Re: 3GB memory restriction for pv domU with PCI

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

On Wed, Oct 13, 2010 at 05:10:32PM -0700, Bruce Edge wrote:
> On Fri, Jun 11, 2010 at 9:42 AM, Konrad Rzeszutek Wilk
> <konrad.wilk@oracle.com> wrote:
> > On Fri, Jun 11, 2010 at 08:54:05AM -0700, Bruce Edge wrote:
> >> On Fri, Jun 11, 2010 at 6:38 AM, Konrad Rzeszutek Wilk
> >> <konrad.wilk@oracle.com> wrote:
> >> > On Fri, Jun 11, 2010 at 09:09:36AM +0300, Pasi Kärkkäinen wrote:
> >> >> On Thu, Jun 10, 2010 at 04:25:54PM -0700, Bruce Edge wrote:
> >>
> >> >> > Here's the domU boot log:
> >>
> >> >> >         memory       = 4096
> >> >
> >> > And also there is a bug where we can't do PCI in PV guests when guest
> >> > has more than 3GB.
> >> >
> >>
> >> Is there any expectation that this 3GB restriction will be resolved in
> >> the short term ?
> >
> > What is "short-term" ? This week = no. This month = likely.
> 
> It looks like this is still a restriction. Is there any plan to allow
> pvops domU's to use more than 4GB ?

Jeremy wrote up some new shinny code where the memory can be fragmented
(so that we can now stick in a big PCI hole). His patches are in
xen/balloon. But I haven't taken those and fiddled with them and changed
the toolstack (xm or xl) to actually take advantage of this.

> 
> How much and who do we have to pay to get it in sooner?
> If this ends up being our only show stopper for pvops, I'll start
> selling lab equipment out the back door to pay for it. :-)

Sheeshh. you are missing the mark. Instead of selling the lab equipment
you _send_ the equipment - that is like a X-mas present for geeks: shiny
new toy! :-)

But jokes aside, I haven't touched this since this last email. And I am
not going to get to it this week nor the next. Then there is one week
where (25th->29th) where I can play with this. After that, Linux Kernel
Summit and the Linux Plumbers Conference is in - so it will be quiet.

If this is a show-stopper right now, you could come with a hack where
the resource check is just ignored.