Messages in this thread | | | Date | Tue, 3 May 2022 15:30:19 -0700 | Subject | Re: [PATCH v5 3/3] x86/tdx: Add Quote generation support | From | Sathyanarayanan Kuppuswamy <> |
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On 5/3/22 3:28 PM, Sathyanarayanan Kuppuswamy wrote: > > > 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.
I mean, I have already implemented the vmap based solution.
> > 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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