Arch Linux

Koatao

Member

Registered: 2018-08-30

Posts: 113

[CLOSED]QEMU SPICE how to achieve bidirectional clipboard with Sway?

Hi,

I have a ArchLinux host and QEMU guest running Sway (Wayland Compositor) with wl-clipboard.

Guest is ran through Libvirt. And I use Virtual Machine Manager as GUI.
Here is my libvirt config for the guest domain: https://pastebin.com/uv7QaAmj.

I must have 3d acceleration on the guest.
My host has an integrated GPU (AMD Ryzen 7 8845HS w/ Radeon 780M Graphics)
If I understand correctly, in this situation, I must use virtio GPU with 3d acceleration on and a SPICE display with OpenGL on.

I'm struggling to achieve bidirectional clipboard sharing between my host and my guest.
I understand that spice-vdagent is not designed for Wayland, and thus it is not 100% functionnal with some compositor like Sway  (I'm guessing anything using wlroots).

As of now, I have clipboard sharing from host to guest like so:
- Copy anything on the host
- Pass the content through xsel to wl-clipboard on the guest:

xsel | wl-copy

It doesn't work the other way around from guest to host (even if I do `wl-paste | xsel` first on the guest).

Did anyone manage do make it work in a similar setup?
Does anyone with better understanding of clipboard and Wayland have some ideas that might work?

I'm thinking about implementing a cheap clipboard sharing solution thought a UNIX socket shared between the host and the guest and some notification system.
But I'm lacking the knowledge and understanding to evaluate how stupid of an idea it is?

PS: I've tried paprika-vdagent but it makes the guest unusable through the SPICE agent.

Last edited by Koatao (2026-06-07 17:23:01)

qinohe

Member

From: Netherlands

Registered: 2012-06-20

Posts: 1,593

Re: [CLOSED]QEMU SPICE how to achieve bidirectional clipboard with Sway?

Far as I know this still doesn't work so for me the following solution works fine
For sharing information I'm using a shared directory, the next line is in my QEMU command on the host

-virtfs local,path=/home/user/share,mount_tag=host0,security_model=mapped,id=host0

And with this line on the guest the shared directory is mounted on the guest

# mkdir /mnt/share && mount -t 9p -o trans=virtio,version=9p2000.L host0 /mnt/share

Since I don't virt-manager you may need to figure that out on your own
You need to at least change 'user' in the first line

edit: for more info on that second line: https://wiki.qemu.org/Documentation/9p

Last edited by qinohe (2026-06-01 08:49:07)

tekstryder

Member

Registered: 2013-02-14

Posts: 530

Re: [CLOSED]QEMU SPICE how to achieve bidirectional clipboard with Sway?

EDIT:

Disregard my irrelevant post (removed).

A quick look into the topic and the functionality is not natively supported in this context (spice-vdagent).

Seems simple enough to establish an SSH tunnel to pass clipboard contents via:

# On Guest: Send clipboard to Host
wl-paste | ssh user@host_ip "wl-copy"

# On Host: Send clipboard to Guest
wl-paste | ssh user@guest_ip "wl-copy"

Set up some keybinds.

Last edited by tekstryder (2026-06-01 12:00:15)

Koatao

Member

Registered: 2018-08-30

Posts: 113

Re: [CLOSED]QEMU SPICE how to achieve bidirectional clipboard with Sway?

For sharing information I'm using a shared directory

Thanks for the reply, I appreciate the share.

I want to avoid as much manual processing as possible.

Seems simple enough to establish an SSH tunnel to pass clipboard contents via:

# On Guest: Send clipboard to Host
wl-paste | ssh user@host_ip "wl-copy"

# On Host: Send clipboard to Guest
wl-paste | ssh user@guest_ip "wl-copy"

Set up some keybinds.

I don't like the idea that my guest can SSH freely on my host. It also means everything needs to be fixed and known prior to setting this thing up. And it doesn't support multiple guest nicely.

But if I combine both of your idea together, I could simply have a keybinding on Sway that copy or paste the clipboard from/to a shared file.
Even if it still means I need to manually press the keybinding, it is way simplier to implement than sharing through a socket (+ it is quite easy to support multiple guests like this).

qinohe

Member

From: Netherlands

Registered: 2012-06-20

Posts: 1,593

Re: [CLOSED]QEMU SPICE how to achieve bidirectional clipboard with Sway?

That sounds like a solid idea, glad you may have found a way in both our solutions
Please let us know how you did implement it, thanks

Koatao

Member

Registered: 2018-08-30

Posts: 113

Re: [CLOSED]QEMU SPICE how to achieve bidirectional clipboard with Sway?

So I finally at time to test it.
It works as it supposed to be.
Mounted a shared filesystem with virtiofs, and I dump or copy the clipboard from a file in it:

wl-paste > "$clipboardFile"

wl-copy --trim-newline< "$clipboardFile"

$clipboardFile being the path to the shared file.

Since I use Ansible, I can automate the set up on the guest.

Don't forget that if you copy a secret, it will stay on the file until it is overwritten!

I marked the thread as CLOSED since this is more a bypass than a decent integrated solution.

One could use a notification system to avoid having to copy from the file manually I guess.

Last edited by Koatao (2026-06-07 17:25:33)

qinohe

Member

From: Netherlands

Registered: 2012-06-20

Posts: 1,593

Re: [CLOSED]QEMU SPICE how to achieve bidirectional clipboard with Sway?

Thanks for sharing your way of using it.
Please edit the title to something else than 'CLOSED' this what moderators use to definitely close a thread, thanks