Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs

[Jean-Philippe Brucker]

On Fri, Mar 19, 2021 at 09:46:45AM -0300, Jason Gunthorpe wrote:
> On Fri, Mar 19, 2021 at 10:58:41AM +0100, Jean-Philippe Brucker wrote:
> 
> > Although there is no use for it at the moment (only two upstream users and
> > it looks like amdkfd always uses current too), I quite like the
> > client-server model where the privileged process does bind() and programs
> > the hardware queue on behalf of the client process.
> 
> This creates a lot complexity, how do does process A get a secure
> reference to B? How does it access the memory in B to setup the HW?

mm_access() for example, and passing addresses via IPC

> Why do we need separation anyhow? SVM devices are supposed to be
> secure or they shouldn't do SVM.

Right

Thanks,
Jean