Re: [RFC v1 0/2] tcg-cpus: split into 3 tcg variants

[Alex Bennée]

Claudio Fontana <cfontana@suse.de> writes:

> The purpose of this series is to split the tcg-cpus into
> 3 variants:
>
> tcg_cpus_mttcg    (multithreaded tcg vcpus)
> tcg_cpus_rr       (single threaded round robin vcpus)
> tcg_cpus_icount   (same as RR, but using icount)

I've no objection to the cosmetic clean-up but I assume the 3 modes will
still be available in TCG enabled binaries.

>
> Alex, I read the comment in tcg_start_vcpu_thread saying:
>
>     /*
>      * Initialize TCG regions--once. Now is a good time, because:
>      * (1) TCG's init context, prologue and target globals have been set up.
>      * (2) qemu_tcg_mttcg_enabled() works now (TCG init code runs before the
>      *     -accel flag is processed, so the check doesn't work then).
>      */
>
> Is this actually current?

Hmm probably not. Now everything is tied to the order of class
initialisation and realisation. AIUI all properties set by the command
line should be complete by the time an object realizes and parent
classes should be processed before their children.

>
> I tried to refactor this (see patch 2), and it seems to work to do
> the init of regions in tcg_init, and it seems that mttcg_enabled is known
> already at that point..
>
> Ciao,
>
> Claudio
>
> Claudio Fontana (2):
>   accel/tcg: split CpusAccel into three TCG variants
>   accel/tcg: split tcg_start_vcpu_thread
>
>  accel/tcg/meson.build       |   9 +-
>  accel/tcg/tcg-all.c         |  13 +-
>  accel/tcg/tcg-cpus-icount.c | 145 +++++++++++
>  accel/tcg/tcg-cpus-icount.h |  20 ++
>  accel/tcg/tcg-cpus-mttcg.c  | 142 ++++++++++
>  accel/tcg/tcg-cpus-mttcg.h  |  25 ++
>  accel/tcg/tcg-cpus-rr.c     | 305 ++++++++++++++++++++++
>  accel/tcg/tcg-cpus-rr.h     |  26 ++
>  accel/tcg/tcg-cpus.c        | 500 +-----------------------------------
>  accel/tcg/tcg-cpus.h        |   9 +-
>  softmmu/icount.c            |   2 +-
>  11 files changed, 697 insertions(+), 499 deletions(-)
>  create mode 100644 accel/tcg/tcg-cpus-icount.c
>  create mode 100644 accel/tcg/tcg-cpus-icount.h
>  create mode 100644 accel/tcg/tcg-cpus-mttcg.c
>  create mode 100644 accel/tcg/tcg-cpus-mttcg.h
>  create mode 100644 accel/tcg/tcg-cpus-rr.c
>  create mode 100644 accel/tcg/tcg-cpus-rr.h


-- 
Alex Bennée