Re: [Qemu-devel] [PATCH v4] cpu: add suboptions support

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 12/20/2013 10:36 AM, Alexey Kardashevskiy wrote:
> On 12/04/2013 01:09 PM, Alexey Kardashevskiy wrote:
>> On 12/03/2013 10:09 PM, Igor Mammedov wrote:
>>> On Tue,  3 Dec 2013 14:42:48 +1100
>>> Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>>>
>>>> This adds suboptions support for -cpu. This keeps @cpu_model in order not
>>>> to break the existing architectures/machines.
>>>>
>>>> Cc: Andreas Färber <afaerber@suse.de>
>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> 
> 
> Ping, anyone?
> Patch is too bad? Any new idea how to rework it? Someone else is coming
> with a new patch?


Andreas, is that what you asked me to ping you about? :)

I guess it is outdated and I have to rework it, I just did not have chance
yet...


> 
> Thanks
> 
> 
>>>> ---
>>>> Changes:
>>>> v4:
>>>> * moved QemuOpts logic to qeom/cpu.c
>>>> * added cpu_opt_get() as the machine init code wants to know the CPU name
>>>> to create a CPU object
>>>> ---
>>>>  include/qom/cpu.h | 41 +++++++++++++++++++++++++++++++++++++++++
>>>>  qom/cpu.c         | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
>>>>  vl.c              | 23 +++++++++++++++++++++++
>>>>  3 files changed, 113 insertions(+)
>>>>
>>>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
>>>> index 7739e00..07330e1 100644
>>>> --- a/include/qom/cpu.h
>>>> +++ b/include/qom/cpu.h
>>>> @@ -124,6 +124,7 @@ typedef struct CPUClass {
>>>>                              int cpuid, void *opaque);
>>>>      int (*write_elf32_qemunote)(WriteCoreDumpFunction f, CPUState *cpu,
>>>>                                  void *opaque);
>>>> +    void (*parse_options)(CPUState *cpu, Error **errp);
>>>>  
>>>>      const struct VMStateDescription *vmsd;
>>>>      int gdb_num_core_regs;
>>>> @@ -327,6 +328,46 @@ static inline hwaddr cpu_get_phys_page_debug(CPUState *cpu, vaddr addr)
>>>>  #endif
>>>>  
>>>>  /**
>>>> + * cpu_parse_options:
>>>> + * @cpu: The CPU to set options for.
>>>> + *
>>>> + * Parses CPU options if the CPU class has a custom handler defined.
>>>> + *
>>>> + * Returns: -1 if a custom handler is defined and failed, 0 otherwise.
>>>> + */
>>>> +static inline int cpu_parse_options(CPUState *cpu)
>>> why not pass up the stack errp, vs returning -1?
>>
>>
>> Oh. Overlooked it. Not sure if we really need Error** here, do we?
>>
>> object_property_parse() will print an error anyway and QEMU then exits and
>> qemu_opt_foreach() cannot carry Error** to the caller so I'll better drop
>> it on this level.
>>
>>
>>> And of cause, there should be a patch that demonstrates an actual user
>>> of  cpu_parse_options().
>>>
>>>> +{
>>>> +    CPUClass *cc = CPU_GET_CLASS(cpu);
>>>> +    Error *err = NULL;
>>>> +
>>>> +    if (cc->parse_options) {
>>>> +        cc->parse_options(cpu, &err);
>>>> +        if (err) {
>>>> +            return -1;
>>>> +        }
>>>> +    }
>>>> +
>>>> +    /* No callback, let arch do it the old way */
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +/**
>>>> + * cpu_default_parse_options_func:
>>>> + * The default handler for CPUClass::parse_options
>>>> + * @cpu: the CPU to set option for.
>>>> + * @errp: the handling error descriptor.
>>>> + */
>>>> +void cpu_default_parse_options_func(CPUState *cpu, Error **errp);
>>> where is it used?
>>> Maybe it should be static inside of qom/cpu.c
>>> and assigned in cpu_class_init() for TYPE_CPU.
>>
>>
>> It is assigned for TYPE_POWERPC_CPU as I really do not want to switch every
>> single CPU in QEMU to use this so this is why it is not static.
>>
>> Below is how I use it for POWERPC. Next time I'll post these patches
>> together, sorry for inconvenience.
>>
>>
>>
>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>> index d93abdc..7e0fb68 100644
>> --- a/hw/ppc/spapr.c
>> +++ b/hw/ppc/spapr.c
>> @@ -33,6 +33,7 @@
>>  #include "sysemu/kvm.h"
>>  #include "kvm_ppc.h"
>>  #include "mmu-hash64.h"
>> +#include "qom/cpu.h"
>>
>>  #include "hw/boards.h"
>>  #include "hw/ppc/ppc.h"
>> @@ -1111,7 +1112,7 @@ static SaveVMHandlers savevm_htab_handlers = {
>>  static void ppc_spapr_init(QEMUMachineInitArgs *args)
>>  {
>>      ram_addr_t ram_size = args->ram_size;
>> -    const char *cpu_model = args->cpu_model;
>> +    const char *cpu_model;
>>      const char *kernel_filename = args->kernel_filename;
>>      const char *kernel_cmdline = args->kernel_cmdline;
>>      const char *initrd_filename = args->initrd_filename;
>> @@ -1131,6 +1132,8 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
>>
>>      msi_supported = true;
>>
>> +    cpu_model = cpu_opt_get("type");
>> +
>>      spapr = g_malloc0(sizeof(*spapr));
>>      QLIST_INIT(&spapr->phbs);
>>
>> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
>> index 1b0ff38..d24920b 100644
>> --- a/target-ppc/translate_init.c
>> +++ b/target-ppc/translate_init.c
>> @@ -7381,6 +7381,10 @@ static void init_ppc_proc(PowerPCCPU *cpu)
>>      /* PowerPC implementation specific initialisations (SPRs, timers, ...) */
>>      (*pcc->init_proc)(env);
>>
>> +    if (cpu_parse_options(CPU(cpu))) {
>> +        exit(1);
>> +    }
>> +
>>      /* MSR bits & flags consistency checks */
>>      if (env->msr_mask & (1 << 25)) {
>>          switch (env->flags & (POWERPC_FLAG_SPE | POWERPC_FLAG_VRE)) {
>> @@ -8676,6 +8680,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void
>> *data)
>>  #endif
>>
>>      dc->fw_name = "PowerPC,UNKNOWN";
>> +    cc->parse_options = cpu_default_parse_options_func;
>>  }
>>
>>  static const TypeInfo ppc_cpu_type_info = {
>>
>>
>>
> 
> 


-- 
Alexey