Xen 4.4.4 along with kernel 4.9.44 containing patches for XSAs (226 - 230) from August 15th are now available in centos-virt-testing. If possible, please test and provide feedback here so we can move these to release soon.
XSA-228 did not affect Xen 4.4 XSA-229 only applies to the kernel
XSA-235 disclosed today only affects ARM and isn't going to be added to these packages.
Thanks.