Re: [PATCH V2] libxl/arm: Create specific IOMMU node to be referred by virtio-mmio device

[Oleksandr <olekstysh@gmail.com>]

On 10.06.22 19:21, Anthony PERARD wrote:

Hello Anthony

> On Tue, May 31, 2022 at 12:06:53AM +0300, Oleksandr Tyshchenko wrote:
>> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>>
>> Reuse generic IOMMU device tree bindings to communicate Xen specific
>> information for the virtio devices for which the restricted memory
>> access using Xen grant mappings need to be enabled.
>>
>> Insert "iommus" property pointed to the IOMMU node with "xen,grant-dma"
>> compatible to all virtio devices which backends are going to run in
>> non-hardware domains (which are non-trusted by default).
>>
>> Based on device-tree binding from Linux:
>> Documentation/devicetree/bindings/iommu/xen,grant-dma.yaml
>>
>> The example of generated nodes:
>>
>> xen_iommu {
>>      compatible = "xen,grant-dma";
>>      #iommu-cells = <0x01>;
>>      phandle = <0xfde9>;
>> };
>>
>> virtio@2000000 {
>>      compatible = "virtio,mmio";
>>      reg = <0x00 0x2000000 0x00 0x200>;
>>      interrupts = <0x00 0x01 0xf01>;
>>      interrupt-parent = <0xfde8>;
>>      dma-coherent;
>>      iommus = <0xfde9 0x01>;
>> };
>>
>> virtio@2000200 {
>>      compatible = "virtio,mmio";
>>      reg = <0x00 0x2000200 0x00 0x200>;
>>      interrupts = <0x00 0x02 0xf01>;
>>      interrupt-parent = <0xfde8>;
>>      dma-coherent;
>>      iommus = <0xfde9 0x01>;
>> };
>>
>> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> The patch looks fine.
>
>> ---
>> !!! This patch is based on non upstreamed yet “Virtio support for toolstack
>> on Arm” V8 series which is on review now:
>> https://lore.kernel.org/xen-devel/1651598763-12162-1-git-send-email-olekstysh@gmail.com/
> With the patch added to the series it depends on: Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

Thanks!


I will send V3 anyway (there is a comment from Julien here). But I will 
send it together with the related series:

https://lore.kernel.org/xen-devel/1654106261-28044-1-git-send-email-olekstysh@gmail.com/


>
> Thanks,
>
-- 
Regards,

Oleksandr Tyshchenko