGS+=-Wall -O2 -g -fno-strict-aliasing -I.
+CFLAGS+=-Wall -fno-strict-aliasing -I.
 ifdef CONFIG_DARWIN
 CFLAGS+= -mdynamic-no-pic
 endif
Index: xen-unstable/Config.mk
===================================================================
--- xen-unstable.orig/Config.mk
+++ xen-unstable/Config.mk
@@ -13,7 +13,7 @@ CONFIG_$(XEN_OS) := y
 
 # Tools to run on system hosting the build
 HOSTCC     = gcc
-HOSTCFLAGS = -Wall -Werror -Wstrict-prototypes -O2 -fomit-frame-pointer
+HOSTCFLAGS:= -Wall -Werror -Wstrict-prototypes $(RPM_OPT_FLAGS)
 
 DISTDIR     ?= $(XEN_ROOT)/dist
 DESTDIR     ?= /