Re: [Qemu-devel] [PATCH] kvm-all.c: Move init of irqchip_inject_ioctl out of kvm_irqchip_create()

[Jan Kiszka]

On 2012-08-14 13:01, Avi Kivity wrote:
> On 08/14/2012 10:33 AM, Jan Kiszka wrote:
>>
>> KVM_IRQ_LINE is old-style, deprecated, KVM_IRQ_LINE_STATUS (i.e
>> injection with feedback to allow lost-tick compensation) is the current
>> standard that other archs should pick up.
> 
> KVM_IRQ_LINE_STATUS may not make sense on all architectures.
> 
> I don't think we're really deprecating KVM_IRQ_LINE or discouraging its
> use.  It's not like the kernel-allocated memory slot ioctls.

I do not think it makes sense to provide both interfaces long term
(provided we ever do a cut). Also, it's almost trivial to provide the
add-on feature of KVM_IRQ_LINE_STATUS, and it keeps the door open for
IRQ decoalescing. If there is no way for an arch to detect coalescing,
it can still return >0 unconditionally.

Jan

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