Certain MMU virtualization operations in Xen 4.2.x through 4.4.x, when using shadow pagetables, are not preemptible, which allows local HVM guest to cause a denial of service (vcpu consumption) by invoking these operations, which process every page assigned to a guest, a different vulnerability than CVE-2014-5146.
https://security.gentoo.org/glsa/201504-04
https://exchange.xforce.ibmcloud.com/vulnerabilities/95235
http://xenbits.xen.org/xsa/advisory-97.html
http://www.securitytracker.com/id/1030723
http://www.securityfocus.com/bid/69199
http://lists.opensuse.org/opensuse-security-announce/2015-02/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2015-02/msg00005.html
http://lists.fedoraproject.org/pipermail/package-announce/2014-August/136981.html
http://lists.fedoraproject.org/pipermail/package-announce/2014-August/136980.html