ChangeLog/2.5

System emulation

Incompatible changes

• The mips32r5-generic CPU was renamed to P5600

Future incompatible changes

• Three options are using different names on the command line and in configuration file. In particular:
  • The "acpi" configuration file section matches command-line option "acpitable";
  • The "boot-opts" configuration file section matches command-line option "boot";
  • The "smp-opts" configuration file section matches command-line option "smp".

-readconfig will standardize on the name for the command line option.

• Behavior of automatic calculation of SMP topology when some SMP topology options for -smp are omitted (sockets, cores, threads) will change in the future. If guest ABI needs to be preserved on upgrades while using the SMP topology options, users should either set set all options explicitly (sockets, cores, threads), or omit all of them.
• Image encryption is fatally flawed, and will be dropped entirely. It'll remain available only in qemu-img, so you can use 'qemu-img convert' to convert encrypted images to uncrypted ones.
• Host floppy device pass-through (block driver "host_floppy") is deprecated, and will be dropped in a future release.
• Block device parameter aio=native has no effect without cache.direct=on. It will be made an error.
• A few devices will be configured with explicit properties instead of implicitly. Unlikely to affect users; for the full list, see the 2.3 ChangeLog.
• QMP command blockdev-add is still a work in progress. It doesn't support all block drivers, it lacks a matching blockdev-del, and more. It might change incompatibly.

ARM

• The "virt" machine type supports passing SMBIOS to the firmware.
• Semihosting support on AArch64
• New i.MX31 SoC.
• The ZynqMP platform supports AHCI.

MIPS

• The mips32r5-generic CPU was renamed to P5600

s390

• Storage keys are migrated.
• New "info skeys" command in HMP to dump the storage key for a given address.

TileGX

• New target.

x86

KVM

• Support for Hyper-V-compatible reporting of crashes.

Xen

• Support for passthrough of Intel integrated GPUs.

GUI

• New syntax for enabling TLS in the VNC server:
  • Equivalent to -vnc hostname:0,tls: -object tls-creds-anon,id=tls0,endpoint=server -vnc hostname:0,tls-creds=tls0
  • Equivalent to -vnc hostname:0,tls,x509=/path/to/certs: -object tls-creds-x509,id=tls0,endpoint=server,dir=/path/to/certs,verify-peer=no -vnc hostname:0,tls-creds=tls0
  • Equivalent to -vnc hostname:0,tls,x509verify=/path/to/certs: -object tls-creds-x509,id=tls0,endpoint=server,dir=/path/to/certs,verify-peer=yes -vnc hostname:0,tls-creds=tls0

Monitor

• New "info iothreads" command.
• New "query-qmp-schema" command allows the caller to introspect the QMP schema used by QEMU.

Block devices and tools

• New "reopen" command in qemu-io.

Guest agent

• Support for dumping the configuration current file with --dump-conf
• Win32 support for guest-set-user-password

User-mode emulation

• The configure option has been removed in a future release.

Known issues

• SDL audio only works with SDL 1.x.
• Problems with QEMU for Windows and builds from newer versions of MinGW-w64, see this thread on qemu-devel (this is not a regression, other versions are also affected)
  • Crash of 64-bit QEMU (Fix)
  • Broken networking (Fix)