All of the KVM virtualization feature changes were recently merged for the in-development Linux 7.0 kernel.
KVM on x86 with Linux 7.0 now supports giving the guest full ownership of the PMU hardware, support for new Intel CPU instructions, fixes, and other updates.
To the AMD SVM code for KVM in Linux 7.0 is support for virtualizing ERAPS. Further improvements to virtualization of ERAPS is expected in a coming cycle. ERAPS is the Enhanced Return Address Predictor Security. AMD ERAPS is introduced on Zen 5 processors and is a security feature for ultimately allowing the guests to use the larger Return Stack Buffer (RSB) in VM contexts that is now up to 64 entries rather than being limited to 32 entries. The AMD code also adds support for fetching SEV-SNP certificates from user-space.
KVM for LoongArch has improved feature detection, lazy-load support for the FPU and binary translation register state, and support for detecting preemption from within a guest. RISC-V KVM in Linux 7.0 enjoys Zalasr, Zilsd and Zclsd extensions support for guests/VMs, transparent huge page support for the hypervisor page tables, and other improvements.
ARM meanwhile adds FEAT_IDST support, preliminary work for guest GICv5 support, various pKVM improvements, and other enhancements. IBM s390 also saw work on KVM in Linux 7.0, including improved performance for nested virtualization and completely new memory management code.
More details on the KVM feature work for Linux 7.0 via this pull request that since landed in Git.
