On Thu, Mar 31, 2011 at 04:49:46PM -0500, Anthony Liguori wrote:
On 03/31/2011 04:38 PM, Michael S. Tsirkin wrote:
That seems like a clearer API, yes. I think it makes it much more
obvious what it's trying to achieve.
-- PMM
Maybe register_dma_area - its' not 100% virtio specific.
It's never been clear to me whether that's true or not. I've heard
mixed things about whether devices DMA to other devices. I've never
been able to find something in a specification stating
authoritatively one way or another.
Regards,
Anthony Liguori
AFAIK the capability of cross-talk between PCI devices
exists in PCI and is optional in PCI Express.
PCI spec says:
Full multi-master capability allowing any PCI master peer-to-peer
access to any PCI master/target.
The Express spec says:
"The capability to route peer-to-peer transactions between hierarchy
domains through a Root Complex is optional and implementation dependent.
For example, an implementation may incorporate a real or virtual Switch
internally within the Root Complex to enable full peer-to- peer support
in a software transparent way."