Hi, Alvin
> -----Original Message-----
> From: Zhang,Alvin <alvinx.zh...@intel.com>
> Sent: Friday, January 15, 2021 3:00 PM
> To: Guo, Jia <jia....@intel.com>; Wang, Haiyue <haiyue.w...@intel.com>;
> Xie, WeiX <weix....@intel.com>
> Cc: dev@dpdk.org; Zhang, AlvinX <alvinx.zh...@intel.com>;
> sta...@dpdk.org
> Subject: [PATCH v3] net/ixgbe: fix configuration of max frame size
>
> From: Alvin Zhang <alvinx.zh...@intel.com>
>
> For 82599 NIC, jumbo frame feature is not supported in IOV mode, but if a VF
> requests to configure the frame size to that not bigger than
> RTE_ETHER_MAX_LEN, the PMD should not return -1.
> This patch keeps ixgbe PMD's handling mode consistent with kernel driver in
> above situation.
>
Why it should not return -1 and what is the kernel driver behaviors related
with this patch?
> In addition, the value set by the command IXGBE_VF_SET_LPE represents
> the max frame size, not the mtu.
>
> Fixes: 1b9ea09c067b ("ixgbe: support X550")
> Fixes: 95a27b3ba5f5 ("net/ixgbe: enable jumbo frame for VF")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Alvin Zhang <alvinx.zh...@intel.com>
> ---
>
> V3: Restore variable name from cur_frame_size to max_frs.
> ---
> drivers/net/ixgbe/ixgbe_pf.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ixgbe/ixgbe_pf.c b/drivers/net/ixgbe/ixgbe_pf.c
> index 833863a..1ffde56 100644
> --- a/drivers/net/ixgbe/ixgbe_pf.c
> +++ b/drivers/net/ixgbe/ixgbe_pf.c
> @@ -555,17 +555,20 @@ int ixgbe_pf_host_configure(struct rte_eth_dev
> *eth_dev) ixgbe_set_vf_lpe(struct rte_eth_dev *dev, __rte_unused
> uint32_t vf, uint32_t *msgbuf) {
> struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data-
> >dev_private);
> - uint32_t new_mtu = msgbuf[1];
> + uint32_t max_frame = msgbuf[1];
> uint32_t max_frs;
> uint32_t hlreg0;
> - int max_frame = new_mtu + RTE_ETHER_HDR_LEN +
> RTE_ETHER_CRC_LEN;
>
> /* X540 and X550 support jumbo frames in IOV mode */
> if (hw->mac.type != ixgbe_mac_X540 &&
> hw->mac.type != ixgbe_mac_X550 &&
> hw->mac.type != ixgbe_mac_X550EM_x &&
> - hw->mac.type != ixgbe_mac_X550EM_a)
> - return -1;
> + hw->mac.type != ixgbe_mac_X550EM_a) {
> + if (max_frame > dev->data-
> >dev_conf.rxmode.max_rx_pkt_len)
This condition is only for X540/X550?
> + return -1;
> +
> + return 0;
> + }
>
Assume that return 0 means success to set vf lpe, return -1 means failed to set
vf lpe. If it is not support in VF, why return 0?
> if (max_frame < RTE_ETHER_MIN_LEN ||
> max_frame >
> RTE_ETHER_MAX_JUMBO_FRAME_LEN) @@ -573,9 +576,9 @@ int
> ixgbe_pf_host_configure(struct rte_eth_dev *eth_dev)
>
> max_frs = (IXGBE_READ_REG(hw, IXGBE_MAXFRS) &
> IXGBE_MHADD_MFS_MASK) >>
> IXGBE_MHADD_MFS_SHIFT;
> - if (max_frs < new_mtu) {
> + if (max_frs < max_frame) {
> hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
> - if (new_mtu > RTE_ETHER_MAX_LEN) {
> + if (max_frame > RTE_ETHER_MAX_LEN) {
> dev->data->dev_conf.rxmode.offloads |=
> DEV_RX_OFFLOAD_JUMBO_FRAME;
> hlreg0 |= IXGBE_HLREG0_JUMBOEN;
> @@ -586,7 +589,7 @@ int ixgbe_pf_host_configure(struct rte_eth_dev
> *eth_dev)
> }
> IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0);
>
> - max_frs = new_mtu << IXGBE_MHADD_MFS_SHIFT;
> + max_frs = max_frame << IXGBE_MHADD_MFS_SHIFT;
> IXGBE_WRITE_REG(hw, IXGBE_MAXFRS, max_frs);
> }
>
> --
> 1.8.3.1
