On Wed, Nov 25, 2020 at 01:05:25AM +0000, Justin He wrote: > > I'd appreciate if you could explain why vfio needs to dma map some > > PROT_NONE > > Virtiofs will map a PROT_NONE cache window region firstly, then remap the sub > region of that cache window with read or write permission. I guess this might > be an security concern. Just CC virtiofs expert Stefan to answer it more accurately. Yep. Since my previous sentence was cut off, I'll rephrase: I was thinking whether qemu can do vfio maps only until it remaps the PROT_NONE regions into PROT_READ|PROT_WRITE ones, rather than trying to map dma pages upon PROT_NONE. Thanks, -- Peter Xu
