Re: Implementing IOMMU support for SDHCI

[Peter Maydell]

On Wed, 26 Feb 2020 at 12:38, Sai Pavan Boddu <address@hidden> wrote:
>
> Hi Poalo/Peter,
>
> We are trying to add SMMU support for dma's used in SD controller on ZynqMP 
> boards. In order to do that we need a clean way to assign MemTxAttrs to each 
> device(i.e all devices which connect to smmu) via "object_add_link_property/ 
> object_set_link_property "  functions.
>
> But in order to do that, first we may need to convert MemTxAttrs as QOM 
> object. I just need some feedback, if its advisable to do so ?

We create and throw around MemTxAttrs structs a lot, I don't think they're
suitable to be QOM objects. I don't think you need it, anyway -- your
problem is rather that the iommu doesn't get an opportunity to sit in
the middle of transactions the way you'd like it to, and making
MemTxAttrs a QOM object doesn't help address that.

thanks
-- PMM