Re: [PATCH] kvm-userspace: fix memslot assignment

[Izik Eidos <izik@qumranet.com>]

Avi Kivity wrote:
> Christian Borntraeger wrote:
>> Am Dienstag, 29. Juli 2008 schrieb Avi Kivity:
>>  
>>> They all start with 0 AFAIK (kvm also starts with 0, it just wants 
>>> it to be a special slot).
>>>     
>>
>> Now my brain hurts....
>> Ok, so I read this as: ppc, ia64 and s390 can start with slot 0 and 
>> it is not a special slot.
>> On x86 slot 0 is special, if
>> * KVM_CAP_SET_TSS_ADDR is not available
>> or
>> * The ioctl VM_CAP_SET_TSS_ADDR returns <=0
>>
>>   
>
> I think this is right.  Izik can you confirm?

yea kernels that dont have KVM_CAP_SET_TSS_ADDR should be treated like that.

>
>> +#if defined(__x86_64__) || defined(__i386__)
>> +#if defined(KVM_CAP_SET_TSS_ADDR)
>> +    if (ioctl(kvm->fd, KVM_CHECK_EXTENSION, KVM_CAP_SET_TSS_ADDR) > 0)
>>   
>
> Should be <= here?
>
>> +        i++;
>> +#else
>> +    i++;
>> +#endif
>> +#endif
>>   
>
> Suggest a helper, kvm_supports_set_tss_addr(), to reduce further 
> braindamage.
>