Re: [Qemu-devel] [PATCH v1 4/5] s390x/pci: Refuse to realize VFIO-PCI if AIS needed but supported

[Cornelia Huck]

On Tue, 10 Oct 2017 18:01:53 +0200
Pierre Morel <address@hidden> wrote:

> Since in the case we have no AIS in KVM only PCI is impacted, do you 
> think we can fence IRQFD for MSI with
> 
> kvm_msi_via_irqfd_allowed = false;
> 
> in kvm_arch_init_irq_routing() ?

Hm, it seems we never set that for s390x... does that imply that we
never support irqfd for pci anyway?

> 
> In fact, if we also verify the AIS availability in the same routine we 
> can avoid the ugly include of vfio/pci.h

If we can get the serialization right (and setting that value to false
does indeed have the desired effect), that's probably the way to go.