[dpdk-dev] [PATCH 2/3] pmd: RX function need keep EXTERNAL_MBUF flag

Ananyev, Konstantin konstantin.ananyev at intel.com
Fri Oct 24 12:46:06 CEST 2014


Hi Changchun,

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Ouyang Changchun
> Sent: Friday, October 24, 2014 9:10 AM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH 2/3] pmd: RX function need keep EXTERNAL_MBUF flag
> 
> Every pmd RX function need keep the EXTERNAL_MBUF flag
> in mbuf.ol_flags, and can't overwrite it when filling ol_flags from
> descriptor to mbuf, otherwise, it probably cause to crash when freeing a mbuf
> and trying to freeing its attached external buffer, say, from guest space.
> 

Don't really like the idea to put:
mb->ol_flags = pkt_flags | (mb->ol_flags & EXTERNAL_MBUF); 
in each and every PMD from now on...

>From other side, it is probably not very good that RX functions update whole ol_flags, not only RX related part.
Wonder can we reserve low 32bits of ol_flags for RX, and high 32bits for TX and generic stuff.
So our ol_flags will look something like that:

union {
	uint64_t ol_raw_flags;
	struct {
		uint32_t rx;
		uint32_t gen_tx;
	} ol_flags
};

And make all PMD RX functions to operate on rx part of the flags only:
mb->ol_flags.rx = pkt_flags;
?

Konstantin

> Signed-off-by: Changchun Ouyang <changchun.ouyang at intel.com>
> ---
>  lib/librte_pmd_e1000/igb_rxtx.c       |  5 +++--
>  lib/librte_pmd_i40e/i40e_rxtx.c       |  8 +++++---
>  lib/librte_pmd_ixgbe/ixgbe_rxtx.c     |  8 +++++---
>  lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c | 12 ++++++++----
>  4 files changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/lib/librte_pmd_e1000/igb_rxtx.c b/lib/librte_pmd_e1000/igb_rxtx.c
> index f09c525..4123310 100644
> --- a/lib/librte_pmd_e1000/igb_rxtx.c
> +++ b/lib/librte_pmd_e1000/igb_rxtx.c
> @@ -786,7 +786,7 @@ eth_igb_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>  		pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(hlen_type_rss);
>  		pkt_flags = pkt_flags | rx_desc_status_to_pkt_flags(staterr);
>  		pkt_flags = pkt_flags | rx_desc_error_to_pkt_flags(staterr);
> -		rxm->ol_flags = pkt_flags;
> +		rxm->ol_flags = pkt_flags | (rxm->ol_flags & EXTERNAL_MBUF);
> 
>  		/*
>  		 * Store the mbuf address into the next entry of the array
> @@ -1020,7 +1020,8 @@ eth_igb_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>  		pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(hlen_type_rss);
>  		pkt_flags = pkt_flags | rx_desc_status_to_pkt_flags(staterr);
>  		pkt_flags = pkt_flags | rx_desc_error_to_pkt_flags(staterr);
> -		first_seg->ol_flags = pkt_flags;
> +		first_seg->ol_flags = pkt_flags |
> +			(first_seg->ol_flags & EXTERNAL_MBUF);
> 
>  		/* Prefetch data of first segment, if configured to do so. */
>  		rte_packet_prefetch((char *)first_seg->buf_addr +
> diff --git a/lib/librte_pmd_i40e/i40e_rxtx.c b/lib/librte_pmd_i40e/i40e_rxtx.c
> index 2b53677..68c3695 100644
> --- a/lib/librte_pmd_i40e/i40e_rxtx.c
> +++ b/lib/librte_pmd_i40e/i40e_rxtx.c
> @@ -637,7 +637,8 @@ i40e_rx_scan_hw_ring(struct i40e_rx_queue *rxq)
>  			pkt_flags = i40e_rxd_status_to_pkt_flags(qword1);
>  			pkt_flags |= i40e_rxd_error_to_pkt_flags(qword1);
>  			pkt_flags |= i40e_rxd_ptype_to_pkt_flags(qword1);
> -			mb->ol_flags = pkt_flags;
> +			mb->ol_flags = pkt_flags |
> +				(mb->ol_flags & EXTERNAL_MBUF);
>  			if (pkt_flags & PKT_RX_RSS_HASH)
>  				mb->hash.rss = rte_le_to_cpu_32(\
>  					rxdp->wb.qword0.hi_dword.rss);
> @@ -873,7 +874,7 @@ i40e_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
>  		pkt_flags = i40e_rxd_status_to_pkt_flags(qword1);
>  		pkt_flags |= i40e_rxd_error_to_pkt_flags(qword1);
>  		pkt_flags |= i40e_rxd_ptype_to_pkt_flags(qword1);
> -		rxm->ol_flags = pkt_flags;
> +		rxm->ol_flags = pkt_flags | (rxm->ol_flags & EXTERNAL_MBUF);
>  		if (pkt_flags & PKT_RX_RSS_HASH)
>  			rxm->hash.rss =
>  				rte_le_to_cpu_32(rxd.wb.qword0.hi_dword.rss);
> @@ -1027,7 +1028,8 @@ i40e_recv_scattered_pkts(void *rx_queue,
>  		pkt_flags = i40e_rxd_status_to_pkt_flags(qword1);
>  		pkt_flags |= i40e_rxd_error_to_pkt_flags(qword1);
>  		pkt_flags |= i40e_rxd_ptype_to_pkt_flags(qword1);
> -		first_seg->ol_flags = pkt_flags;
> +		first_seg->ol_flags = pkt_flags |
> +			(first_seg->ol_flags & EXTERNAL_MBUF);
>  		if (pkt_flags & PKT_RX_RSS_HASH)
>  			rxm->hash.rss =
>  				rte_le_to_cpu_32(rxd.wb.qword0.hi_dword.rss);
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> index 1aefe5c..77e8689 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> @@ -949,7 +949,8 @@ ixgbe_rx_scan_hw_ring(struct igb_rx_queue *rxq)
>  			/* reuse status field from scan list */
>  			pkt_flags |= rx_desc_status_to_pkt_flags(s[j]);
>  			pkt_flags |= rx_desc_error_to_pkt_flags(s[j]);
> -			mb->ol_flags = pkt_flags;
> +			mb->ol_flags = pkt_flags |
> +				(mb->ol_flags & EXTERNAL_MBUF);
> 
>  			if (likely(pkt_flags & PKT_RX_RSS_HASH))
>  				mb->hash.rss = rxdp[j].wb.lower.hi_dword.rss;
> @@ -1271,7 +1272,7 @@ ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>  		pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(hlen_type_rss);
>  		pkt_flags = pkt_flags | rx_desc_status_to_pkt_flags(staterr);
>  		pkt_flags = pkt_flags | rx_desc_error_to_pkt_flags(staterr);
> -		rxm->ol_flags = pkt_flags;
> +		rxm->ol_flags = pkt_flags | (rxm->ol_flags & EXTERNAL_MBUF);
> 
>  		if (likely(pkt_flags & PKT_RX_RSS_HASH))
>  			rxm->hash.rss = rxd.wb.lower.hi_dword.rss;
> @@ -1515,7 +1516,8 @@ ixgbe_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>  				rx_desc_status_to_pkt_flags(staterr));
>  		pkt_flags = (uint16_t)(pkt_flags |
>  				rx_desc_error_to_pkt_flags(staterr));
> -		first_seg->ol_flags = pkt_flags;
> +		first_seg->ol_flags = pkt_flags |
> +				(first_seg->ol_flags & EXTERNAL_MBUF);
> 
>  		if (likely(pkt_flags & PKT_RX_RSS_HASH))
>  			first_seg->hash.rss = rxd.wb.lower.hi_dword.rss;
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
> index e813e43..af7b1cd 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
> @@ -156,10 +156,14 @@ desc_to_olflags_v(__m128i descs[4], struct rte_mbuf **rx_pkts)
>  	ptype1 = _mm_or_si128(ptype1, vtag1);
>  	vol.dword = _mm_cvtsi128_si64(ptype1) & OLFLAGS_MASK_V;
> 
> -	rx_pkts[0]->ol_flags = vol.e[0];
> -	rx_pkts[1]->ol_flags = vol.e[1];
> -	rx_pkts[2]->ol_flags = vol.e[2];
> -	rx_pkts[3]->ol_flags = vol.e[3];
> +	rx_pkts[0]->ol_flags = vol.e[0] |
> +		(rx_pkts[0]->ol_flags & EXTERNAL_MBUF);
> +	rx_pkts[1]->ol_flags = vol.e[1] |
> +		(rx_pkts[1]->ol_flags & EXTERNAL_MBUF);
> +	rx_pkts[2]->ol_flags = vol.e[2] |
> +		(rx_pkts[2]->ol_flags & EXTERNAL_MBUF);
> +	rx_pkts[3]->ol_flags = vol.e[3] |
> +		(rx_pkts[3]->ol_flags & EXTERNAL_MBUF);
>  }
>  #else
>  #define desc_to_olflags_v(desc, rx_pkts) do {} while (0)
> --
> 1.8.4.2



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