对网络方面的知识有所欠缺，光看网卡 bond 文档对与 mode 4 的机制和数据流向不太清晰

IEEE 802.3ad Dynamic link aggregation. Creates aggregation groups that share the same speed and duplex settings. Utilizes all slaves in the active aggregator according to the 802.3ad specification.
Slave selection for outgoing traffic is done according to the transmit hash policy, which may be changed from the default simple XOR policy via the xmit_hash_policy option, documented below. Note that not all transmit policies may be 802.3ad compliant, particularly in regards to the packet mis-ordering requirements of section 43.2.4 of the 802.3ad standard. Differing peer implementations will have varying tolerances for noncompliance.
Prerequisites:
Ethtool support in the base drivers for retrieving the speed and duplex of each slave.
A switch that supports IEEE 802.3ad Dynamic link aggregation.
Most switches will require some type of configuration to enable 802.3ad mode.

这里写传出流量选择是根据传输哈希策略完成的

但是如果我使用某个 slave 网卡的 sr-iov 的 vf 发送数据还会经过哈希规则么，为什么？