[Qemu-devel] [PATCH v7 0/8] Shared Library Module Support

[Fam Zheng]

This series implements feature of shared object building as described in:

http://wiki.qemu.org/Features/Modules

The main idea behind modules is to isolate dependencies on third party
libraries from qemu executables, such as libglusterfs or librbd, so that the
end users can install core qemu package with fewer dependencies.  And only for
those who want to use particular modules, need they install qemu-foo
sub-package, which in turn requires libbar and libbiz packages.

It's implemented in three steps:

1. The first patches fix current build system to correctly handle nested
   variables and object specific options:

    [01/08] ui/Makefile.objs: delete unnecessary cocoa.o dependency
    [02/08] make.rule: fix $(obj) to a real relative path
    [03/08] rule.mak: allow per object cflags and libs

2. The Makefile changes adds necessary options and rules to build DSO objects:

    [04/08] build-sys: introduce common-obj-m and block-obj-m for DSO

3. The next patch adds framework to load modules from installed directory:

    [05/08] module: implement module loading function

A few more changes are following to complete it:

    [06/08] Makefile: install modules with "make install"
    [07/08] .gitignore: ignore module related files (dll, so, mo)

In the end of series, the block drivers are converted:

    [08/08] block: convert block drivers linked with libs to modules

v7: While the discussion on module path and loading restriction goes on, more
input and revisions are apparently necessary to achieve a proper design.
However I'd like to send this revision for building system fixes spotted from
reviewers, to make it easier for early testing:

    [01] Add Peter's patch for ui/Makefile.objs. (Peter)
    [02] Move nested vars prefixing to immediately after unnest-vars-1 (Paolo)
         Fix order of libcacard/Makefile and unnest-vars in Makefile. (Daniel)
    [03] Fix link command if no libtool. (Peter)
    [04] Squash in "--enable-modules". (Paolo)
         Fix a missing comma in no dso building.
    [05] Don't load modules in *-user. (Peter)
         #ifdef out module loading code if no --enable-modules. (Daniel)

v6: Dropping RFC.

    [01] Move addprefix to unnest-vars.
    [01] Drop unnest-vars in tests/Makefile.
    [03] Move "all: modules" to Makefile.
    [03] Add empty modules: in rules.mak, for clarity.
    [03] .mo is no longer storing object list, just an empty file now. In
    expand-objs, objects are extracted with $foo.mo-objs). another reason for
    this is for makefile.target, objects in .mo file would be prefixed with
    ../, so generated two times in one "make all", which always outdates the
    link target.
    [04] Use CONFIG_MODDIR instead of CONFIG_PREFIX for module searching.
    [06] Added make install.
    [07] New.
    [08] Drop qed changes, added iscsi, ssh, rbd and gluster as modules.

v5: Keep foo.mo-objs idea for module objects.
    Unnest block-obj-m and common-obj-m in Makefile.target.
    Move add-modules to unnest-vars to be reused in Makefile.target.
    Use /dev/null to replace realpath for expand-objs.

v4: Added --enable-modules in the end of series.
    Make nested-vars and obj-base as arguemnts to unnest-vars.
    Take Paolo's idea in comments for v2 and switch back module objects syntax
    to:
        $(obj)/foo.mo : $(addprefix $(obj)/, bar.o biz.o qux.o)

    because this needs less duplication among Makefiles.

Fam Zheng (7):
  make.rule: fix $(obj) to a real relative path
  rule.mak: allow per object cflags and libs
  build-sys: introduce common-obj-m and block-obj-m for DSO
  module: implement module loading function
  Makefile: install modules with "make install"
  .gitignore: ignore module related files (dll, so, mo)
  block: convert block drivers linked with libs to modules

Peter Maydell (1):
  ui/Makefile.objs: delete unnecessary cocoa.o dependency

 .gitignore            |  3 ++
 Makefile              | 28 ++++++++++++++++++-
 Makefile.objs         | 18 ++----------
 Makefile.target       | 21 +++++++++++---
 block.c               |  1 +
 block/Makefile.objs   | 11 +++++++-
 configure             | 74 ++++++++++++++++++++++++++++++++-----------------
 include/qemu/module.h |  9 ++++++
 rules.mak             | 77 ++++++++++++++++++++++++++++++++++++++++++---------
 scripts/create_config | 10 +++++++
 ui/Makefile.objs      |  2 --
 util/module.c         | 55 ++++++++++++++++++++++++++++++++++++
 vl.c                  |  2 ++
 13 files changed, 249 insertions(+), 62 deletions(-)

-- 
1.8.3.1