On 25/06/2015 18:10, Andreas Färber wrote:
> Am 25.06.2015 um 18:02 schrieb Paolo Bonzini:
>> On 25/06/2015 18:00, Andreas Färber wrote:
>>>> - if (!mmio_registered) {
>>>> - ICCBus *b = ICC_BUS(qdev_get_parent_bus(dev));
>>>> - memory_region_add_subregion(b->apic_address_space, 0,
>>>> &s->io_memory);
>>>> - mmio_registered = true;
>>>> - }
>>>> +
>>>> + root = address_space_root_memory_region(cpu->as);
>>>> + memory_region_add_subregion_overlap(root,
>>>> + s->apicbase &
>>>> MSR_IA32_APICBASE_BASE,
>>>> + &s->io_memory,
>>>> + 0x1000);
>>>>
>>
>> I had already remarked that this patch is wrong. cpu->as is completely
>> unused on KVM, for example.
>
> Ah, then I don't understand this [RESEND]. ;)
> Either way, not on my plate ATM, it seems.
>
> Did you also outline how it is supposed to be done instead?
I said "I think this patch is incorrect, because you do not install a
separate address space for each CPU. Also, the CPU address space is
only used with TCG so it should be guarded by "if (tcg_enabled())"."
By the way, now TCG _is_ installing a separate address space per CPU
already, so the patch can simply guard the code with "if (tcg_enabled())".
Paolo
