Re: [PATCH v3 13/16] powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests

[Thiago Jung Bauermann]

Hello Christoph,

Thanks for your review.

Christoph Hellwig <hch@xxxxxx> writes:

> On Tue, Aug 06, 2019 at 02:22:34AM -0300, Thiago Jung Bauermann wrote:
>> @@ -1318,7 +1319,10 @@ void iommu_init_early_pSeries(void)
>>  	of_reconfig_notifier_register(&iommu_reconfig_nb);
>>  	register_memory_notifier(&iommu_mem_nb);
>>  
>> -	set_pci_dma_ops(&dma_iommu_ops);
>> +	if (is_secure_guest())
>> +		set_pci_dma_ops(NULL);
>> +	else
>> +		set_pci_dma_ops(&dma_iommu_ops);
>
> Shoudn't:
>
> 	if (!is_secure_guest())
> 		set_pci_dma_ops(&dma_iommu_ops);
>
> be enough here, given that NULL is the default?

Indeed, it is enough.

> Also either way I think this conditional needs a comment explaining
> why it is there.

Good point. I added the commit message as a comment in the code.
New version of this patch below.