diff mbox series

[bpf-next,v2,1/3] net: add priv_flags for allow tx skb without linear

Message ID 30ae1c94b5c26919bd90bb251761c526edfbaf56.1611048724.git.xuanzhuo@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series xsk: build skb by page | expand

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netdev/source_inline success Was 0 now: 0
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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 7149 this patch: 7149
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch warning CHECK: spaces preferred around that '<<' (ctx:VxV)
netdev/build_allmodconfig_warn success Errors and warnings before: 7558 this patch: 7558
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Xuan Zhuo Jan. 19, 2021, 9:45 a.m. UTC
In some cases, we hope to construct skb directly based on the existing
memory without copying data. In this case, the page will be placed
directly in the skb, and the linear space of skb is empty. But
unfortunately, many the network card does not support this operation.
For example Mellanox Technologies MT27710 Family [ConnectX-4 Lx] will
get the following error message:

    mlx5_core 0000:3b:00.1 eth1: Error cqe on cqn 0x817, ci 0x8, qn 0x1dbb, opcode 0xd, syndrome 0x1, vendor syndrome 0x68
    00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00000030: 00 00 00 00 60 10 68 01 0a 00 1d bb 00 0f 9f d2
    WQE DUMP: WQ size 1024 WQ cur size 0, WQE index 0xf, len: 64
    00000000: 00 00 0f 0a 00 1d bb 03 00 00 00 08 00 00 00 00
    00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00000020: 00 00 00 2b 00 08 00 00 00 00 00 05 9e e3 08 00
    00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    mlx5_core 0000:3b:00.1 eth1: ERR CQE on SQ: 0x1dbb

So a priv_flag is added here to indicate whether the network card
supports this feature.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Suggested-by: Alexander Lobakin <alobakin@pm.me>
---
 include/linux/netdevice.h | 3 +++
 1 file changed, 3 insertions(+)

Comments

Jason Wang Jan. 20, 2021, 3:01 a.m. UTC | #1
On 2021/1/19 下午5:45, Xuan Zhuo wrote:
> In some cases, we hope to construct skb directly based on the existing
> memory without copying data. In this case, the page will be placed
> directly in the skb, and the linear space of skb is empty. But
> unfortunately, many the network card does not support this operation.
> For example Mellanox Technologies MT27710 Family [ConnectX-4 Lx] will
> get the following error message:
>
>      mlx5_core 0000:3b:00.1 eth1: Error cqe on cqn 0x817, ci 0x8, qn 0x1dbb, opcode 0xd, syndrome 0x1, vendor syndrome 0x68
>      00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>      00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>      00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>      00000030: 00 00 00 00 60 10 68 01 0a 00 1d bb 00 0f 9f d2
>      WQE DUMP: WQ size 1024 WQ cur size 0, WQE index 0xf, len: 64
>      00000000: 00 00 0f 0a 00 1d bb 03 00 00 00 08 00 00 00 00
>      00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>      00000020: 00 00 00 2b 00 08 00 00 00 00 00 05 9e e3 08 00
>      00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>      mlx5_core 0000:3b:00.1 eth1: ERR CQE on SQ: 0x1dbb
>
> So a priv_flag is added here to indicate whether the network card
> supports this feature.


I don't see Mellanox engineers are copied. I wonder if we need their 
confirmation on whether it's a bug or hardware limitation.

Thanks
diff mbox series

Patch

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 02dcef4..54501eb 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1525,6 +1525,7 @@  struct net_device_ops {
  * @IFF_FAILOVER_SLAVE: device is lower dev of a failover master device
  * @IFF_L3MDEV_RX_HANDLER: only invoke the rx handler of L3 master device
  * @IFF_LIVE_RENAME_OK: rename is allowed while device is up and running
+ * @IFF_TX_SKB_NO_LINEAR: allow tx skb linear is empty
  */
 enum netdev_priv_flags {
 	IFF_802_1Q_VLAN			= 1<<0,
@@ -1558,6 +1559,7 @@  enum netdev_priv_flags {
 	IFF_FAILOVER_SLAVE		= 1<<28,
 	IFF_L3MDEV_RX_HANDLER		= 1<<29,
 	IFF_LIVE_RENAME_OK		= 1<<30,
+	IFF_TX_SKB_NO_LINEAR		= 1<<31,
 };
 
 #define IFF_802_1Q_VLAN			IFF_802_1Q_VLAN
@@ -1590,6 +1592,7 @@  enum netdev_priv_flags {
 #define IFF_FAILOVER_SLAVE		IFF_FAILOVER_SLAVE
 #define IFF_L3MDEV_RX_HANDLER		IFF_L3MDEV_RX_HANDLER
 #define IFF_LIVE_RENAME_OK		IFF_LIVE_RENAME_OK
+#define IFF_TX_SKB_NO_LINEAR		IFF_TX_SKB_NO_LINEAR
 
 /**
  *	struct net_device - The DEVICE structure.