Hello! I have updated and successfully tested an old patch set introducing eventfd support for virtio-mmio, enabling to use vhost-net with it: https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html I would like to upstream it, since virtio-mmio is still there. I know that some of you consider it deprecated, however i believe this is not entirely true. Because you can add it to machine models which are not supposed to have PCI (like vexpress). An old patch set relied on additional "eventfd" option in order to disable the support if not implemented in kernel. My version simply checks kvm_eventfds_enabled() for this purpose, so backwards compatibility is much better. I confirm that this solution significantly improves the network performance even without using irqfd.
Kind regards, Pavel Fedin Expert Engineer Samsung Electronics Research center Russia
