Re: [Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

Tianyu Lan
2021-08-13T16:43:36Z

Hi Christoph:
I followed your this suggestion to rework the latest
version(https://lkml.org/lkml/2021/8/9/805). I just remove the arch
prefix from your suggested name arch_dma_map_decrypted because the
platform may populate their map/umap callback in the ops. But from your
latest comment(https://lkml.org/lkml/2021/8/12/149), these names confuse
vs the actual dma_map_* calls... Could you help to give the right
function name? The new map function is to map bounce buffer in the
trust/Isolation VM and these buffers are DMA memory.

On 7/20/2021 9:54 PM, Christoph Hellwig wrote:
>> - set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
>> - memset(vaddr, 0, bytes);
>> + mem->vstart = (void *)set_memory_decrypted_map((unsigned long)vaddr, bytes);
> Please always pass kernel virtual addresses as pointers.
>
> And I think these APIs might need better names, e.g.
>
> arch_dma_map_decrypted and arch_dma_unmap_decrypted.
>
> Also these will need fallback versions for non-x86 architectures that
> currently use memory encryption.