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

[Oleksandr <olekstysh@xxxxxxxxx>]

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@xxxxxxxx>
> >
> > 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@xxxxxxxx>
> 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@xxxxxxxxx/
> With the patch added to the series it depends on: Reviewed-by: Anthony PERARD 
> <anthony.perard@xxxxxxxxxx>
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@xxxxxxxxx/


> Thanks,
--
Regards,

Oleksandr Tyshchenko