Many KVM Updates Land In Linux 6.3

A lot of Kernel-based Virtual Machine (KVM) updates were merged for the Linux 6.3 cycle to further enhance the open-source virtualization stack.

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.