[Xen-devel] [RFC 0/2] Cap SMMU s2 input-size based on p2m tables

["Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxx>]

From: "Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxxx>

Hi,

This is a first try at fixing the issue I'm seeing on ZynqMP with
missmatched setup of the SMMU and the shared page-tables with p2m.

I've only handled the case of having an SMMU that supports larger
s2 input-sizes than what p2m wants to use.

To support the case were the system has SMMUs that can only do smaller
input-sizes than the CPU, I think we will need to walk the device-tree
when creating domains and somehow cap the p2m IPA size to the largest
supported S2 size across the SMMUs used by that particular domain.
The max IPA size may need to be domain specific.
I did not implement this but I did make the max size domain specific.
Julien, you mentioned you might have access to such a system?

Does this look reasonable or should we be fixing this some other way?
I could make the patch simpler I guess by having a global (not
domain specific) max value set once aswell.

Comments?

Best regards,
Edgar

Edgar E. Iglesias (2):
  xen/arm: Save and expose the p2m IPA address size
  xen/iommu: smmu: Use the p2m IPA size as S2 input-size

 xen/arch/arm/p2m.c                 |  7 ++++++-
 xen/drivers/passthrough/arm/smmu.c | 17 +++++++++++++++--
 xen/include/asm-arm/p2m.h          |  3 +++
 3 files changed, 24 insertions(+), 3 deletions(-)

-- 
1.9.1


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