On Fri, Mar 15, 2013 at 05:12:38PM -0700, sfel...@cumulusnetworks.com wrote: > From: Scott Feldman <sfel...@cumulusnetworks.com> > > Socket buffer sizes were hard-coded to 4K. Bump this up to 12K to handle > typical > MTU=9000 Jumbo frame pkt. Ran into this limitation when using -netdev UDP > sockets > to connect VM-to-VM, where VM interface is configure with MTU=9000. Using > virtio_net NIC model. Test is simple: ping -M do -s 8500 <target>. This test > will attempt to ping with unfragmented packet of given size. Without patch, > size is limited to < 4K (minus protocol hdrs). With patch, ping test works > with pkt size up to 9000 (again, minus protocol hdrs). > > Signed-off-by: Scott Feldman <sfel...@cumulusnetworks.com> > --- > net/net.c | 2 +- > net/socket.c | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-)
grep reveals that VDE is limited in a similar way. tap-win32 may be affected too. I noticed that Linux tap goes straight for: net/tap.c:#define TAP_BUFSIZE (4096 + 65536) The 4096 is reserved for network/virtio headers. Please move TAP_BUFSIZE to include/net/net.h and rename it to NET_BUFSIZE. Then socket, vde, and tap-win32 can use it. Stefan
