lkml.org 
[lkml]   [2021]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 1/3] mlx5_vdpa: should exclude header length and fcs from mtu
    From
    Date

    On 2021/2/6 下午8:29, Si-Wei Liu wrote:
    > When feature VIRTIO_NET_F_MTU is negotiated on mlx5_vdpa,
    > 22 extra bytes worth of MTU length is shown in guest.
    > This is because the mlx5_query_port_max_mtu API returns
    > the "hardware" MTU value, which does not just contain the
    > Ethernet payload, but includes extra lengths starting
    > from the Ethernet header up to the FCS altogether.
    >
    > Fix the MTU so packets won't get dropped silently.
    >
    > Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>


    Acked-by: Jason Wang <jasowang@redhat.com>


    > ---
    > drivers/vdpa/mlx5/core/mlx5_vdpa.h | 4 ++++
    > drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 ++++++++++++++-
    > 2 files changed, 18 insertions(+), 1 deletion(-)
    >
    > diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
    > index 08f742f..b6cc53b 100644
    > --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
    > +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
    > @@ -4,9 +4,13 @@
    > #ifndef __MLX5_VDPA_H__
    > #define __MLX5_VDPA_H__
    >
    > +#include <linux/etherdevice.h>
    > +#include <linux/if_vlan.h>
    > #include <linux/vdpa.h>
    > #include <linux/mlx5/driver.h>
    >
    > +#define MLX5V_ETH_HARD_MTU (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN)
    > +
    > struct mlx5_vdpa_direct_mr {
    > u64 start;
    > u64 end;
    > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
    > index dc88559..b8416c4 100644
    > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
    > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
    > @@ -1907,6 +1907,19 @@ static int mlx5_get_vq_irq(struct vdpa_device *vdv, u16 idx)
    > .free = mlx5_vdpa_free,
    > };
    >
    > +static int query_mtu(struct mlx5_core_dev *mdev, u16 *mtu)
    > +{
    > + u16 hw_mtu;
    > + int err;
    > +
    > + err = mlx5_query_nic_vport_mtu(mdev, &hw_mtu);
    > + if (err)
    > + return err;
    > +
    > + *mtu = hw_mtu - MLX5V_ETH_HARD_MTU;
    > + return 0;
    > +}
    > +
    > static int alloc_resources(struct mlx5_vdpa_net *ndev)
    > {
    > struct mlx5_vdpa_net_resources *res = &ndev->res;
    > @@ -1992,7 +2005,7 @@ static int mlx5v_probe(struct auxiliary_device *adev,
    > init_mvqs(ndev);
    > mutex_init(&ndev->reslock);
    > config = &ndev->config;
    > - err = mlx5_query_nic_vport_mtu(mdev, &ndev->mtu);
    > + err = query_mtu(mdev, &ndev->mtu);
    > if (err)
    > goto err_mtu;
    >

    \
     
     \ /
      Last update: 2021-02-08 05:42    [W:3.956 / U:0.140 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site