[ovs-dev,v13,2/4] dpif-netdev: Show netdev offloading flags.

From: Flavio Leitner <fbl@sysclose.org>

This patch modifies netdev_get_status to include information about
checksum offload status by port, allowing the user to gain insight into
where checksum offloading is active.

Signed-off-by: Flavio Leitner <fbl@sysclose.org>
Co-authored-by: Mike Pattrick <mkp@redhat.com>
Signed-off-by: Mike Pattrick <mkp@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
---
 Since v9:
  - Removed entire ovs-appctl dpif-netdev/offload-show command, replaced
    with a field in the netdev status.
  - Removed duplicative field tx_tso_offload from netdev-dpdk.c
 Since v10:
  - No change
 Since v11:
  - Removed depricated documentation
  - Clarified offload direction in status field
---
 lib/netdev-dpdk.c     |  5 -----
 lib/netdev-provider.h |  1 +
 lib/netdev.c          | 30 +++++++++++++++++++++++++++---
 tests/dpif-netdev.at  | 18 ++++++++++++++++++
 4 files changed, 46 insertions(+), 8 deletions(-)

On 5/17/23 05:11, Mike Pattrick wrote:
> From: Flavio Leitner <fbl@sysclose.org>
> 
> This patch modifies netdev_get_status to include information about
> checksum offload status by port, allowing the user to gain insight into
> where checksum offloading is active.
> 
> Signed-off-by: Flavio Leitner <fbl@sysclose.org>
> Co-authored-by: Mike Pattrick <mkp@redhat.com>
> Signed-off-by: Mike Pattrick <mkp@redhat.com>
> Reviewed-by: David Marchand <david.marchand@redhat.com>
> ---
>  Since v9:
>   - Removed entire ovs-appctl dpif-netdev/offload-show command, replaced
>     with a field in the netdev status.
>   - Removed duplicative field tx_tso_offload from netdev-dpdk.c
>  Since v10:
>   - No change
>  Since v11:
>   - Removed depricated documentation
>   - Clarified offload direction in status field
> ---
>  lib/netdev-dpdk.c     |  5 -----
>  lib/netdev-provider.h |  1 +
>  lib/netdev.c          | 30 +++++++++++++++++++++++++++---
>  tests/dpif-netdev.at  | 18 ++++++++++++++++++
>  4 files changed, 46 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index fb0dd43f7..560694dbc 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -1753,11 +1753,6 @@ netdev_dpdk_get_config(const struct netdev *netdev, struct smap *args)
>          } else {
>              smap_add(args, "rx_csum_offload", "false");
>          }
> -        if (dev->hw_ol_features & NETDEV_TX_TSO_OFFLOAD) {
> -            smap_add(args, "tx_tso_offload", "true");
> -        } else {
> -            smap_add(args, "tx_tso_offload", "false");
> -        }
>          smap_add(args, "lsc_interrupt_mode",
>                   dev->lsc_interrupt_mode ? "true" : "false");
>  
> diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
> index b5420947d..fcf52bdd9 100644
> --- a/lib/netdev-provider.h
> +++ b/lib/netdev-provider.h
> @@ -37,6 +37,7 @@ extern "C" {
>  struct netdev_tnl_build_header_params;
>  #define NETDEV_NUMA_UNSPEC OVS_NUMA_UNSPEC
>  
> +/* Keep this enum updated with translation to string below. */

What is this comment referring to?

>  enum netdev_ol_flags {
>      NETDEV_TX_OFFLOAD_IPV4_CKSUM = 1 << 0,
>      NETDEV_TX_OFFLOAD_TCP_CKSUM = 1 << 1,
> diff --git a/lib/netdev.c b/lib/netdev.c
> index c79778378..cc03308fb 100644
> --- a/lib/netdev.c
> +++ b/lib/netdev.c
> @@ -43,6 +43,7 @@
>  #include "netdev-provider.h"
>  #include "netdev-vport.h"
>  #include "odp-netlink.h"
> +#include "openvswitch/json.h"
>  #include "openflow/openflow.h"
>  #include "packets.h"
>  #include "openvswitch/ofp-print.h"
> @@ -1373,9 +1374,32 @@ netdev_get_next_hop(const struct netdev *netdev,
>  int
>  netdev_get_status(const struct netdev *netdev, struct smap *smap)
>  {
> -    return (netdev->netdev_class->get_status
> -            ? netdev->netdev_class->get_status(netdev, smap)
> -            : EOPNOTSUPP);
> +    int err = EOPNOTSUPP;
> +
> +    /* Set offload status only if relevant. */
> +    if (netdev_get_dpif_type(netdev) &&
> +        strcmp(netdev_get_dpif_type(netdev), "system")) {
> +
> +#define OL_ADD_STAT(name, bit) \
> +        smap_add(smap, "tx_" name "_csum_offload", \
> +                 netdev->ol_flags & bit ? "true" : "false");
> +
> +        OL_ADD_STAT("ip", NETDEV_TX_OFFLOAD_IPV4_CKSUM);
> +        OL_ADD_STAT("tcp", NETDEV_TX_OFFLOAD_TCP_CKSUM);
> +        OL_ADD_STAT("udp", NETDEV_TX_OFFLOAD_UDP_CKSUM);
> +        OL_ADD_STAT("sctp", NETDEV_TX_OFFLOAD_SCTP_CKSUM);
> +#undef OL_ADD_STAT
> +        smap_add(smap, "tx_tcp_seg_offload", netdev->ol_flags & \
> +                NETDEV_TX_OFFLOAD_TCP_TSO ? "true" : "false");

Don't use line continuation is a normal C code.  And it's likely
better to write this way:

        smap_add(smap, "tx_tcp_seg_offload",
                 (netdev->ol_flags & NETDEV_TX_OFFLOAD_TCP_TSO)
                 ? "true" : "false");

Or the macro can be re-used by moving the '_csum' part to the 'name'.

> +
> +        err = 0;
> +    }
> +
> +    if (!netdev->netdev_class->get_status) {
> +        return err;
> +    }
> +
> +    return netdev->netdev_class->get_status(netdev, smap);
>  }
>  
>  /* Returns all assigned IP address to  'netdev' and returns 0.
> diff --git a/tests/dpif-netdev.at b/tests/dpif-netdev.at
> index baab60a22..60d789beb 100644
> --- a/tests/dpif-netdev.at
> +++ b/tests/dpif-netdev.at
> @@ -650,6 +650,24 @@ AT_CHECK([ovs-appctl revalidator/resume])
>  OVS_VSWITCHD_STOP
>  AT_CLEANUP
>  
> +AT_SETUP([dpif-netdev - check tx packet checksum offloading])
> +OVS_VSWITCHD_START(
> +  [add-port br0 p1 \
> +   -- set interface p1 type=dummy options:pstream=punix:$OVS_RUNDIR/p0.sock \
> +   -- set bridge br0 datapath-type=dummy \
> +                     other-config:datapath-id=1234 fail-mode=secure])
> +
> +AT_CHECK([ovs-vsctl get interface p1 status | sed -n 's/^{\(.*\).*}$/\1/p'], [0], [dnl
> +tx_ip_csum_offload="false", tx_sctp_csum_offload="false", tx_tcp_csum_offload="false", tx_tcp_seg_offload="false", tx_udp_csum_offload="false"
> +], [])
> +
> +AT_CHECK([ovs-vsctl get interface br0 status | sed -n 's/^{\(.*\).*}$/\1/p'], [0], [dnl
> +tx_ip_csum_offload="false", tx_sctp_csum_offload="false", tx_tcp_csum_offload="false", tx_tcp_seg_offload="false", tx_udp_csum_offload="false"
> +], [])
> +
> +OVS_VSWITCHD_STOP
> +AT_CLEANUP
> +
>  # SEND_UDP_PKTS([p_name], [p_ofport])
>  #
>  # Sends 128 packets to port 'p_name' with different UDP destination ports.