Re: XEN ARM dt passthrough

[Julien Grall <julien@xxxxxxx>]

On 21/02/2023 09:43, Peter van der Perk wrote:
> Hi,
Hello,

> I'm trying to follow this guide to passthrough a device tree device.
> https://xenbits.xen.org/docs/unstable/misc/arm/passthrough.txt
>
> The device doesn't have an IOMMU thus I've enabled
> xen,force-assign-without-iommu
> In the guest dts but when I create the VM I get the following message.
The property xen,force-assign-without-iommu is to be used for dom0less 
domain. When a domain is created by xl...
> user@imx8mpnavq:~/guest$ sudo xl create domU_test
> Parsing config from domU_test
> libxl: error: libxl_create.c:1135:libxl__domain_config_setdefault: passthrough 
> not supported on this platform
... you want to avoid specifying "dtdev" in the configuration file.

Note that this device passthrough without an IOMMU only work with the 
device is not DMA-capable.
If it is DMA-capable, then you will need to direct-map the domain and 
there will no isolation.
Cheers,

--
Julien Grall