[dpdk-stable] [PATCH] net/ixgbe: fix configuration of max frame size

[Alvin Zhang <alvinx.zhang@intel.com>]

For some types of NIC, jumbo frame is not supported in IOV mode,
so if a VF requests to configure the frame size to not bigger
than IXGBE_ETH_MAX_LEN, the kernel driver returns 0, but the DPDK
ixgbe PMD returens -1, this will cause the VF to fail to start
when the PF driven by DPDK ixgbe PMD.

This patch keeps ixgbe PMD's handling mode consistent with kernel
driver in above situation.

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: stable@dpdk.org

Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
---
 drivers/net/ixgbe/ixgbe_pf.c | 52 +++++++++++++++++++++++++++++++-----
 1 file changed, 46 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_pf.c b/drivers/net/ixgbe/ixgbe_pf.c
index ca30be71eb..2e46e30b79 100644
--- a/drivers/net/ixgbe/ixgbe_pf.c
+++ b/drivers/net/ixgbe/ixgbe_pf.c
@@ -552,16 +552,44 @@ static int
 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;
-	int max_frame = new_mtu + RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN;
+	uint32_t hlreg0;
 
 	/* 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) {
+		struct ixgbe_vf_info *vfinfo =
+			*IXGBE_DEV_PRIVATE_TO_P_VFDATA(dev->data->dev_private);
+
+		switch (vfinfo[vf].api_version) {
+		case ixgbe_mbox_api_11:
+		case ixgbe_mbox_api_12:
+		case ixgbe_mbox_api_13:
+			 /**
+			  * Version 1.1&1.2&1.3 supports jumbo frames on VFs
+			  * if PF has jumbo frames enabled which means legacy
+			  * VFs are disabled.
+			  */
+			if (dev->data->dev_conf.rxmode.max_rx_pkt_len >
+			    IXGBE_ETH_MAX_LEN)
+				break;
+			/* fall through */
+		default:
+			/**
+			 * If the PF or VF are running w/ jumbo frames enabled,
+			 * we return -1 as we cannot support jumbo frames on
+			 * legacy VFs.
+			 */
+			if (max_frame > IXGBE_ETH_MAX_LEN ||
+			    dev->data->dev_conf.rxmode.max_rx_pkt_len >
+			    IXGBE_ETH_MAX_LEN)
+				return -1;
+			break;
+		}
+	}
 
 	if (max_frame < RTE_ETHER_MIN_LEN ||
 			max_frame > RTE_ETHER_MAX_JUMBO_FRAME_LEN)
@@ -569,8 +597,20 @@ ixgbe_set_vf_lpe(struct rte_eth_dev *dev, __rte_unused uint32_t vf, uint32_t *ms
 
 	max_frs = (IXGBE_READ_REG(hw, IXGBE_MAXFRS) &
 		   IXGBE_MHADD_MFS_MASK) >> IXGBE_MHADD_MFS_SHIFT;
-	if (max_frs < new_mtu) {
-		max_frs = new_mtu << IXGBE_MHADD_MFS_SHIFT;
+	if (max_frs < max_frame) {
+		hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
+		if (max_frame > IXGBE_ETH_MAX_LEN) {
+			dev->data->dev_conf.rxmode.offloads |=
+				DEV_RX_OFFLOAD_JUMBO_FRAME;
+			hlreg0 |= IXGBE_HLREG0_JUMBOEN;
+		} else {
+			dev->data->dev_conf.rxmode.offloads &=
+				~DEV_RX_OFFLOAD_JUMBO_FRAME;
+			hlreg0 &= ~IXGBE_HLREG0_JUMBOEN;
+		}
+		IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0);
+
+		max_frs = max_frame << IXGBE_MHADD_MFS_SHIFT;
 		IXGBE_WRITE_REG(hw, IXGBE_MAXFRS, max_frs);
 	}
 
-- 
2.20.1