On Mon, 14 Dec 2015, Jan Beulich wrote: > >>> On 11.12.15 at 17:56, <ian.campb...@citrix.com> 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. > > And I don't think it's not possible - if anything, the infrastructure to > do so is just missing. I'm definitely not going to make this a build time > check, since I deem it very wrong namely when considering > --with-system-qemu (as in that case there shouldn't be any > dependency on the precise Xen tools versions in use - using plural > intentionally here to point out the possibility of multiple ones being > present).
Compile time checks are indeed suboptimal, but so are runtime checks: what if we backport the fix to more Xen releases? What if we revert the fix on the Xen tree for any reason? I think that a feature flag is the best course of action. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
