similar to: virtio: Subtle changes to virtio_net flags breaks VXLAN on Google Cloud

On Tue, Jan 17, 2017 at 04:20:49PM +0000, Rolf Neugebauer wrote: > Commits: > > fd2a0437dc33 virtio_net: introduce virtio_net_hdr_{from,to}_skb > e858fae2b0b8 virtio_net: use common code for virtio_net_hdr and skb > GSO conversion > > introduced a subtle (but unexplained) difference in how virtio_net > flags are derived from skb->ip_summed fields on transmit from the

There's no need for the guest to validate the checksum if it have been validated by host nics. So this patch introduces a new flag - VIRTIO_NET_HDR_F_DATA_VALID which is used to bypass the checksum examing in guest. The backend (tap/macvtap) may set this flag when met skbs with CHECKSUM_UNNECESSARY to save cpu utilization. No feature negotiation is needed as old driver just ignore this flag.

There's no need for the guest to validate the checksum if it have been validated by host nics. So this patch introduces a new flag - VIRTIO_NET_HDR_F_DATA_VALID which is used to bypass the checksum examing in guest. The backend (tap/macvtap) may set this flag when met skbs with CHECKSUM_UNNECESSARY to save cpu utilization. No feature negotiation is needed as old driver just ignore this flag.

Another checksum offload problem was reported on xen-users, when using a domU as a firewall: http://lists.xensource.com/archives/html/xen-users/2006-04/msg01150.html It also fails without VLANs. The path from dom0->domU with ip_summed==CHECKSUM_HW/proto_csum_blank==1 is broken. - skb_checksum_setup() assumes that a checksum will definitely be calculated in dev_queue_xmit(), but the

Hi, This patches introduce virtio_net_hdr_{from,to}_skb functions for conversion of GSO information between skb and virtio_net_hdr. Mike Rapoport (6): virtio_net: add _UAPI prefix to virtio_net header guards virtio_net: introduce virtio_net_hdr_{from,to}_skb macvtap: use common code for virtio_net_hdr and skb GSO conversion tuntap: use common code for virtio_net_hdr and skb GSO

Hi, This patches introduce virtio_net_hdr_{from,to}_skb functions for conversion of GSO information between skb and virtio_net_hdr. Mike Rapoport (6): virtio_net: add _UAPI prefix to virtio_net header guards virtio_net: introduce virtio_net_hdr_{from,to}_skb macvtap: use common code for virtio_net_hdr and skb GSO conversion tuntap: use common code for virtio_net_hdr and skb GSO

On Wed, 23 Sep 2015 19:45:08 +0100 David Woodhouse <dwmw2 at infradead.org> wrote: > Commit 7d82410950aa ("virtio: add explicit big-endian support to memory > accessors") accidentally changed the virtio_net header used by > AF_PACKET with PACKET_VNET_HDR from host-endian to big-endian. > Hi David, Oops my bad... I obviously overlooked this one when adding

On Wed, 23 Sep 2015 19:45:08 +0100 David Woodhouse <dwmw2 at infradead.org> wrote: > Commit 7d82410950aa ("virtio: add explicit big-endian support to memory > accessors") accidentally changed the virtio_net header used by > AF_PACKET with PACKET_VNET_HDR from host-endian to big-endian. > Hi David, Oops my bad... I obviously overlooked this one when adding

On Wed, Jun 28, 2017 at 08:05:06PM +0800, Jason Wang wrote: > > > On 2017?06?28? 12:01, Michael S. Tsirkin wrote: > > On Wed, Jun 28, 2017 at 11:40:30AM +0800, Jason Wang wrote: > > > > > > On 2017?06?28? 11:31, Michael S. Tsirkin wrote: > > > > On Wed, Jun 28, 2017 at 10:45:18AM +0800, Jason Wang wrote: > > > > > On 2017?06?28? 10:17,

On Wed, Jun 28, 2017 at 08:05:06PM +0800, Jason Wang wrote: > > > On 2017?06?28? 12:01, Michael S. Tsirkin wrote: > > On Wed, Jun 28, 2017 at 11:40:30AM +0800, Jason Wang wrote: > > > > > > On 2017?06?28? 11:31, Michael S. Tsirkin wrote: > > > > On Wed, Jun 28, 2017 at 10:45:18AM +0800, Jason Wang wrote: > > > > > On 2017?06?28? 10:17,

Now that we have SCTP offload capabilities in the kernel, we can add them to virtio as well. First step is SCTP checksum. We need a new freature in virtio to negotiate this support since SCTP is excluded with the stardard checksum and requires a little bit extra. This series proposes VIRTIO_NET_F_SCTP_CSUM feature bit. As the "little bit extra", the kernel uses a new bit in the skb

Now that we have SCTP offload capabilities in the kernel, we can add them to virtio as well. First step is SCTP checksum. We need a new freature in virtio to negotiate this support since SCTP is excluded with the stardard checksum and requires a little bit extra. This series proposes VIRTIO_NET_F_SCTP_CSUM feature bit. As the "little bit extra", the kernel uses a new bit in the skb

Commit 501db511397f ("virtio: don't set VIRTIO_NET_HDR_F_DATA_VALID on xmit") in fact disables VIRTIO_HDR_F_DATA_VALID on receiving path too, fixing this by adding a hint (has_data_valid) and set it only on the receiving path. Cc: Rolf Neugebauer <rolf.neugebauer at docker.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/macvtap.c | 2 +-

Commit 501db511397f ("virtio: don't set VIRTIO_NET_HDR_F_DATA_VALID on xmit") in fact disables VIRTIO_HDR_F_DATA_VALID on receiving path too, fixing this by adding a hint (has_data_valid) and set it only on the receiving path. Cc: Rolf Neugebauer <rolf.neugebauer at docker.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/macvtap.c | 2 +-

Note: stub out endian-ness conversion for now. We'll add a flag to control it for BE guests later. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- This will be needed once __virtio16 typedefs come in. drivers/net/tun.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index

Note: stub out endian-ness conversion for now. We'll add a flag to control it for BE guests later. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- This will be needed once __virtio16 typedefs come in. drivers/net/tun.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index

From: Rusty Russell <rusty at rustcorp.com.au> [Cornelia Huck: converted some missed fields] Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/drivers/net/virtio_net.c

From: Rusty Russell <rusty at rustcorp.com.au> [Cornelia Huck: converted some missed fields] Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12

From: Rusty Russell <rusty at rustcorp.com.au> [Cornelia Huck: converted some missed fields] Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12

From: Rusty Russell <rusty at rustcorp.com.au> [Cornelia Huck: converted some missed fields] Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12