On Wed, 17 Apr 2019 at 12:51, Pascal Van Leeuwen <pvanleeuwen@xxxxxxxxxxxxxxxx> wrote: > > Hi, > > I'm trying to fix the inside-secure driver to pass all testmgr > tests and I have one final issue remaining with the AEAD ciphers. > As it was not clear at all what the exact problem was, I spent > some time reverse engineering testmgr and I got the distinct > impression that it is using scatter particles that cross page > boundaries. On purpose, even. > > While the inside-secure driver is built on the premise that > scatter particles are continuous in device space. As I can't > think of any reason why you would want to scatter/gather other > than to handle virtual-to-physical address translation ... > In any case, this should affect all other other operations as > well, but maybe those just got "lucky" by getting particles > that were still contiguous in device space, despite the page > crossing (to *really* verify this, you would have to fully > randomize your page allocation!) > > Anyway, assuming that I *should* be able to handle particles > that are *not* contiguous in device space, then there should > probably already exist some function in the kernel API that > converts a scatterlist with non-contiguous particles into a > scatterlist with contiguous particles, taking into account the > presence of an IOMMU? Considering pretty much every device > driver would need to do that? > Does anyone know which function(s) to use for that? > Hello Pascal, Scatterlists are made up of struct page/offset tuples, and so they should map transparently onto physical ranges. It looks like the AEAD skcipher walk API lacks a *_async() variant setting the SKCIPHER_WALK_PHYS bit, like we have for the ordinary block ciphers. Plumbing that into crypto/skcipher.c should be rather straight-forward. -- Ard.
