Changes 2.9.0:

== Warning of unsupported host systems ==
This release includes changes to the configure script so that it will now report some host operating systems and
platforms as "unsupported". These are host setups which we do not have access to and are thus unable to test. They will continue to work in this 2.9 release (though configure will warn you about the unsupported status), but in a future QEMU release we may drop support for those hosts unless somebody volunteers to help us with maintaining them (and can provide build/CI machines).

This affects the CPU architectures:
* ia64
and the OSes:
* GNU/kFreeBSD
* DragonFly BSD
* NetBSD
* OpenBSD
* Solaris
* AIX
* Haiku

== System emulation ==
=== Incompatible changes ===
* Improvements to "-drive":
** "-drive"'s <tt>if</tt> option defaults to "none" on machines that do not have an onboard IDE or SCSI controller.
** "-drive if=scsi" does not work anymore with PC machine types, as it created an obsolete SCSI controller model. QEMU supports better controllers (megasas, mptsas, virtio-scsi) but which to use depends on the guest you are using.
** "Orphan" -drive options, where an <tt>if</tt> option is not supported by the emulated machine (e.g. "if=mtd" on x86) is now a fatal error. It had been triggering a warning since version 2.2.
=== 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.
* Devices "allwinner-a10", "pc87312", "ssi-sd" will be configured with explicit properties instead of implicitly.  This is unlikely to affect users.
* For x86, specifying a CPUID feature with both "+feature/-feature" and "feature=on/off" will cause a warning.  The current behavior for this combination ("+feature/-feature" wins over "feature=on/off") will be changed so that "+feature" and "-feature" will be synonyms for "feature=on" and "feature=off" respectively).


(adam)