> -----Original Message----- > From: Alex Williamson [mailto:alex.william...@redhat.com] > Sent: Wednesday, April 03, 2013 11:32 PM > To: Joerg Roedel > Cc: Sethi Varun-B16395; Yoder Stuart-B08248; Wood Scott-B07421; > iommu@lists.linux-foundation.org; linuxppc-...@lists.ozlabs.org; linux- > ker...@vger.kernel.org; ga...@kernel.crashing.org; > b...@kernel.crashing.org > Subject: Re: [PATCH 5/5 v11] iommu/fsl: Freescale PAMU driver and iommu > implementation. > > On Tue, 2013-04-02 at 18:18 +0200, Joerg Roedel wrote: > > Cc'ing Alex Williamson > > > > Alex, can you please review the iommu-group part of this patch? > > Sure, it looks pretty reasonable. AIUI, all PCI devices are below some > kind of host bridge that is either new and supports partitioning or old > and doesn't. I don't know if that's a visibility or isolation > requirement, perhaps PCI ACS-ish. In the new host bridge case, each > device gets a group. This seems not to have any quirks for multifunction > devices though. On AMD and Intel IOMMUs we test multifunction device ACS > support to determine whether all the functions should be in the same > group. Is there any reason to trust multifunction devices on PAMU? > [Sethi Varun-B16395] In the case where we can partition endpoints we can distinguish transactions based on the bus,device,function number combination. This support is available in the PCIe controller (host bridge).
> I also find it curious what happens to the iommu group of the host > bridge. In the partitionable case the host bridge group is removed, in > the non-partitionable case the host bridge group becomes the group for > the children, removing the host bridge. It's unique to PAMU so far that > these host bridges are even in an iommu group (x86 only adds pci > devices), but I don't see it as necessarily wrong leaving it in either > scenario. Does it solve some problem to remove them from the groups? > Thanks, [Sethi Varun-B16395] The PCIe controller isn't a partitionable entity, it would always be owned by the host. -Varun _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu