Messages in this thread | | | Subject | Re: [PATCH V2 5/7] dt-bindings: Add xen,dev-domid property description for xen-grant DMA ops | From | Oleksandr <> | Date | Wed, 18 May 2022 17:12:35 +0300 |
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On 17.05.22 03:27, Rob Herring wrote:
Hello Rob, all
> On Sat, May 07, 2022 at 09:19:06PM +0300, 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> >> --- >> Changes RFC -> V1: >> - update commit subject/description and text in description >> - move to devicetree/bindings/arm/ >> >> Changes V1 -> V2: >> - update text in description >> - change the maintainer of the binding >> - fix validation issue >> - reference xen,dev-domid.yaml schema from virtio/mmio.yaml >> --- >> .../devicetree/bindings/arm/xen,dev-domid.yaml | 37 ++++++++++++++++++++++ >> Documentation/devicetree/bindings/virtio/mmio.yaml | 7 ++++ >> 2 files changed, 44 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..750e89e >> --- /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 virtualized devices (e.g. virtio) >> + >> +maintainers: >> + - Stefano Stabellini <sstabellini@kernel.org> >> + >> +select: true > Omit. No need to apply this on every single node.
ok, will do
> >> + >> +description: >> + 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: > I kind of think 'dev' is redundant. Is there another kind of domid > possible?
In general, yes. It is driver(frontend) domid. But, at least for now, I don't see why we will need an additional property for that.
> Maybe xen,backend-domid or just xen,domid? I don't know Xen > too well, so ultimately up to you all.
xen,domid sounds ambiguous to me.
xen,backend-domid sounds perfectly fine to me, I even think it fits better.
Stefano, Juergen, would you be happy with new xen,backend-domid name?
If yes, Stefano could you please clarify, would you be OK if I retained your R-b tags (for all patches in current series which touch that property) after doing such renaming?
> >> + $ref: /schemas/types.yaml#/definitions/uint32 >> + description: >> + The domid (domain ID) of the domain where the device (backend) is running. >> + >> +additionalProperties: true >> + >> +examples: >> + - | >> + virtio@3000 { >> + compatible = "virtio,mmio"; >> + reg = <0x3000 0x100>; >> + interrupts = <41>; >> + >> + /* The device is located in Xen domain with ID 1 */ >> + xen,dev-domid = <1>; >> + }; >> diff --git a/Documentation/devicetree/bindings/virtio/mmio.yaml b/Documentation/devicetree/bindings/virtio/mmio.yaml >> index 10c22b5..29a0932 100644 >> --- a/Documentation/devicetree/bindings/virtio/mmio.yaml >> +++ b/Documentation/devicetree/bindings/virtio/mmio.yaml >> @@ -13,6 +13,9 @@ description: >> See https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=virtio for >> more details. >> >> +allOf: >> + - $ref: /schemas/arm/xen,dev-domid.yaml# >> + >> properties: >> compatible: >> const: virtio,mmio >> @@ -33,6 +36,10 @@ properties: >> description: Required for devices making accesses thru an IOMMU. >> maxItems: 1 >> >> + xen,dev-domid: >> + description: Required when Xen grant mappings need to be enabled for device. >> + $ref: /schemas/types.yaml#/definitions/uint32 > No need to define the type again nor describe it again. > > Instead, just change additionalProperties to unevaluateProperties in > this doc. The diff is the latter takes $ref's into account.
ok, will do. Could you please clarify, shall I use?
unevaluatedProperties: false
or
unevaluatedProperties:
type: object
I am not too familiar with this stuff. Both variants seem to pass validation.
Thank you.
> >> + >> required: >> - compatible >> - reg >> -- >> 2.7.4 >> >> -- Regards,
Oleksandr Tyshchenko
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