Hello Christoph,
Christoph Hellwig <h...@lst.de> writes: > On Sat, Aug 15, 2020 at 05:45:36PM -0300, Thiago Jung Bauermann wrote: >> POWER secure guests (i.e., guests which use the Protection Execution >> Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but >> they don't need the SWIOTLB memory to be in low addresses since the >> hypervisor doesn't have any addressing limitation. >> >> This solves a SWIOTLB initialization problem we are seeing in secure guests >> with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved >> memory, which leaves no space for SWIOTLB in low addresses. > > What about just open coding the allocation and using > swiotlb_init_with_tbl? Yes, that works too. I just sent a v2 implementing that change. I just had to add a small accessor function so that I could set no_iotlb_memory from outside swiotlb.c. Thank you for the quick review. -- Thiago Jung Bauermann IBM Linux Technology Center
