PostgreSQL crash fix and QEMU isolation work

PostgreSQL developers fixed a crash regression on the 18 stable branch and examined logical replication correctness around toasted columns. QEMU threads advanced RFCs on vhost-user memory isolation, TCG TLB APIs, and qdev realization lifecycle rules.

PostgreSQL 18 crash in pg_strupper under C locale

A crash in pg_strupper() under the C locale on REL_18_STABLE appeared after a recent commit. Participants on pgsql-hackers diagnosed the regression and a fix was pushed. Operators tracking the 18 stable line need the correction to avoid the crash path.

Logical replication row filters null toasted columns

A bug report showed that logical replication row filters can turn unchanged toasted columns into NULL on the subscriber. Discussion on pgsql-hackers covered the failure mode and fix approaches. The issue matters for replication correctness on tables that use TOAST storage.

QEMU vhost-user memory isolation RFC

An RFC series proposes vhost-user memory isolation through bounce buffers and shadow virtqueues so devices avoid direct guest memory access. The qemu-devel thread drew substantial technical review. Stronger isolation boundaries would reduce the trust placed in vhost-user backends.

pg_wal_preallocate SQL function

A patch proposes a superuser function pg_wal_preallocate() that eagerly creates future WAL segments. Thread discussion examined the interface, limits tied to max_wal_size, and automatic alternatives. The function would give operators explicit control when WAL segment creation latency is a concern.

TCG tlb_fill API range change

Richard Henderson posted an RFC to change TCG tlb_fill and probe_access to take (addr, first, last) address range tuples. The main drivers are RISC-V vector and ARM MTE cross-page cases. The API shift aims to make multi-page accesses correct inside the emulator.

QEMU qdev realization lifecycle series

A v3 patch series refactors qdev realized state tracking and adds a qdev_is_realized accessor for the 11.2 cycle. The work clarifies and enforces the device realization lifecycle. Clearer contracts help device model authors avoid inconsistent realization states.