Messages in this thread | | | Date | Tue, 3 May 2022 15:28:47 -0700 | Subject | Re: [PATCH v5 3/3] x86/tdx: Add Quote generation support | From | Sathyanarayanan Kuppuswamy <> |
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On 5/3/22 3:24 PM, Dave Hansen wrote: > On 5/2/22 18:27, Kirill A. Shutemov wrote: >>> Again, Dave and Andi already commented you should use vmap() to avoid breaking >>> up the direct-mapping. Please use vmap() instead. >>> >>> https://lore.kernel.org/all/ce0feeec-a949-35f8-3010-b0d69acbbc2e@linux.intel.com/ >>> >>> Will review the rest later. >> I would rather convert it to use DMA API for memory allocation. It will >> tap into swiotlb buffer that already converted and there's no need to >> touch direct mapping. Both allocation and freeing such memory is cheaper >> because of that. > > Sathya, I don't quite understand why you are so forcefully declining to > incorporate review feedback on this point. I gave very specific > feedback about the kind of mapping you need and that you should avoid > fragmenting the direct map if at all possible. > > Why is this code still fragmenting the direct map?
I have already implemented it and testing it now.
In this discussion, we are comparing the use of DMA API for memory allocation vs vmap/sharing it in driver itself.
-- Sathyanarayanan Kuppuswamy Linux Kernel Developer
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