On Tue, Mar 15, 2011 at 12:18 PM, Ben Pfaff <b...@nicira.com> wrote: > Some Linux network drivers support a feature called "VLAN acceleration", > associated with a data structure called a "vlan_group". A vlan_group is, > abstractly, a dictionary that maps from a VLAN ID (in the range 0...4095) > to a VLAN device, that is, a Linux network device associated with a > particular VLAN, e.g. "eth0.9" for VLAN 9 on eth0. > > Some drivers that support VLAN acceleration have bugs that fall roughly > into the following categories: > > * Some NICs strip VLAN tags on receive if no vlan_group is registered, > so that the tag is completely lost. > > * Some drivers size their receive buffers based on whether a vlan_group > is enabled, meaning that a maximum size packet with a VLAN tag will > not fit if a vlan_group is not configured. > > * On transmit some drivers expect that VLAN acceleration will be used > if it is available (which can only be done if a vlan_group is > configured). In these cases, the driver may fail to parse the packet > and correctly setup checksum offloading and/or TSO. > > The correct long term solution is to fix these driver bugs. To cope until > then, we have prepared a patch to the Linux kernel network stack that works > around these problems. This commit adds support for the workaround > implemented by that patch. > > Signed-off-by: Ben Pfaff <b...@nicira.com>
Acked-by: Jesse Gross <je...@nicira.com> _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
