On Fri, Jan 08, 2021 at 12:41:30PM -0700, Warner Losh wrote:
> The FreeBSD project has rewritten bsd-user. We've been working on this for
> quite some time (the earliest commits date from 2013). Maybe a dozen people
> have worked on this over time, and there's 3 or 4 active developers focused
> on FreeBSD changes at the moment.
The fact that you have 3-4 people involved in this work is will be very
helpful to you going forward with a QEMU maintenance.
The biggest problem with getting code merged into QEMU is an insufficient
number of reviewers for the amount of patches sent. Since we have a rule
that patches need a review from someone else who isn't the author, if there
are two people with expertize to review patches in a given QEMU subsystem,
then they can become self-sufficient and review each others patches on
qemu-devel, which then makes merging much more productive.
Yes. That's my hope too. We've been doing this internally for changes we've been landing lately, so I think expanding our process to also do this with qemu upstream will be a natural progression...
If anyone wants to be automatically CC'd on patches for bsd-user for the
purposes of acting as a designated reviewer, they can added to MAINTAINERS
file to, alongside the primary maintainer(s).
I'll be adding myself, at least, to MAINTAINERS and encouraging the others that have been working on this to take the time to review when I post. They are quite willing, but may lack the time, alas, so I'll do what I can to time the patches such that at least one of them has the time in a reasonable time frame...
> So, my new plan is to rebase what changes I can to the tip of master and
> submit those for review. I'll work with the developers on the FreeBSD side
> to ensure they are included in reviews in addition to the normal qemu-devel
> list. This will allow us to pare down the deltas between our code and
> upstream to allow us to make progress. The changes will be held to the
> standard 'makes things better'. Given how broken bsd-user is today in qemu
> upstream, at first that will a very easy standard to make.
>
> The first patch I'll submit will be changing MAINTAINERS to point to me,
> since I'm acting as the point person in this effort. I'll then re-submit
> some other changes that I've submitted in the past, but CC the FreeBSD
> folks that are currently active (they were only CC'd to former developers
> who lack the time to review).
> But before I get too far down this path, I thought I'd send out what's
> going on to qemu-devel so I can get feedback and adjust the plan into
> something that's mutually agreeable so time I put towards this is not
> wasted.
No objections from me. Since current bsd-user is orphaned, largely
unusable, and you're volunteering your time to make it better, I'm
supportive of whatever you believe is the most time efficient way
to improve bsd-user.
I presume some of the current QEMU maintainers knowledgable about
linux-user will be able to review the patches, and as mentioned
above, if other BSD devs currently active in bsd-user work can
also provide reviews on qemu-devel that'll be useful long term.
Yes. Many of the patches are copied from there, as well as the initial version coming largely from there as well (it seems, I wasn't around at the time and base this entirely on code similarities).
The FreeBSD project makes such heavy use of this, that I really want to find some way we can stay current and maybe even have better abstractions that make all user-mode emulation easier...
Warner