Re: [Qemu-devel] [PATCH ppc-next v2 42/52] target-ppc: Convert CPU definitions

["Andreas Färber" <afaerber@suse.de>]

Am 22.02.2013 17:32, schrieb Alexander Graf:
> 
> On 22.02.2013, at 17:31, Andreas Färber wrote:
> 
>> Am 22.02.2013 15:23, schrieb Alexander Graf:
>>>
>>> On 18.02.2013, at 10:16, Andreas Färber wrote:
>>>
>>>> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
>>>> index 2c64c63..e601059 100644
>>>> --- a/target-ppc/kvm.c
>>>> +++ b/target-ppc/kvm.c
>>>> @@ -1263,7 +1263,7 @@ static void kvmppc_host_cpu_initfn(Object *obj)
>>>>
>>>>    assert(kvm_enabled());
>>>>
>>>> -    if (pcc->info->pvr != mfpvr()) {
>>>> +    if (pcc->pvr != mfpvr()) {
>>>>        fprintf(stderr, "Your host CPU is unsupported.\n"
>>>>                "Please choose a supported model instead, see -cpu ?.\n");
>>>>        exit(1);
>>>> @@ -1275,30 +1275,38 @@ static void kvmppc_host_cpu_class_init(ObjectClass *oc, void *data)
>>>>    PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
>>>>    uint32_t host_pvr = mfpvr();
>>>>    PowerPCCPUClass *pvr_pcc;
>>>> -    ppc_def_t *spec;
>>>>    uint32_t vmx = kvmppc_get_vmx();
>>>>    uint32_t dfp = kvmppc_get_dfp();
>>>>
>>>> -    spec = g_malloc0(sizeof(*spec));
>>>> -
>>>>    pvr_pcc = ppc_cpu_class_by_pvr(host_pvr);
>>>>    if (pvr_pcc != NULL) {
>>>> -        memcpy(spec, pvr_pcc->info, sizeof(*spec));
>>>> +        pcc->pvr          = pvr_pcc->pvr;
>>>> +        pcc->svr          = pvr_pcc->svr;
>>>> +        pcc->insns_flags  = pvr_pcc->insns_flags;
>>>> +        pcc->insns_flags2 = pvr_pcc->insns_flags2;
>>>> +        pcc->msr_mask     = pvr_pcc->msr_mask;
>>>> +        pcc->mmu_model    = pvr_pcc->mmu_model;
>>>> +        pcc->excp_model   = pvr_pcc->excp_model;
>>>> +        pcc->bus_model    = pvr_pcc->bus_model;
>>>> +        pcc->flags        = pvr_pcc->flags;
>>>> +        pcc->bfd_mach     = pvr_pcc->bfd_mach;
>>>> +#ifdef TARGET_PPC64
>>>> +        pcc->sps          = pvr_pcc->sps;
>>>> +#endif
>>>> +        pcc->init_proc    = pvr_pcc->init_proc;
>>>> +        pcc->check_pow    = pvr_pcc->check_pow;
>>>
>>> It would be nice to have field copying more streamlined. This way, whoever adds a new field to the class needs to know that he also has to change this piece of code, which is non-obvious.
>>>
>>> Speaking of which, why aren't you copying parent_reset for example?
>>
>> parent_reset is already assigned by the .parent's class_init before this
>> class_init is executed.
>>
>>> Or asked differently: Why can't we do a memcpy? We're really trying to do a subclass of the parent class here, no?
>>
>> I did suggest making it a subclass in the cover letter, as follow-up. :)
>>
>> The issue is we need to know which parent class. And we do not have any
>> guarantee that in ..._register_types() the types corresponding to our
>> PVR have already been registered.
>>
>> Therefore we would need to move host CPU type registration to
>> kvm_arch_init(), as suggested by Eduardo for x86. A side effect would be
>> that the type is not yet registered at -cpu ? time. If that is
>> acceptable to you (we might hard-code its output within CONFIG_KVM), I
>> can send you a patch.
> 
> Yes, I think that's the most reasonable way forward. We can always print it explicitly in -cpu ?.

Done: http://patchwork.ozlabs.org/patch/222735/

Tested the POWER5+ case of no matching PVR and the TCG case.
Wasn't able to test on POWER7 after messing up my command line. ;)

Andreas

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