On 18/1/07 15:35, "Gerd Hoffmann" <kraxel@xxxxxxx> wrote:
>> Excuse my ignorance, but why do you have to guess the guest's size?
>> Doesn't dom0 know?
>
> No, right now there is no hypercall to get that information. Which
> brings the discussion back onto the table: Should we add one? pvfb
> isn't the only driver with that kind of problems.
>
> And it better shouldn't be a dom0-only hypercall, otherwise driver
> domains will not be able to use it ...
Do the same as you did with blkback. Add a protocol version or bitwidth
field to xenstore. Update frontend driver to write that field. Make tools
write a default value for pv guests for backward compat. This is even better
than with blkfront/blkback because there are definitely no PV-on-HVM pvfb
driver frontends out in the wild (and it's HVM that makes things harder).
Speaking of which, we should add the protocol/bitwidth field to blkfront
asap...
 -- Keir
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel