* 6.1.0 release has NetBSD NVMM support.
* Fix NetBSD NVMM compile errors.
* Remove integrated Alpha patches.
Changelog:
Highlights include:
* block: support for changing block node options after creation via
'blockdev-reopen' QMP command
* Crypto: more performant backend recommendations and improved documentation
* I2C: emulation support for I2C muxes (pca9546, pca9548) and PMBus
* TCG Plugins: now enabled by default, with new execlog and cache modelling
plugins.
* ARM: new board support for Aspeed (rainier-bmc, quanta-q7l1), npcm7xx
(quanta-gbs-bmc), and Cortex-M3 (stm32vldiscovery) based machines
* ARM: Aspeed support of Hash and Crypto Engine
* ARM: emulation support for SVE2 (including bfloat16), integer matrix
multiply accumulate operations, TLB invalidate in Outer Shareable domain,
TLB range invalidate, and more.
* PowerPC: pseries: support for detecting hotplug failures in newer guests
* PowerPC: pseries: increased maximum CPU count
* PowerPC: pseries: emulation support for some POWER10 prefixed instructions
* PowerPC: new board support for Genesi/bPlan Pegasos II (pegasos2)
* RISC-V: updates to OpenTitan platform support, including OpenTitan timer
* RISC-V: support for virtio-vga
* RISC-V: documentation improvements and general code cleanups/fixes
* s390: emulation support for the vector-enhancements facility
* s390: support for gen16 CPU models
* x86: new Intel CPU model versions with support for XSAVES instruction
* x86: added ACPI based PCI hotplug support for Q35 machine (now the default)
* x86: improvements to emulation of AMD virtualization extensions
* and lots more...
qemu-system-alpha where FEN traps were never generated. Fixes
a whole slew of FP-related problems on NetBSD/alpha running in
Qemu (including a broken jot(1)).
Bump package version to qemu-6.0.0nb2.
* Add zstd dependency.
Changelog:
== System emulation ==
=== Incompatible changes ===
Consult the [https://qemu-project.gitlab.io/qemu/system/removed-features.html 'Removed features' ] page for details of suggested replacement functionality
* The deprecated ''pc-1.0'', ''pc-1.1'', ''pc-1.2'' and ''pc-1.3'' machine types have been removed (they likely could not be used for live migration from old QEMU versions anymore anyway). Use a newer ''pc-i440fx-...'' machine type instead.
* TileGX emulation has been removed without replacement
* The ''change'' QMP command has been removed. Use ''blockdev-change-medium'' or ''change-vnc-password'' instead.
* The ''-show-cursor'' option has been removed. Use ''-display sdl,show-cursor=on'' instead.
* The ''-realtime'' option has been removed. Use ''-overcommit mem-lock=on|off' instead.
* The ''-tb-size'' option has been removed. Use ''-accel tcg,tb-size=...'' instead.
* The configure script --enable/disable-git-update args have been replaced with --with-git-submodules
* The ''-usbdevice audio'' option has been removed. Use ''-device usb-audio'' instead.
* The ''-usbdevice ccid'' option has been removed with no replacement
* The ''-vnc'' parameter ''acl'' option, and ''acl_*'' monitor commands have been removed.
* The ''pretty'' option is no longer accepted when used with the human monitor
* The ''change'' QMP command has been removed. Use ''blockdev-change-medium'' or ''change-vnc-password'' instead.
* The ''query-events'' QMP command has been removed
* The ''migrate_set_speed'', ''migrate_set_downtime'' and ''migrate-set-cache-size'' QMP/HMP commands have been removed.
* The ''query-cpus'' QMP command has been removed
* The ''arch'' field in the ''query-cpus-fast'' command has been removed
* The ''-chardev'' parameter ''wait'' option is no longer accepted for socket clients
* The ''ide-drive'' device type has been removed
* The ''scsi-disk'' device type has been removed
* The ''encryption_key_missing'' field has been removed from block device info data
* The ''status'' field has been removed from dirty bitmap info
* The ''dirty-bitmaps'' field has been removed from the ''BlockInfo'' struct
* The ''file'' block driver no longer permits use with block devices
* The use of ''-global'' to set floppy controllers is removed. Use ''-device floppy,...'' instead.
* The ''-drive'' option must now use ''if=none'' for drives the onboard device does not pick up.
* The ''object-add'' QMP command member ''props'' has been removed. Its contents may be used with less nesting instead.
* The mips ''fulong2e'' machine alias has been removed. Use ''fuloong2e'' instead.
=== New deprecated options and features ===
Consult the [https://www.qemu.org/docs/master/system/deprecated.html "Deprecated Features"] chapter of the QEMU System Emulation User's Guide for further details of the deprecations and their suggested replacements.
* The --enable-fips option has been deprecated. Consumers wishing to have FIPS compliance must build QEMU with libcrypt and gnutls, NOT nettle.
* The ''-writeconfig'' option has been deprecated. The functionality of ''-writeconfig'' is limited and the code does not even try to detect cases where it prints incorrect syntax (for example if values have a quote in them). It will be removed without replacement.
* Boolean parameters such as ''share=on'' / ''share=off'' could be written in short form as ''share'' and ''noshare''. This is now deprecated and will cause a warning.
* ''-chardev'' backend aliases ''tty'' and ''parport'' are aliases that will be removed. Instead, the actual backend names ''serial'' and ''parallel'' should be used.
* The ''delay'' option for socket character devices is now deprecated.
* Userspace local APIC with KVM (''-M kernel-irqchip=off'')
* hexadecimal sizes with scaling multipliers (e.g. ''0x20M'')
* ''-spice password=string'' is deprecated now. Use ''password-secret'' option instead.
* ''opened'' property of ''rng-*'' objects
* ''loaded'' property of ''secret'' and ''secret_keyring''
* MIPS ''Trap-and-Emulate'' KVM support
=== 68k ===
* Add a new machine, virt, based on virtio devices
=== Alpha ===
=== Arm ===
* QEMU now supports emulation of the Arm-v8.1M architecture and the Cortex-M55 CPU
* Emulation of the ARMv8.4-TTST extension is now supported
* Emulation of the ARMv8.4-SEL2 extension is now supported
* Emulation of the FEAT_SSBS extension is now supported
* Emulation of the PAuth extension now supports an optional IMPDEF pauth algorithm which is not cryptographically secure but is much faster to compute
* Emulation of the ARMv8.4-DIT extension is now supported. (Note that QEMU's implementation does not in fact provide any timing guarantees; emulation of the extension is purely to support guests which query its presence and work with the PSTATE.DIT bit.)
* Emulation of the ARMv8.5-MemTag extension is now supported for linux-user. (It was already supported for system emulation.)
* xlnx-zynqmp boards now support the Xilinx ZynqMP CAN controllers
* the sbsa-ref board now supports Cortex-A53/57/72 cpus
* the xlnx-versal board now has USB support, and a model of the XRAMs and the XRAM controller
* the sabrelite board emulation has been improved and it can now run U-Boot
* the npcm7xx boards support more devices: ADC, PWM, SMBus, EMC, MFT
* the gdbstub's representation of SVE registers allows GDB to properly handle aliasing
* the 'virt' board now provides a mechanism for secure (EL3) firmware to power down or reset the system
* documentation for vexpress/versatile has been updated with example kernel configuration/command lines
* A new board model mps3-an524 (using Cortex-M33) is now implemented
* A new board model mps3-an547 (using Cortex-M55) is now implemented
=== AVR ===
=== Hexagon ===
* QEMU can now emulate Qualcomm's Hexagon DSP units.
=== HPPA ===
=== Microblaze ===
=== MIPS ===
* Loongson-3 "virt" machine added
=== Nios2 ===
=== OpenRISC ===
=== PowerPC ===
* Deprecated 'compat' property of server class POWER cpus removed (use the 'max-cpu-compat' machine option instead)
* You can now explicitly choose 'kvm_type=auto' rather than only being able to do that by not setting it at all.
* powernv machine type now defaults to 1GiB of RAM
* powernv now allows an external BMC
* pseries will now send MEM_UNPLUG_ERROR QAPI message in cases where it can detect that a memory unplug has failed
* pseries will now allow cpu unplug requests to be retried, even if the guest hasn't responded to them yet.
* This will re-signal the guest, which might an unplug to complete which the guest previous rejected
=== Renesas RX ===
=== Renesas SH ===
=== RISC-V ===
* Improve the sifive_u DTB generation
* Add QSPI NOR flash to Microchip PFSoC
* Improvements to the Microchip PFSoc to improve support with the SDK
* A range of fixes to the Hypervisor extension
* Fix some mstatus mask defines
* Ibex PLIC and UART improvements
* OpenTitan memory layout update (Breaking change)
* Initial steps towards support for 32-bit CPUs on 64-bit builds
* Automate GDB XML generation (should fix GDB E14 errors)
* Sifive OTP handle OTP access failures
* Correctly generate a PMP failure when no PMP entry is configured
* Fixes to PMP region checking
* Fix 32-bit Linux boot problems with DTB placement
* OpenSBI upgraded to v0.9
* Support the QMP dump-guest-memory command
* Add support for the SiFive SPI controller (sifive_u)
* Initial RISC-V system documentation
* Support for high PCIe memory in the virt machine
* Fixes to the vector extensions CSR accesses
* ramfb support in the virt machine
=== s390 ===
* Linux kernels built with clang-11 and clang-12 now work correctly under tcg
=== SPARC ===
=== TileGX ===
* TileGX has been removed without replacement.TileGX was only implemented in linux-user mode, but support for this CPU was removed from the upstream Linux kernel in 2018, and it has also been dropped from glibc, so there is no new Linux development taking place with this architecture, rendering the linux-user mode emulation rather useless. For running older binaries, users can simply use older versions of QEMU.
=== Tricore ===
* Added Triboard with tc27x SoC
=== x86 ===
* TCG can emulate the PKS feature (protection keys for supervisor pages).
* Intel PT can now be exposed to KVM guests when <code>CPUID.(EAX=14,ECX=0).ECX[LIP]</code> (bit 31) is 1. Previous versions only supported Intel PT when LIP=0
* New <code>sev-inject-launch-secret</code> QMP command
* The WHPX accelerator supports accelerated APIC ("-accel whpx,kernel-irqchip=on")
* The microvm machine type got a second (optional) ioapic for the virtio-mmio irq lines, which in turn allows 24 (instead of 8) virtio-mmio devices.
* Support for running SEV-ES encrypted guests.
=== Xtensa ===
=== Device emulation and assignment ===
==== ACPI ====
* new ''-machine'' options ''oem-id'' and ''oem-table-id'' to allow setting custom values for ''OEM ID'' and ''OEM table ID'' ACPI table fields
* in QEMU 5.1, PCI root UID changed to from 1 to 0 for all x86 machine types, this caused issues in Windows guest with virtio devices being re-enumeraed as new devices. QEMU 6.0 fixes it by reverting UID to 1 for 5.1 and older machine types. See commit 0a343a5add75 for details. For 5.2 and later machine types it might be necessary to reconfigure/reinstall Windows VM, if used disk image was created on 5.1 and older machine types.
* Support for user provided PCI NIC index on ''pc'' machine type with help of new ''acpi-index'' PCI device option. For linux guests, It lets user to use ''onboard'' naming scheme ''enoX'' where X is set with ''acpi-index'' option. It makes NIC naming independent from which PCI slot it is plugged in. Works with cold and hot-plugged NICs, as long as used PCI bus is managed by ACPI PCI hotplug (which is enabled for PCI root bus and bridges present at boot time by default on latest ''pc'' machine type ).
==== Audio ====
==== Block devices ====
* virtio-blk reports <tt>--device virtio-blk-pci,discard_granularity=</tt> in the virtio-blk <tt>discard_sector_alignment</tt> configuration space field so that guests with new machine types can take advantage of this information. Previously virtio-blk devices reported <tt>--device virtio-blk-pci,logical_block_size=</tt> instead.
==== Graphics ====
==== Input devices ====
==== IPMI ====
==== Multi-process QEMU ====
* The experimental <code>-machine x-remote</code> and <code>-device x-pci-proxy-dev</code> options have been added to support out-of-process device emulation. Currently only the <code>lsi53c895</code> SCSI device can be emulated in a separate process. Please see [https://qemu.readthedocs.io/en/latest/system/multi-process.html the documentation] and [[Features/MultiProcessQEMU]] for details on this experimental feature, which is still subject to change.
==== Network devices ====
==== NVDIMM ====
* nvdimm devices will check that <code>-device nvdimm,unarmed=on</code> option is used when using <code>-object memory-backend-file,readonly=on</code>
==== NVMe ====
===== Emulated NVMe Controller =====
* ''Highlights''
** The implemented spec version has been bumped to v1.4
** Experimental support for Zoned Namespaces (TP 4053) has been added
** Experimental support for NVM Subsystems, multipath I/O and namespace sharing
** Experimental support for Metadata and End-to-End Data Protection
* ''New commands''
** Dataset Management
** Compare
** Simple Copy (TP 4065)
** Format NVM
** Verify
* ''Other new features''
** Support for reporting the Deallocated or Unwritten Logical Block Error (DULBE)
** Namespace UUID reported as a Namespace Descriptor
** Support for Namespace Types (TP 4056)
** Support for triggering a SMART Critical Warning through QMP
** Controller Memory Buffer support has been enhanced for NVMe v1.4 (to revert to v1.3 behavior, use the new <code>legacy-cmb</code> controller parameter)
** Persistent Memory Region RDS/WDS support
* ''New log pages''
** Commands Supported and Effects
==== PCI/PCIe ====
* The 'pvpanic-pci' device is a PCI-device version of the 'pvpanic' ISA device, which can be used on systems with only PCI and no ISA bus as a mechanism for the guest to inform QEMU that it has paniced.
==== SCSI ====
* Rework of the ESP SCSI emulation to allow mixed FIFO/(P)DMA commands along with various other fixes
==== SD card ====
==== SMBIOS ====
==== TPM ====
==== USB ====
* Support for writing usb traffic to package capture files for inspection with wireshark has been added. Use the new pcap=<file> property added to all usb devices to enable this.
==== VFIO ====
==== virtio ====
==== Xen ====
* A new [https://qemu.readthedocs.io/en/latest/system/guest-loader.html guest loader] which allows testing of Xen-like hypervisors booting kernels without messing around with firmware/bootloaders
==== fw_cfg ====
==== 9pfs ====
==== virtiofs ====
* Security fix for CVE-2020-35517 - prevent opening of special files
* Security fix for CVE-2021-20263 - when used with xattrmap, drop remapped security.capability
* Performance improvements with new guest kernel feature FUSE_KILLPRIV_V2
==== Semihosting ====
* Added support for RiscV (ARM style s= Character devices ===
=== Crypto subsystem ===
==== experimental qmp interface ====
=== GUI ===
* vnc: support for cursors with alpha channel has been added.
* vnc: support for extended desktop resize has been added. With virtio-vga the guest displab representation for SVE registers
=== TCG Plugins ===
* New API for querying details about HW access
* Bug fix to avoid double counting some instructions when using -icount
=== Host support ===
=== Memory backends ===
* hostmem-file: added readonly=lation to NBD_STATE_HOLE.
* ''qemu-img'' gained more accurate parsing for size values. Previously, only 53 significant digits were supported, and large sizes could end up with inadvertent rounding; now the parser supports a full 64 bits of precision.
* The ''object-add'' QMP command is now available in qemu-storage-daemon.
* qemu-storage-daemon supports a ''--pidfile'' option now
* The ''parallels'' image format driver has gained support for dirty bitmaps in read-only mode
=== Tracing ===
=== Miscellaneous ===
* The command line option ''-object'' (or ''--object'') accepts JSON input now in all binaries (system emulators and tools). In tools, it also supports non-scalar options using the dotted key syntax known from options like ''--blockdev''.
* The QMP command ''object-add'' is now covered by the QAPI schema and clients can use schema introspection to detect object types and options supported by the given QEMU binary.
* A new command line option ''-action'', with suboptions ''panic'', ''shutdown'', ''reboot'' and ''watchdog''. ''-action'' subsumes the pre-existing options ''-no-shutdown'' (''-action panic=pause,shutdown=pause''), ''-no-reboot'' (''-action reboot=shutdown'') and ''-watchdog-action''; plus, it allows the user to choose whether guest panic should pause the guest (''-action panic=pause''), shut it down (''-action panic=poweroff'', the default) or be ignored (''-action panic=none'').
* A new generic machine option ''confidential-guest-support'' was added to (partially) unify configuration for AMD SEV memory encrypt, POWER PEF and s390 Protected Virtualization, plus future methods of protecting a guest from eavesdropping by a compromised hypervisor.
* A new [https://qemu.readthedocs.io/en/latest/system/guest-loader.html guest loader] whications.
== User-mode emulation ==
=== binfmt_misc ===
Added support of 'P' flag (preserve-argv[0])
With kernel v5.12, QEMU can detect if it is started with preserve-argv[0] flag and adjust the list of arguments accordingly.
=== Hexagon ===
Added support for the Qualcomm Hexagon processor, in linux-user mode only.
For more information, see [https://www.youtube.com/watch?v=3EpnTYBOXCI our presenation from the 2019 KVM Forum]
or the [https://github.com/qemu/qemu/blob/master/target/hexagon/README README] file
== TCG ==
* Added support for Apple Silicon hosts (macOS)
after advancing the PC past the faulting instruction as defined by the
architecture spec, actually store it in the stack frame passed to the
operating system.
Fixes the difference in behavior between Qemu and real hardware in
PR bin/56198.
would select the nvmm library when it wasn't disabled that later was not
found.
While here, also fix a curses issue introduced in version 5.2.0nb2; it would
not find the appropriate library.
Changelog:
IMPORTANT NOTE: in this release we have switched our build system to internally use Meson. Building should be broadly unchanged for most users, but please see the [[#Build Information|Build Information]] section of the changelog for details and for '''the list of new [[#Build Dependencies |build dependencies]] you now need to install'''.
== System emulation ==
=== Incompatible changes ===
=== New deprecated options and features ===
Consult the [https://www.qemu.org/docs/master/system/deprecated.html "Deprecated Features"] chapter of the QEMU System Emulation User's Guide for the full list of historically deprecated features/options.
In particular, note that the Unicore32 and lm32 guest support have been deprecated and will be removed in a future version. They are now only built if explicitly enabled in --target-list.
=== 68k ===
=== Alpha ===
=== Arm ===
* ARMv8.2 FEAT_FP16 (half-precision floating point) is now implemented for AArch32 emulation (AArch64 already supported this)
* AArch64 BTI is now supported in linux-user emulation mode (it was already implemented for system emulation)
* The SMMUv3 model now supports SMMUv3.2 range invalidation
* The sbsa-ref board now has an embedded controller model for guest powerdown and reboot requests
* The sbsa-ref board now has an SBSA-compatible generic watchdog device
* The Raspberry Pi boards now emulate the CPRMAN clock manager device
* Support for KVM on 32-bit host CPUs (deprecated in 5.0) has now been removed. (32-bit KVM guests on 64-bit hosts remain supported.)
* Two new board models in the mps2 family: mps2-an386 (Cortex-M4 based) and mps2-an500 (Cortex-M7 based)
* New board models in the raspi family: raspi3ap (the Pi 3 model A+), raspi0 (the Pi Zero) and raspi1ap (the Pi A+)
* New Nuvoton iBMC board models: npcm750-evb, quanta-gsj
* The 'max' CPU now implements a 48-bit physical address size when using TCG emulation.
* The 'virt' board supports kvm-steal-time (enabled by default for virt-5.2 and on) so that a guest OS can account for time when its CPUs were not running due to the host not scheduling the corresponding vCPU threads.
=== AVR ===
=== HPPA ===
* Added power button emulation
* Boots NetBSD
* Boots old Linux CDs, e.g debian-0.5 and debian-0.6.1
* Artist framebuffer fixes when running dtwm on HP-UX
* Artist graphics allows screen resolution up to 2048 x 2048 pixels
* fw_cfg interface added
=== Microblaze ===
=== MIPS ===
=== Nios2 ===
=== OpenRISC ===
=== PowerPC ===
* The pseries machine now respects the nvdimm= machine option (previously NVDIMMs could be attached even with nvdimm=off)
* The pseries machine now does a better job of reflecting the user specified NUMA distances in the guest (PAPR limitations mean it's still a pretty poor approximation, though)
* We now fail more gracefully if attempting to run an HPT guest as a nested KVM guest (which isn't supported in the kernel for now)
* spapr_vscsi should now properly report that it does not support hotplug
* The pnv machine now allows firmware images up to 16MiB, instead of just 4 MiB (this matches the limit on physical FSP machines)
=== Renesas RX ===
=== Renesas SH ===
=== RISC-V ===
* Improvements to the Ibex (OpenTitan) PLIC
* OpenSBI v0.8 included by default
* Generic OpenSBI platform used when no -bios argument is supplied
* Support for a noMMU Linux kernel with the `-kernel` option
* A dummy L2 cache controller for the sifive_u is now included
* Support for the SiFive OTP device
* PMPCFG CSR setting bug fixed for RV64
* Improvements to the floating point helpers
* Experimental Hypervisor support updated to v0.6.1 and bug fixes
* Support for NUMA sockets on Virt and Spike Machines
* Support for the Microchip PolarFire SoC Icicle Kit
* Fix for crash seen when running 'poweroff' command on virt machine
* virt and sifive_u machines allow a custom dtb argument
* Support for migrating machines
=== s390 ===
* KVM: The diagnose 0x318 instruction is now supported.
* TCG: More instructions that were introduced with the z14 are now emulated.
* zPCI: vfio-pci devices now report real hardware features for functions, instead of emulated values (needs host kernel support.)
* virtiofs is now also supported on s390x via ccw
=== SPARC ===
* sun4m: fix panic when booting NetBSD with the TCX framebuffer
* sun4u: fix for sabre PCI IRQs being lost due to memory overflow
=== TileGX ===
=== Tricore ===
=== x86 ===
* A new KVM feature which improves the handling of asynchronous page faults is available with ''-cpu ...,kvm-async-pf-int''. This requires Linux 5.8.
=== Xtensa ===
* DFPU coprocessor with single and double precision floating point opcodes is now supported
* NMI is now supported
=== Device emulation and assignment ===
==== ACPI ====
==== Audio ====
==== Block devices ====
==== Graphics ====
==== Input devices ====
==== IPMI ====
==== Network devices ====
==== NVDIMM ====
==== NVMe ====
* Add support for mandatory features of version 1.3 of the NVM Express specification
* Add support for the Abort, Asynchronous Event Request and Get Log Page commands
* Add support for Scatter Gather Lists (supported descriptors: Data Block, Bit Bucket, Segment and Last Segment)
* Allow the device to be configured with the "Admin Only" command set
* Support multiple namespaces through the new nvme-ns device
* The unallocated Intel PCI Vendor and Device ID has been replaced with a QEMU allocated "Red Hat" ID
* Support per-namespace SMART log
==== PCI/PCIe ====
==== SCSI ====
==== SD card ====
==== SMBIOS ====
* The OEM Strings data can now be loaded from a file
==== TPM ====
==== USB ====
==== VFIO ====
==== virtio ====
==== Xen ====
==== fw_cfg ====
==== 9pfs ====
* Significant [https://lists.gnu.org/archive/html/qemu-devel/2020-01/msg05539.html performance improvement of Treaddir] requests.
* A performance warning is now logged on host side if 'msize' is set to a very small value, which especially includes Linux 9P clients not having any user specified 'msize' parameter at all. Simply setting 'msize' (on client/guest side) to any value larger than 8192 will cause the warning to disappear. See [https://wiki.qemu.org/Documentation/9psetup#msize msize documentation] for details.
==== virtiofs ====
* virtiofsd xattrmap option to allow the host to see different xattr names to the guest
* virtiofsd alternate sandbox option for environments where pivot_root isn't available
* virtiofsd 'submount' mechanism (requiring newer guest kernel) allows different host mounts to be seen as separate submounts in the guest, avoiding inode clashes.
==== Semihosting ====
=== Audio ===
=== Character devices ===
* Inverted logic in QAPI handling the "tight" option for abstract UNIX sockets was fixed.
* The QAPI schema now only reports support for abstract UNIX sockets on platforms where it is available (Linux).
=== Crypto subsystem ===
==== experimental qmp interface ====
=== GUI ===
* Spice: add support for SIDE and EXTRA mouse buttons. Improve HiDPI, set physical dimensions of client monitors.
* Build spice and opengl as modules
=== GDBStub ===
=== Host support ===
=== Memory backends ===
=== Migration ===
* A new 'block-bitmap-mapping' migration parameter is added, allowing finer control of which bitmaps to migrate, even when node names differ between source and destination.
* Migration over 'vsock' is now allowed, for nested environments or hosts with hardware that looks like a vsock.
* A new 'calc-dirty-rate'/'query-dirty-rate' call gathers an approximation of the rate at which the guest is dirtying RAM and thus gives an idea about whether precopy migration is likely to proceed.
* The default migration bandwidth has been increased to 1Gbps; users are still encouraged to tune it to their own hardware.
* TLS+multifd is now supported for higher bandwidth encrypted migration.
* Migration with dirty bitmaps has several bugs fixed.
=== Monitor ===
==== QMP ====
* Command block_resize no longer blocks the main loop.
==== HMP ====
* Command block_resize no longer blocks the main loop.
=== Network ===
=== Block device backends and tools ===
* qcow2 files now support extended L2 entries that allow subcluster-based allocation (enable with <code>extended_l2=on</code> when creating the image).
* Using qemu as an NBD client has fewer scenarios where network timeouts stall guest execution
* More explicit errors are reported when use of O_DIRECT fails
* The 'block-export-add' QMP command has been introduced to support qemu-storage-daemon, and replaces the now-deprecated 'nbd-server-add' command.
* The 'vhost-user-blk' export type has been added, allowing qemu-storage-daemon to act as a vhost-user-blk device backend.
* qemu-nbd now supports multiple '-B name' options for exposing multiple dirty bitmaps at once; it also supports a new '-A' option for exposing the new "qemu:allocation-depth" metadata context over NBD.
=== Tracing ===
* Add support of dtrace backend on macOS
=== Miscellaneous ===
* The roms/edk2 submodule and the bundled edk2 binaries have been updated to [https://bugs.launchpad.net/qemu/+bug/1852196 edk2-stable202008].
== User-mode emulation ==
* ppc64abi32-linux-user is deprecated and only built when explicitly enabled in--target-list
* tilegx-linux-user is deprecated and only built when explicitly enabled in--target-list
* better reporting when we can't mmap the guest_base we want on systems without MAP_FIXED_NOREPLACE
== TCG ==
== Guest agent ==
* New commands: <code>guest-get-devices</code>, <code>guest-get-disks</code> & <code>guest-ssh-{get,add,remove}-authorized-keys</code>
* Support <code>guest-get-fsinfo</code> for non-PCI virtio devices, too
== Build Information ==
* The build system is now partly based on Meson. However, building is still done with ''configure'' and ''make'' as in previous versions of QEMU.
* Binaries for emulators are placed in the root build directory, for example as ''qemu-system-ppc'' instead of ''ppc-softmmu/qemu-system-ppc''. Symbolic links from the old binary are preserved to simplify the transition.
* In-tree builds are not supported anymore. The build system will try to cater for ''./configure && make && make install'' by building QEMU in a directory named ''build'', but you are encouraged to switch to out-of-tree builds instead.
* ivshmem-client and ivshmem-server are not installed anymore. They are merely examples, and not to be used in production.
* QEMU installations are now relocatable. For example, if QEMU is configured with ''bindir=/usr/local/bin'' and ''datadir=/usr/local/share'', when QEMU is launched as ''/opt/local/qemu-5.2/bin/qemu-system-x86_64'' it will look automatically for data files in ''/opt/local/qemu-5.2/share''. Note that directories configured outside the prefix (as is often the case for ''/etc'' and ''/var'') will not be relocated! Previously this was done only under Windows and only for emulators.
=== Python ===
* Python 3.6 or newer is now required to build QEMU.
=== GIT submodules ===
=== Container Based Builds ===
* All Debian 9 based cross-compiler containers have been updated to Debian 10
=== Build Dependencies ===
* Ninja 1.7 or newer is now required to build QEMU:
* '''$ apt-get install ninja-build''' (Debian/Ubuntu and derivative distros)
* '''$ dnf/yum install ninja-build''' (RHEL/Fedora/CentOS and derivative distros)
* '''$ brew install ninja''' (macOS with HomeBrew)
* '''$ pkg install ninja''' (FreeBSD)
=== Windows ===
* qemu-nbd is now built on mingw, and works for simple cases even if it can't duplicate the full functionality available on Unix systems
=== Testing and CI ===
* a new script can wait on gitlab to finish with a pass/fail status (scripts/ci/gitlab-status)
