Re: [qemu-s390x] [PATCH v1 0/5][RFC] Refactoring of AIS support

[Christian Borntraeger]

On 10/30/2017 01:42 PM, Cornelia Huck wrote:
> On Mon, 30 Oct 2017 09:28:09 +0100
> Christian Borntraeger <address@hidden> wrote:
> 
>> Now I thought about that for a while and I start to think that we cannot 
>> implement ais
>> in QEMU and cover all cases.
>> One aspect was certainly passthrough (like you handled in patch 4).
>> Another aspect is that some interrupts might be injected from the kernel - 
>> even for
>> emulated devices. e.g. virtio-pci together with vhost-net, will inject 
>> interrupts via
>> the set_irq callback. I think disabling irqfd for these cases is not a good 
>> idea.
> 
> Is there still a fallback for irqfd emulation?

it might disable dataplane or other things. (it once did). So I think we should 
not
go down this path.

> 
>>
>> So what about adding a new KVM capability (for 4.14), fixup the other things 
>> in
>> QEMU and then bind it to the new capability?
> 
> For 4.15, surely?
> 
> Probably the only way we can make this work correctly...
>