Re: Mirage Xenstore Stub Domain

[James Bielman <jamesjb@xxxxxxxxx>]

I've hit another snag with the Xenstore stub domain.  I've built "ocaml-xenstore-xen" with Mirari, and I'm launching it early in the dom0 boot process with "init-xenstore-domain".  The xenstore kernel seems to hang with 100% CPU usage trying to write to the console (which makes some sense to me, since nothing is reading from the ring buffer yet).  My guess is that the loop in "OS.Console.write_all" is the culprit---if I stub this function out to return zero, it starts up and works just fine.

I've been trying to figure out if this is a bootstrapping issue that's somewhat unavoidable or a bug, but I don't yet have enough of a handle on how LWT works to be sure.

James

On Mon, Jul 8, 2013 at 4:25 PM, James Bielman <jamesjb@xxxxxxxxx> wrote:

Thanks! It builds for me now after following your process and hacking up a quick and dirty mirari config file.

Cheers,

James

On Mon, Jul 8, 2013 at 3:10 PM, David Scott <scott.dj@xxxxxxxxx> wrote:

Hi James,

I think you're right -- some key interfaces have changed. Since some of the changes are fairly fresh in my memory, I did a first pass at fixing the code.

The blog post is a bit out of date now. The best way to start is to:

opam init

opam switch 4.00.1

opam remote add xapi-project git://github.com/xapi-project/opam-repo-dev

opam remote add mirage git://github.com/mirage/opam-repo-dev

opam install mirage-xen xenstore

and then clone the repo and build in the 'xen' directory. For me the files compile but fail to link. The next thing to do is to investigate using the 'mirari' tool to link a xen kernel, like the other examples in the mirage/mirage-skeleton repo. This is fallout from the recent (very good IMHO) change to avoid using a special 'opam compiler switch' to install mirage kernels. You can now use a regular (unpatched) compiler and link in the 'mirage-xen' package.

Sorry for the build breakage!

Cheers

Dave

On Mon, Jul 8, 2013 at 10:10 PM, James Bielman <jamesjb@xxxxxxxxx> wrote:

Hi all,

I am attempting to build the Mirage Xenstore stub domain by following these instructions on the Mirage blog:

  http://www.openmirage.org/blog/xenstore-stub-domain

However, I'm running into some trouble---it looks like the interfaces for shared memory rings and grant tables have changed since the "xs_transport_domain" module was written.  I'm using Mirage as installed from "opam" and the "ocaml-xenstore-xen" module from the Git repository at:

   git://github.com/djs55/ocaml-xenstore-xen

Is there is an updated repository elsewhere that works with the latest Mirage?  If not, I may take a stab at bringing it up to date, and would appreciate any insight available on gotchas I might run into.

Thanks,

James

--
Dave Scott