Re: upstream merge status for 2.6.35, .36?

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

On Mon, Jun 07, 2010 at 07:12:18PM +0200, Josip Rodin wrote:
> On Mon, Jun 07, 2010 at 10:57:43AM -0400, Konrad Rzeszutek Wilk wrote:
> > > so the end-result should be bulletproof (as much as it can be :).
> > 
> > There are some outstanding issues that we know of. I hadn't yet gotten
> > my head around them, but here is a list of Xen PCI frontend bugs:
> > 
> > 1). Pass in 4GB or more to DomU. All the memory that the guest sees are
> > RAM and there are no "holes" for the PCI devices, akin to what you have
> > on a normal machine (the hole is 256MB and it shifts 256MB of RAM above
> > the 4GB - we don't do that yet in DomU). Workaround: use less memory, or
> > some magic Linux kernel parameter (memhole?) to create a hole.
> 
> Does this just mean you can't have PCI frontend in those domUs?

Yes you can, except you are limited to 4GB for each guest.

> IOW it may be a regression compared to Xen .18, but not compared to what's
> in mainline at the moment?

The issue is that Linux 2.6.18 had a different system for resources structs,
which in .31 changed. It is not a Xen specific issue, but rather how the Linux
kernel sets up resources structures from the E820 map.