Re: [Qemu-devel] [PATCH v11 04/28] x86-iommu: q35: generalize find_add_as()

[Peter Xu <peterx@redhat.com>]

On Sat, Jul 09, 2016 at 10:14:48AM +0200, Jan Kiszka wrote:
> On 2016-07-05 10:19, Peter Xu wrote:
> > Remove VT-d calls in common q35 codes. Instead, we provide a general
> > find_add_as() for x86-iommu type.
> > 
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> >  hw/i386/intel_iommu.c         | 15 ++++++++-------
> >  include/hw/i386/intel_iommu.h |  5 -----
> >  include/hw/i386/x86-iommu.h   |  3 +++
> >  3 files changed, 11 insertions(+), 12 deletions(-)
> 
> You claim to remove something from "common q35 code", but I don't see
> changes to it. Instead, the patch introduces a method that seems to
> remain unused outside the implementing class (I just grep'ed your tree).
> Anything missing?

Right. The commit message lost its point after I did the rebase to
Marcel's "-device intel_iommu" patches... Thanks for pointing it out.

Before the rebase, there is one q35_host_dma_iommu() in pc_q35.c, and
originally this patch did remove something from q35. While in Marcel's
commit (621d983a1f), q35_host_dma_iommu() is renamed to
vtd_host_dma_iommu(), and it's put inside intel_iommu.c. After that,
this commit message stopped making sense.

So I think at least the commit message of this patch could be fixed
into something like:

   "Introduce common find_add_as() interface for x86-iommu."

And if I now see this... A better solution is to provide a more common
interface directly in x86-iommu.c to find address spaces, and let
Intel/AMD IOMMUs share this functionality. After all, we are doing
merely the same thing to maintain namespaces in both Intel/AMD IOMMUs
(vtd_find_add_as() and bridge_host_amdvi()). So, do you (and mst?)
think I should respin to a v12, or we can first fix commit message of
this patch, then I post another patch basd on this series for a better
cleanup?

Thanks,

-- peterx