On Wed, Jun 16, 2021 at 01:10:02PM +0800, Claire Chang wrote: > On Wed, Jun 16, 2021 at 12:59 PM Christoph Hellwig <hch@xxxxxx> wrote: > > > > On Wed, Jun 16, 2021 at 12:04:16PM +0800, Claire Chang wrote: > > > Just noticed that after propagating swiotlb_force setting into > > > io_tlb_default_mem->force, the memory allocation behavior for > > > swiotlb_force will change (i.e. always skipping arch_dma_alloc and > > > dma_direct_alloc_from_pool). > > > > Yes, I think we need to split a "use_for_alloc" flag from the force flag. > > How about splitting is_dev_swiotlb_force into is_swiotlb_force_bounce > (io_tlb_mem->force_bounce) and is_swiotlb_force_alloc > (io_tlb_mem->force_alloc)? Yes, something like that. I'd probably not use force for the alloc side given that we otherwise never allocte from the swiotlb buffer.