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Re: [Qemu-devel] [PATCH 3/5] target-i386: call x86_cpu_realize() after A
liu ping fan
Re: [Qemu-devel] [PATCH 3/5] target-i386: call x86_cpu_realize() after APIC is initialized.
Wed, 11 Jul 2012 15:32:14 +0800
On Mon, Jul 9, 2012 at 8:57 PM, Andreas Färber <address@hidden> wrote:
> Am 09.07.2012 12:59, schrieb igor:
>> On 06/20/2012 03:35 PM, Andreas Färber wrote:
>>> Am 20.06.2012 14:59, schrieb Igor Mammedov:
>>>> It's not correct to make CPU runnable (i.e. calling x86_cpu_realize())
>>>> when not all properties are set (APIC in this case).
>>>> Fix it by calling x86_cpu_realize() at board level after APIC is
>>>> initialized, right before cpu_reset().
>>>> Signed-off-by: Igor Mammedov <address@hidden>
>>>> hw/pc.c | 1 +
>>>> target-i386/helper.c | 2 --
>>>> 2 files changed, 1 insertion(+), 2 deletions(-)
>>>> diff --git a/hw/pc.c b/hw/pc.c
>>>> index 8368701..8a662cf 100644
>>>> --- a/hw/pc.c
>>>> +++ b/hw/pc.c
>>>> @@ -948,6 +948,7 @@ static X86CPU *pc_new_cpu(const char *cpu_model)
>>>> env->apic_state = apic_init(env, env->cpuid_apic_id);
>>>> qemu_register_reset(pc_cpu_reset, cpu);
>>>> + x86_cpu_realize(OBJECT(cpu), NULL);
>>>> return cpu;
>>>> diff --git a/target-i386/helper.c b/target-i386/helper.c
>>>> index c52ec13..b38ea7f 100644
>>>> --- a/target-i386/helper.c
>>>> +++ b/target-i386/helper.c
>>>> @@ -1161,8 +1161,6 @@ X86CPU *cpu_x86_init(const char *cpu_model)
>>>> return NULL;
>>>> - x86_cpu_realize(OBJECT(cpu), NULL);
>>>> return cpu;
>>> This will require changes in linux-user and possibly bsd-user. Having a
>>> cpu_realize() would probably help with avoiding #ifdef'ery.
>>> Unfortunately deriving CPUState from DeviceState proves a bit difficult
>>> in the meantime (it worked at one point, now there's lots of circular
>>> header dependencies), and realize support for Object got stopped.
>> As alternative to keep, I could leave x86_cpu_realize() in
>> cpu_x86_init() and keep pc_cpu_reset() in pc_new_cpu(). That will result
>> in calling cpu_reset() 3 instead of 2 times.
>> Later when apic_init is moved inside cpu.c, a pc_cpu_reset() in
>> pc_new_cpu() would be unnecessary and could be cleaned up then.
> Let me explain in more detail what I was thinking about: cpu_init() and
> cpu_x86_init() today return an initialized/realized object. I don't want
> bugs to creep into the user emulators because someone is not aware that
> x86 is semantically differing from all other targets.
> What I did for a qemu-rl78 machine is to inline cpu_rl78_init() so that
> I could put code in between, i.e., for x86: object_new(), APIC/BSP
> stuff, x86_cpu_realize(). That way any addition to the realize function
> will still affect the user emulators.
> The downside is that when we add x86 CPU subclasses we'd have to
What do you mean " add x86 CPU subclasses" ? Derive from class X86CPU
? And any scene for that?
> remember to update two places. The solution to that would be to split
> out a x86_cpu_new() function used from cpu_x86_init() and wherever you
> need it for the PC machine. Then the code is still maintainable in one
> central place and you get to do your APIC cleanups, and we don't depend
> on a central realize implementation or device parent, what do you think?
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