KVM & Xen Don't Change Much With Linux 4.15
The Kernel-based Virtual Machine (KVM) work this time around isn't too exciting with no big ticket items debuting for Linux 4.15. KVM for this next kernel release finally has Python 3 support within the Python script that collects runtime statistics from the KVM kernel module. Most of the other work is relatively small additions and fixes. There is some optimizations to ARM's timer handling, PowerPC support for running in a hashed page table MMU mode and single-threaded mode support on POWER9, s390 prep work for exitless interrupts and crypto, and on the x86 front are some fixes, improved emulation in a few areas, and other small work.
The KVM changes are documented here.
The Xen pull request doesn't have too much either. Xen changes include VDSO support of the PV clock interface, support for Xen para-virtualized guests to handle Intel 5-level paging systems, and adding Xen pvcalls front-end driver using the para-virtualized socket interface.
Not part of these pull requests but perhaps most exciting about Linux 4.15 on the virtualization front is AMD Secure Encrypted Virtualization support (SEV) for the new EPYC processors.