Arm CCA in KVM, mm flags, and low-level cleanups

Kernel traffic on 2026-08-09 was dominated by large revision series for Arm confidential computing in KVM and new memory-management flags aimed at guest_memfd. Further patches advanced unconditional VMA locking, BPF aggregate returns, Rust IRQ primitives, and assorted subsystem fixes.

Arm CCA Realm support for KVM

A 45-patch series at v16 adds Arm Confidential Compute Architecture support to KVM on arm64, covering an RMI firmware layer and protected VM handling. The work enables Realm-based confidential VMs under KVM. Developers building confidential-computing stacks on Arm hardware need to track the interface and lifecycle changes.

ALLOC_UNMAPPED and AS_NO_DIRECT_MAP

Version 3 of a 26-patch mm series introduces ALLOC_UNMAPPED together with AS_NO_DIRECT_MAP for direct-map management. The flags target guest_memfd and ASI use cases that require pages kept out of the linear map. Virtualization and memory-isolation work depends on these controls becoming available.

Unconditional per-VMA locks

A v4 five-patch set makes per-VMA locks unconditional across all configs, dropping the former Kconfig guards. Related cleanups land in binder and networking code that previously special-cased the feature. mm and subsystem maintainers gain simpler locking assumptions once the series lands.

BPF 16-byte aggregate returns

Thirteen patches extend the BPF verifier, JIT, and BTF to support aggregate and __int128 return values up to 16 bytes. Values are passed in the R0:R2 register pair for subprograms and kfuncs. The change removes size limits that previously forced awkward workarounds in helpers and programs.

SUNRPC TLS control-record fixes

Seven patches correct length handling, uninitialized data, and alert processing in SUNRPC server and client TLS control-record paths. The defects sit on the security-sensitive TLS control plane. NFS and RPC deployments that enable TLS should apply the corrections.

Refcounted IRQ disable for Rust

Version 4 of a 17-patch series adds refcounted interrupt-disable and SpinLockIrq primitives for Rust. The set has been merged into tip locking/core. Rust kernel code obtains safer, reference-counted IRQ management matching existing C patterns.

Arm64 data-type profiling in perf

A 23-patch series brings data-type profiling to arm64 perf, enabling perf annotate --data-type via instruction tracking and DWARF. The capability already existed on other architectures. Performance analysts on arm64 can now examine data types directly in annotated profiles.

Xilinx TSN Endpoint MAC driver

Twenty patches introduce a driver and DSA integration for the AMD/Xilinx 802.1 TSN Endpoint Ethernet MAC. The series supplies Time-Sensitive Networking support for that hardware. Embedded and industrial networking developers gain a mainline path for the controller.