Andrew Melnychenko
2022-Dec-01 21:56 UTC
[PATCH v4 0/6] TUN/VirtioNet USO features support.
Added new offloads for TUN devices TUN_F_USO4 and TUN_F_USO6. Technically they enable NETIF_F_GSO_UDP_L4 (and only if USO4 & USO6 are set simultaneously). It allows the transmission of large UDP packets. UDP Segmentation Offload (USO/GSO_UDP_L4) - ability to split UDP packets into several segments. It's similar to UFO, except it doesn't use IP fragmentation. The drivers may push big packets and the NIC will split them(or assemble them in case of receive), but in the case of VirtioNet we just pass big UDP to the host. So we are freeing the driver from doing the unnecessary job of splitting. The same thing for several guests on one host, we can pass big packets between guests. Different features USO4 and USO6 are required for qemu where Windows guests can enable disable USO receives for IPv4 and IPv6 separately. On the other side, Linux can't really differentiate USO4 and USO6, for now. For now, to enable USO for TUN it requires enabling USO4 and USO6 together. In the future, there would be a mechanism to control UDP_L4 GSO separately. New types for virtio-net already in virtio-net specification: https://github.com/oasis-tcs/virtio-spec/issues/120 Test it WIP Qemu https://github.com/daynix/qemu/tree/USOv3 Andrew (5): uapi/linux/if_tun.h: Added new offload types for USO4/6. driver/net/tun: Added features for USO. uapi/linux/virtio_net.h: Added USO types. linux/virtio_net.h: Support USO offload in vnet header. drivers/net/virtio_net.c: Added USO support. Andrew Melnychenko (1): udp: allow header check for dodgy GSO_UDP_L4 packets. drivers/net/tap.c | 10 ++++++++-- drivers/net/tun.c | 8 +++++++- drivers/net/virtio_net.c | 24 +++++++++++++++++++++--- include/linux/virtio_net.h | 9 +++++++++ include/uapi/linux/if_tun.h | 2 ++ include/uapi/linux/virtio_net.h | 5 +++++ net/ipv4/udp_offload.c | 3 ++- net/ipv6/udp_offload.c | 3 ++- 8 files changed, 56 insertions(+), 8 deletions(-) -- 2.38.1
Michael S. Tsirkin
2022-Dec-01 22:33 UTC
[PATCH v4 0/6] TUN/VirtioNet USO features support.
On Thu, Dec 01, 2022 at 11:56:38PM +0200, Andrew Melnychenko wrote:> Added new offloads for TUN devices TUN_F_USO4 and TUN_F_USO6. > Technically they enable NETIF_F_GSO_UDP_L4 > (and only if USO4 & USO6 are set simultaneously). > It allows the transmission of large UDP packets. > > UDP Segmentation Offload (USO/GSO_UDP_L4) - ability to split UDP packets > into several segments. It's similar to UFO, except it doesn't use IP > fragmentation. The drivers may push big packets and the NIC will split > them(or assemble them in case of receive), but in the case of VirtioNet > we just pass big UDP to the host. So we are freeing the driver from doing > the unnecessary job of splitting. The same thing for several guests > on one host, we can pass big packets between guests. > > Different features USO4 and USO6 are required for qemu where Windows > guests can enable disable USO receives for IPv4 and IPv6 separately. > On the other side, Linux can't really differentiate USO4 and USO6, for now. > For now, to enable USO for TUN it requires enabling USO4 and USO6 together. > In the future, there would be a mechanism to control UDP_L4 GSO separately. > > New types for virtio-net already in virtio-net specification: > https://github.com/oasis-tcs/virtio-spec/issues/120 > > Test it WIP Qemu https://github.com/daynix/qemu/tree/USOv3 > > Andrew (5): > uapi/linux/if_tun.h: Added new offload types for USO4/6. > driver/net/tun: Added features for USO. > uapi/linux/virtio_net.h: Added USO types. > linux/virtio_net.h: Support USO offload in vnet header. > drivers/net/virtio_net.c: Added USO support. > > Andrew Melnychenko (1): > udp: allow header check for dodgy GSO_UDP_L4 packets.I don't see patches except 0 on list.> drivers/net/tap.c | 10 ++++++++-- > drivers/net/tun.c | 8 +++++++- > drivers/net/virtio_net.c | 24 +++++++++++++++++++++--- > include/linux/virtio_net.h | 9 +++++++++ > include/uapi/linux/if_tun.h | 2 ++ > include/uapi/linux/virtio_net.h | 5 +++++ > net/ipv4/udp_offload.c | 3 ++- > net/ipv6/udp_offload.c | 3 ++- > 8 files changed, 56 insertions(+), 8 deletions(-) > > -- > 2.38.1 > > _______________________________________________ > Virtualization mailing list > Virtualization at lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/virtualization >