Re: [PATCH v3 0/5] Clean up VMD DMA Map Ops

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Mon, Jan 13, 2020 at 12:01:13PM -0600, Bjorn Helgaas wrote:
> On Mon, Jan 13, 2020 at 05:13:38PM +0000, Derrick, Jonathan wrote:
> > On Mon, 2020-01-13 at 12:08 +0000, Lorenzo Pieralisi wrote:
> > > On Fri, Jan 10, 2020 at 10:21:08AM -0700, Jon Derrick wrote:
> > > > v2 Set: https://lore.kernel.org/linux-iommu/1578580256-3483-1-git-send-email-jonathan.derrick@intel.com/T/#t
> > > > v1 Set: https://lore.kernel.org/linux-iommu/20200107134125.GD30750@8bytes.org/T/#t
> > > > 
> > > > VMD currently works with VT-d enabled by pointing DMA and IOMMU actions at the
> > > > VMD endpoint. The problem with this approach is that the VMD endpoint's
> > > > device-specific attributes, such as the DMA Mask Bits, are used instead.
> > > > 
> > > > This set cleans up VMD by removing the override that redirects DMA map
> > > > operations to the VMD endpoint. Instead it introduces a new DMA alias mechanism
> > > > into the existing DMA alias infrastructure.
> > > > 
> > > > v1 added a pointer in struct pci_dev that pointed to the DMA alias' struct
> > > > pci_dev and did the necessary DMA alias and IOMMU modifications.
> > > > 
> > > > v2 introduced a new weak function to reference the 'Direct DMA Alias', and
> > > > removed the need to add a pointer in struct device or pci_dev. Weak functions
> > > > are generally frowned upon when it's a single architecture implementation, so I
> > > > am open to alternatives.
> > > > 
> > > > v3 references the pci_dev rather than the struct device for the PCI
> > > > 'Direct DMA Alias' (pci_direct_dma_alias()). This revision also allows
> > > > pci_for_each_dma_alias() to call any DMA aliases for the Direct DMA alias
> > > > device, though I don't expect the VMD endpoint to need intra-bus DMA aliases.
> > > > 
> > > > Changes from v2:
> > > > Uses struct pci_dev for PCI Device 'Direct DMA aliasing' (pci_direct_dma_alias)
> > > > Allows pci_for_each_dma_alias to iterate over the alias mask of the 'Direct DMA alias'
> > > > 
> > > > Changes from v1:
> > > > Removed 1/5 & 2/5 misc fix patches that were merged
> > > > Uses Christoph's staging/cleanup patches
> > > > Introduce weak function rather than including pointer in struct device or pci_dev.
> > > > 
> > > > Based on Joerg's next:
> > > > https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git/
> > > > 
> > > > Jon Derrick (5):
> > > >   x86/pci: Add a to_pci_sysdata helper
> > > >   x86/PCI: Expose VMD's PCI Device in pci_sysdata
> > > >   PCI: Introduce pci_direct_dma_alias()
> > > >   PCI: vmd: Stop overriding dma_map_ops
> > > >   x86/pci: Remove X86_DEV_DMA_OPS
> > > > 
> > > >  arch/x86/Kconfig               |   3 -
> > > >  arch/x86/include/asm/device.h  |  10 ---
> > > >  arch/x86/include/asm/pci.h     |  31 ++++-----
> > > >  arch/x86/pci/common.c          |  45 ++----------
> > > >  drivers/iommu/intel-iommu.c    |  18 +++--
> > > >  drivers/pci/controller/Kconfig |   1 -
> > > >  drivers/pci/controller/vmd.c   | 152 +----------------------------------------
> > > >  drivers/pci/pci.c              |  19 +++++-
> > > >  drivers/pci/search.c           |   7 ++
> > > >  include/linux/pci.h            |   1 +
> > > >  10 files changed, 61 insertions(+), 226 deletions(-)
> > > 
> > > Jon, Christoph,
> > > 
> > > AFAICS this series supersedes/overrides:
> > > 
> > > https://patchwork.kernel.org/patch/11114831/
> > > 
> > > Please let me know if that's correct, actually I was waiting to
> > > see consensus on the patch above but if this series supersedes
> > > it I would drop it from the PCI review queue.
> > > 
> > > Thanks,
> > > Lorenzo
> > 
> > It does supercede it (with Christoph's blessing). By the way, I have
> > been basing on Joerg's repo  due to the v1/RFC IOMMU modifcations. As
> > there's more pci work at this point, should I base it on Bjorn's repo
> > instead?
> 
> In general if I'm going to apply something, I prefer it based on my
> "master" branch unless there's a reason to the contrary.  I think
> Lorenzo works pretty much the same way.
> 
> Lorenzo will probably handle this series, but I applied it
> experimentally to check out the brace thing, and it applied fine to my
> "master" branch.  So I think everything's fine as-is.

I think it is mostly x86+core PCI code, VMD code is mostly deletions
so I think you can take it, let me know, I can ACK the VMD changes
straight away.

Thanks,
Lorenzo
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu