Re: [PATCH 2/3] xen/virtio: use dom0 as default backend for CONFIG_XEN_VIRTIO_FORCE_GRANT

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 6 Oct 2022, Oleksandr Tyshchenko wrote:
> On 06.10.22 10:14, Juergen Gross wrote:
> 
> Hello Juergen
> 
> > With CONFIG_XEN_VIRTIO_FORCE_GRANT set the default backend domid to 0,
> > enabling to use xen_grant_dma_ops for those devices.
> >
> > Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> > ---
> >   drivers/xen/grant-dma-ops.c | 3 +++
> >   1 file changed, 3 insertions(+)
> 
> 
> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> > diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
> > index f29759d5301f..a00112235877 100644
> > --- a/drivers/xen/grant-dma-ops.c
> > +++ b/drivers/xen/grant-dma-ops.c
> > @@ -349,6 +349,9 @@ void xen_grant_setup_dma_ops(struct device *dev)
> >     if (dev->of_node) {
> >             if (xen_dt_grant_setup_dma_ops(dev, data))
> >                     goto err;
> > +   } else if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) {
> > +           dev_info(dev, "Using dom0 as backend\n");
> > +           data->backend_domid = 0;
> >     } else {
> >             /* XXX ACPI device unsupported for now */
> >             goto err;
> 
> -- 
> Regards,
> 
> Oleksandr Tyshchenko
>