Messages in this thread |  | | | Date | Mon, 19 May 2008 15:32:10 +0900 | | Subject | Re: [PATCH 0/2] x86: per-device dma_mapping_ops | | From | FUJITA Tomonori <> | |
On Fri, 16 May 2008 07:24:33 +0200
Andi Kleen <andi@firstfloor.org> wrote:
> FUJITA Tomonori wrote:
> > On Thu, 15 May 2008 12:48:04 +0200
> > Andi Kleen <andi@firstfloor.org> wrote:
> >
> >>> I thought that KVM people want to do it per device (in the first
> >>> case). So with my patchse, they can replace the dma_ops pointer in
> >>> dev_archdata with what they want.
> >> But where would they save the original pointer?
> >
> > Yeah, we need an extra mechanism for that but it's same for the
> > system-wide dma_ops pointer (i.e. without my patches), isn't it?
> >
> > I'm still not sure how this patchset make it impossible to have stack
> > dma_ops. These people need per-device dma_ops and we can do stack
> > per-device dma_ops?
>
> Anybody who does stack ops in your scheme would need to hook into new
> device creation and an own per device saving pointer. Also there
> are livetime issues when to wrap.
But is that what those people want, setting up dma_ops per device?
I think that creating a hook is not difficult and we could put a
mechnism to save a pointer in asm-x86/{dma-mapping.h, device.h}.
> It's certainly possible, but likely complicated
Hmm, let's see what those people think about on this. I'll repost a
patchset for -mm with CC'ing those people.
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