On Wed, 2008-08-13 at 16:01 +0100, Daniel P. Berrange wrote: > On Wed, Aug 13, 2008 at 03:53:27PM +0100, Mark McLoughlin wrote: > > By enabling this flag on the tap fds we create, we greatly increase > > the achievable throughput with virtio_net. > > > > However, we need to be careful to only set the flag when a) KVM has > > support for this ABI and b) the value of the flag is queryable using > > the TUNGETIFF ioctl. > > This suggests to me that QEMU should be a the one enabling this > flag, not libvirt. It has to be done before adding it to the bridge and can't be changed afterwards. (Which perhaps suggests the kernel API is a little dumb, but ...) > Its going to need todo this anyway for the > scenario where QEMU allocates the TAP fd, so it might as well > enable it for pre-allocated TAP fds passed in from external > apps. Yeah, it already does it for the fds it allocates. Cheers, Mark. -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list