[dpdk-dev] [PATCH v5] net/ixgbe: fix over using multicast table for VF

[Wei Zhao]

According to the current implementation, all VFs will set bit
IXGBE_VMOLR_ROMPE during initialization, this cause any VF
will accept packets that match the MTA table. Since the MTA
table is shared by all VFs which means if one VF update MTA
table in function ixgbe_vf_set_multicast, then all other VFs
will receive multicast packets which cause unnecessary
performance overhead.

So it's better to set VF's ROPE bit of register VMOLR only
if multicast address filter is required on that VF.
Also, the ROPE bit should be reset when multicast address
filter is requested to clean.

This patch also aligns to the related fix on ixgbe
kernel driver 5.3.7.

Fixes: 00e30184daa0 ("ixgbe: add PF support")

Signed-off-by: Wei Zhao <wei.zhao1 at intel.com>

---

v2:
change patch name and fix typo in log.

v3:
fix typo and disable MTA when detect
all zero MAC address configuration.

v4:
change code to disable MTA when detect
entry number of MAC address is 0 of configuration from vf.

v5:
change git log comment, title and code format.
---
 drivers/net/ixgbe/ixgbe_pf.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ixgbe/ixgbe_pf.c b/drivers/net/ixgbe/ixgbe_pf.c
index 4b833ff..be0c076 100644
--- a/drivers/net/ixgbe/ixgbe_pf.c
+++ b/drivers/net/ixgbe/ixgbe_pf.c
@@ -351,7 +351,7 @@ ixgbe_vf_reset_event(struct rte_eth_dev *dev, uint16_t vf)
 	int rar_entry = hw->mac.num_rar_entries - (vf + 1);
 	uint32_t vmolr = IXGBE_READ_REG(hw, IXGBE_VMOLR(vf));
 
-	vmolr |= (IXGBE_VMOLR_ROPE | IXGBE_VMOLR_ROMPE |
+	vmolr |= (IXGBE_VMOLR_ROPE |
 			IXGBE_VMOLR_BAM | IXGBE_VMOLR_AUPE);
 	IXGBE_WRITE_REG(hw, IXGBE_VMOLR(vf), vmolr);
 
@@ -503,6 +503,7 @@ ixgbe_vf_set_multicast(struct rte_eth_dev *dev, uint32_t vf, uint32_t *msgbuf)
 	const uint32_t IXGBE_MTA_BIT_MASK = (0x1 << IXGBE_MTA_BIT_SHIFT) - 1;
 	uint32_t reg_val;
 	int i;
+	u32 vmolr = IXGBE_READ_REG(hw, IXGBE_VMOLR(vf));
 
 	/* Disable multicast promiscuous first */
 	ixgbe_disable_vf_mc_promisc(dev, vf);
@@ -516,6 +517,12 @@ ixgbe_vf_set_multicast(struct rte_eth_dev *dev, uint32_t vf, uint32_t *msgbuf)
 		vfinfo->vf_mc_hashes[i] = hash_list[i];
 	}
 
+	if (nb_entries == 0) {
+		vmolr &= ~IXGBE_VMOLR_ROMPE;
+		IXGBE_WRITE_REG(hw, IXGBE_VMOLR(vf), vmolr);
+		return 0;
+	}
+
 	for (i = 0; i < vfinfo->num_vf_mc_hashes; i++) {
 		mta_idx = (vfinfo->vf_mc_hashes[i] >> IXGBE_MTA_BIT_SHIFT)
 				& IXGBE_MTA_INDEX_MASK;
@@ -525,6 +532,9 @@ ixgbe_vf_set_multicast(struct rte_eth_dev *dev, uint32_t vf, uint32_t *msgbuf)
 		IXGBE_WRITE_REG(hw, IXGBE_MTA(mta_idx), reg_val);
 	}
 
+	vmolr |= IXGBE_VMOLR_ROMPE;
+	IXGBE_WRITE_REG(hw, IXGBE_VMOLR(vf), vmolr);
+
 	return 0;
 }
 
-- 
2.7.5