Postgres promotion hang and QEMU ARM work

PostgreSQL developers examined a promotion hang tied to a recent ProcSignalBarrier change and kept iterating on logical replication conflict logging. QEMU activity centered on ARM64 MSHV and named CPU model support, QAPI schema formalization, USB stability fixes, multi-target helper prefixes, and Arm Realm confidential guests.

Postgres 19 promotion hang on stuck clients

A ProcSignalBarrier change in commit 67c20979 left Postgres 19 promotion hanging when backends remain blocked on client writes. Participants on pgsql-hackers discussed the failure mode and a patch was proposed. High availability operators should track the fix because delayed promotion lengthens failover windows.

ARM64 support for the QEMU MSHV accelerator

A v6 fourteen patch series adds ARM64 guest support to QEMU's MSHV accelerator by refactoring the x86 path and introducing a new ARM backend for vCPU, MMIO, and vGIC. Three developers exchanged seventeen messages refining the work. The series widens hypervisor choices for ARM guests running on the Microsoft Hypervisor.

Formal QAPI schema links for QOM properties

A sixty five patch v7 series replaces free form property types in QEMU with formal QAPI schema links used by QOM and qdev introspection. Four participants produced seventy five messages iterating on the design. Structured introspection improves tooling and configuration consistency across devices.

Conflict log history table for logical replication

PostgreSQL hackers continued active review of patches that add a conflict log history table for logical replication, spanning one hundred thirty eight messages from fourteen participants. The table would retain past conflict records for later diagnosis. Operators running logical or multi node setups gain clearer audit trails when data diverges.

Named Arm64 CPU models for KVM live migration

An RFC v4 twenty five patch series proposes hierarchical named Arm64 CPU models for KVM together with QMP introspection so live migration can succeed across heterogeneous hosts. Four developers discussed the seventy two message thread. Named models simplify migration planning when host CPU feature sets differ.

USB fixes for guest triggerable crashes

A pull request merges eleven USB fixes into QEMU, several of which address crashes and memory errors that a guest can trigger in the emulator. Two participants handled the thirteen message exchange. Workloads that exercise USB devices obtain improved stability from the corrections.

Target prefixes for multi target helper linking

A twenty six patch series introduces TARGET_ARCH_PREFIX on helpers so QEMU can avoid ad hoc renames when statically linking multiple targets. Four developers exchanged thirty messages on the approach. The change reduces build complexity for multi architecture QEMU binaries.

Arm RME Realm support in QEMU

An RFC v4 twenty four patch series adds Arm RME confidential guest support to the QEMU VMM, integrating with KVM guest-memfd and the RMM. Six participants covered fifty six messages. The work advances confidential computing options for Arm guests under QEMU.