# Kvm and parallel ports **URL:** \ **Category:** Rocky Linux Help & Support\ **Created:** [November 28, 2021, 2:22am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738 "2021-11-28T02:22:37Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![sweh](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/sweh/32/1287_2.png) [@sweh](https://forums.rockylinux.org/u/sweh)\ **Post date:** [November 28, 2021, 2:22am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/1 "2021-11-28T02:22:37Z")
This isn’t something Rocky can solve, 'cos it’s broken upstream, but maybe someone has a solution… I had a CentOS 6 machine and a WinXP virtual machine. I was able to forward the parallel port to the VM, so ancient Windows software could talk to the parallel port directly. Surprisingly it worked. I upgraded this machine to Rocky 8. And I find this functionality has been removed. `virsh start` complains that `isa-parport` is an unknown driver. What a PITA. (The other problem I had with mpt2sas was fixed with ELrepo, but I don’t see a solution to this!) ---
**Author:** ![neil](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/neil/32/34_2.png) [@neil](https://forums.rockylinux.org/u/neil)\ **Post date:** [November 28, 2021, 2:28pm UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/2 "2021-11-28T14:28:40Z")
Try using just ‘parport’ for the chardev instead of isa-parport. You’ll likely need to edit the xml for the guest, which you should backup first (using `virsh edit` and `virsh dump-xml`, respectively. Hope that helps! ---
**Author:** ![sweh](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/sweh/32/1287_2.png) [@sweh](https://forums.rockylinux.org/u/sweh)\ **Post date:** [November 28, 2021, 2:57pm UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/3 "2021-11-28T14:57:41Z")
I’m using this structure: ``` ``` `virsh` converts that to ``` -chardev parport,id=charparallel0,path=/dev/parport0 \ -device isa-parallel,chardev=charparallel0,id=parallel0 \ ``` and that’s where it’s failing 'cos `qemu-kvm` doesn’t support that any more. ---
**Author:** ![jr-acme](https://avatars.discourse-cdn.com/v4/letter/j/ed655f/32.png) [@jr-acme](https://forums.rockylinux.org/u/jr-acme)\ **Post date:** [February 16, 2022, 6:21am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/4 "2022-02-16T06:21:17Z")
Did you ever find a solution? I didn’t realize qemu-kvm doesn’t “support” this anymore. I’ve tried it on another distro (ubuntu) but I don’t want to use that long term. ---
**Author:** ![sweh](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/sweh/32/1287_2.png) [@sweh](https://forums.rockylinux.org/u/sweh)\ **Post date:** [February 16, 2022, 11:06am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/5 "2022-02-16T11:06:48Z")
No ☹ I haven’t got it working ☹ ---
**Author:** ![jr-acme](https://avatars.discourse-cdn.com/v4/letter/j/ed655f/32.png) [@jr-acme](https://forums.rockylinux.org/u/jr-acme)\ **Post date:** [February 16, 2022, 5:50pm UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/6 "2022-02-16T17:50:15Z")
I was reading through some documentation on red hat’s website where they explicitly stated that parallel port support is “not happening”, but I don’t quite understand why it still works in ubuntu LTS? I _have_ to have parallel port passthrough, so I think I could compile qemu from source on the machine that needs it. Or figure out a different method of passing the port through. If I find a solution that isn’t switching distros I’ll make sure to post here. ---
**Author:** ![desercat](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/desercat/32/1192_2.png) [@desercat](https://forums.rockylinux.org/u/desercat)\ **Post date:** [March 17, 2022, 2:56am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/7 "2022-03-17T02:56:14Z")
Sorry I _may_ – probably _am_ off, but are you talking about a KVM **SWITCH**??? I use a KVM 4 position **SWITCH** to change between 4 different computers? it uses hot keys. If that is NOT what is under discussion SORRY; but if SO, then I’m not sure what RH is talking about as my KVM **SWITCH** works just fine. ---
**Author:** ![jlehtone](https://avatars.discourse-cdn.com/v4/letter/j/e9a140/32.png) [@jlehtone](https://forums.rockylinux.org/u/jlehtone)\ **Post date:** [March 17, 2022, 7:17am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/8 "2022-03-17T07:17:50Z")
KVM as in keyboard, video, and mouse is hardware that lets you connect one set of peripherals into multiple computers. KVM as in kernel virtual machine is software in Linux kernel that facilitates virtual machines. ---
**Author:** ![desercat](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/desercat/32/1192_2.png) [@desercat](https://forums.rockylinux.org/u/desercat)\ **Post date:** [March 17, 2022, 8:36am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/9 "2022-03-17T08:36:17Z")
Ah!!! That you for the clarification. I was only aware of the first definition, but had I thought about it “VM” usually refers to Virtual Machines , the “K” threw me into thinking it was a KVM “SWITCH” . D. O’Cat – Happy St. Patrick’s Day ---
**Author:** ![jr-acme](https://avatars.discourse-cdn.com/v4/letter/j/ed655f/32.png) [@jr-acme](https://forums.rockylinux.org/u/jr-acme)\ **Post date:** [March 17, 2022, 3:42pm UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/10 "2022-03-17T15:42:18Z")
Oh That’s pretty funny! I didn’t “realize” that they both had the same name if that makes sense. Happy St. Patrick’s day ---
**Author:** ![jlehtone](https://avatars.discourse-cdn.com/v4/letter/j/e9a140/32.png) [@jlehtone](https://forums.rockylinux.org/u/jlehtone)\ **Post date:** [March 17, 2022, 8:51pm UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/11 "2022-03-17T20:51:00Z")
Well, in both acronyms you can reach multiple “machines” from one set of peripherals … Sorry, can’t help with the parallel. Have to do the old Obi-Wan: _… that is a name I have not heard in a long time …_ ---
**Author:** ![desercat](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/desercat/32/1192_2.png) [@desercat](https://forums.rockylinux.org/u/desercat)\ **Post date:** [March 18, 2022, 9:02am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/12 "2022-03-18T09:02:46Z")
Use the Source jlehtone … I mean FORCE Hehehehe… ---
**Author:** ![Corsari](https://avatars.discourse-cdn.com/v4/letter/c/ecb155/32.png) [@Corsari](https://forums.rockylinux.org/u/Corsari)\ **Post date:** [August 13, 2023, 8:38am UTC](https://forums.rockylinux.org/t/kvm-and-parallel-ports/4738/13 "2023-08-13T08:38:27Z")
with reference to the first original post in this thread given that you have an host hardware with Intel HW Virtualization in BIOS including VT-d and a parallel LTP ECP port does any of you know which working combination of virtualization system and platform does allow to have a working passthrough for a parallel LPT ECP port ? Thank you goal: have that parallel LTP ECP port available and working in a Windows XP virtualized guest Thank you Robert