Re: [PATCH 20/20] target/loongarch: Add linux-user emulation support

[maobibo <maobibo@loongson.cn>]

在 2021年06月30日 17:36, Alex Bennée 写道:
> 
> maobibo <maobibo@loongson.cn> writes:
> 
>> 在 2021年06月29日 21:42, Peter Maydell 写道:
>>> On Mon, 28 Jun 2021 at 13:05, Song Gao <gaosong@loongson.cn> wrote:
>>>>
>>>> Add files to linux-user/loongarch64
>>>> Add file to default-configs
>>>> Add loongarch to target/meson.build
>>>>
>>>> Signed-off-by: Song Gao <gaosong@loongson.cn>
>>>> ---
>>>>  MAINTAINERS                                        |   1 +
>>>>  default-configs/targets/loongarch64-linux-user.mak |   4 +
>>>>  include/elf.h                                      |   2 +
>>>>  linux-user/elfload.c                               |  58 ++++
>>>>  linux-user/loongarch64/cpu_loop.c                  | 177 ++++++++++++
>>>>  linux-user/loongarch64/signal.c                    | 193 +++++++++++++
>>>>  linux-user/loongarch64/sockbits.h                  |   1 +
>>>>  linux-user/loongarch64/syscall_nr.h                | 307 +++++++++++++++++++++
>>>>  linux-user/loongarch64/target_cpu.h                |  36 +++
>>>>  linux-user/loongarch64/target_elf.h                |  14 +
>>>>  linux-user/loongarch64/target_fcntl.h              |  12 +
>>>>  linux-user/loongarch64/target_signal.h             |  28 ++
>>>>  linux-user/loongarch64/target_structs.h            |  49 ++++
>>>>  linux-user/loongarch64/target_syscall.h            |  46 +++
>>>>  linux-user/loongarch64/termbits.h                  | 229 +++++++++++++++
>>>>  linux-user/syscall_defs.h                          |   8 +-
>>>>  meson.build                                        |   2 +-
>>>>  qapi/machine-target.json                           |   4 +-
>>>>  target/loongarch/meson.build                       |  19 ++
>>>>  target/meson.build                                 |   1 +
>>>>  20 files changed, 1185 insertions(+), 6 deletions(-)
>>>
>>> This is a massive patch that would benefit from being split up
>>> into multiple smaller patches.
>>>
>>> I'm told by a kernel developer that loongarch hasn't yet been
>>> accepted into the Linux kernel mainline. Until it has been, the
>>> syscall ABI for it is not yet stable, so we won't be able to take
>>> the linux-user patches for it yet. (We have been burned in the
>>> past by taking linux-user architecture support patches without
>>> realizing they weren't for a stable ABI, and then being out of
>>> sync with the eventual upstream kernel ABI that was accepted.)
>>>
>>> We can certainly do code review in the meantime, though.
>> Thanks for reviewing the big series patches. It is understandable that
>> there should be linux kernel merged for one new architecture support
>> firstly, and then there will be linux-user simulator later.
>>
>> We are planning to submit patch to linux kernel for LoongArch support,
>> there is the link:
>> https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson.git/log/?h=loongarch-next
>>
>> And we will continueto  submit softmmu support for LoongArch. And is there
>> any extra requirements for softmmu simulation for new architecture,
>> such as gcc/binutils/bios?
> 
> Ideally if there are some pre-built toolchains either as part of a
> distro (we've used Debian Sid before for some) or easily to install in a
> docker container as binary tarballs (like we do for tricore) then we can
> enable basic check-tcg functionality.
> 
> Going forward having stable URLs for test images of distros means we can
> also enable check-acceptance tests.
Thanks for guidance, it requires that linux kernel/gcc/glibc are submitted
already. My meaning is that linux-user emulation depends on kernel 
syscall ABI, softmmu emulation does not have such dependency, on the contrast
system emulation can be used to verify linux kernel. Is there any requirement
for system emulation of new architecture?

bibo,mao

> 
>>
>> regards
>> bibo, mao
>>
>>
>>>
>>> thanks
>>> -- PMM
>>>
> 
>