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...@linux.intel.com>
发送时间: 2020年8月7日 9:08
收件人: FelixCui-oc <felixcui...@zhaoxin.com>; Joerg Roedel <j...@8bytes.org>; 
io...@lists.linux-foundation.org; linux-kernel@vger.kernel.org; David Woodhouse 
<dw...@infradead.org>
抄送: baolu...@linux.intel.com; RaymondPang-oc <raymondpang...@zhaoxin.com>; 
CobeChen-oc <cobechen...@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...@linux.intel.com>
发送时间: 2020年8月6日 10:36
收件人: FelixCui-oc <felixcui...@zhaoxin.com>; Joerg Roedel
<j...@8bytes.org>; io...@lists.linux-foundation.org;
linux-kernel@vger.kernel.org; David Woodhouse <dw...@infradead.org>
抄送: baolu...@linux.intel.com; RaymondPang-oc
<raymondpang...@zhaoxin.com>; CobeChen-oc <cobechen...@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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