Re: [PATCH 1/2] qemu: Drop support for C implementation of virtiofsd
On 12/12/23 13:07, Peter Krempa wrote:
On Tue, Dec 12, 2023 at 12:50:52 +0100, Michal Privoznik wrote:
> Virtiofsd has two implementations: C and Rust. The former is now
> deprecated (QEMU commit v7.0.0-rc0~52^2~1) and in fact removed
> from QEMU (QEMU commit v8.0.0-rc0~55). While Rust version was
> originally a drop in replacement it is not the case anymore. Some
> arguments are silently ignored (like file locking) and there's no
> way to make them work for both implementations.
>
> Remove support for the C implementation.
Note that the virtiofs support in qemu seems to start dating from
qemu-5.0 thus was already availabile at least in RHEL/CentOS 8
Now the rust version:
https://repology.org/project/virtiofsd/versions
is not available there.
Since according to our platform support policy we're still about to
support rhel-8 for another ~7 months I'm not sure we should be doing
this. At least not with any form of proper justification, that this
commit message is not providing.
Fair enough. I've noticed some warnings emitted by virtiofsd when I was
debugging something else and I thought: let's fix them. And while Rust
version was supposed to be a drop in replacement it's not the case
anymore (though - I wonder if that ever was the case) as it has moved on.
Now, what we usually do in this case is: capabilities. We could run the
binary and try to guess if it is C or Rust version. But writing all of
that code just so that it can be deleted in ~7 months, just no. So let's
keep the code as is and these can be applied after RHEL-8 is dropped.
Though, one could argue that the set of users that runs libvirt from git
but qemu from repo on RHEL/CentOS 8 is relatively small, the rule we
have is a bit different.
Michal