Re: Help: Information required for AXI DMA passthrough for PL masters in ZCU102 dev kit

[Julien Grall <julien@xxxxxxx>]

On 26/04/2021 15:41, Prem Harikrishnan wrote:
> Hello everyone,
Hi Prem,

> I am using the latest version of the xilinx mpsoc zcu102 development 
> board and i am trying to create a barematal application that uses the 
> AXI DMA on the programmable logic, using the scatter gather example from 
> the xilinx repository. This works perfectly well for the baremetal 
> application. The diagram below represents the information flow. The AXI 
> DMA and the AXI data FIFO are in the Programable logic (FPGA). This AXI 
> DMA is out of the box IP from Vivado and uses a single channel (Does not 
> use AxUSER) which means the AXI ID cannot manually be set.
>
> Now i want to make this as a baremetal hypervisor guest, in future this 
> will be replaced by a custom IP with cache colouring enabled. I want to 
> pass through the AXI DMA in the PL. (Not to be used by Dom0)
>
> I followed this tutorial Baremetal + DomU 
> <https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842536/XEN+EL1+Baremetal+DomU>  
> guest changed the base address to 0x4000000,(1GB allocated to Dom-0) to 
> create my EL1 binary. I used Petalinux 2020.2 to generate my linux, xen 
> image and use tftp to boot.
>  From what i understand from the xilinx tutorials Xen+and+PL+Masters 
> <https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842066/Xen+and+PL+Masters> 
> section 3 and MPSOC SMMU 
> <https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841981/Zynq+UltraScale+MPSOC+SMMU> 
> section 4, stream ids are required by the SMMU to get the correct 
> address translation.
> I am still unable to figure out how to get the iommu property for my AXI 
> DMA and how to set the dtdev config for my hypervisor guest.
>
> I can also see some new updates with the XEN 2020.1 and 2020.2 releases 
> which i can be useful to my application
>   *   1:1 memory mappings for Xen virtual machines, enabling device
>     assignments without SMMU
>   *
>       Static assignment of PL blocks, including bus-mastering blocks, to
>     Xen virtual machines
>   *   Support for PL Device Passthrough to DomU in Xen
You are usiong a version of Xen that has been customised by Xilinx. So I 
would recommend to contact them directly.
I have CCed Stefano who might be able to help you.

Best regards,

--
Julien Grall