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SubjectRe: 答复: 答复: 答复: 答复: 答复 : 答复: 答复: [PATCH] iommu/vt-d:Add support for ACPI device in RMRR
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Hi,

On 2020/8/7 11:29, FelixCui-oc wrote:
> Hi baolu,
> I understand what you mean is that you want to put the following processing code in the acpi_device_create_direct_mappings() into the probe_acpi_namespace_devices() ,right?
> If you mean it , I think it's OK.

Yes. If the acpi device has companion physical devices, then probe the
companion devices; otherwise, probe the acpi device instead. Also, let's
put detecting and probing acpi devices in different patches so that they
could be easier for reviewing.

Best regards,
baolu

>
> if (pn_dev == NULL) {
> acpi_device->bus->iommu_ops = &intel_iommu_ops;
> ret = iommu_probe_device(acpi_device);
> if (ret) {
> pr_err("acpi_device probe fail! ret:%d\n", ret);
> return ret;
> }
> return 0;
> }
>
> Best regards
> Felix cui-oc
>
>
>
>
>
> -----邮件原件-----
> 发件人: Lu Baolu <baolu.lu@linux.intel.com>
> 发送时间: 2020年8月7日 9:08
> 收件人: FelixCui-oc <FelixCui-oc@zhaoxin.com>; Joerg Roedel <joro@8bytes.org>; iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org; David Woodhouse <dwmw2@infradead.org>
> 抄送: baolu.lu@linux.intel.com; RaymondPang-oc <RaymondPang-oc@zhaoxin.com>; CobeChen-oc <CobeChen-oc@zhaoxin.com>
> 主题: Re: 答复: 答复: 答复: 答复: 答复: 答复: [PATCH] iommu/vt-d:Add support for ACPI device in RMRR
>
> Hi Felix,
>
> On 2020/8/6 14:51, FelixCui-oc wrote:
>> Hi baolu,
>> >Sure. Before that, let me sync my understanding with you. You have an acpi namespace device in ANDD table, it also shows up in the device scope of a RMRR.
>> >Current code doesn't enumerate that device for the RMRR, hence iommu_create_device_direct_mappings() doesn't work for this device.
>>
>> >At the same time, probe_acpi_namespace_devices() doesn't work for this device, hence you want to add a home-made
>> >acpi_device_create_direct_mappings() helper.
>>
>> Your understanding is right.
>> But there is a problem that even if the namespace device in rmrr is enumerated in the code, probe_acpi_namespace_devices() also doesn't work for this device.
>> This is because the dev parameter of the iommu_create_device_direct_mappings() is not the namespace device in RMRR.
>> The actual parameter passed in is the namespace device's physical node device.
>> In iommu_create_device_direct_mappings(), the physical node device passed in cannot match the namespace device in rmrr->device[],right?
>> We need acpi_device_create_direct_mappings() helper ?
>>
>> In addition, adev->physical_node_list is related to the __HID of namespace device reported by the bios.
>> For example, if the __HID reported by the bios belongs to acpi_pnp_device_ids[], adev->physical_node_list has no devices.
>> So in acpi_device_create_direct_mappings(), I added the case that adev->physical_node_list is empty.
>
> Got you. Thanks!
>
> Have you ever tried to have probe_acpi_namespace_devices() handle the case of empty adev->physical_node_list at the same time?
>
> Best regards,
> baolu
>
>>
>>
>> Best regards
>> Felix cui
>>
>>
>>
>>
>> -----邮件原件-----
>> 发件人: Lu Baolu <baolu.lu@linux.intel.com>
>> 发送时间: 2020年8月6日 10:36
>> 收件人: FelixCui-oc <FelixCui-oc@zhaoxin.com>; Joerg Roedel
>> <joro@8bytes.org>; iommu@lists.linux-foundation.org;
>> linux-kernel@vger.kernel.org; David Woodhouse <dwmw2@infradead.org>
>> 抄送: baolu.lu@linux.intel.com; RaymondPang-oc
>> <RaymondPang-oc@zhaoxin.com>; CobeChen-oc <CobeChen-oc@zhaoxin.com>
>> 主题: Re: 答复: 答复: 答复: 答复: 答复: [PATCH] iommu/vt-d:Add support for ACPI
>> device in RMRR
>>
>> Hi Felix,
>>
>> On 8/5/20 3:37 PM, FelixCui-oc wrote:
>>> Hi baolu,
>>> Let me talk about why acpi_device_create_direct_mappings() is needed and please tell me if there is an error.
>>
>> Sure. Before that, let me sync my understanding with you. You have an acpi namespace device in ANDD table, it also shows up in the device scope of a RMRR. Current code doesn't enumerate that device for the RMRR, hence iommu_create_device_direct_mappings() doesn't work for this device.
>>
>> At the same time, probe_acpi_namespace_devices() doesn't work for this
>> device, hence you want to add a home-made
>> acpi_device_create_direct_mappings() helper.
>>
>> Did I get it right?
>>
>>> In the probe_acpi_namespace_devices() function, only the device in the addev->physical_node_list is probed,
>>> but we need to establish identity mapping for the namespace device in RMRR. These are two different devices.
>>
>> The namespace device has been probed and put in one drhd's device list.
>> Hence, it should be processed by probe_acpi_namespace_devices(). So the question is why there are no devices in addev->physical_node_list?
>>
>>> Therefore, the namespace device in RMRR is not mapped in probe_acpi_namespace_devices().
>>> acpi_device_create_direct_mappings() is to create direct mappings for namespace devices in RMRR.
>>
>> Best regards,
>> baolu
>>

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