Hi All! On Tue, Jan 20, 2015 at 2:47 PM, Roger Pau Monné <roger....@citrix.com> wrote:
> Hello, > > I should probably have done this earlier because I've been aware of this > issue for a long time (since I've started dealing with the PV blk > protocol). > > The current way to describe PV protocols in Xen is very inefficient > IMHO. Using C structs as "the description" of a binary protocol seems > very wrong, specially taking into account that different ABIs can > generate different layouts for the same C struct. This is for example a > problem in the PV blk protocol, since the binary layout of the > structures change depending on the bitness. > > In order to avoid this, I would like to request that any new PV protocol > that's added to Xen be described in binary terms, just like it's > normally done with other protocols. As a reference see for example the > following section from the TCP RFC: > > http://tools.ietf.org/html/rfc793#page-15 Guys, what do you think about using an Interface Description Language such as Google Protocol Buffers or something like? With best regards, > I think this is both more easy to understand and removes the bitness > problem of using C structs. > > Then each user of this protocol could define it's own set of structures > that would map to the binary layout, which should be almost trivial. > There would be no problem with using __packed or similar gcc'isms as > each implementation could choose the more convenient way to represent > this layout internally. > > Roger. > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel > -- *Vitaly Chernooky | Senior Developer - Product Engineering and Development* GlobalLogic P *+380.44.4929695 ext.1136* M *+380.98.7920568* S cvv_2k www.globallogic.com http://www.globallogic.com/email_disclaimer.txt
_______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
