[Ksummit-discuss] [CORE TOPIC] Device error handling / reporting / isolation

[Joerg Roedel]

On Fri, May 09, 2014 at 01:19:08PM -0700, James Bottomley wrote:
> On Fri, 2014-05-09 at 20:13 +0000, Luck, Tony wrote:
> > Defending against buggy hardware is interesting from a RAS perspective.
> > You don't want a card with a stuck address line scribbling on memory
> > that you didn't want it to touch.
> 
> But for a laptop or desktop kernel, how far do we want to go?  In
> theory, once the iommu is turned on, it corrals the device, since access
> to non programmed addresses (those without IOTLB entries) produces a
> fault.  Is there anything extra we need to do beyond turning on the
> IOMMU?

Especially for Laptops and Desktops proper fault handling is important.
Newer GPUS can use the IOMMU to directly access process address spaces
and support demand paging and CPU page-table layouts. Support for these
features in Linux is already being worked on, so handling faults in a
meaningful way is important there too.


	Joerg