Re: [XenPPC] Re: consolidated xencomm

[Hollis Blanchard <hollisb@us.ibm.com>]

On Thu, 2006-11-16 at 15:52 -0600, Hollis Blanchard wrote:
> 
> The patch I cited earlier today is a bug fix that applies to PowerPC
> as well, but the code is not shared, and the patch did not fix both
> architectures.

First let me apologize for getting annoyed. I was wrong on a couple
fronts:
- Yamahata-san has in fact patched PowerPC's usercopy.c to fix bugs
along with IA64.
- This particular patch was not needed on PowerPC at all.

Also, I didn't realize Tristan was leaving Bull, so I can understand the
motivation to check something in short-term and sort it out later.

This patch was a surprise to me because I hadn't realized that IA64 had
in fact forked xencomm, and I did a fair amount of work in the PPC tree
to support IA64 and never got feedback on it. (That must have been about
the time Tristan left.) Here is my original mail on the subject.
(Strangely I can't find it in the xen-ia64-devel archives.)

> Subject: xencomm porting and "inline" handles
> From: Hollis Blanchard <hollisb@us.ibm.com>
> To: Tristan Gingold <Tristan.Gingold@bull.net>
> Cc: xen-ia64-devel <xen-ia64-devel@lists.xensource.com>
> Message-Id: <1158086273.14752.53.camel@basalt.austin.ibm.com>
> Date: Tue, 12 Sep 2006 13:37:54 -0500
[snip]
> The Xen changes are committed to xenppc-unstable.hg . In Xen,
> architectures need to provide:
> - XENCOMM_INLINE_FLAG in arch-foo.h
> - paddr_to_maddr(). I'm open to alternative names, but a standard
> function seems useful outside xencomm. (I wish we had one for Linux.)
> - asm/guest_access.h that just #includes xen/xencomm.h
> 
> Once you have IA64-specific implementations for the above, I will
> submit the whole thing to xen-devel. (Note that Linux doesn't actually
> have to use it right now; it won't break anything.)
> 
> The Linux are committed to linux-ppc-2.6.hg . I think for Linux
> architectures just need to supply:
> - XENCOMM_INLINE_FLAG in arch-foo.h
> - xencomm_vtop()
[snip]

This work is still present in
http://xenbits.xensource.com/ext/xenppc-unstable.hg , and I would
appreciate comments about getting this code shared.

-- 
Hollis Blanchard
IBM Linux Technology Center