At the moment, exec ignores high bits in each address,
for efficiency.
This is incorrect: devices can do full 64 bit DMA, it's
only the CPU that is limited by target address space.
Using full 64 bit addresses was clocked at 12% performance
hit on a microbenchmark.
To solve, teach pagetables to skip
Il 11/11/2013 17:40, Michael S. Tsirkin ha scritto:
> At the moment, exec ignores high bits in each address,
> for efficiency.
> This is incorrect: devices can do full 64 bit DMA, it's
> only the CPU that is limited by target address space.
> Using full 64 bit addresses was clocked at 12% performan
