ChangeLog/8.2

From QEMU

System emulation

Removed features and incompatible changes

Consult the 'Removed features' page for details of suggested replacement functionality.

  • The HAX accelerator is not supported anymore; the project has been retired. Use "whpx" or "hvf" respectively on Windows and macOS.
  • The old machine types pc-i440fx-1.4 to pc-i440fx-1.7 have been removed; use a newer machine type instead
  • In addition to -audiodev and -audio, QEMU does not create default audio backends anymore if the -nodefaults option are used on the command line.
  • If an audio backend is created with -audiodev, each audio client (a sound card or VNC) that wants to use it has to specify an audiodev= property. Previously, the first audiodev command line option would be used as a fallback. However -audio can now be used to configure one or more default audio backends, in lieu of the (deprecated and now removed) QEMU_AUDIO_* environment variables.
  • Running QEMU with KVM requires Linux 4.4 or newer. A future version of QEMU will increase the minimum requirement for Arm hosts to Linux 4.19 (also when running KVM); if this is too restrictive for your use case, please contact us at qemu-devel@nongnu.org.

New deprecated options and features

Consult the "Deprecated Features" chapter of the QEMU System Emulation User's Guide for further details of the deprecations and their suggested replacements.

68k

  • The Macintosh Quadra 800 (q800) emulation now can boot:
    • MacOS 7.1 - 8.1, with or without virtual memory enabled
    • A/UX 3.0.1
    • NetBSD 9.3
    • Linux (via EMILE)

Alpha

Arm

  • The following machines support the new audiodev property: integratorcp, musicpal, n800, n810, realview-eb, realview-eb-mpcore, realview-pb-a8, realview-pbx-a9, akita, borzoi, spitz, terrier, versatilepb, versatileab, vexpress-a9, vexpress-a15, xlnx-zcu102 z2
  • Xilinx Versal board now models the CFU/CFI
  • Xilinx Versal board now models the TRNG device
  • New CPU type: cortex-a710
  • New architectural features now emulated:
    • FEAT_PACQARMA3
    • FEAT_EPAC
    • FEAT_Pauth2
    • FEAT_FPAC
    • FEAT_FPACCOMBINE
    • FEAT_TIDCP1
    • FEAT_MOPS
    • FEAT_HBC
    • FEAT_HPMN0
  • The SMMUv3 now advertises the SMMUv3.1-XNX feature

AVR

Hexagon

HPPA

  • New 64-bit PA-RISC 2.0 CPU emulation, enable with "-cpu hppa64" and "-cpu hppa" for 32-bit CPU (default)
  • New HP C3700 machine emulation, includes an emulated Astro memory controller and some Elroy PCI bridges
  • Start 64-bit machine with "-machine C3700" and 32-bit CPU with "-machine B160L"
  • Improved TLB performance
  • Block-TLB (BTLB) support for 32-bit PA-RISC CPUs
  • New SeaBIOS-hppa version 10 to support HP C3000 with Astro & Elroy

LoongArch

Microblaze

MIPS

  • The fuloong2e machine supports the new audiodev property.

Nios2

  • signal tests disabled due to bitrot

OpenRISC

PowerPC

  • The pegasos2 and 40p machines support the new audiodev property.

Renesas RX

Renesas SH

RISC-V

ISA and Extensions

  • Add zmmul isa string
  • Add smepmp isa string
  • Add RISC-V vector cryptographic instruction set support
  • Implement WARL behaviour for mcountinhibit/mcounteren
  • Add Zihintntl extension ISA string to DTS
  • Fix zfa fleq.d and fltq.d
  • Add RISC-V KVM AIA Support
  • Fix riscv,pmu DT node path in the virt machine
  • Update CSR bits name for svadu extension
  • Mark zicond non-experimental
  • Align the AIA model to v1.0 ratified spec
  • Use env_archcpu for better performance
  • Rename ext_icboz to ext_zicboz
  • Rename ext_icbom to ext_zicbom
  • Rename ext_icsr to ext_zicsr
  • Rename ext_ifencei to ext_zifencei
  • Add RISC-V Virtual IRQs and IRQ filtering support
  • Rename epmp to smepmp and expose the extension
  • Support zicntr/zihpm flags and disable support
  • Update RISC-V vector crypto to ratified v1.0.0
  • Support discontinuous PMU counters

Machines

  • Remove 'host' CPU from TCG
  • riscv_htif Fixup printing on big endian hosts
  • Add support for the max CPU
  • Detect user choice in TCG
  • Remove RVG warning
  • Change default linux-user cpu to 'max'
  • Update 'virt' machine core limit
  • Add query-cpu-model-expansion API

Fixes and Misc

  • Fix page_check_range use in fault-only-first
  • Fix upper/lower mtime write calculation
  • Make rtc variable names consistent
  • Use abi type for linux-user target_ucontext
  • Fix satp_mode_finalize() when satp_mode.supported = 0
  • Fix non-KVM --enable-debug build
  • Add new extensions to hwprobe
  • Use accelerated helper for AES64KS1I
  • Allocate itrigger timers only once
  • Respect mseccfg.RLB for pmpaddrX changes
  • Don't read the CSR in riscv_csrrw_do64
  • Clear CSR values at reset and sync MPSTATE with host
  • Fix the typo of inverted order of pmpaddr13 and pmpaddr14
  • Replace GDB exit calls with proper shutdown
  • Support KVM_GET_REG_LIST
  • Deprecate capital 'Z' CPU properties
  • Fix vfwmaccbf16.vf
  • Clear pmp/smepmp bits on reset
  • Ignore pmp writes when RW=01
  • Correct CSR_MSECCFG operations
  • Clear the Ibex/OpenTitan SPI interrupts even if disabled
  • Set the OpenTitan priv to 1.12.0

s390x

  • Emulated VFMIN and VFMAX instructions now correctly raise a specification exceptions when bits 1-3 of M5 are set
  • Fixed emulated VSTL instruction with a large length
  • Fixed emulated VREP instruction to use a 16-bit immediate
  • Fixed the "ignored match" case in the emulated VSTRS instruction
  • Enable crypto adapter passthrough (vfio-ap) for protected virtualization guests
  • Support s390x CPU topology (books and drawers, STSI 15.1.x instruction, PTF instruction) with KVM

SPARC

Tricore

  • Added TC37x CPU that implements ISA v1.6.2
  • Added CRCN, FTOU, FTOHP, and HPTOF instructions
  • Fixed RCPW/RRPW_INSERT instructions for width=0
  • Fixed RCRR_INSERT using the wrong destination register
  • Fixed FTOUZ being only available from ISA v1.3.1 upwards

x86

Xen emulation under KVM

  • Support PV console and network devices.
  • Bug fixes to support running Xen PV guests under "shim", documented in the "Xen HVM guest support" page.
  • Simplify command line for block and network devices.

TCG

  • Support for SHA instructions.

Xtensa

Device emulation and assignment

ACPI / SMBIOS

Audio

  • Added virtio-sound device which implements capture and playback from inside a guest using the configured audio backend of the host machine. It is documented in the "Device Emulation / virtio sound" page.

Block devices

  • Parallels Format Driver
    • Improved 'qemu-img check' facility
      • Recover from broken data_off in the header
      • Drop clusters outside of the image file
      • De-duplicate clusters located on the same offset in the host file
    • Introduced ability to execute check automatically (if disk image is opened in read/write mode) if corruption is detected by open
    • Cluster allocation is now based on the cluster used bitmap (clusters could be allocated in holes inside image file)
    • Minimal DISCARD & WRITE_ZEROES support

Graphics

  • New virtio-gpu rutabaga device. It allows various abstractions of GPU and display virtualization, coming from the Android/CrosVM graphical stack Rutabaga doc. This should help Android Emulator use upstream QEMU, and offers alternative solutions (or context types) than virgl.
  • ati-vga pixman-less support and fixes
  • virtio-gpu blob=true VM can now be migrated

I2C

Input devices

IPMI

Multi-process QEMU

Network devices

NVDIMM

NVMe

PCI/PCIe

  • Added Astro Memory controller with Elroy PCI host busses for PA-RISC (hppa) machines

SCSI

SD card

SMBIOS

TPM

USB

VFIO

virtio

  • virtio-mem now supports to dynamically consume multiple memslots instead of statically a single big one. The feature can be enabled using "dynamic-memslots=on", which can severely reduce KVM memory slot metadata overhead with large virtio-mem devices that only expose a small amount of memory to the VM. Note that the feature is incompatible with vhost devices that provide less than 509 memslots, like most vhost-user devices.
  • Added virtio-sound device. See Audio section/virtio-sound

vDPA

Xen

  • Support PV unplug for AHCI disks with the q35 platform.
  • Allow creation of PV console devices from the command line.
  • Allow creation of PV network devices, including '-nic xxx,model=xen-net-device' and the default NIC.
  • Support '-drive file=FILENAME,if=xen' for creating PV block devices with automatic names.

fw_cfg

9pfs

virtiofs

Semihosting

Audio

Character devices

Crypto subsystem

Authorization subsystem

GUI

  • cocoa: add zoom-to-fit display option
  • gtk: various minor fixes

GDBStub

  • fixes cases where wrong threads were reported to gdb

TCG Plugins

  • fix bug in reporting too many instructions to qemu_plugin_tb_n_insns()
  • fix locking on execlog
  • windows support

Host support

Memory backends

  • memory-backend-file now supports the "rom" parameter. "share=off,readonly=off,rom=on" can be used for VM-templating with R/O files: open the file R/O, but create writable RAM instead of Read Only Memory (ROM).
  • "VM templating" documentation was added

Migration

  • Legacy compression migration is deprecated ("compress" as capability, "compress-level", "compress-threads", "compress-wait-thread", "decompress-threads" as parameters). Suggest to use multifd compression instead.
  • Block migration is deprecated. QMP command "migrate" parameters "blk" and "inc" are deprecated. Suggest to use driver-mirror with NBD instead.
  • Fixed race conditions for postcopy migration when preempt mode is enabled.
  • Postcopy recovery now allows network failure to happen even during RECOVER phase.
  • Added migration parameter "avail-switchover-bandwidth" migration parameter, can be used when the user observes extremely slow bandwidth during migration, causing migration to never complete.
  • Initial part of migration mode "cpr-reboot" integrated.

Monitor

QMP

HMP

Network

Block device backends and tools

  • The qemu NBD implementation for both server and client now supports the recent NBD protocol extension of 64-bit extended headers. When both sides of an NBD connection support this extension, commands like write zeroes or block status can operate on 64-bit effect lengths, rather than being capped to transaction sizes smaller than 4G.

Tracing

Semihosting

Miscellaneous

  • Allow dump-guest-memory to output standard kdump format

User-mode emulation

runtime

binfmt_misc

alpha

  • Emulated /proc/cpuinfo output in linux-user

arm/arm64/aarch64

  • Emulated /proc/cpuinfo output in linux-user

LoongArch

HPPA

s390

x86

TCG backends

RISC-V

Guest agent

Build Information

  • Coding style has been updated to allow loop variables
  • It is possible to build a non-relocatable binary of QEMU with the configure option --disable-relocatable. The default remains a relocatable install (that is, all the directories within the install prefix are computed based on the path to the executable).

Build Dependencies

  • Building QEMU now requires Python 3.8. As a consequence, building on Debian 10 is not supported anymore (unless a newer version of Python is installed by other means).
  • Building QEMU now uses the tomli library if Python is older than version 3.11. However, version 2.0.1 is bundled in case tomli is not installed on the host.
  • The libfdt library is no longer bundled with QEMU. However, if QEMU is configured with --enable-download and the library is absent, then it will be downloaded and built together if any emulators need it.
  • The Pixman library is no longer strictly required. The VC, VNC, Gtk, Spice, screendump features and a few devices still require it.
  • When running make check-avocado, the Avocado testing framework and pycdlib must be present if the build tree was configured with --disable-download. Until 8.1, Avocado was always downloaded from PyPI.

Windows

Testing and CI

  • ccache has been enabled for CI builds
  • container backend is now selected by configure script

Known issues