RSS (Receive Side Scaling) support on virtio vhost adapter in v1.4

This is probably not the question for VyOS particularly, but may be someone knows. I’m running VyOS 1.4 KVM guest with vhost interfaces configured like this:

    <interface type='bridge'>
      <mac address='52:54:00:b4:26:1b'/>
      <source bridge='ovsbr0'/>
      <virtualport type='openvswitch'>
        <parameters interfaceid='7002497c-4352-4da9-a686-c039135d5348'/>
      <target dev='eth1'/>
      <model type='virtio'/>
      <driver name='vhost' queues='8' rx_queue_size='1024' tx_queue_size='1024'/>
      <alias name='net1'/>
      <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/>

The guest VyOS node shows multiqueue support for the interface:

$ ethtool -l eth1
Channel parameters for eth1:
Pre-set maximums:
RX:             n/a
TX:             n/a
Other:          n/a
Combined:       8
Current hardware settings:
RX:             n/a
TX:             n/a
Other:          n/a
Combined:       8

But the incoming traffic is being processed by the only one queue:

$ ethtool -S eth1|egrep "rx_queue_._packets"
     rx_queue_0_packets: 0
     rx_queue_1_packets: 0
     rx_queue_2_packets: 0
     rx_queue_3_packets: 1187
     rx_queue_4_packets: 0
     rx_queue_5_packets: 0
     rx_queue_6_packets: 0
     rx_queue_7_packets: 1870640

I was told that RSS support is something new for the virtio, but here we have 6.1.36 on guest VyOS system. Do you know guys if there is a way to tell whether RSS should be supported by virtio vhost adapters or not? And if yes - which kernel version or/and probably qemu version?

Thank you,