Re: Rust in QEMU roadmap

[Paul Durrant]

On 05/12/2024 12:00, Daniel P. Berrangé wrote:
> On Wed, Nov 27, 2024 at 01:22:00PM +0100, Paolo Bonzini wrote:
> > On Wed, Nov 27, 2024 at 1:18 PM Daniel P. Berrangé <berrange@redhat.com> wrote:
> > > I question the usefulness of the 'syslog' trace target. I can't see
> > > it being desirable as a option for 'production' builds, and it seems
> > > uneccessarily indirect for developers. What's its compelling USP ?
> > >
> > > WRT 'ftrace', IIUC, the Linux 'perf' command has built-in support
> > > for using USDT probes now:
> > >
> > >    https://www.brendangregg.com/perf.html#StaticUserTracing
> >
> > I also wonder if 'ftrace' is duplicating 'log' these days. Anyhow, if
> > we can deprecate 'syslog' and 'ftrace' that would be good to know
> > independent of Rust.
>
> I looked back at the history of syslog and re-discovered that I raised
> the same question when it was first proposed. It was said that syslog
> was to be used by XenServer for some kind of logging they wanted:
>
>    https://lists.nongnu.org/archive/html/qemu-devel/2016-08/msg00336.html
>
> I've CC'd Paul as it'd be useful to know if Xen did end up using this
> feature or not, as we don't want to rip the rug from under them.

Pretty sure we did use it in XenServer. I've not been involved for more 
than 5 years now so maybe someone else who's still working on XenServer 
knows better... Not sure of the right contact though, unfortunately.

  Paul