| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
Re: [Xen-devel] Essay on an important Xen decision (long)
On 10 Jan 2006, at 19:55, Anthony Liguori wrote:
You seem to conclude that the only possible solutions are making the
dom0 either P==M or P2M. Is it not possible to make dom0 VP?
If the only issue for making dom0 VP is DMA, wouldn't it be easier to
modify the Linux DMA subsystem[1] to make a special hypercall to
essentially pin a VP to a particular MFN that could be used for the
DMA? One could imagine the hypervisor reversing low memory
specifically for DMA such that bounce buffers could be avoided too.
VP makes a lot of interesting memory optimizations considerably easier
(memory compacting, swapping, etc.).
On an architecture where VP is cheaper to implement than on x86, it may
well make sense to do that in preference to P2M. As you say, it makes
certain future extensions less of a pain to implement.
If ia64 does decide to back off from the P==M route then I suspect VP
is the way to go (which is I think how ia64 domU's currently work
anyway).
-- Keir
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
| |
|
Home