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Date: Mon, 30 Oct 2017 13:42:33 +0100
From: Cornelia Huck <cohuck@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v1 0/5][RFC] Refactoring of AIS support
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To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Pierre Morel <pmorel@linux.vnet.ibm.com>, qemu-devel@nongnu.org, agraf@suse.de, zyimin@linux.vnet.ibm.com, pasic@linux.vnet.ibm.com, qemu-s390x@nongnu.org

On Mon, 30 Oct 2017 09:28:09 +0100
Christian Borntraeger <borntraeger@de.ibm.com> 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?

> 
> 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...