[Qemu-devel] Making TCG configurable in system mode

[Alvise Rigo]

Hi all,

I am looking at the possibility to add a new QEMU configuration option
to make TCG optional (in qemu-system-*). What I am exploring is a way
to exclude any of the TCG code not needed by KVM from the QEMU binary.
There has been a previous attempt in the past from Paolo Bonzini,
namely https://github.com/bonzini/qemu/tree/disable-tcg, that
eventually was not upstreamed. I was looking into this work mainly,
mostly to understand if the same approach can be respinned and used to
support all the QEMU's targets. Any input on this is welcome.

I was also wondering if an approach could be based on the recent patch
series that allows to use the TCG frontend as a library --
https://www.mail-archive.com/address@hidden/msg415514.html.
Making qemu-user and qemu-system users of such a library might help in
having TCG optional. Obviously this solution introduces many other
challenges and I'm not even sure if it's actually viable.

I would like to hear your opinion on this, ideally to identify what
would be the best direction to follow for bringing this new feature
into QEMU.

Thank you,
alvise