[dpdk-dev,1/2] vhost: fix TCP csum not set
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Commit Message
As PKT_TX_TCP_SEG flag in mbuf->ol_flags implies PKT_TX_TCP_CKSUM,
applications, e.g., testpmd, don't set PKT_TX_TCP_CKSUM when TSO
is set.
This leads to that packets get dropped in VM tcp stack layer because
of bad TCP csum.
To fix this, we make sure TCP NEEDS_CSUM info is set into virtio net
header when PKT_TX_TCP_SEG is set, so that VM tcp stack will not
check the TCP csum.
Fixes: 859b480d5afd ("vhost: add guest offload setting")
Cc: stable@dpdk.org
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: Jiayu Hu <jiayu.hu@intel.com>
Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
---
lib/librte_vhost/virtio_net.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
Comments
On 06/07/2017 08:41 AM, Jianfeng Tan wrote:
> As PKT_TX_TCP_SEG flag in mbuf->ol_flags implies PKT_TX_TCP_CKSUM,
> applications, e.g., testpmd, don't set PKT_TX_TCP_CKSUM when TSO
> is set.
>
> This leads to that packets get dropped in VM tcp stack layer because
> of bad TCP csum.
>
> To fix this, we make sure TCP NEEDS_CSUM info is set into virtio net
> header when PKT_TX_TCP_SEG is set, so that VM tcp stack will not
> check the TCP csum.
>
> Fixes: 859b480d5afd ("vhost: add guest offload setting")
> Cc: stable@dpdk.org
>
> Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Cc: Jiayu Hu <jiayu.hu@intel.com>
> Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
> ---
> lib/librte_vhost/virtio_net.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 48219e0..0a7e023 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -114,11 +114,16 @@ update_shadow_used_ring(struct vhost_virtqueue *vq,
> static void
> virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
> {
> - if (m_buf->ol_flags & PKT_TX_L4_MASK) {
> + uint64_t csum_l4 = m_buf->ol_flags & PKT_TX_L4_MASK;
> +
> + if (m_buf->ol_flags & PKT_TX_TCP_SEG)
> + csum_l4 |= PKT_TX_TCP_CKSUM;
> +
> + if (csum_l4) {
> net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
> net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
>
> - switch (m_buf->ol_flags & PKT_TX_L4_MASK) {
> + switch (csum_l4) {
> case PKT_TX_TCP_CKSUM:
> net_hdr->csum_offset = (offsetof(struct tcp_hdr,
> cksum));
>
On Wed, Jun 07, 2017 at 09:25:38PM +0200, Maxime Coquelin wrote:
>
>
> On 06/07/2017 08:41 AM, Jianfeng Tan wrote:
> >As PKT_TX_TCP_SEG flag in mbuf->ol_flags implies PKT_TX_TCP_CKSUM,
> >applications, e.g., testpmd, don't set PKT_TX_TCP_CKSUM when TSO
> >is set.
> >
> >This leads to that packets get dropped in VM tcp stack layer because
> >of bad TCP csum.
> >
> >To fix this, we make sure TCP NEEDS_CSUM info is set into virtio net
> >header when PKT_TX_TCP_SEG is set, so that VM tcp stack will not
> >check the TCP csum.
> >
> >Fixes: 859b480d5afd ("vhost: add guest offload setting")
> >Cc: stable@dpdk.org
> >
> >Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> >Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> >Cc: Jiayu Hu <jiayu.hu@intel.com>
> >Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
>
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Series applied to dpdk-next-virtio.
Thanks!
--yliu
@@ -114,11 +114,16 @@ update_shadow_used_ring(struct vhost_virtqueue *vq,
static void
virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
{
- if (m_buf->ol_flags & PKT_TX_L4_MASK) {
+ uint64_t csum_l4 = m_buf->ol_flags & PKT_TX_L4_MASK;
+
+ if (m_buf->ol_flags & PKT_TX_TCP_SEG)
+ csum_l4 |= PKT_TX_TCP_CKSUM;
+
+ if (csum_l4) {
net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
- switch (m_buf->ol_flags & PKT_TX_L4_MASK) {
+ switch (csum_l4) {
case PKT_TX_TCP_CKSUM:
net_hdr->csum_offset = (offsetof(struct tcp_hdr,
cksum));