[PATCH 1/7] KVM: api: add kvm_irq_routing_extended_msi

On 06/07/2015 17:37, Andre Przywara wrote:

Wouldn't:
    if (kvm_vm_check_extension(s, KVM_CAP_MSI_DEVID)) {
        kroute.flags = KVM_MSI_VALID_DEVID;
        kroute.u.msi.devid = (pci_bus_num(dev->bus) << 8) | dev->devfn;
    }

be saner (without a global variable)?
That would make the interface more consistent, with a new flag being
protected by a new capability.

I agree that your version is niceer, but you still need to cache the
kvm_vm_check_extension result... in a global variable. :)

Paolo