On Wed, Oct 03, 2012 at 04:14:17PM +0930, Rusty Russell wrote: > "Michael S. Tsirkin" <mst@xxxxxxxxxx> writes: > > > Thinking about Sasha's patches, we can reduce ring usage > > for virtio net small packets dramatically if we put > > virtio net header inline with the data. > > This can be done for free in case guest net stack allocated > > extra head room for the packet, and I don't see > > why would this have any downsides. > > I've been wanting to do this for the longest time... but... > > > Even though with my recent patches qemu > > no longer requires header to be the first s/g element, > > we need a new feature bit to detect this. > > A trivial qemu patch will be sent separately. > > There's a reason I haven't done this. I really, really dislike "my > implemention isn't broken" feature bits. We could have an infinite > number of them, for each bug in each device. > > So my plan was to tie this assumption to the new PCI layout. I don't object but old qemu has this limitation for s390 as well, and that's not using PCI, right? So how do we detect new hypervisor there? -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
