Re:Former Nvidia Dev's Thoughts on Vulkan/Mantle
by pandaman on Friday March 13, 2015 @01:30AM
(#9195782)
You are describing GPU from 1990s. Modern GPU is essentially a general purpose computer sitting on the PCIe bus and able to do anything the CPU can. It does not have to run pure functions (e.g. see how it can be used for normal graphics tasks in [1]) and can write any location in the memory it can see. Securing it is as easy/hard as securing a CPU: if you screw up and expose some memory to the GPU it can be owned just like the memory exposed to a CPU task[2].
1. https://software.intel.com/en-us/blogs/2013/07/18/order-inde...
2. http://beta.ivc.no/wiki/index.php/Xbox_360_King_Kong_Shader_...
Invalid data would simply cause a GPU task to fail while the other tasks happily continue to be executed. Since they are pure and don't interact with one another there is no need for process isolation or virtualization.
Basically, its easy to sandbox a GPU when the only data it contains are values (no pointers) and pure functions (no shared memory). Even with the simplified model the driver still everything it needs to enforce security.