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Subject: Re: [PATCH V1 4/6] dt-bindings: Add xen, dev-domid property
 description for xen-grant DMA ops
To:     Stefano Stabellini <sstabellini@kernel.org>
Cc:     xen-devel@lists.xenproject.org,
        virtualization@lists.linux-foundation.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
        Jason Wang <jasowang@redhat.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzk+dt@kernel.org>,
        Julien Grall <julien@xen.org>, Juergen Gross <jgross@suse.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Christoph Hellwig <hch@infradead.org>
References: <1650646263-22047-1-git-send-email-olekstysh@gmail.com>
 <1650646263-22047-5-git-send-email-olekstysh@gmail.com>
 <alpine.DEB.2.22.394.2204221527500.915916@ubuntu-linux-20-04-desktop>
From:   Oleksandr <olekstysh@gmail.com>
Message-ID: <638a5b09-ce9e-ab7e-0a5e-d81afe851cc1@gmail.com>
Date:   Sat, 23 Apr 2022 17:37:55 +0300
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On 23.04.22 02:00, Stefano Stabellini wrote:

Hello Stefano

> On Fri, 22 Apr 2022, Oleksandr Tyshchenko wrote:
>> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>>
>> Introduce Xen specific binding for the virtualized device (e.g. virtio)
>> to be used by Xen grant DMA-mapping layer in the subsequent commit.
>>
>> This binding indicates that Xen grant mappings scheme needs to be
>> enabled for the device which DT node contains that property and specifies
>> the ID of Xen domain where the corresponding backend resides. The ID
>> (domid) is used as an argument to the grant mapping APIs.
>>
>> This is needed for the option to restrict memory access using Xen grant
>> mappings to work which primary goal is to enable using virtio devices
>> in Xen guests.
>>
>> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> Looks OK to me. Just a couple of grammar improvements below. Aside from
> those, I have no further comments.

thank you, I agree with proposed comments, will update


>
>
>> ---
>> Changes RFC -> V1:
>>     - update commit subject/description and text in description
>>     - move to devicetree/bindings/arm/
>> ---
>>   .../devicetree/bindings/arm/xen,dev-domid.yaml     | 37 ++++++++++++++++++++++
>>   1 file changed, 37 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/arm/xen,dev-domid.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/arm/xen,dev-domid.yaml b/Documentation/devicetree/bindings/arm/xen,dev-domid.yaml
>> new file mode 100644
>> index 00000000..ef0f747
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/xen,dev-domid.yaml
>> @@ -0,0 +1,37 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/arm/xen,dev-domid.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Xen specific binding for the virtualized device (e.g. virtio)
> NIT: Xen specific binding for virtualized devices (e.g. virtio)
>
>
>> +maintainers:
>> +  - Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>> +
>> +select: true
>> +
>> +description:
>> +  This binding indicates that Xen grant mappings scheme needs to be enabled
>> +  for that device and specifies the ID of Xen domain where the corresponding
>> +  device (backend) resides. This is needed for the option to restrict memory
>> +  access using Xen grant mappings to work.
> NIT:
>
> This binding indicates that Xen grant mappings need to be enabled for
> the device, and it specifies the ID of the domain where the
> corresponding device (backend) resides. The property is required to
> restrict memory access using Xen grant mappings.
>
>
>> +properties:
>> +  xen,dev-domid:
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    description:
>> +      The domid (domain ID) of the domain where the device (backend) is running.
>> +
>> +additionalProperties: true
>> +
>> +examples:
>> +  - |
>> +    virtio_block@3000 {
>> +            compatible = "virtio,mmio";
>> +            reg = <0x3000 0x100>;
>> +            interrupts = <41>;
>> +
>> +            /* The device is located in Xen domain with ID 1 */
>> +            xen,dev-domid = <1>;
>> +    };

-- 
Regards,

Oleksandr Tyshchenko