On Tue, May 17, 2022 at 01:02:00PM +0100, Robin Murphy wrote: >> So how to inform the SCSI driver of this caching limit then so that it may >> limit the SGL length? > > Driver-specific mechanism; block-layer-specific mechanism; redefine this > whole API to something like dma_opt_mapping_size(), as a limit above which > mappings might become less efficient or start to fail (callback to my > thoughts on [1] as well, I suppose); many options. Just not imposing a > ridiculously low *maximum* on everyone wherein mapping calls "should not be > larger than the returned value" when that's clearly bollocks.
Well, for swiotlb it is a hard limit. So if we want to go down that route we need two APIs, one for the optimal size and one for the hard limit. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
