Documentation is not great I admit. The problem is that we don't have anyone who is a capable tech writer in the team. It's not something that you can improvise.
However, all incompatible changes are documented and also announced at least 8 months in advance.
It may seem like there are many, but in practice they are in very old, mostly unused or very badly designed corners. For example configuration of audio was overhauled last year, and is now the same as basically all other backends (e.g. -audio pa,model=sb16; compare with -nic user,model=e1000 for a network card).
As a general thought, would it be possible to put out a "call for tech writers" post or similar on the front of the qemu website, or even a prominent blog post in the blog section?
However, all incompatible changes are documented and also announced at least 8 months in advance.
https://www.qemu.org/docs/master/about/removed-features.html
https://www.qemu.org/docs/master/about/deprecated.html
It may seem like there are many, but in practice they are in very old, mostly unused or very badly designed corners. For example configuration of audio was overhauled last year, and is now the same as basically all other backends (e.g. -audio pa,model=sb16; compare with -nic user,model=e1000 for a network card).