Re: [PATCH v2 4/6] docs/about/deprecated: Deprecate the qemu-system-arm binary

[Thomas Huth <thuth@redhat.com>]

On 03/03/2023 12.16, Peter Maydell wrote:
> On Thu, 2 Mar 2023 at 16:31, Thomas Huth <thuth@redhat.com> wrote:
>>
>> qemu-system-aarch64 is a proper superset of qemu-system-arm,
>> and the latter was mainly still required for 32-bit KVM support.
>> But this 32-bit KVM arm support has been dropped in the Linux
>> kernel a couple of years ago already, so we don't really need
>> qemu-system-arm anymore, thus deprecated it now.
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
>>   docs/about/deprecated.rst | 10 ++++++++++
>>   1 file changed, 10 insertions(+)
>>
>> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
>> index a30aa8dfdf..21ce70b5c9 100644
>> --- a/docs/about/deprecated.rst
>> +++ b/docs/about/deprecated.rst
>> @@ -45,6 +45,16 @@ run 32-bit guests by selecting a 32-bit CPU model, including KVM support
>>   on x86_64 hosts. Thus users are recommended to reconfigure their systems
>>   to use the ``qemu-system-x86_64`` binary instead.
>>
>> +``qemu-system-arm`` binary (since 8.0)
>> +''''''''''''''''''''''''''''''''''''''
>> +
>> +``qemu-system-aarch64`` is a proper superset of ``qemu-system-arm``.
> 
> I think this is not quite true -- at the moment if you want
> "every feature we implement, 32-bit" the only way to get
> that is 'qemu-system-arm -cpu max'. The '-cpu max' on
> qemu-system-aarch64 is 64-bit, and we don't implement for TCG
> the "-cpu max,aarch64=off" syntax that we do for KVM that would
> let the user say "no 64-bit support".

Ok ... so what does that mean now? ... can we continue with this patch, e.g. 
after rephrasing the text a little bit, or do we need to implement "-cpu 
max,aarch64=off" for TCG first?

  Thomas