Re: [PULL 00/17] Migration 20230209 patches

[Peter Maydell]

On Fri, 10 Feb 2023 at 14:21, Juan Quintela <quintela@redhat.com> wrote:
>
> Peter Maydell <peter.maydell@linaro.org> wrote:
> > Fails to build the user-mode emulators:
>
> This is weird.

> > https://gitlab.com/qemu-project/qemu/-/jobs/3749435025
> >
> > In file included from ../authz/base.c:24:
> > ../authz/trace.h:1:10: fatal error: trace/trace-authz.h: No such file
> > or directory
> > 1 | #include "trace/trace-authz.h"
>
> This series only have one change for traces:
>
> diff --git a/util/trace-events b/util/trace-events
> index c8f53d7d9f..16f78d8fe5 100644
> --- a/util/trace-events
> +++ b/util/trace-events
> @@ -93,6 +93,7 @@ qemu_vfio_region_info(const char *desc, uint64_t 
> region_ofs, uint64_t region_siz
>  qemu_vfio_pci_map_bar(int index, uint64_t region_ofs, uint64_t region_size, 
> int ofs, void *host) "map region bar#%d addr 0x%"PRIx64" size 0x%"PRIx64" ofs 
> 0x%x host %p"
>
>  #userfaultfd.c
> +uffd_detect_open_mode(int mode) "%d"
>  uffd_query_features_nosys(int err) "errno: %i"
>  uffd_query_features_api_failed(int err) "errno: %i"
>  uffd_create_fd_nosys(int err) "errno: %i"
>
> Rest of trace mentions are for the removal of migration.multifd.c.orig
>
> And I don't play with authentication at all.
>
> This is Fedora 37.
>
> > https://gitlab.com/qemu-project/qemu/-/jobs/3749435094
> > In file included from ../authz/simple.c:23:
> > ../authz/trace.h:1:10: fatal error: trace/trace-authz.h: No such file
> > or directory
>
> Problem is that this trace file is not generated, but I can think how
> any change that I did can influence this.
>
> > 1 | #include "trace/trace-authz.h"
> >
> >
> > https://gitlab.com/qemu-project/qemu/-/jobs/3749434963
> > In file included from ../authz/listfile.c:23:
> > ../authz/trace.h:1:10: fatal error: trace/trace-authz.h: No such file
> > or directory
> > 1 | #include "trace/trace-authz.h"
>
> Looking at the ouptut of these, they are not informatives at all.
>
> I am going to try to compile linux-user without system, and see if that
> brings a clue.

Yes, I suspect this is a "user-mode only build" specific failure
(you may need --disable-system --disable-tools to see it).

meson.build only puts authz into trace_events_subdirs "if have_block"
(which is to say "if have_system or have_tools"). However the
bit of meson.build that says "subdir('authz') does not have
the same condition on it -- it's just been put in the list without
any condition on it. So I think that in a build-only-user-emulators
config meson will not generate trace events for the subdirectory
but will try to build it, which falls over.

Contrast 'block', 'nbd', 'scsi', which are all guarded by
'if have_block' for their subdir() lines, to match the guard on
the trace_events_subdirs. OTOH 'io' is also mismatched-guards...

Why this only shows up with your pullreq I have no idea.

thanks
-- PMM