ChangeLog/4.2

From QEMU

System emulation

Incompatible changes

  • The minimum version of the glib library is now 2.48

New deprecated options and features

Consult the "Deprecated Features" appendix for the full list of historically deprecated features/options.

Alpha

68k

Arm

HPPA

Microblaze

MIPS

  • Fixed bug involving emulation of ST.W instruction in system mode only (there was no bug in Linux user mode).

Nios2

OpenRISC

PowerPC

  • Behavior for unplug of multifunction PCI devices has been changed to match x86. Attempting to unplug any function will cause an unplug of the whole slot.
  • There are now separate machine types for POWER8 based and POWER9 based non-virtualized machines (powernv8 & powernv9).
  • Default RAM size for powernv machines has been increased to 1.75G which should allow more things to work with the default parameters.

RISC-V

s390

SH

SPARC

TileGX

Tricore

x86

Xtensa

Device emulation and assignment

ACPI

Audio

Block devices

GPIO

Graphics

Input devices

IPMI

Network devices

NVDIMM

PCI/PCIe

SCSI

SMBIOS

TPM

USB

VFIO

virtio

Xen

fw_cfg

9pfs

Semihosting

Audio

Character devices

Crypto subsystem

GUI

Host support

  • Any backend that supports connection as an Inet client (NBD, chardev, network device, monitor...) can now request to use TCP keep-alive with the server.

Memory backends

Monitor

  • bugs in gdbstub handling of F and ! packets have been fixed

Migration

Network

Block device backends and tools

  • Block drivers can now support BDRV_REQ_PREFETCH for more efficient handling of copy-on-read requests; the NBD driver has wired this up to NBD_CMD_CACHE.
  • The LUKS block driver supports falloc/full preallocation

Tracing

Miscellaneous

User-mode emulation

Alpha

TCG

Guest agent

Build Information

Python

  • The minimum supported version of Python is now 3.5.

GIT submodules

Container Based Builds

  • The docker.py tooling now supports podman containers [1] as an alternative to docker.

Build Dependencies

  • The minimum version of the glib library is now 2.48

Testing

Windows

Known issues