From: Oleksandr <olekstysh@gmail.com>
To: Rob Herring <robh@kernel.org>, Arnd Bergmann <arnd@arndb.de>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
"open list:DRM DRIVER FOR QEMU'S CIRRUS DEVICE"
<virtualization@lists.linux-foundation.org>,
DTML <devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
Jason Wang <jasowang@redhat.com>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Julien Grall <julien@xen.org>, Juergen Gross <jgross@suse.com>,
Stefano Stabellini <sstabellini@kernel.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Christoph Hellwig <hch@infradead.org>,
Jean-Philippe Brucker <jean-philippe@linaro.org>
Subject: Re: [PATCH V2 5/7] dt-bindings: Add xen,dev-domid property description for xen-grant DMA ops
Date: Thu, 19 May 2022 02:48:31 +0300 [thread overview]
Message-ID: <40758f3b-cab3-2096-1711-18837bc2f73b@gmail.com> (raw)
In-Reply-To: <20220518185904.GA3685644-robh@kernel.org>
On 18.05.22 21:59, Rob Herring wrote:
Hello Rob, Arnd
> On Wed, May 18, 2022 at 03:32:27PM +0100, Arnd Bergmann wrote:
>> On Sat, May 7, 2022 at 7:19 PM Oleksandr Tyshchenko <olekstysh@gmail.com> wrote:
>>> 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
>>> +
>>> required:
>>> - compatible
>>> - reg
>> Sorry for joining the discussion late. Have you considered using the
>> generic iommu
>> binding here instead of a custom property? This would mean having a device
>> node for the grant-table mechanism that can be referred to using the 'iommus'
>> phandle property, with the domid as an additional argument.
>>
>> It does not quite fit the model that Linux currently uses for iommus,
>> as that has an allocator for dma_addr_t space, but it would think it's
>> conceptually close enough that it makes sense for the binding.
> Something common is almost always better.
agree
>
> That may also have the issue that fw_devlink will make the 'iommu'
> driver a dependency to probe.
Looks like I ran into it while experimenting. I generated the following
nodes in guest DT using Xen toolstack:
[snip]
xen_dummy_iommu {
compatible = "xen,dummy-iommu";
#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>;
};
[snip]
And got:
virtio-mmio 2000000.virtio: deferred probe timeout, ignoring dependency
>
> Rob
--
Regards,
Oleksandr Tyshchenko
next prev parent reply other threads:[~2022-05-18 23:48 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-07 18:19 [PATCH V2 0/7] virtio: Solution to restrict memory access under Xen using xen-grant DMA-mapping layer Oleksandr Tyshchenko
2022-05-07 18:19 ` [PATCH V2 1/7] arm/xen: Introduce xen_setup_dma_ops() Oleksandr Tyshchenko
2022-05-07 18:52 ` Catalin Marinas
2022-05-07 18:19 ` [PATCH V2 2/7] xen/grants: support allocating consecutive grants Oleksandr Tyshchenko
2022-05-11 18:00 ` Oleksandr
2022-05-11 21:09 ` Boris Ostrovsky
2022-05-12 6:11 ` Oleksandr
2022-05-12 20:01 ` Boris Ostrovsky
2022-05-13 5:33 ` Juergen Gross
2022-05-13 10:43 ` Oleksandr
2022-05-14 2:34 ` Boris Ostrovsky
2022-05-16 5:59 ` Juergen Gross
2022-05-16 16:00 ` Boris Ostrovsky
2022-05-16 18:30 ` Oleksandr
2022-05-16 18:57 ` Boris Ostrovsky
2022-05-07 18:19 ` [PATCH V2 3/7] xen/grant-dma-ops: Add option to restrict memory access under Xen Oleksandr Tyshchenko
2022-05-09 21:39 ` Stefano Stabellini
2022-05-07 18:19 ` [PATCH V2 4/7] xen/virtio: Enable restricted memory access using Xen grant mappings Oleksandr Tyshchenko
2022-05-09 21:39 ` Stefano Stabellini
2022-05-07 18:19 ` [PATCH V2 5/7] dt-bindings: Add xen,dev-domid property description for xen-grant DMA ops Oleksandr Tyshchenko
2022-05-09 21:39 ` [PATCH V2 5/7] dt-bindings: Add xen, dev-domid " Stefano Stabellini
2022-05-17 0:27 ` [PATCH V2 5/7] dt-bindings: Add xen,dev-domid " Rob Herring
2022-05-18 14:12 ` Oleksandr
2022-05-18 14:32 ` Arnd Bergmann
2022-05-18 16:06 ` Oleksandr
2022-05-18 16:39 ` Arnd Bergmann
2022-05-18 23:32 ` Oleksandr
2022-05-19 1:06 ` Stefano Stabellini
2022-05-19 6:03 ` Oleksandr
2022-05-23 17:30 ` Oleksandr
2022-05-24 1:58 ` Stefano Stabellini
2022-05-24 16:01 ` Rob Herring
2022-05-24 18:34 ` Saravana Kannan
2022-05-25 16:30 ` Oleksandr
2022-05-24 16:11 ` Oleksandr
2022-05-24 17:59 ` Stefano Stabellini
2022-05-25 11:15 ` Oleksandr
2022-05-18 18:59 ` Rob Herring
2022-05-18 23:48 ` Oleksandr [this message]
2022-05-07 18:19 ` [PATCH V2 6/7] xen/grant-dma-ops: Retrieve the ID of backend's domain for DT devices Oleksandr Tyshchenko
2022-05-09 21:39 ` Stefano Stabellini
2022-05-07 18:19 ` [PATCH V2 7/7] arm/xen: Assign xen-grant DMA ops for xen-grant DMA devices Oleksandr Tyshchenko
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