virtio-9p filesharing issue

[Taryel Hlontsi <xhaaix%gmail.com@localhost>]

Hi all,

Recently I was trying NetBSD10 amd64 as a KVM/QEMU guest on Linux host 
and wanted to configure a shared directory with the new vio9p driver.
However I did not succeed. It looks like something was detected as a 9P 
transport device but that's about it.

Maybe someone has some clues on how to configure it properly?

HOSTS (if it matters):
Debian 12 on Ext4
Ubuntu 24.04 on XFS

GUEST:
uname -a
NetBSD zed.home 10.0 NetBSD 10.0 (GENERIC) #0: Thu Mar 28 08:33:33 UTC 
2024 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC 
amd64
The NetBSD current produces the same result

My libvirt filesystem config:
    <filesystem type="mount" accessmode="mapped">
      <source dir="/home/tar/Public/share"/>
      <target dir="/mnt"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x08" 
function="0x0"/>
    </filesystem>

dmesg | grep -E 'vio|virtio'
[     1.016364] virtio0 at pci0 dev 6 function 0
[     1.016364] virtio0: console device (id 3, rev. 0x00)
[     1.016364] virtio0: autoconfiguration error: no matching child 
driver; not configured
[     1.016364] virtio1 at pci0 dev 7 function 0
[     1.016364] virtio1: memory balloon device (id 5, rev. 0x00)
[     1.016364] viomb0 at virtio1: features: 0x10000000<INDIRECT_DESC>
[     1.016364] virtio1: allocated 8192 byte for virtqueue 0 for 
inflate, size 128
[     1.016364] virtio1: allocated 8192 byte for virtqueue 1 for 
deflate, size 128
[     1.016364] virtio1: interrupting at ioapic0 pin 11
[     1.016364] virtio2 at pci0 dev 8 function 0
[     1.016364] virtio2: 9P transport device (id 9, rev. 0x00)
[     1.016364] virtio2: autoconfiguration error: no matching child 
driver; not configured

modstat | grep -E 'vio|virtio'
if_vioif                   driver   builtin  -        0       - virtio
ld_virtio                  driver   builtin  -        0       - ld,virtio
viomb                      driver   builtin  -        0       - virtio
vioscsi                    driver   builtin  -        0       - virtio
virtio                     driver   builtin  -        5       - -
virtio_pci                 driver   builtin  -        0       - pci,virtio

Thank you