Hi;
Thanks reporting this,

Sadly, current Linux kernel version 5.8 is not supported either as Host nor Guest in Virtualbox upstream.

As soon an update on this will be published upstream, we will provide updated packages.

Therefore:
(In reply to Alex Grant from comment #0)
> Solving the problem (operations inside the guest Mageia-8.0):
> su
> password
> 
> urpme virtualbox-guest-additions-6.1.12-8.mga8.x86_64.rpm
> 
> wget 
> https://download.virtualbox.org/virtualbox/6.0.24/VBoxGuestAdditions_6.0.24.
> iso
> mkdir /111; mount -o loop,ro ./VBoxGuestAdditions_6.0.24.iso /111; cd /111;
> sh ./VBoxLinuxAdditions.ru; reboot

This is a dirty workaround obtain by chance. You use an older VBoxGuestAdditions version : 6.0.24 < 6.1.12-8 provided by our RPM.

> 
> p.s. I apologize for my poor English (this is an online translator)...
Don't excuse you! We can read well ;)

Holding this in Bugsquad until upstream updates come.

Keywords: (none) => Triaged, UPSTREAM

Okay, Aurelien Oudelet. :)

Also as a workaround,
In your mga8 guest VM, you can still use kernel-5.7.9-desktop-1.mga8 which still works.

Thank you, but it doesn't suit me. I install Mageia through the network and collect live-usb-flash drives with different DE from them. So I need all the latest stuff usually. In addition, this fits into the General concept of testing: You update and I collect, I collect - You update, etc.

Virtualbox updated to version 6.1.14 and fixes run on 5.8 kernel series.
This should resolve this bug.

Keywords: UPSTREAM => NEEDINFO

Created attachment 11875 [details]
vbox-additions-6.1.14-3-kernel-5.8.8-1

Good afternoon, Aurelien Oudelet. For a clean check, I installed a new Mageia-8 VM over the network in which virtualbox-guest-additions = 6.1.14-3 and kernel = 5.8.8-1. The bidirectional clipboard still doesn't work (see the screenshot of vbox-additions-6.1.14-kernel-5.8.8-1). Let me remind you that my host system is Mageia-7.1 and it has VirtualBox 6.0.24 r139119 + Oracle_VM_VirtualBox_Extension_Pack-6.0.24.vbox-extpack. As the main desktop environment, I use "Budgie-10.5.1" and additional - "MATE-1.22.1". I don't know how a guy with a similar problem from a related topic is doing right now, but I still have the same result - in both environments, the result is negative. I am very sorry... :(

So sorry to see this.
Seems virtualbox additions are outdated in Mageia 7.1

Requesting an update if possible.
Assigning to all packagers, no registered one.
CC'ing recent commiters.

CC: (none) => ghibomgx
Version: Cauldron => 7
Assignee: bugsquad => pkg-bugs
Severity: normal => major
Source RPM: (none) => VirtualBox v6.0.24r139119
Target Milestone: --- => Mageia 7
Keywords: NEEDINFO => (none)

In other words, there are drastic changes between these versions that do not allow you to work with a higher release from a lower release? It's weird. This is the first time I have such problems, usually with the clipboard it has never been like this. Could partially not work Drag & Drop in different DE, but the buffer... Weird. :) Thank you for your assistance.

I was unable to confirm the problem when communicating between M7 virtualbox 6.0.24 host and an M8 guest, as for some reason my vbox 6.0.24 would fail to create an M8 64-bit guest. Mageia 64-bit was not an option under "New." Updating to 6.1.16 has eliminated that problem.

I was able to try the bidirectional clipboard after the update, and problems with that seem to have disappeared, as well.

Someone else should confirm, but it looks to me like this one is fixed by updating M7 to vbox 6.1.16.

CC: (none) => andrewsfarm

Hi, Thomas Andrews.

On my Mageia-7.1, I updated the following packages from "Mageia Core Updates Testing":
---
- cpupower-5.9.11-3.mga7.x86_64
- dkms-vboxadditions-6.1.16-1.mga7.noarch
- dkms-virtualbox-6.1.16-1.mga7.noarch
- kernel-desktop-devel-5.9.11-3.mga7-1-1.mga7.x86_64
- kernel-desktop-devel-latest-5.9.11-3.mga7.x86_64
- virtualbox-6.1.16-1.mga7.x86_64
- virtualbox-guest-additions-6.1.16-1.mga7.x86_64
- virtualbox-kernel-5.7.19-desktop-3.mga7-6.1.16-1.mga7.x86_64
- virtualbox-kernel-desktop-latest-6.1.16-1.mga7.x86_64

My "Guest" - Mageia-8-Cauldron-MATE-x86_64, Kernel-5.9.11-desktop-3.mga8

After the update, the problem with the bidirectional clipboard is no longer there. It works well. I will say more, even "Drag and Drop" works.

So everything is fine. :)

Now the bidirectional shared clipboard works perfectly.

Host (Mageia-7.1):
---
> rpm -qi virtualbox
Name        : virtualbox
Version     : 6.1.16
Release     : 4.mga7
Architecture: x86_64
Install Date: Вт 22 дек 2020 11:17:01
Group       : Emulators
Size        : 125842199
License     : GPLv2
Signature   : RSA/SHA256, Чт 17 дек 2020 03:50:39, Key ID b742fa8b80420f66
Source RPM  : virtualbox-6.1.16-4.mga7.src.rpm
Build Date  : Чт 17 дек 2020 03:08:17
Build Host  : localhost
Relocations : (not relocatable)
Packager    : tmb <tmb>
Vendor      : Mageia.Org
URL         : https://www.virtualbox.org/
Summary     : A general-purpose full virtualizer for x86 hardware
Description :
VirtualBox is a general-purpose full virtualizer for x86 hardware.
> uname -a
Linux localhost 5.7.19-desktop-3.mga7 #1 SMP Sun Oct 18 15:46:00 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Guest (Mageia-8-Cauldron):
---
> uname -a
Linux localhost 5.10.2-desktop-1.mga8 #1 SMP Mon Dec 21 13:01:59 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Thank You for your cooperation.

For more information, see the screenshot "Host<->Guest copy check".

Created attachment 12133 [details]
Host<->Guest copy check

I will close this bug so as not to distract You from more important things.

Resolution: (none) => FIXED
Status: NEW => RESOLVED