On Mon, Oct 19, 2020 at 11:36:16AM -0500, Tom Lendacky wrote: > > Is RDMA missing something? I don't see anything special in VFIO for > > instance and the two are very similar - does VFIO work with SME, eg > > DPDK or something unrelated to virtualization? > > If user space is mapping un-encrypted memory, then, yes, it would seem > that there is a gap in the support where the pgprot_decrypted() would be > needed in order to override the protection map. It isn't "memory" it is PCI BAR pages, eg memory mapped IO > > Is there a reason not to just add prot_decrypted() to > > io_remap_pfn_range()? Is there use cases where a caller actually wants > > encrypted io memory? > > As long as you never have physical memory / ram being mapped in this path, > it seems that applying pgprot_decrypted() would be ok. I think the word 'io' implies this is the case.. Let me make a patch for this avenue then, I think it is not OK to add pgprot_decrypted to every driver.. We already have the special distinction with io and non-io remap, that seems better. > > I saw your original patch series edited a few drivers this way, but > > not nearly enough. So I feel like I'm missing something.. Does vfio > > work with SME? I couldn't find any sign of it calling prot_decrypted() > > either? > > I haven't tested SME with VFIO/DPDK. Hum, I assume it is broken also. Actually quite a swath of drivers and devices will be broken under this :\ Jason
