search for: skb_put

...wire that are sent from one domU to another while they travel over the dom0 bridge. This has worked fine as long as I was tinkering with UDP packets only - but when I try to reinject TCP frames with an increased length, I run into a BUG() because net/netfilter/nfnetlink_queue.c:nfqnl_mangle() calls skb_put() which requires the skb to be aligned, which it apparently isn''t in a Xen environment. I''ve ported my network scenario to a Usermode Linux setup and it''s working perfectly fine there, so I presume this has something to do with Xen''s network driver implementatio...

...*/ > pkt_hdr = virtio_vsock_hdr(pkt); > payload_len = pkt->len; >- payload_buf = pkt->data; > > skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len, > GFP_ATOMIC); >@@ -160,7 +191,13 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) > skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr)); > > if (payload_len) { >- skb_put_data(skb, payload_buf, payload_len); >+ if (skb_is_nonlinear(skb)) { >+ void *data = skb_put(skb, payload_len); >+ >+ virtio_transport_copy_nonlinear_skb(skb, data, payload_len); >+ } else { >...

Hi: Here are the patches I used for testing KVM with virtio-net using TSO. There are three patches for the tun device which are basically Rusty's patches with the mmap turned into copying (for correctness). Two patches are for the virtio-net frontend, one required to support receiving SG/TSO, and the other useful for testing SG per se. The other patch is to the KVM backend to make all this

Hi: Here are the patches I used for testing KVM with virtio-net using TSO. There are three patches for the tun device which are basically Rusty's patches with the mmap turned into copying (for correctness). Two patches are for the virtio-net frontend, one required to support receiving SG/TSO, and the other useful for testing SG per se. The other patch is to the KVM backend to make all this

..._hdr_sz); > + > + skb = build_skb(xdp->data_hard_start, buflen); > + if (!skb) { > + err = -ENOMEM; > + goto err; > + } So fundamentally why is it called XDP? We just build and skb, don't we? > + > + skb_reserve(skb, xdp->data - xdp->data_hard_start); > + skb_put(skb, xdp->data_end - xdp->data); > + > + skb_set_network_header(skb, ETH_HLEN); > + skb_reset_mac_header(skb); > + skb->protocol = eth_hdr(skb)->h_proto; > + > + if (vnet_hdr_len) { > + err = virtio_net_hdr_to_skb(skb, gso, tap_is_little_endian(q)); > + if (err...

...o_transport_init_zcopy_skb(vsk, skb, iter, true); >+} >+ >+static int virtio_transport_copy_payload(struct sk_buff *skb, >+ struct vsock_sock *vsk, >+ struct virtio_vsock_pkt_info *info, >+ size_t len) >+{ >+ void *payload; >+ int err; >+ >+ payload = skb_put(skb, len); >+ err = memcpy_from_msg(payload, info->msg, len); >+ if (err) >+ return -1; >+ >+ if (msg_data_left(info->msg)) >+ return 0; >+ >+ if (info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) { >+ struct virtio_vsock_hdr *hdr; >+ >+ hdr = virtio_vsock_hdr...

1) Turn GSO on virtio net into an all-or-nothing (keep checksumming separate). Having multiple bits is a pain: if you can't support something you should handle it in software, which is still a performance win. 2) Make VIRTIO_NET_HDR_GSO_ECN a flag in the header, so it can apply to IPv6 or v4. 3) Rename VIRTIO_NET_F_NO_CSUM to VIRTIO_NET_F_CSUM (ie. means we do checksumming). 4)

1) Turn GSO on virtio net into an all-or-nothing (keep checksumming separate). Having multiple bits is a pain: if you can't support something you should handle it in software, which is still a performance win. 2) Make VIRTIO_NET_HDR_GSO_ECN a flag in the header, so it can apply to IPv6 or v4. 3) Rename VIRTIO_NET_F_NO_CSUM to VIRTIO_NET_F_CSUM (ie. means we do checksumming). 4)

...if (!skb) > - return ERR_PTR(-ENOMEM); > + if (!skb) { > + skb = ERR_PTR(-ENOMEM); > + goto out; So goto out will skip put_page, and we did do get_page above. Seems wrong. You should goto err_skb or something like this. > + } > > skb_reserve(skb, pad - delta); > skb_put(skb, len); > - get_page(alloc_frag->page); > - alloc_frag->offset += buflen; > > return skb; > > -err_redirect: > - put_page(alloc_frag->page); > err_xdp: > + alloc_frag->offset -= buflen; > + put_page(alloc_frag->page); > +out: Out here isn...

...if (!skb) > - return ERR_PTR(-ENOMEM); > + if (!skb) { > + skb = ERR_PTR(-ENOMEM); > + goto out; So goto out will skip put_page, and we did do get_page above. Seems wrong. You should goto err_skb or something like this. > + } > > skb_reserve(skb, pad - delta); > skb_put(skb, len); > - get_page(alloc_frag->page); > - alloc_frag->offset += buflen; > > return skb; > > -err_redirect: > - put_page(alloc_frag->page); > err_xdp: > + alloc_frag->offset -= buflen; > + put_page(alloc_frag->page); > +out: Out here isn...

...NET_SKB_OFF VNET_SKB_LEN(VNET_SKB_PAD) + +static struct sk_buff *vnet_build_skb(struct virtnet_info *vi, + void *buf, + unsigned int len, unsigned int truesize) +{ + struct sk_buff *skb = build_skb(buf, truesize); + + if (!skb) + return NULL; + + skb_reserve(skb, VNET_SKB_PAD); + skb_put(skb, VNET_SKB_LEN(len)); + + return skb; +} + static struct sk_buff *receive_mergeable(struct net_device *dev, struct virtnet_info *vi, struct receive_queue *rq, @@ -354,14 +374,13 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, unsigned int len) { void...

...NET_SKB_OFF VNET_SKB_LEN(VNET_SKB_PAD) + +static struct sk_buff *vnet_build_skb(struct virtnet_info *vi, + void *buf, + unsigned int len, unsigned int truesize) +{ + struct sk_buff *skb = build_skb(buf, truesize); + + if (!skb) + return NULL; + + skb_reserve(skb, VNET_SKB_PAD); + skb_put(skb, VNET_SKB_LEN(len)); + + return skb; +} + static struct sk_buff *receive_mergeable(struct net_device *dev, struct virtnet_info *vi, struct receive_queue *rq, @@ -354,14 +374,13 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, unsigned int len) { void...

...uct sk_buff *tun_build_skb(struct tun_struct *tun, > build: > skb = build_skb(buf, buflen); > if (!skb) { > + put_page(alloc_frag->page); > skb = ERR_PTR(-ENOMEM); > goto out; > } > > - skb_reserve(skb, pad - delta); > + skb_reserve(skb, pad); > skb_put(skb, len); > > return skb; > > err_xdp: > - alloc_frag->offset -= buflen; > - put_page(alloc_frag->page); > + this_cpu_inc(tun->pcpu_stats->rx_dropped); This fixes bug in previous patch which dropped it. OK :) > out: > rcu_read_unlock(); > lo...

...uct sk_buff *tun_build_skb(struct tun_struct *tun, > build: > skb = build_skb(buf, buflen); > if (!skb) { > + put_page(alloc_frag->page); > skb = ERR_PTR(-ENOMEM); > goto out; > } > > - skb_reserve(skb, pad - delta); > + skb_reserve(skb, pad); > skb_put(skb, len); > > return skb; > > err_xdp: > - alloc_frag->offset -= buflen; > - put_page(alloc_frag->page); > + this_cpu_inc(tun->pcpu_stats->rx_dropped); This fixes bug in previous patch which dropped it. OK :) > out: > rcu_read_unlock(); > lo...

Hi all: This series tries to batch submitting packets to underlayer socket through msg_control during sendmsg(). This is done by: 1) Doing userspace copy inside vhost_net 2) Build XDP buff 3) Batch at most 64 (VHOST_NET_BATCH) XDP buffs and submit them once through msg_control during sendmsg(). 4) Underlayer sockets can use XDP buffs directly when XDP is enalbed, or build skb based on XDP

Hi all: This series tries to batch submitting packets to underlayer socket through msg_control during sendmsg(). This is done by: 1) Doing userspace copy inside vhost_net 2) Build XDP buff 3) Batch at most 64 (VHOST_NET_BATCH) XDP buffs and submit them once through msg_control during sendmsg(). 4) Underlayer sockets can use XDP buffs directly when XDP is enalbed, or build skb based on XDP

Hi all: This series tries to batch submitting packets to underlayer socket through msg_control during sendmsg(). This is done by: 1) Doing userspace copy inside vhost_net 2) Build XDP buff 3) Batch at most 64 (VHOST_NET_BATCH) XDP buffs and submit them once through msg_control during sendmsg(). 4) Underlayer sockets can use XDP buffs directly when XDP is enalbed, or build skb based on XDP

...,11 @@ static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) struct skb_vnet_hdr *hdr; int err; - skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); + skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp); if (unlikely(!skb)) return -ENOMEM; - skb_put(skb, MAX_PACKET_LEN); + skb_put(skb, GOOD_PACKET_LEN); hdr = skb_vnet_hdr(skb); sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); @@ -542,20 +544,20 @@ static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) int err; if (gfp & __GFP_WAIT) { - if (skb_page_f...

...,11 @@ static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) struct skb_vnet_hdr *hdr; int err; - skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); + skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp); if (unlikely(!skb)) return -ENOMEM; - skb_put(skb, MAX_PACKET_LEN); + skb_put(skb, GOOD_PACKET_LEN); hdr = skb_vnet_hdr(skb); sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); @@ -542,20 +544,20 @@ static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) int err; if (gfp & __GFP_WAIT) { - if (skb_page_f...

...,11 @@ static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) struct skb_vnet_hdr *hdr; int err; - skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); + skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp); if (unlikely(!skb)) return -ENOMEM; - skb_put(skb, MAX_PACKET_LEN); + skb_put(skb, GOOD_PACKET_LEN); hdr = skb_vnet_hdr(skb); sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); @@ -542,20 +544,20 @@ static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) int err; if (gfp & __GFP_WAIT) { - if (skb_page_f...