This update for xen fixes the following issues: Security issues fixed: - CVE-2018-3639: Spectre V4 #226;#128;#147; Speculative Store Bypass aka quot;Memory Disambiguationquot; This feature can be controlled by the quot;ssbd=on/offquot; commandline flag for the XEN hypervisor. - CVE-2018-10982: x86 vHPET interrupt injection errors - CVE-2018-10981: qemu may drive Xen into unbounded loop Other bugfixes: - Upstream patches from Jan - additional fixes related to Page Table Isolation . - qemu-system-i386 cannot handle more than 4 HW NICs