Motivation and higher level steps:

https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg04628.html

v1 -> v2:

* 1/3 (cpu-throttle): provide a description in the commit message

* 2/3 (cpu-timers, icount): in this v2 separate icount from cpu-timers,
  as icount is actually TCG-specific. Only build it under CONFIG_TCG.

  To do this, qtest had to be detached from icount. To this end, a
  trivial global counter for qtest has been introduced.

* 3/3 (CpuAccelInterface): provided a description.

This is point 8) in that plan. The idea is to extract the unrelated parts
in cpus, and register interfaces from each single accelerator to the main
cpus module (cpus.c).

While doing this RFC, I noticed some assumptions about Windows being
either TCG or HAX (not considering WHPX) that might need to be revisited.
I added a comment there.

The thing builds successfully based on Linux cross-compilations for
windows/hax, windows/whpx, and I got a good build on Darwin/hvf.

Tests run successully for tcg and kvm configurations, but did not test on
windows or darwin.

Welcome your feedback and help on this,

Claudio

Claudio Fontana (3):
  cpu-throttle: new module, extracted from cpus.c
  cpu-timers: new module extracted from cpus.c
  cpus: implement cpus interfaces for per-accelerator threads

 MAINTAINERS                          |    3 +
 Makefile.target                      |    9 +-
 accel/kvm/Makefile.objs              |    2 +
 accel/kvm/kvm-all.c                  |   15 +-
 accel/kvm/kvm-cpus-interface.c       |   94 ++
 accel/kvm/kvm-cpus-interface.h       |    8 +
 accel/qtest.c                        |   85 +-
 accel/stubs/kvm-stub.c               |    3 +-
 accel/tcg/Makefile.objs              |    1 +
 accel/tcg/cpu-exec.c                 |   43 +-
 accel/tcg/tcg-all.c                  |   19 +-
 accel/tcg/tcg-cpus-interface.c       |  523 +++++++++
 accel/tcg/tcg-cpus-interface.h       |    8 +
 accel/tcg/translate-all.c            |    3 +-
 cpu-throttle.c                       |  122 ++
 cpu-timers.c                         |  776 +++++++++++++
 cpus.c                               | 2015 ++++------------------------------
 docs/replay.txt                      |    6 +-
 exec.c                               |    4 -
 hw/core/cpu.c                        |    1 +
 hw/core/ptimer.c                     |    6 +-
 hw/i386/x86.c                        |    1 +
 include/exec/cpu-all.h               |    4 +
 include/exec/exec-all.h              |    4 +-
 include/hw/core/cpu.h                |   37 -
 include/qemu/main-loop.h             |    5 +
 include/qemu/timer.h                 |   20 -
 include/sysemu/cpu-throttle.h        |   50 +
 include/sysemu/cpu-timers.h          |   73 ++
 include/sysemu/cpus.h                |   56 +-
 include/sysemu/hw_accel.h            |   57 +-
 include/sysemu/kvm.h                 |    2 +-
 include/sysemu/replay.h              |    4 +-
 migration/migration.c                |    1 +
 migration/ram.c                      |    1 +
 qtest.c                              |    2 +-
 replay/replay.c                      |    6 +-
 softmmu/vl.c                         |    8 +-
 stubs/Makefile.objs                  |    1 +
 stubs/clock-warp.c                   |    4 +-
 stubs/cpu-get-clock.c                |    2 +-
 stubs/cpu-get-icount.c               |   14 +-
 stubs/cpu-synchronize-state.c        |   15 +
 target/alpha/translate.c             |    3 +-
 target/arm/helper.c                  |    7 +-
 target/i386/Makefile.objs            |    7 +-
 target/i386/hax-all.c                |    6 +-
 target/i386/hax-cpus-interface.c     |   85 ++
 target/i386/hax-cpus-interface.h     |    8 +
 target/i386/hax-i386.h               |    2 +
 target/i386/hax-posix.c              |   12 +
 target/i386/hax-windows.c            |   20 +
 target/i386/hvf/Makefile.objs        |    2 +-
 target/i386/hvf/hvf-cpus-interface.c |   83 ++
 target/i386/hvf/hvf-cpus-interface.h |    8 +
 target/i386/hvf/hvf.c                |    5 +-
 target/i386/kvm.c                    |    4 +-
 target/i386/whpx-all.c               |    3 +
 target/i386/whpx-cpus-interface.c    |   96 ++
 target/i386/whpx-cpus-interface.h    |    8 +
 target/riscv/csr.c                   |    8 +-
 tests/ptimer-test-stubs.c            |    6 +
 tests/test-timed-average.c           |    2 +-
 util/main-loop.c                     |    4 +-
 util/qemu-timer.c                    |    9 +-
 65 files changed, 2524 insertions(+), 1977 deletions(-)
 create mode 100644 accel/kvm/kvm-cpus-interface.c
 create mode 100644 accel/kvm/kvm-cpus-interface.h
 create mode 100644 accel/tcg/tcg-cpus-interface.c
 create mode 100644 accel/tcg/tcg-cpus-interface.h
 create mode 100644 cpu-throttle.c
 create mode 100644 cpu-timers.c
 create mode 100644 include/sysemu/cpu-throttle.h
 create mode 100644 include/sysemu/cpu-timers.h
 create mode 100644 stubs/cpu-synchronize-state.c
 create mode 100644 target/i386/hax-cpus-interface.c
 create mode 100644 target/i386/hax-cpus-interface.h
 create mode 100644 target/i386/hvf/hvf-cpus-interface.c
 create mode 100644 target/i386/hvf/hvf-cpus-interface.h
 create mode 100644 target/i386/whpx-cpus-interface.c
 create mode 100644 target/i386/whpx-cpus-interface.h

-- 
2.16.4