Re: [PATCH 0/3] hw/arm/virt: Use generic CPU invalidation

[Gavin Shan <gshan@redhat.com>]

Hi Philippe,

On 7/14/23 02:29, Philippe Mathieu-Daudé wrote:
> On 13/7/23 14:34, Gavin Shan wrote:
>> On 7/13/23 21:52, Marcin Juszkiewicz wrote:
>>> W dniu 13.07.2023 o 13:44, Peter Maydell pisze:
>>>
>>>> I see this isn't a change in this patch, but given that
>>>> what the user specifies is not "cortex-a8-arm-cpu" but
>>>> "cortex-a8", why do we include the "-arm-cpu" suffix in
>>>> the error messages? It's not valid syntax to say
>>>> "-cpu cortex-a8-arm-cpu", so it's a bit misleading...
>>>
>>> Internally those cpu names are "max-{TYPE_ARM_CPU}" and similar for other architectures.
>>>
>>> I like the change but it (IMHO) needs to cut "-{TYPE_*_CPU}" string from names:
>>>
>>> 13:37 marcin@applejack:qemu$ ./build/aarch64-softmmu/qemu-system-aarch64 -M virt -cpu cortex-r5
>>> qemu-system-aarch64: Invalid CPU type: cortex-r5-arm-cpu
>>> The valid types are: cortex-a7-arm-cpu, cortex-a15-arm-cpu, cortex-a35-arm-cpu, cortex-a55-arm-cpu, cortex-a72-arm-cpu, cortex-a76-arm-cpu, a64fx-arm-cpu, neoverse-n1-arm-cpu, neoverse-v1-arm-cpu, cortex-a53-arm-cpu, cortex-a57-arm-cpu, host-arm-cpu, max-arm-cpu
>>>
>>> 13:37 marcin@applejack:qemu$ ./build/aarch64-softmmu/qemu-system-aarch64 -M virt -cpu cortex-a57-arm-cpu
>>> qemu-system-aarch64: unable to find CPU model 'cortex-a57-arm-cpu'
>>>
>>
>> The suffix of CPU types are provided in hw/arm/virt.c::valid_cpu_types in PATCH[2].
>> In the generic validation, the complete CPU type is used. The error message also
>> have complete CPU type there.
> 
> In some places (arm_cpu_list_entry, arm_cpu_add_definition) we use:
> 
>    g_strndup(typename, strlen(typename) - strlen("-" TYPE_ARM_CPU))
> 
> Maybe extract as a helper? cpu_typename_name()? :)
> 

Yeah, it's definitely a good idea. The helper is needed by all architectures,
not ARM alone. The following CPU types don't have explicit definition of
XXXX_CPU_TYPE_SUFFIX. We need take "-" TYPE_CPU as the suffix.

     target/microblaze/cpu.c  TYPE_MICROBLAZE_CPU
     target/hppa/cpu.c        TYPE_HPPA_CPU
     target/nios2/cpu.c       TYPE_NIOS2_CPU

     target/microblaze/cpu-qom.h:#define TYPE_MICROBLAZE_CPU "microblaze-cpu"
     target/hppa/cpu-qom.h:      #define TYPE_HPPA_CPU       "hppa-cpu"
     target/nios2/cpu.h:         #define TYPE_NIOS2_CPU      "nios2-cpu"

I think the function name can be cpu_model_name() since we have called it
as 'model' in cpu.c::parse_cpu_option(). Something like below. Please let
me know if you have more comments.

     target/xxxx/cpu.h
     -----------------

     static inline char *cpu_model_name(const char *typename)
     {
         return g_strndup(typename, strlen(typename) - strlen(TYPE_XXX_CPU_SUFFIX));
     }

Thanks,
Gavin