Re: Question about mapping between domains

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-07-17 at 10:43 +0300, Oleksandr Dmytryshyn wrote:
> Hi, Ian. Thank You for tips.
> 
> On Mon, Jul 13, 2015 at 12:04 PM, Ian Campbell <ian.campbell@citrix.com> wrote:
> > There is an additional quirk for a 1:1 mapped dom0 which is that we
> > don't actually decrease reservation when ballooning, but keep the 1:1
> > mfn in anticipation of ballooning it back in later.
> Currently we have this quirk enabled in DomD (driver domain)
> 
> > If you can't arrange to use already ballooned buffers for your DMA
> > buffer then you will need to manually balloon it out before and balloon
> > it back in later.
> I've tried this and all is working (I can map and then unmap memory in both
> directions DomU -> DomD, DomD -> DomU)
> 
> > You may also want to extend the dom0 1:1 quirk described above to your
> > 1:1 mapped domD.
> Currently this quirk is enabled in DomD. In this case I can map memory from
> DomU to DomD (as it done in all PV drivers). But is this quirk is

                                                   ^if?

> enabled in DomU, I can also map memory from DomD to DomU.

Does this mean everything is working as you need, or is there a further
issue which needs addressing?

Ian.