On Fri, Aug 07, 2026 at 03:34:47PM +0000, Mostafa Saleh wrote: > On Fri, Aug 07, 2026 at 10:58:10AM -0300, Jason Gunthorpe wrote: > > On Fri, Aug 07, 2026 at 02:18:31PM +0100, Will Deacon wrote: > > > > > > I was under the impression that there is a possibility of using swiotlb > > > > instead of restricted-dma-pool with pKVM. > > > > > > Yes, that patch enables swiotlb as a possibility for protected guests > > > but with your patch we avoid shrinking the swiotlb buffer even when > > > restricted dma pools are being used and that's a waste of memory. > > > > I also thought we switched pkvm to use CC-like swiotlb as part of the > > alignment in this rework? Mostafa ? > > Yes, now protected VMs can use the SWIOTLB for bouncing. However for > Android (and kvmtool), use restricted DMA. so SWIOTLB is not used.
Oh? Why? > However, I do not think we should over engineer this in the code, > swiotlb can be set from the cmdline and now through Kconfig also. That's fine for android, but real users buying a cloud VM and sticking a distro on it shouldn't be expected to have to mess with cmdline just go get a halfway working system Jason
