Re: [Qemu-devel] QEMU build breakage on ARM against Xen 4.9 caused by libxendevicemodel

[Paul Durrant]

> -----Original Message-----
> From: Stefano Stabellini [mailto:address@hidden
> Sent: 18 April 2017 18:41
> To: Paul Durrant <address@hidden>
> Cc: 'Stefano Stabellini' <address@hidden>; address@hidden;
> Anthony Perard <address@hidden>; Wei Liu
> <address@hidden>; address@hidden; address@hidden; xen-
> address@hidden
> Subject: RE: QEMU build breakage on ARM against Xen 4.9 caused by
> libxendevicemodel
> 
> On Tue, 18 Apr 2017, Paul Durrant wrote:
> > > -----Original Message-----
> > > From: Stefano Stabellini [mailto:address@hidden
> > > Sent: 15 April 2017 01:40
> > > To: Stefano Stabellini <address@hidden>
> > > Cc: Paul Durrant <address@hidden>; address@hidden;
> > > Anthony Perard <address@hidden>; Wei Liu
> > > <address@hidden>; address@hidden; address@hidden; xen-
> > > address@hidden
> > > Subject: Re: QEMU build breakage on ARM against Xen 4.9 caused by
> > > libxendevicemodel
> > >
> > > On Fri, 14 Apr 2017, Stefano Stabellini wrote:
> > > > Hi Paul,
> > > >
> > > > The following commit in my qemu "next" branch breaks the build on
> arm
> > > > and arm64:
> > > >
> > > > commit 670271647ad15e9d937ced7a72c892349c709216
> > > > Author: Paul Durrant <address@hidden>
> > > > Date:   Tue Mar 7 10:55:34 2017 +0000
> > > >
> > > >     xen: use libxendevicemodel when available
> > > >
> > > > See the appended build log. Sorry for not realizing it sooner.
> > >
> > > As I imagined, this bug is easy to solve. It is reproducible on x86 too,
> > > if you pass -DXC_WANT_COMPAT_DEVICEMODEL_API=1 to configure
> and
> > > forcefully disable Xen 4.9 detection in the configure script.
> > >
> > > If QEMU detects xen_ctrl_version = 480, the build will fail against Xen
> > > 4.9, even when -DXC_WANT_COMPAT_DEVICEMODEL_API=1 is
> specified.
> > >
> > > The appended patch solves the problem. However, Xen 4.9 detection
> and
> > > compilation remain broken.
> >
> > Ok, that fix looks fine to me.
> 
> I merged this change into "use libxendevicemodel when available" in my
> next branch.
> 
> Are you going to take care of getting the QEMU build on ARM to work
> against Xen 4.9 (properly detecting 4.9, without
> -DXC_WANT_COMPAT_DEVICEMODEL_API=1)?
> 

I can take a look once I get access to some h/w. Since the 4.9 detection should 
merely be based upon the presence of libxendevicemodel, I can't really imagine 
why ARM should behave any differently to x86.

  Paul

> 
> > >
> > > ---
> > >
> > > diff --git a/include/hw/xen/xen_common.h
> > > b/include/hw/xen/xen_common.h
> > > index 274accc..b1f5f53 100644
> > > --- a/include/hw/xen/xen_common.h
> > > +++ b/include/hw/xen/xen_common.h
> > > @@ -9,7 +9,6 @@
> > >  #undef XC_WANT_COMPAT_EVTCHN_API
> > >  #undef XC_WANT_COMPAT_GNTTAB_API
> > >  #undef XC_WANT_COMPAT_MAP_FOREIGN_API
> > > -#undef XC_WANT_COMPAT_DEVICEMODEL_API
> > >
> > >  #include <xenctrl.h>
> > >  #include <xenstore.h>
> > > @@ -154,6 +153,7 @@ static inline int xendevicemodel_set_mem_type(
> > >
> > >  #else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 490 */
> > >
> > > +#undef XC_WANT_COMPAT_DEVICEMODEL_API
> > >  #include <xendevicemodel.h>
> > >
> > >  #endif
> >