Allow irqfd to be used for virtio-pci on s390x if the kernel supports it. This improves s390x virtio-pci performance when using kvm acceleration by allowing kvm to deliver interrupts instead of QEMU.
Reviewed-by: Eric Farman <[email protected]> Signed-off-by: Matthew Rosato <[email protected]> --- v2: - add review tag - tweak commit message (David) --- hw/s390x/s390-pci-bus.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c index e8e41c8a9a..88852acf45 100644 --- a/hw/s390x/s390-pci-bus.c +++ b/hw/s390x/s390-pci-bus.c @@ -900,6 +900,7 @@ static void s390_pcihost_realize(DeviceState *dev, Error **errp) s390_pci_init_default_group(); css_register_io_adapters(CSS_IO_ADAPTER_PCI, true, false, S390_ADAPTER_SUPPRESSIBLE, errp); + kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled(); } static void s390_pcihost_unrealize(DeviceState *dev) -- 2.51.0
