Re: [Qemu-devel] [PATCH qom-next 11/12] target-i386: initialize APIC at CPU level

[Jan Kiszka]

On 2012-05-30 16:52, Igor Mammedov wrote:
> On 05/30/2012 04:38 PM, Jan Kiszka wrote:
>> On 2012-05-30 16:27, Igor Mammedov wrote:
>>>>> +
>>>>> +#ifndef CONFIG_USER_ONLY
>>>>> +#define MSI_ADDR_BASE 0xfee00000
>>>>> +
>>>>> +static void x86_cpu_apic_init(X86CPU *cpu, Error **errp)
>>>>> +{
>>>>> +    static int apic_mapped;
>>>>> +    CPUX86State *env =&cpu->env;
>>>>> +
>>>>> +    if (env->apic_state == NULL) {
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    if (qdev_init(env->apic_state)) {
>>>>> +        error_set(errp, QERR_DEVICE_INIT_FAILED,
>>>>> +                  object_get_typename(OBJECT(env->apic_state)));
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    /* XXX: mapping more APICs at the same memory location */
>>>>> +    if (apic_mapped == 0) {
>>>>> +        /* NOTE: the APIC is directly connected to the CPU - it is not
>>>>> +           on the global memory bus. */
>>>>> +        /* XXX: what if the base changes? */
>>>>> +        sysbus_mmio_map(sysbus_from_qdev(env->apic_state), 0, 
>>>>> MSI_ADDR_BASE);
>>>>> +        apic_mapped = 1;
>>>>>        }
>>>>>    }
>>>>> +#endif
>>>>>
>>>>>    void x86_cpu_realize(Object *obj, Error **errp)
>>>>>    {
>>>>>        X86CPU *cpu = X86_CPU(obj);
>>>>>
>>>>> +    x86_cpu_apic_init(cpu, errp);
>>>>> +    if (error_is_set(errp)) {
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>
>>>> I guess you are lacking #ifndef CONFIG_USER_ONLY here already (for the
>>>> sake of bisectability). Or, likely better, let x86_cpu_apic_init do
>>>> nothing for usermode emulation.
>>> initially x86_cpu_apic_init() was doing nothing for usermode, hence lack of
>>> #ifndef CONFIG_USER_ONLY, but then for patch 12/12 #ifndef CONFIG_USER_ONLY
>>> required here any way so I've removed usermode stub x86_cpu_apic_init() and
>>> squashed change in wrong patch :(.
>>>
>>> And since I need #ifndef in initfn anyway then probably there is no point
>>> in having x86_cpu_apic_init(), I'll move its body in initfn then.
>>
>> I think a function is cleaner, and we have some other examples for this
>> already in this context. Its body could easily be #ifdef'ed out (the
>> other reason for #ifdef in the initfn are temporary, no?).
> Yes, is temporary.
> However if Peter could be persuaded not to object for putting mapping of APIC 
> base
> into apic's initfn then x86_cpu_apic_init() would be temporary as well 
> (qdev_init part
> goes away with realize property and apic base mapping could be moved into it's
> own property setter in apic object and default mapping set in its initfn).
> Andreas seems liked putting it there.
> Then overall code would look cleaner and with less ifdefs.

"Unfortunately", the mapping belongs to the CPU because it actually
performs it as we pointed out.

Jan

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