Re: [00/15] swiotlb cleanup

[Ian Campbell <Ian.Campbell@eu.citrix.com>]

On Mon, 2009-07-13 at 18:53 +0900, FUJITA Tomonori wrote:
> On Mon, 13 Jul 2009 10:40:29 +0100
> Ian Campbell <Ian.Campbell@eu.citrix.com> wrote:
> 
> > On Mon, 2009-07-13 at 05:20 +0100, FUJITA Tomonori wrote:
> > > On Fri, 10 Jul 2009 15:02:00 +0100
> > > Ian Campbell <Ian.Campbell@citrix.com> wrote:
> > > 
> > > > On Fri, 2009-07-10 at 14:35 +0900, FUJITA Tomonori wrote:
> > > > > I don't think that we need to take account of dom0 support; we don't
> > > > > have a clear idea about an acceptable dom0 design (it needs to use
> > > > > swiotlb code? I don't know yet), we don't even know we will have dom0
> > > > > support in mainline. That's why I didn't CC this patchset to Xen
> > > > > camp.
> > > > 
> > > > The core domain 0 patches which were the subject of the discussions a
> > > > few week back are completely orthogonal to the swiotlb side of things
> > > 
> > > ? If we don't merge dom0 patch, we don't need dom0 changes to
> > > swiotlb. We don't know we would have dom0 support in mainline. Or I
> > > overlooked something?
> > [...]
> > > As far as I know, you have not posted anything about changes to
> > > swiotlb for domU. I can't discuss it. If you want, please send
> > > patches.
> > 
> > There are no separate domU swiotlb patches -- the exact the same patches
> > as we have already been discussing are useful and necessary for both
> > domU and dom0.
> 
> Hmm, you guys introduced the swiotlb hooks by saying that it's for
> only dom0.

That was just sloppy wording on our part. domain 0 is the major usecase
today so there is a tendency to think in those terms but the changes are
actually relevant to any domain with access to a physical device that
can do DMA, this includes domU via PCI passthrough.

> I don't see any comments like 'this is useful to dom0 too'. I'm still
                                                      ^U?
> not sure what exactly part is useful to domU.

All of it...

Ian.