From: Baolu Lu <baolu.lu@linux.intel.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: baolu.lu@linux.intel.com, "Tian, Kevin" <kevin.tian@intel.com>,
Joerg Roedel <joro@8bytes.org>,
Christoph Hellwig <hch@infradead.org>,
"Raj, Ashok" <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Jean-Philippe Brucker <jean-philippe@linaro.com>,
"Jiang, Dave" <dave.jiang@intel.com>,
Vinod Koul <vkoul@kernel.org>, Eric Auger <eric.auger@redhat.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"Pan, Jacob jun" <jacob.jun.pan@intel.com>,
Zhangfei Gao <zhangfei.gao@linaro.org>,
"Zhu, Tony" <tony.zhu@intel.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v10 08/12] iommu/sva: Refactoring iommu_sva_bind/unbind_device()
Date: Tue, 26 Jul 2022 16:47:00 +0800 [thread overview]
Message-ID: <d8f2646d-be6a-9636-3e9d-8e1d65ecb0c4@linux.intel.com> (raw)
In-Reply-To: <20220725144758.GG3747@nvidia.com>
On 2022/7/25 22:47, Jason Gunthorpe wrote:
> On Mon, Jul 25, 2022 at 06:22:06PM +0800, Baolu Lu wrote:
>> On 2022/7/25 15:50, Tian, Kevin wrote:
>>>> From: Baolu Lu <baolu.lu@linux.intel.com>
>>>> Sent: Sunday, July 24, 2022 9:48 PM
>>>>>
>>>>> The API is really refcounting the PASID:
>>>>>
>>>>>> +struct iommu_sva *iommu_sva_bind_device(struct device *dev,
>>>>>> + struct mm_struct *mm);
>>>>>> +void iommu_sva_unbind_device(struct iommu_sva *handle);
>>>>>
>>>>> So what you need to do is store that 'iommu_sva' in the group's PASID
>>>>> xarray.
>>>>>
>>>>> The bind logic would be
>>>>>
>>>>> sva = xa_load(group->pasid, mm->pasid)
>>>>> if (sva)
>>>>> refcount_inc(sva->users)
>>>>> return sva
>>>>> sva = kalloc
>>>>> sva->domain = domain
>>>>> xa_store(group->pasid, sva);
>>>>
>>>> Thanks for the suggestion. It makes a lot of sense to me.
>>>>
>>>> Furthermore, I'd like to separate the generic data from the caller-
>>>> specific things because the group->pasid_array should also be able to
>>>> serve other usages. Hence, the attach/detach_device_pasid interfaces
>>>> might be changed like below:
>>>>
>>>> /* Collection of per-pasid IOMMU data */
>>>> struct group_pasid {
>>>> struct iommu_domain *domain;
>>>> void *priv;
>>>> };
>>>>
>>>
>>> Is there any reason why pasid refcnt is sva specific and needs to be
>>> in a priv field?
>>
>> I am going to store the iommu_sva data which represents the bind
>> relationship between device and domain.
>
> Why do you need that?
>
> If you are starting at the pasid xarray then you already know the
> group/device, so we don't need to store it again.
>
> The only thing needed is the refcount so just store a refcount in this
> structure and be done with it. If someone needs to add something later
> then we can use a union or something, but right now adding an untagged
> void * is bad.
Fair enough. I will update it accordingly.
Best regards,
baolu
next prev parent reply other threads:[~2022-07-26 8:47 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-05 5:06 [PATCH v10 00/12] iommu: SVA and IOPF refactoring Lu Baolu
2022-07-05 5:06 ` [PATCH v10 01/12] iommu: Add max_pasids field in struct iommu_device Lu Baolu
2022-07-23 13:57 ` Jason Gunthorpe
2022-07-31 11:54 ` Yi Liu
2022-07-31 13:33 ` Baolu Lu
2022-07-05 5:07 ` [PATCH v10 02/12] iommu: Add max_pasids field in struct dev_iommu Lu Baolu
2022-07-23 14:02 ` Jason Gunthorpe
2022-07-31 11:55 ` Yi Liu
2022-07-05 5:07 ` [PATCH v10 03/12] iommu: Remove SVM_FLAG_SUPERVISOR_MODE support Lu Baolu
2022-07-31 12:01 ` Yi Liu
2022-07-31 13:39 ` Baolu Lu
2022-07-05 5:07 ` [PATCH v10 04/12] iommu: Add attach/detach_dev_pasid iommu interface Lu Baolu
2022-07-07 1:51 ` Tian, Kevin
2022-07-23 14:11 ` Jason Gunthorpe
2022-07-24 7:03 ` Baolu Lu
2022-07-25 14:40 ` Jason Gunthorpe
2022-07-26 6:23 ` Baolu Lu
2022-07-26 13:57 ` Jason Gunthorpe
2022-07-27 3:20 ` Tian, Kevin
2022-07-27 11:53 ` Jason Gunthorpe
2022-07-28 3:06 ` Tian, Kevin
2022-07-28 11:59 ` Jason Gunthorpe
2022-07-29 2:49 ` Baolu Lu
2022-07-29 2:56 ` Tian, Kevin
2022-07-29 3:20 ` Baolu Lu
2022-07-29 4:22 ` Tian, Kevin
2022-07-30 6:17 ` Baolu Lu
2022-07-29 2:51 ` Tian, Kevin
2022-07-29 12:22 ` Jason Gunthorpe
2022-07-30 6:23 ` Baolu Lu
2022-07-28 2:44 ` Baolu Lu
2022-07-28 6:27 ` Baolu Lu
2022-08-02 2:19 ` Baolu Lu
2022-08-02 12:37 ` Jason Gunthorpe
2022-08-03 13:07 ` Baolu Lu
2022-08-03 19:03 ` Jason Gunthorpe
2022-08-04 2:03 ` Tian, Kevin
2022-08-04 2:42 ` Baolu Lu
2022-07-24 7:23 ` Baolu Lu
2022-07-24 8:39 ` Baolu Lu
2022-07-24 9:13 ` Baolu Lu
2022-07-25 7:46 ` Tian, Kevin
2022-07-25 10:11 ` Baolu Lu
2022-07-31 12:10 ` Yi Liu
2022-07-05 5:07 ` [PATCH v10 05/12] iommu: Add IOMMU SVA domain support Lu Baolu
2022-07-07 1:52 ` Tian, Kevin
2022-07-07 3:01 ` Baolu Lu
2022-07-23 14:15 ` Jason Gunthorpe
2022-07-31 12:19 ` Yi Liu
2022-07-05 5:07 ` [PATCH v10 06/12] iommu/vt-d: Add " Lu Baolu
2022-07-23 14:16 ` Jason Gunthorpe
2022-07-31 12:20 ` Yi Liu
2022-07-05 5:07 ` [PATCH v10 07/12] arm-smmu-v3/sva: " Lu Baolu
2022-07-23 14:20 ` Jason Gunthorpe
2022-07-24 11:58 ` Baolu Lu
2022-07-05 5:07 ` [PATCH v10 08/12] iommu/sva: Refactoring iommu_sva_bind/unbind_device() Lu Baolu
2022-07-05 17:43 ` Jean-Philippe Brucker
2022-07-07 1:56 ` Tian, Kevin
2022-07-07 3:02 ` Baolu Lu
2022-07-23 14:26 ` Jason Gunthorpe
2022-07-24 13:48 ` Baolu Lu
2022-07-25 7:39 ` Jean-Philippe Brucker
2022-07-25 8:02 ` Tian, Kevin
2022-07-25 8:47 ` Jean-Philippe Brucker
2022-07-25 9:33 ` Baolu Lu
2022-07-25 9:52 ` Jean-Philippe Brucker
2022-07-25 14:46 ` Jason Gunthorpe
2022-07-25 7:50 ` Tian, Kevin
2022-07-25 10:22 ` Baolu Lu
2022-07-25 14:47 ` Jason Gunthorpe
2022-07-26 8:47 ` Baolu Lu [this message]
2022-07-31 12:36 ` Yi Liu
2022-07-31 13:45 ` Baolu Lu
2022-07-31 12:55 ` Yi Liu
2022-07-31 13:51 ` Baolu Lu
2022-07-05 5:07 ` [PATCH v10 09/12] iommu: Remove SVA related callbacks from iommu ops Lu Baolu
2022-07-23 14:27 ` Jason Gunthorpe
2022-07-31 12:38 ` Yi Liu
2022-07-05 5:07 ` [PATCH v10 10/12] iommu: Prepare IOMMU domain for IOPF Lu Baolu
2022-07-07 1:58 ` Tian, Kevin
2022-07-23 14:33 ` Jason Gunthorpe
2022-07-24 14:04 ` Baolu Lu
2022-07-25 14:49 ` Jason Gunthorpe
2022-07-31 12:50 ` Yi Liu
2022-07-31 13:47 ` Baolu Lu
2022-07-05 5:07 ` [PATCH v10 11/12] iommu: Per-domain I/O page fault handling Lu Baolu
2022-07-07 2:06 ` Tian, Kevin
2022-07-23 14:34 ` Jason Gunthorpe
2022-07-05 5:07 ` [PATCH v10 12/12] iommu: Rename iommu-sva-lib.{c,h} Lu Baolu
2022-07-23 14:34 ` Jason Gunthorpe
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