update Xen version to 4.2.1

Config.mk

@@ -202,7 +202,7 @@ QEMU_UPSTREAM_URL ?= git://xenbits.xen.org/qemu-upstream-4.2-testing.git
 SEABIOS_UPSTREAM_URL ?= git://xenbits.xen.org/seabios.git
 endif
 OVMF_UPSTREAM_REVISION ?= b0855f925c6e2e0b21fbb03fab4b5fb5b6876871
-QEMU_UPSTREAM_REVISION ?= qemu-xen-4.2.0
+QEMU_UPSTREAM_REVISION ?= qemu-xen-4.2.1
 SEABIOS_UPSTREAM_TAG ?= rel-1.6.3.2
 # Sun Mar 11 09:27:07 2012 -0400
 # Update version to 1.6.3.2
@@ -214,7 +214,7 @@ ETHERBOOT_NICS ?= rtl8139 8086100e
 # CONFIG_QEMU ?= `pwd`/$(XEN_ROOT)/../qemu-xen.git
 CONFIG_QEMU ?= $(QEMU_REMOTE)
 
-QEMU_TAG ?= xen-4.2.1-rc2
+QEMU_TAG ?= xen-4.2.1
 
 # Short answer -- do not enable this unless you know what you are
 # doing and are prepared for some pain.

xen/Makefile

@@ -2,7 +2,7 @@
 # All other places this is stored (eg. compile.h) should be autogenerated.
 export XEN_VERSION       = 4
 export XEN_SUBVERSION    = 2
-export XEN_EXTRAVERSION ?= .1-rc2$(XEN_VENDORVERSION)
+export XEN_EXTRAVERSION ?= .1$(XEN_VENDORVERSION)
 export XEN_FULLVERSION   = $(XEN_VERSION).$(XEN_SUBVERSION)$(XEN_EXTRAVERSION)
 -include xen-version