Re: [PATCH 00/03] Preventing zero GPU virtual address allocation

Chris Wilson
2015-05-20T14:09:46Z

On Wed, May 20, 2015 at 04:54:19PM +0300, David Weinehall wrote:
> This patch series (one patch each for libdrm, the kernel, and beignet)
> aims to provide a means to add a context-specific means to prevent
> a mapping to GPU virtual address zero. This is needed at least by
> Beignet (possibly in other use-cases too, though I don't know of any
> other) to allow use of address zero to represent NULL.

Urm, you cannot allow absolute addressing period. What happens to the
object at 0 when the user reads from it or writes to it? You have to
have an object at 0 for the user's NULL pointer access.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre