On Wed, Aug 12, 2009 at 02:27:31PM -0500, Anthony Liguori wrote: > Arnd Bergmann wrote: >>> As I pointed out earlier, most code in virtio net is asymmetrical: guest >>> provides buffers, host consumes them. Possibly, one could use virtio >>> rings in a symmetrical way, but support of existing guest virtio net >>> means there's almost no shared code. >>> >> >> The trick is to swap the virtqueues instead. virtio-net is actually >> mostly symmetric in just the same way that the physical wires on a >> twisted pair ethernet are symmetric (I like how that analogy fits). >> > > It's already been done between two guests. See > http://article.gmane.org/gmane.linux.kernel.virtualization/5423 > > Regards, > > Anthony Liguori
Yes, this works by copying data (see PATCH 5/5). Another possibility is page flipping. Either will kill performance. -- MST _______________________________________________ Virtualization mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/virtualization
