similar to: [PATCH RFC] vhost-net: add dhclient work-around from userspace

Userspace virtio server has the following hack so guests rely on it, and we have to replicate it, too: Use port number to detect incoming IPv4 DHCP response packets, and fill in the checksum for these. The issue we are solving is that on linux guests, some apps that use recvmsg with AF_PACKET sockets, don't know how to handle CHECKSUM_PARTIAL; The interface to return the relevant information

Userspace virtio server has the following hack so guests rely on it, and we have to replicate it, too: Use port number to detect incoming IPv4 DHCP response packets, and fill in the checksum for these. The issue we are solving is that on linux guests, some apps that use recvmsg with AF_PACKET sockets, don't know how to handle CHECKSUM_PARTIAL; The interface to return the relevant information

On Wed, Sep 23, 2015 at 07:45:08PM +0100, David Woodhouse 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. > > Since virtio_legacy_is_little_endian() is a very long identifier, > define a VIO_LE macro and use

On Wed, Sep 23, 2015 at 07:45:08PM +0100, David Woodhouse 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. > > Since virtio_legacy_is_little_endian() is a very long identifier, > define a VIO_LE macro and use

On Thu, Sep 24, 2015 at 09:25:45AM +0200, Greg Kurz wrote: > 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

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 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

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 guest to the host/backend. Prior to the patches the flags would be set to VIRTIO_NET_HDR_F_NEEDS_CSUM if

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 guest to the host/backend. Prior to the patches the flags would be set to VIRTIO_NET_HDR_F_NEEDS_CSUM if

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.

On Fri, Jan 20, 2017 at 02:32:42PM +0800, Jason Wang wrote: > 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> >

Implement skb_partial_csum_set, for setting partial csums on untrusted packets. Use it in virtio_net (replacing buggy version there), it's also going to be used by TAP for partial csum support. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- drivers/net/virtio_net.c | 11 +---------- include/linux/skbuff.h | 1 + net/core/skbuff.c | 29

Implement skb_partial_csum_set, for setting partial csums on untrusted packets. Use it in virtio_net (replacing buggy version there), it's also going to be used by TAP for partial csum support. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- drivers/net/virtio_net.c | 11 +---------- include/linux/skbuff.h | 1 + net/core/skbuff.c | 29

Hi folks I have created a script file (dsmark+policing.sh attached) to check graphic an text outputs of simutations, against original examples/dsmark+policing coding (see TCNG Reference Manual-pg.90). It uses tcng coding (*.tcsim file attached) and old tc coding (*.tcsim_old file attached) inserted in tcsim files. Observation 1: The graphic outputs from (*.tc included in *.tcsim) and (*.tc_old

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 +-

Feedback welcome, as always! (There's been talk of a virtualization git tree, in which case there'll be a decent home for these patches soon). Cheers, Rusty. == Add feature and GSO support to virtio net driver. If you don't do GSO, you can simply ignore the first sg element of every outgoing packet, and tack a dummy one on every incoming. Signed-off-by: Rusty Russell

Feedback welcome, as always! (There's been talk of a virtualization git tree, in which case there'll be a decent home for these patches soon). Cheers, Rusty. == Add feature and GSO support to virtio net driver. If you don't do GSO, you can simply ignore the first sg element of every outgoing packet, and tack a dummy one on every incoming. Signed-off-by: Rusty Russell