Linux 6.5 KVM Brings Guest Snapshots For RISC-V, AMD PerfMonV2 For VMs

The Kernel-based Virtual Machine (KVM) changes were submitted today that are ready for introduction in the Linux 6.5 kernel.

First up on the 64-bit Arm side is an eager page-splitting optimization for dirty logging, hVHE mode support, enabling the use of Branch Target Identification (BTI) within the hypervisor, and an erratum workaround for upcoming AmpereOne processors.

There are various RISC-V KVM improvements for Linux 6.5 but most notable is guest snapshot support now working for KVM guests. RISC-V KVM guests can now enjoy working live snapshot support of VMs.

Last year saw PerfMonV2 support merged into Linux 5.19 for the new performance monitoring perf capabilities found with AMD Zen 4 server processors. With Linux 6.5 that PerfMonV2 support is now accessible to KVM guests running on AMD EPYC 9004 series processors.

There is also an optimization to avoid unnecessary TR/TSS after VM exit on AMD CPUs, a new KVM x86 option to avoid creating NX hugepage recovery threads, and a variety of other enhancements.

More details on the KVM changes for Linux 6.5 via this pull.