Re: [Qemu-devel] [PATCH 07/12] kvm: Drop KVM_CAP build dependencies

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

On 2011-06-14 13:17, Alexander Graf wrote:
> 
> On 14.06.2011, at 13:07, Jan Kiszka wrote:
> 
>> On 2011-06-14 13:05, Alexander Graf wrote:
>>>
>>> On 08.06.2011, at 16:11, Jan Kiszka wrote:
>>>
>>>> No longer needed with accompanied kernel headers. We are only left with
>>>> build dependencies that are controlled by kvm arch headers.
>>>
>>> This should completely rule out all CAPs right? IIRC, all CAPs are defined in generic code, so we don't get number overlaps.
>>
>> "We are only left with build dependencies that are controlled by kvm
>> arch headers." E.g. KVM_CAP_VCPU_EVENTS.
>>
>>>
>>>>
>>>> CC: Alexander Graf <agraf@suse.de>
>>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>> ---
>>>> kvm-all.c |    8 --------
>>>> 1 files changed, 0 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/kvm-all.c b/kvm-all.c
>>>> index 4a9910a..cbc2532 100644
>>>> --- a/kvm-all.c
>>>> +++ b/kvm-all.c
>>>> @@ -757,21 +757,17 @@ int kvm_init(void)
>>>>    s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO);
>>>>
>>>>    s->broken_set_mem_region = 1;
>>>> -#ifdef KVM_CAP_JOIN_MEMORY_REGIONS_WORKS
>>>>    ret = kvm_check_extension(s, KVM_CAP_JOIN_MEMORY_REGIONS_WORKS);
>>>>    if (ret > 0) {
>>>>        s->broken_set_mem_region = 0;
>>>>    }
>>>> -#endif
>>>>
>>>> #ifdef KVM_CAP_VCPU_EVENTS
>>>
>>> ... which leaves the question why this one is still here :).
>>
>> See above (does PPC support it?).
> 
> Well, regardless of support, the #ifdef shouldn't be required, right?
> 
> include/linux/kvm.h:518:#define KVM_CAP_VCPU_EVENTS 41
> 
> ... as long as there's a runtime check :)

Are all types and dependent constants available? Maybe it is the case
here, but you cannot generally assume this if a CAP is per-arch.

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux