Re: 9p file system for xen

[Wei Liu <wei.liu2@citrix.com>]

On Mon, Nov 16, 2015 at 09:36:24AM -0700, Linda wrote:
> Hi Wei,
> 
> On 11/16/2015 8:16 AM, Wei Liu wrote:
> >Hi Linda
> >
> >On Fri, Nov 13, 2015 at 10:23:22AM -0700, Linda wrote:
> >>Hello,
> >>      I worked this summer as an intern under Julien Grall and Wei Liu.  My
> >>project was to develop a prototype/proof of concept xen front/back end for
> >>the 9p file system.  I mostly hacked the virtio 9p system.
> >>     This project was not complete, at the end of the summer.  Julien said
> >>that you all wanted to include this in the next release of xen in January,
> >>and offered to take it over.  I told Julien I wanted to continue working on
> >>it, which I have been doing, very much in the background.
> >>     I came upon a bug in my code recently that made me aware that I am not
> >>clear what the expectation for what I deliver should be: i.e., whether it's
> >>still a prototype, or whether this should be production software.
> >>     Right now, I do not modify the toolstack (I never learned how), but
> >>rather start and pause my guest, and then modify xenstore, manually.   I can
> >>fix my bug in the same manner, but this will limit the usefulness of what I
> >>deliver.  To do more will hit up against the limitations of my time and
> >>knowledge.
> >>     So please let me know what you're expecting, especially wrt the user
> >>interface, and when I would need to complete everything for this release.
> >>
> >If I interpret this correctly, you have a prototype that's working? Do
> >you have your code somewhere?
> No.  I hit a bug that I would fix differently, depending on my goal.
> >I think we would still like to include it in next release if possible --
> >that would require a properly implemented solution, not just a
> >prototype.  Let's assess the current situation and then decide what to
> The situation is, given my current knowledge and what my availability has
> been (it may improve), I can either:
>     a.  Get a decent prototype working by the end of the year.  This would
> have certain values pre-written in xenstore, that I'm currently doing
> manually.  There are potentially some issues with mounting that I suspect
> need to be different for xen than they are for virtio - so either way, I
> need a clarification of how xen people want this to work.
>     b.  Make sure what I've written is working, and pass it on to someone
> else to update the toolstack, and resolve the issues, described above.  In
> this scenario, I would need to know how much time that someone would need
> and just devote a week to getting this to them.
> 

Your description is too vague. I don't have clear idea what kind of bug
you encountered and what suggestion I can give.

The code freeze for next release is going to be end of March next year.
As software engineer often overestimates the progress he or she can
make, I would say we shall aim for getting something working as soon as
possible. Get the design straight and something clean by the end of this
year would be good.

> Either way, my next step is to sync up my qemu with the current qemu, and
> merge everything, and then my github will be correct, at which point you'll
> be able to access my most recent code.
> 

That would be a good first step. You don't actually need to fix the bug
for that if you don't know how to proceed yet.

Wei.