Re: tmem docs

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, May 28, 2013 at 09:20:28AM -0700, Dan Magenheimer wrote:
> > From: Konrad Rzeszutek Wilk
> > Subject: Re: [Xen-devel] tmem docs
> > 
> > On Tue, May 28, 2013 at 12:26:15AM +0000, James Harper wrote:
> > > > On Mon, May 27, 2013 at 09:14:09AM +0000, James Harper wrote:
> > > > > Where is the best place to read about tmem hypercall abi? Should I start
> > > > > with the Linux implementation?
> > > >
> > > > I'm not really answering your question here.. but if you didn't see these links,
> > > > take a look, they might help:
> > > > http://lists.xen.org/archives/html/xen-devel/2013-05/msg01892.html
> > >
> > > That all tells me about how great tmem is, and some of the interfaces exposed by Linux, but I can't
> > find anything about the interfaces exposed by Xen that Windows would need to use. It seems that the
> > interface is fairly thin though, and I have a few Windows related problems to solve first before I can
> > even think about making use of tmem.
> > 
> > Let's CC Dan here. He has a stash of documents on that.
> > 
> > But looking at the include/public/tmem.h it is very slim on comments. The ones
> > that are of interest to you (I think) are:
> > 
> > TMEM_DESTROY_POOL, TMEM_NEW_POOL, TMEM_PUT_PAGE, and TMEM_GET_PAGE.
> > 
> > > Thanks
> > > James
> 
> Hi James --
> 
> I'll be working for a few more weeks and would be happy
> to answer any questions I can.  However, I am no longer on the
> xen-devel email list so you will need to cc me directly.
> 
> I'm gathering you are trying to connect a Windows kernel to the
> Xen tmem ABI?  There have been various ideas proposed about
> connecting up Linux _userland_ apps to tmem and it may be possible
> to do that for Windows as well.  However, the existing ABI
> is probably best suited for a guest kernel, and I've never
> had access to Windows kernel source so I'm not in a position
> to judge how easy or how hard it would be to modify Windows
> kernel source to adapt it.  KY Srinivasan is currently working
> on cross-guest memory capacity optimization for Linux on HyperV
> and has expressed some interest in tmem for Windows so you
> may want to contact him to see if he's given it any thought.
> (kys@microsoft.com) KY was an early Xen contributor also.
> 
> The tmem ABI spec is here:
> 
> https://oss.oracle.com/projects/tmem/dist/documentation/api/tmemspec-v001.pdf 

Awesome.
> 
> As you can see by the date, that spec version is very old (2008)
> but, on quick scan, it is still 99% accurate.  The main difference
> I see is that (page 2, line 18) object identifiers are now
> 192-bit instead of 64-bit.  See reason for that change here:
> http://lists.xen.org/archives/html/xen-devel/2010-09/msg00069.html 
> 

Is there a source for the spec so I can modify it (And also
put the spec in the Xen codebase).