KubeVirt v1.9.0 introduces significant advancements in performance and flexibility, highlighted by experimental migration compression, cross-architecture emulation support, and deep optimizations for NVIDIA Grace hardware. The release also signals a shift toward cgroup v2 by deprecating v1 and streamlines the user experience by enabling VM Templates by default and graduating long-standing features like VMExport and Persistent Reservations to General Availability.

Experimental Live Migration compression support (zstd) — Platform engineers can now significantly reduce migration times and network impact for large VM fleets by enabling zstd compression in MigrationPolicies.

Cross-Architecture Virtualization via software emulation — Enables running VMs on heterogenous clusters where host and guest architectures differ (e.g., ARM64 on AMD64) using software emulation, providing flexibility for testing and legacy workload support.

NVIDIA Grace GPU and SMMUv3/IOMMUFD passthrough support — Users running high-performance workloads like NVIDIA Grace GPUs now get optimized PCI placement, NUMA-aware topology, and IOMMUFD support for near-native performance.

Deprecation of cgroup v1 support — Users relying on cgroup v1 must plan a migration to cgroup v2, as support is now deprecated and slated for removal in the next release.

Default-on VM Templates and graduation of core features to GA — Simplifies VM management by enabling the Template feature by default and graduating several core features like VMExport, Persistent Reservations, and VideoConfig to GA.