Re: [libvirt] [Xen-devel] [PATCH] libxl: use LIBXL_API_VERSION 0x040200

On Thu, Apr 14, 2016 at 12:37 AM, Jim Fehlig <jfehlig(a)suse.com&gt; wrote: > To ensure the libvirt libxl driver will build with future versions > of Xen where the libxl API may change in incompatible ways, > explicitly use LIBXL_API_VERSION 0x040200. The libxl driver > does use new libxl APIs that have been added since Xen 4.2, but > currently it does not make use of any changes made to existing > APIs such as libxl_domain_create_restore or libxl_set_vcpuaffinity. > The version can be bumped if/when the libxl driver consumes the > changed APIs. > > Further details can be found in the following discussion thread > > https://www.redhat.com/archives/libvir-list/2016-April/msg00178.html > Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > --- > src/Makefile.am | 1 + > src/libxl/libxl_conf.h | 12 ------------ > src/libxl/libxl_domain.c | 15 --------------- > 3 files changed, 1 insertion(+), 27 deletions(-) > > diff --git a/src/Makefile.am b/src/Makefile.am > index 08ff301..259a474 100644 > --- a/src/Makefile.am > +++ b/src/Makefile.am > @@ -1311,6 +1311,7 @@ endif ! WITH_DRIVER_MODULES > > libvirt_driver_libxl_impl_la_CFLAGS = \ > $(LIBXL_CFLAGS) \ > + -DLIBXL_API_VERSION=0x040200 \ > -I$(srcdir)/access \ > -I$(srcdir)/conf \ > -I$(srcdir)/secret \ > diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h > index 3c0eafb..24e2911 100644 > --- a/src/libxl/libxl_conf.h > +++ b/src/libxl/libxl_conf.h > @@ -69,18 +69,6 @@ > # endif > > > -/* libxl interface for setting VCPU affinity changed in 4.5. In fact, a new > - * parameter has been added, representative of 'VCPU soft affinity'. If one > - * does not care about it (and that's libvirt case), passing NULL is the > - * right thing to do. To mark that change, LIBXL_HAVE_VCPUINFO_SOFT_AFFINITY > - * is defined. */ > -# ifdef LIBXL_HAVE_VCPUINFO_SOFT_AFFINITY > -# define libxl_set_vcpuaffinity(ctx, domid, vcpuid, map) \ > - libxl_set_vcpuaffinity((ctx), (domid), (vcpuid), (map), NULL) > -# define libxl_set_vcpuaffinity_all(ctx, domid, max_vcpus, map) \ > - libxl_set_vcpuaffinity_all((ctx), (domid), (max_vcpus), (map), NULL) > -# endif Just checking with this -- the LIBXL_API_VERSION is meant for *forward* compatibility, but I think the LIBXL_HAVE_* macros are for *backwards* compatibility, isn't that right? If you compile this against an older version of Xen without LIBXL_HAVE_VCPU_SOFT_AFFINITY (say, 4.4), will it break with this patch?