@@ -110,8 +110,8 @@ Limitations
~~~~~~~~~~~
The current OvS userspace `TSO` implementation supports flat and VLAN networks
-only (i.e. no support for `TSO` over tunneled connection [VxLAN, GRE, IPinIP,
-etc.]).
+only, as well as a limited selection of protocols. Currently VxLAN, Geneve,
+and GRE are supported.
The NIC driver must support and advertise checksum offload for TCP and UDP.
However, SCTP is not mandatory because very few drivers advertised support
@@ -120,12 +120,6 @@ in Open vSwitch. Currently, if the NIC supports that, then the feature is
enabled, otherwise TSO can still be enabled but SCTP packets sent to the NIC
will be dropped.
-There is no software implementation of TSO, so all ports attached to the
-datapath must support TSO or packets using that feature will be dropped
-on ports without TSO support. That also means guests using vhost-user
-in client mode will receive TSO packet regardless of TSO being enabled
-or disabled within the guest.
-
All kernel devices that use the raw socket interface (veth, for example)
require the kernel commit 9d2f67e43b73 ("net/packet: fix packet drop as of
virtio gso") in order to work properly. This commit was merged in upstream
@@ -31,6 +31,9 @@ Post-v3.4.0
that does not have a specific value defined, rather than being
treated as a global value, aligning the behavior with that of
the kernel datapath.
+ * Packets marked for TSO and egressing on an interface which doesn't
+ support that feature will now be segmented in software, even when
+ tunnel encapsulated.
- Linux TC offload:
* Add support for matching tunnel flags if the kernel supports it.
* Add support for the "Don't Fragment" (DF) flag in the encap action,
Update userspace TSO documentation to indicate the current support for GRE tunnels. Also add an item to the NEWS file for this feature. Signed-off-by: Mike Pattrick <mkp@redhat.com> --- Documentation/topics/userspace-tso.rst | 10 ++-------- NEWS | 3 +++ 2 files changed, 5 insertions(+), 8 deletions(-)