Re: [PATCH] iommu: Add device name to iommu map/unmap trace events

Re: [PATCH] iommu: Add device name to iommu map/unmap trace events

[Joerg Roedel]

On Tue, Feb 09, 2021 at 06:06:20PM +0530, Sai Prakash Ranjan wrote:
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 5e7fe519430a..6064187d9bb6 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -87,6 +87,7 @@ struct iommu_domain {
>  	void *handler_token;
>  	struct iommu_domain_geometry geometry;
>  	void *iova_cookie;
> +	char dev_name[32];
>  };

No, definitly not. A domain is a device DMA address space which can be
used by more than one device. Just look at IOMMU groups with more than
one member device, in this case just one device name would be very
misleading.

Regards,

	Joerg

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Re: [PATCH] iommu: Add device name to iommu map/unmap trace events

[chenxiang (M)]

Hi,


在 2021/2/12 18:50, Joerg Roedel 写道:
> On Tue, Feb 09, 2021 at 06:06:20PM +0530, Sai Prakash Ranjan wrote:
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index 5e7fe519430a..6064187d9bb6 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -87,6 +87,7 @@ struct iommu_domain {
>>   	void *handler_token;
>>   	struct iommu_domain_geometry geometry;
>>   	void *iova_cookie;
>> +	char dev_name[32];
>>   };
> No, definitly not. A domain is a device DMA address space which can be
> used by more than one device. Just look at IOMMU groups with more than
> one member device, in this case just one device name would be very
> misleading.

Is it possible to use group id to identify different domains?


>
> Regards,
>
> 	Joerg
> _______________________________________________
> iommu mailing list
> iommu@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/iommu
>
> .
>



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Re: [PATCH] iommu: Add device name to iommu map/unmap trace events

[Joerg Roedel]

On Tue, Apr 06, 2021 at 02:56:53PM +0800, chenxiang (M) wrote:
> Is it possible to use group id to identify different domains?

No, the best is to do this during post-processing of your traces by also
keeping tack of domain-device attachments/detachments.

Regards,

	Joerg

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