There were many changes across the board in KVM affecting the different CPU architectures with Linux 6.3. For those wondering about these KVM happenings the highlights for v6.3 include:
- KVM on x86/x86_64 has various AVIC and APICv bug fixes.
- Intel's new fast REP string features are now exposed under KVM: fast zero-length REP MOVSB, fast short REP STOSB, and fast short REP {CMPSB,SCASB}.
- PEBS (Precise Event Based Sampling) support for Intel 4th Gen Xeon Scalable "Sapphire Rapids" processors as well as future processors.
- Support for Microsoft Hyper-V extended hypercalls.
- Hyper-V invariant TSC control support.
- SBI PMU extension support for guests on RISC-V.
- KVM on ARM now provides a virtual cache topology to the guest to help avoid inconsistencies in migration on heterogeneous systems.
- Preparations toward being able to support nested virtualization on ARM with KVM.
More details on all of the KVM feature changes for Linux 6.3 via this pull .