KVM Virtualization Gets New Features In Linux 3.10

The Linux 3.10 kernel will feature new improvements and features when it comes to KVM (Kernel-based Virtual Machine) virtualization.

The KVM pull request for the Linux 3.10 merge window was volleyed on Sunday morning to the kernel mailing list. Interesting bits include:

- A new emulated device API.

- The KVM x86/x86_64 virtualization now supports VMCS shadow support and other nested VMX improvements. In digging through this "VMCS shadow" feature, from another patch it's explaned as, "On new Intel platform, it introduces a new feature called VMCS shadowing, where non-root VMREAD/VMWRITE will not trigger VM-Exit, and the hardware will read/write the virtual VMCS instead. This is proved to have performance improvement with the feature."

- APIC virtualization and posted interrupt hardware support for x86 virtualization.

- The other prominent x86 KVM change is optimized MMIO SPTE zapping.

- PowerPC KVM virtualization in this next kernel features in-kernel MPIC emulation with IRQFD support, in-kernel XICS emulation, and E6500 support.

- ARM and S390 Linux users also have some small changes to KVM in Linux 3.10.