virtio-fs: tag not found

[kvz]

Describe the issue
I'm not successful in mounting a directory on a virtualized Ubuntu ARM VM from a macOS 13 host using Apple Virtualization.

Steps completed inside the Ubuntu guest:

sudo apt install -y binfmt-support
sudo mkdir -p /media/rosetta
sudo mount -t virtiofs rosetta /media/rosetta

sudo /usr/sbin/update-binfmts --install rosetta /media/rosetta/rosetta \
  --magic "\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x3e\x00" \
  --mask "\xff\xff\xff\xff\xff\xfe\xfe\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff" \
  --credentials yes --preserve no --fix-binary yes

grep -q ^rosetta /etc/fstab || echo "rosetta	/media/rosetta	virtiofs	ro,nofail	0	0" |sudo tee -a /etc/fstab

sudo modprobe virtiofs
sudo apt install spice-vdagent

And the VM is configured to have at least one api2 tagged share as can be seen here:

I don't see the shares however in my config.plist, added below, is that to be expected?

Strangely enough, you can see virtiofs shared folders do work conceptually, because the Rosetta drive is mounted that way and I can confirm I can remount it without errors like so:

$ sudo umount -lf /media/rosetta
$ sudo mount -t virtiofs rosetta /media/rosetta
$ ls -al /media/rosetta
total 260
drwxr-xr-x 3 vagrant vagrant     96 Oct 26 09:27 .
-rwxr-xr-x 1 vagrant vagrant 540360 Sep 30 22:24 rosetta

So I think something goes wrong with the way that UTM allows me to share additional folders.

Configuration

• UTM Version: 4.0.9
• macOS Version: 13.0.1 (22A400)
• Mac Chip: M1

Crash log

$ sudo mkdir -p /srv/current
$ sudo chown -R ${USER} /srv/current
$ sudo mount -t virtiofs api2 /srv/current
mount: /srv/current: wrong fs type, bad option, bad superblock on api2, missing codepage or helper program, or other error.

Debug log

$ sudo dmesg
[  735.874267] virtio-fs: tag <api2> not found
[  750.993736] virtio-fs: tag </api2> not found
[  756.242520] virtio-fs: tag </Users/kvz/code/api2> not found

As you can see I tried different variations of the api2 shared folder tag, none of which worked.

Upload VM
config.plist.zip

[osy]

Please see https://docs.getutm.app/guest-support/linux/#virtfs the correct command is

$ sudo mount -t 9p -o trans=virtio share [mount point] -oversion=9p2000.L

[kvz]

I got it working with mount binds at any rate, so thank you very much @osy 🎉

Here are my full instructions for mounting two shared folders nested inside one another on Ubuntu ARM 22 with Apple Virtualization on an M1 in case someone else stumbles into something similar:

sudo grep -q ^virtiofs /etc/initramfs-tools/modules || echo "virtiofs" |sudo tee -a /etc/initramfs-tools/modules 
sudo update-initramfs -uk all
sudo modprobe virtiofs 
sudo mkdir -p /media/share
sudo umount -lf /media/share
sudo mkdir -p /srv/current/api2
sudo grep -q ^share /etc/fstab || echo "share	/media/share	virtiofs	rw,nofail	0	0" |sudo tee -a /etc/fstab
sudo grep -q ^/media/share/api2 /etc/fstab || echo "/media/share/api2	/srv/current	none	defaults,bind	0	0" |sudo tee -a /etc/fstab
sudo grep -q ^/media/share/content /etc/fstab || echo "/media/share/content	/srv/current/crm/webroot	none	defaults,bind	0	0" |sudo tee -a /etc/fstab
sudo chown -R ${USER} /media/share
sudo mount -a
# sudo journalctl -xe

[saoj]

Would you mind sharing how you solved this? When I try to mount on Ventura I get the following:

$ sudo mount -t virtiofs vms_shared_folder /Users/soliveira/vms_shared_folder
mount_virtiofs: fs_tag vms_shared_folder not found
mount: /Users/soliveira/vms_shared_folder failed with 1

[osy]

https://docs.getutm.app/guest-support/macos/#virtiofs

[saoj]

My bad. This needs to be executed in the virtual machine (Ubuntu), not in the host machine (Mac). And the correct command for the virtual machine (Ubuntu) is:

sudo mount -t 9p -o trans=virtio share /home/soliveira/host-wp -oversion=9p2000.L

That's of course after you have properly configured the sharing folder under UTM configurations for your VM.

[kokoskiwi]

please help me @osy @kvz @saoj #6078

[burningalchemist]

Hey @osy, I bumped into the same issue on MacOS 14.1 (both host/guest) after the update:

~ sw_vers
ProductName:            macOS
ProductVersion:         14.1
BuildVersion:           23B74
~ mkdir -m 777 -p hostshare
~ file hostshare
hostshare: directory
~ mount_virtiofs share hostshare
mount_virtiofs: fs_tag share not found
~

It worked well for me since 13+. I'm wondering if I'm missing something or it's a common (new) issue. Tried to restart the host, the vm, re-adding the shared directory with no success.

UTM Version is 4.4.4, AVF.

Thank you. :)

[burningalchemist]

Seems to be a solution: #5875 (comment) 👍