Re: [RFC PATCH 0/2] iommu/s390: Fix iommu-groups and add sysfs support

[Gerald Schaefer <gerald.schaefer@de.ibm.com>]

On Thu, 27 Apr 2017 17:28:23 +0200
Joerg Roedel <joro@8bytes.org> wrote:

> Hey,
> 
> here are two patches for the s390 PCI and IOMMU code. It is
> based on the assumption that every pci_dev that points to
> the same zpci_dev shares a single dma-table (and thus a
> single address space).

Well, there is a separate zpci_dev for each pci_dev on s390,
and each of those has its own separate dma-table (thus not shared).

> 
> If this assupmtion is true (as it looks to me from reading
> the code) then the iommu-group setup code in the s390 iommu
> driver needs to be updated.

Given this "separate zpci_dev for each pci_dev" situation, I don't
see what this update actually changes, compared to the previous code,
see also my comments to that patch.

> 
> These patches do this and also add support for the
> iommu_device_register interface to the s390 iommu driver.
> 
> Any comments and testing appreciated.
> 
> Thanks,
> 
> 	Joerg
> 
> Joerg Roedel (2):
>   iommu/s390: Fix IOMMU groups
>   iommu/s390: Add support for iommu_device handling
> 
>  arch/s390/include/asm/pci.h |  8 +++++
>  arch/s390/pci/pci.c         | 10 ++++++-
>  drivers/iommu/s390-iommu.c  | 71 ++++++++++++++++++++++++++++++++++++++-------
>  3 files changed, 78 insertions(+), 11 deletions(-)
>