On Mon, 2015-12-14 at 11:19 +0000, Stefano Stabellini wrote: > On Fri, 11 Dec 2015, Ian Campbell wrote: > > On Fri, 2015-12-11 at 16:44 +0000, Stefano Stabellini wrote: > > > > > > It is not possible to do this at runtime. I think we should do this > > > at > > > compile time because in any case it is not supported to run a QEMU > > > built > > > for a given Xen version on a different Xen version. > > > > I am currently working pretty hard to make this possible in the future, > > it > > would be a shame to add another reason it wasn't possible at this > > stage. > > > > I proposed (in <1445442435.9563.184.ca...@citrix.com>) that as well as > > the > > various stable libraries extracted from libxenctrl we will probably > > also > > want to have a libxendevicemodel.so at some point, to provide a stable > > way > > to interface with all the stuff which being a DM involves. > > I understand the direction we are heading toward, but unfortunately we > are still pretty far from it. I don't think we want to block this patch > until we have a stable libxendevicemodel ABI?
No, but I would appreciate if such things were explicitly considered on a case by case by case basis rather than just bundled under a generic "it's not possible yet", since there may be cases where we want to hold off, or more likely where doing something a particular way now will ease things for the transition in the future. > Also this particular > change regards PCI passthrough, which is not convered by the proposed > ABI yet. > > > > Maybe that library could contain a way to get this information? (In > > which > > case it could be hardcoded at compile time now and I'll see what I can > > do > > when I get to producing the library). > > Given the choice, I would rather have only compile time or only run time > Xen version checks in QEMU and not both to avoid complexity. Especially > as long as the underlying libraries don't make any stability guarantees. "that library" obviously will make such guarantees as a matter of design. Ian. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
