On Tue, Oct 11, 2011 at 03:14:52PM +0200, Alexander Graf wrote:
> > rep/ins is effectively equivalent to DMA except in how it's handled within
> > QEMU.
>
> No, DMA has a lot bigger granularities in kvm/user interaction. We can easily
> DMA a 50MB region with a single kvm/user exit. For PIO we can at most do page
> granularity.
>
Not only granularity, but double copy too. May be Anthony is referring
to real HW in which case I also do not see how it can be true since one
operation is synchronous and another is not.
--
Gleb.
