Re: [PATCH v6 00/11] Support disabling TCG on ARM (part 2)

[Claudio Fontana]

On 1/31/21 12:50 PM, Philippe Mathieu-Daudé wrote:
> Cover from Samuel Ortiz from (part 1) [1]:
> 
>   This patchset allows for building and running ARM targets with TCG
>   disabled. [...]
> 
>   The rationale behind this work comes from the NEMU project where
>   we're trying to only support x86 and ARM 64-bit architectures,
>   without including the TCG code base. We can only do so if we can
>   build and run ARM binaries with TCG disabled.
> 
> Peter mentioned in v5 [6] that since 32-bit host has been removed,
> we have to remove v7 targets. This is not done in this series, as
> linking succeeds, and there is enough material to review (no need
> to spend time on that extra patch if the current approach is not
> accepted).
> 
> CI: https://gitlab.com/philmd/qemu/-/pipelines/249272441
> 
> v6:
> - rebased on "target/arm/Kconfig" series
> - introduce/use tcg_builtin() for realview machines
> 
> v5:
> - addressed Paolo/Richard/Thomas review comments from v4 [5].
> 
> v4 almost 2 years later... [2]:
> - Rebased on Meson
> - Addressed Richard review comments
> - Addressed Claudio review comments
> 
> v3 almost 18 months later [3]:
> - Rebased
> - Addressed Thomas review comments
> - Added Travis-CI job to keep building --disable-tcg on ARM
> 
> v2 [4]:
> - Addressed review comments from Richard and Thomas from v1 [1]
> 
> Regards,
> 
> Phil.
> 
> [1]: https://lists.gnu.org/archive/html/qemu-devel/2018-11/msg02451.html
> [2]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg689168.html
> [3]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg641796.html
> [4]: https://lists.gnu.org/archive/html/qemu-devel/2019-08/msg05003.html
> [5]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg746041.html
> [6]: https://www.mail-archive.com/qemu-devel@nongnu.org/msg777669.html
> 
> Based-on: <20210131111316.232778-1-f4bug@amsat.org>
>           "target: Provide target-specific Kconfig"
> 
> Philippe Mathieu-Daudé (9):
>   sysemu/tcg: Introduce tcg_builtin() helper
>   exec: Restrict TCG specific headers
>   target/arm: Restrict ARMv4 cpus to TCG accel
>   target/arm: Restrict ARMv5 cpus to TCG accel
>   target/arm: Restrict ARMv6 cpus to TCG accel
>   target/arm: Restrict ARMv7 R-profile cpus to TCG accel
>   target/arm: Restrict ARMv7 M-profile cpus to TCG accel
>   target/arm: Reorder meson.build rules
>   .travis.yml: Add a KVM-only Aarch64 job
> 
> Samuel Ortiz (1):
>   target/arm: Do not build TCG objects when TCG is off
> 
> Thomas Huth (1):
>   target/arm: Make m_helper.c optional via CONFIG_ARM_V7M
> 
>  default-configs/devices/aarch64-softmmu.mak |  1 -
>  default-configs/devices/arm-softmmu.mak     | 27 --------
>  include/exec/helper-proto.h                 |  2 +
>  include/sysemu/tcg.h                        |  2 +
>  target/arm/cpu.h                            | 12 ----
>  hw/arm/realview.c                           |  7 +-
>  target/arm/cpu_tcg.c                        |  4 +-
>  target/arm/helper.c                         |  7 --
>  target/arm/m_helper-stub.c                  | 73 +++++++++++++++++++++
>  tests/qtest/cdrom-test.c                    |  6 +-
>  .travis.yml                                 | 32 +++++++++
>  hw/arm/Kconfig                              | 38 +++++++++++
>  target/arm/Kconfig                          | 17 +++++
>  target/arm/meson.build                      | 28 +++++---
>  14 files changed, 196 insertions(+), 60 deletions(-)
>  create mode 100644 target/arm/m_helper-stub.c
> 

Looking at this series, just my 2 cents on how I would suggest to go forward:
I could again split my series in two parts, with only the TCG Ops in the first 
part.

Then this series could be merged, enabling --disable-tcg for ARM,

then I could extend the second part of my series to include ARM as well.

Wdyt? (Probably Richard?)

Thanks,

Claudio