From: "guanghuifeng@linux•alibaba.com" <guanghuifeng@linux•alibaba.com>
To: Jason Gunthorpe <jgg@ziepe•ca>
Cc: boris.brezillon@collabora•com, robh@kernel•org,
steven.price@arm•com, adrian.larumbe@collabora•com,
maarten.lankhorst@linux•intel.com, mripard@kernel•org,
tzimmermann@suse•de, airlied@gmail•com, liviu.dudau@arm•com,
joro@8bytes•org, will@kernel•org, robin.murphy@arm•com,
alex@shazbot•org, dri-devel@lists•freedesktop.org,
linux-kernel@vger•kernel.org, iommu@lists•linux.dev,
kvm@vger•kernel.org, linux-arm-kernel@lists•infradead.org,
kevin.tian@intel•com, baolu.lu@linux•intel.com,
suravee.suthikulpanit@amd•com, dwmw2@infradead•org,
xlpang@linux•alibaba.com, oliver.yang@linux•alibaba.com,
shiyu.zsq@linux•alibaba.com, wei.guo.simon@linux•alibaba.com,
alikernel-developer <alikernel-developer@linux•alibaba.com>
Subject: Re: [PATCH 1/9] iommu: introduce iova_to_phys_length in iommu_domain_ops
Date: Mon, 1 Jun 2026 22:14:27 +0800 [thread overview]
Message-ID: <ff2a4364-8463-42cb-9a2b-fae1ef64c423@linux.alibaba.com> (raw)
In-Reply-To: <20260601134322.GY2487554@ziepe.ca>
在 2026/6/1 21:43, Jason Gunthorpe 写道:
> On Mon, Jun 01, 2026 at 04:41:48PM +0800, guanghuifeng@linux•alibaba.com wrote:
>>>> +/**
>>>> + * iommu_iova_to_phys_length - Translate IOVA and return mapping page size
>>>> + * @domain: IOMMU domain to query
>>>> + * @iova: IO virtual address to translate
>>>> + * @mapped_length: Output parameter for the PTE page size (e.g. 4KB/2MB/1GB)
>>>> + *
>>>> + * Like iommu_iova_to_phys() but additionally returns the page size of the
>>>> + * PTE mapping at @iova through @mapped_length.
>>>> + *
>>>> + * Return: The physical address for the given IOVA, or 0 if no translation.
>>>> + */
>>> When introducing the new function I would like to fix this 0 error as
>>> well, it should return PHYS_MAX for error
>> Implementations such as arm_smmu_iova_to_phys/DOMAIN_NS(iova_to_phys)
>> all use a return value of 0 as an invalid state, so 0 is used as the
>> representation of an invalid state to maintain compatibility.
> I know, but this bad choice has already caused bugs so if we are
> changing everything I would prefer we fix it.
OK, there are a lot of changes in the current commit. This issue will be
fixed in a subsequent series patch.
>>>> +phys_addr_t iommu_iova_to_phys_length(struct iommu_domain *domain,
>>>> + dma_addr_t iova,
>>>> + size_t *mapped_length)
>>>> {
>>>> + if (mapped_length)
>>>> + *mapped_length = 0;
>>>> +
>>>> if (domain->type == IOMMU_DOMAIN_IDENTITY)
>>>> return iova;
>>>> if (domain->type == IOMMU_DOMAIN_BLOCKED)
>>>> return 0;
>>> Any domain that doesn't have an op should fail, blocked is one example
>> In accordance with the implementation of iommu_iova_to_phys, it returns a
>> phy value of 0 in invalid states.
> Detect the invalid states by looking at ops not domain->type
>
>>> I suggest you approach the patch plan a little differently, the first
>>> patches should implement the new function and an iommput
>>> implementation
>>>
>>> Arrange things so the normal iova_to_phys calls the new function if it
>>> is available and discards the length.
>>>
>>> Then convert callers that can take advantage of it. Have the fallback
>>> path also compute the length by iterating internally.
>>>
>>> Finally one patch per driver implementing the new op, this could even
>>> be a second series.
>>>
>>> Don't remove iova_to_phys(), it is fine for things that don't need the
>>> length.
>> Does this mean retaining the iommu_iova_to_phys implementation but
>> implementing it through domain->ops->iova_to_phys_length (mapped_length is
>> NULL)?
> Yes
>
> Jason
next prev parent reply other threads:[~2026-06-01 14:15 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260529115116.GR2487554@ziepe.ca>
2026-05-31 9:36 ` [PATCH 0/9] iommu: introduce iova_to_phys_length for efficient IOVA-to-physical translation Guanghui Feng
2026-05-31 9:36 ` [PATCH 1/9] iommu: introduce iova_to_phys_length in iommu_domain_ops Guanghui Feng
2026-05-31 23:51 ` Jason Gunthorpe
2026-06-01 8:41 ` guanghuifeng
2026-06-01 13:43 ` Jason Gunthorpe
2026-06-01 14:14 ` guanghuifeng [this message]
2026-06-01 14:31 ` Jason Gunthorpe
2026-05-31 9:36 ` [PATCH 2/9] iommu/io-pgtable: introduce iova_to_phys_length in io_pgtable_ops Guanghui Feng
2026-05-31 9:36 ` [PATCH 3/9] iommu/generic_pt: implement iova_to_phys_length Guanghui Feng
2026-05-31 23:54 ` Jason Gunthorpe
2026-06-01 9:23 ` guanghuifeng
[not found] ` <fa924b86-1ca9-4819-8330-0d5f6ede8923@linux.alibaba.com>
2026-06-01 14:32 ` Jason Gunthorpe
2026-06-02 7:20 ` guanghuifeng
2026-06-02 12:32 ` Jason Gunthorpe
2026-05-31 9:36 ` [PATCH 4/9] iommu/arm-smmu: " Guanghui Feng
2026-05-31 9:36 ` [PATCH 5/9] iommu: apple-dart/ipmmu/mtk_iommu " Guanghui Feng
2026-05-31 9:36 ` [PATCH 6/9] iommu: direct page-table drivers " Guanghui Feng
2026-05-31 9:36 ` [PATCH 7/9] vfio/iommufd: use iova_to_phys_length for efficient unmap Guanghui Feng
2026-05-31 23:58 ` Jason Gunthorpe
2026-05-31 9:36 ` [PATCH 8/9] drm/gpu, iommu/io-pgtable: switch to iova_to_phys_length Guanghui Feng
2026-05-31 9:36 ` [PATCH 9/9] iommu: remove deprecated iova_to_phys from domain_ops and io_pgtable_ops Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 00/30] iommu: introduce iova_to_phys_length for efficient IOVA-to-physical translation Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 01/30] iommu: introduce iova_to_phys_length in iommu_domain_ops Guanghui Feng
2026-06-03 1:08 ` Jason Gunthorpe
2026-06-02 10:46 ` [PATCH v2 02/30] iommu/io-pgtable-arm: introduce iova_to_phys_length in io_pgtable_ops Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 03/30] iommu/io-pgtable-arm-v7s: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 04/30] iommu/io-pgtable-dart: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 05/30] iommu/generic_pt: implement iova_to_phys_length Guanghui Feng
2026-06-03 1:11 ` Jason Gunthorpe
2026-06-02 10:46 ` [PATCH v2 06/30] iommu/arm-smmu-v3: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 07/30] iommu/arm-smmu: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 08/30] iommu/qcom_iommu: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 09/30] iommu/apple-dart: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 10/30] iommu/ipmmu-vmsa: " Guanghui Feng
2026-06-03 1:13 ` Jason Gunthorpe
2026-06-02 10:46 ` [PATCH v2 11/30] iommu/mtk_iommu: " Guanghui Feng
2026-06-03 1:17 ` Jason Gunthorpe
2026-06-02 10:46 ` [PATCH v2 12/30] iommu/exynos: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 13/30] iommu/fsl_pamu: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 14/30] iommu/msm: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 15/30] iommu/mtk_v1: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 16/30] iommu/omap: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 17/30] iommu/rockchip: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 18/30] iommu/s390: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 19/30] iommu/sprd: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 20/30] iommu/sun50i: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 21/30] iommu/tegra-smmu: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 22/30] iommu/virtio: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 23/30] vfio/iommufd: use iova_to_phys_length for efficient unmap Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 24/30] drm/panfrost: switch to iova_to_phys_length Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 25/30] drm/panthor: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 26/30] iommu/io-pgtable: selftests " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 27/30] iommu/io-pgtable-arm: remove deprecated iova_to_phys wrapper Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 28/30] iommu/io-pgtable-arm-v7s: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 29/30] iommu/io-pgtable-dart: " Guanghui Feng
2026-06-02 10:46 ` [PATCH v2 30/30] iommu: remove iova_to_phys from domain_ops and io_pgtable_ops Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 00/32] iommu: introduce iova_to_phys_length and remove iova_to_phys Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 01/32] iommu: introduce iova_to_phys_length in iommu_domain_ops Guanghui Feng
2026-06-04 2:44 ` Baolu Lu
2026-06-04 14:16 ` Jason Gunthorpe
2026-06-03 15:17 ` [PATCH v3 02/32] iommu/io-pgtable-arm: introduce iova_to_phys_length in io_pgtable_ops Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 03/32] iommu/io-pgtable-arm-v7s: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 04/32] iommu/io-pgtable-dart: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 05/32] iommu/generic_pt: implement iova_to_phys_length Guanghui Feng
2026-06-04 3:30 ` Baolu Lu
2026-06-04 14:12 ` Jason Gunthorpe
2026-06-03 15:17 ` [PATCH v3 06/32] iommu/arm-smmu-v3: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 07/32] iommu/arm-smmu: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 08/32] iommu/qcom_iommu: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 09/32] iommu/apple-dart: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 10/32] iommu/ipmmu-vmsa: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 11/32] iommu/mtk_iommu: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 12/32] iommu/exynos: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 13/32] iommu/fsl_pamu: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 14/32] iommu/msm: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 15/32] iommu/mtk_v1: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 16/32] iommu/omap: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 17/32] iommu/rockchip: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 18/32] iommu/s390: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 19/32] iommu/sprd: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 20/32] iommu/sun50i: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 21/32] iommu/tegra-smmu: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 22/32] iommu/virtio: " Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 23/32] vfio: use iova_to_phys_length for efficient unmap Guanghui Feng
2026-06-04 14:27 ` Jason Gunthorpe
2026-06-03 15:17 ` [PATCH v3 24/32] iommufd: " Guanghui Feng
2026-06-04 14:26 ` Jason Gunthorpe
2026-06-03 15:17 ` [PATCH v3 25/32] iommufd/selftest: switch to iommu_iova_to_phys_length Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 26/32] drm/panfrost: switch to iova_to_phys_length Guanghui Feng
2026-06-03 15:17 ` [PATCH v3 27/32] drm/panthor: " Guanghui Feng
2026-06-03 15:18 ` [PATCH v3 28/32] iommu/io-pgtable: selftests " Guanghui Feng
2026-06-03 15:18 ` [PATCH v3 29/32] iommu/io-pgtable-arm: remove deprecated iova_to_phys wrapper Guanghui Feng
2026-06-03 15:18 ` [PATCH v3 30/32] iommu/io-pgtable-arm-v7s: " Guanghui Feng
2026-06-03 15:18 ` [PATCH v3 31/32] iommu/io-pgtable-dart: " Guanghui Feng
2026-06-03 15:18 ` [PATCH v3 32/32] iommu: remove iova_to_phys from domain_ops and io_pgtable_ops Guanghui Feng
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