[Qemu-devel] Re: [Patch] Small fix for qemu APIC for Mac OS X support

[Jan Kiszka <jan.kiszka@siemens.com>]

Am 24.11.2010 12:00, Alexander Graf wrote:
>>>> According to to the Intel IA-32 Software Developers Manual Vol 3 page
>>>> 290, the version should be 0x14 Pentium 4/Xeon CPUs anyway.
>>>>
>>>> Signed-off-by: Andrew de Quincey <adq@lidskialf.net>
>>>>
>>>> diff --git a/hw/apic.c b/hw/apic.c
>>>> index 5f4a87c..20304e0 100644
>>>> --- a/hw/apic.c
>>>> +++ b/hw/apic.c
>>>> @@ -704,7 +704,7 @@ static uint32_t apic_mem_readl(void *opaque,
>>>> target_phys_addr_t addr)
>>>>         val = s->id << 24;
>>>>         break;
>>>>     case 0x03: /* version */
>>>> -        val = 0x11 | ((APIC_LVT_NB - 1) << 16); /* version 0x11 */
>>>> +        val = 0x14 | ((APIC_LVT_NB - 1) << 16); /* version 0x14 */
>>>
>>> What exactly changed between the versions? Did new registers get introduced or subtle behavior change? Is there some proper documentation on the changed between the apic versions?
>>
>> I've been trying to find out; I'm still searching intel's docs to find
>> an 0x11 version to compare with :(
> 
> Please try very hard. I haven't found anything myself either yet, but without a spec it's hard to justify these changes upstream :(.
> 
>> The failure mode is that mac os X SL whines about the APIC being an
>> unexpected version (0x11) and it wants 0x14 as a minimum.
> 
> Yup, I remember that issue. To really make this all useful, we also need to change the numbers in KVM though.

Also, the version has to be set depending on the emulated CPU (even more
when there will be emulation differences).

Jan

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