Re: [dpdk-dev] [PATCH v4] net/ixgbe: fix multicast table enable error for VF

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Zhao1, Wei
> Sent: Monday, January 7, 2019 2:16 PM
> To: dev@dpdk.org
> Cc: stable@dpdk.org; Zhang, Qi Z <qi.z.zhang@intel.com>; Wu, Jingjing
> <jingjing.wu@intel.com>; Zhao1, Wei <wei.zhao1@intel.com>
> Subject: [PATCH v4] net/ixgbe: fix multicast table enable error for VF

How about change the title to:

"fix over using multicast table for VF"

?

> 
> In ixgbe PMD code, all vf ars set with bit IXGBE_VMOLR_ROMPE, which make vf
> accept packets that match the MTA table, if some vf update IXGBE_MTA in
> function ixgbe_vf_set_multicast, then all vf will receive packets from these
> address.
> So there is need to set VMOLR register bit ROPE only after this vf has been set
> multicast address. If this bit is set when pf host doing initialization, this vf will
> receive multicast packets with address written in MTA table.And also disable
> MTA when detect entry number of MAC address is 0 of configuration from vf.
> Align to ixgbe pf kernel 5.3.7 code to fix this bug.


I did below re-word to make it easy to understand.

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@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.
> ---
>  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..4e4d39a 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) {

It's better to write as

	If (nb_entries == 0)

to follow the coding guideline.



> +		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