yet another issue with MTU 9000 on eth on vlan and macvtap

I was wondering how to configure mtu 9000 on a ethernet interface and a vlan, furthermore on the vlan I have a macvtap.

If I configure eth4 for mtu 9000, the mtu of the vlan cannot be 9000 anymore because of the bits needed for the vlan. Is linux just ‘automatically’ correcting this? And how do other child interfaces know about this?

If I create the macvtap on the vlan, it takes automatically the mtu 9000 from the parent/vlan again 9000.

If we then add a VM to the vlan interface it also automatically gets a macvtap with an mtu 9000 on the host. But what mtu should I then set within the VM? Also 9000?

  +------+   | eth4 |   | 9000 |   +------+       |   +------+       |---|e4.601|       |   | 9000 |       |   +------+       |       |   +------+       \---|e4.529|           | 9000 |           +------+            |   |            |  +------+            |  |macvtp| <- host            |  | 9000?|            |  +------+            |            |  +------+            \--|macvtp| <- VM               | 9000?|               +------+