How does one create a Windows (11 25H2) VM with GPU passthrough (in Fedora 42)?

My Desire

To summarise, I want to create a Windows 11 25H2 Enterprise Insider Preview Canary virtual machine on my Fedora 42 installation. Ideally, via virt-manager (because VirtualBox taints the kernel).

However, I don't know whether anything needs to be modified to achieve this, what that would be if so, nor how to verify, when achieved, that it is operative (except by playing a game).

To elaborate:

My Environment

My OS (and DE) are, per /etc/os-release:

NAME="Fedora Linux"
VERSION_ID=42
VARIANT="KDE Plasma Desktop Edition"

Effort Undertaken To Achieve This

I have installed virt-manager (per rpmreaper):

L      3.5M virt-manager              5.0.0-2.fc42.noarch
        229K ├─> gtk-vnc2                  1.5.0-3.fc42.x86_64
        133K ├─> libvirt-glib              5.0.0-6.fc42.x86_64
         29K ├─> python3                   3.13.9-1.fc42.x86_64
         20K ├─> python3-gobject           3.50.0-3.fc42.x86_64
        282K ├─> spice-gtk3                0.42-6.fc42.x86_64
        6.2M ├─> virt-manager-common       5.0.0-2.fc42.noarch
        1.0M ├─> vte291                    0.80.4-1.fc42.x86_64
        316K │┌> dconf                     0.40.0-15.fc42.x86_64
 l      305K ├┴> dconf                     0.40.0-15.fc42.i686
       23.1M │┌> gtk3                      3.24.49-2.fc42.x86_64
       24.0M └┴> gtk3                      3.24.49-2.fc42.i686

However, VirtualBox is also available to me.

I err on not bothering to add amd_iommu=on to /etc/default/grub, because IOMMU support appears to be detected without it, as discussion.fedoraproject.org/t/73815/3 explains.

I don't know what else needs to be done, nor how to verify; the information online is sparse, terse, and inconsistent.

My Rationale

I want GPU passthrough because:

1. Some applications do not operate without HW acceleration.

2. I want to play some games that do not operate under Wine, or its Proton superset.

I want it on a VM because:

1. As superuser.com/a/1865269 explains, I have had it install its EFI on the wrong storage device, causing a reinstallation of another OS to cause it to become inaccessible. This matters on a machine with solely NVMe-based storage.

2. When I last installed the desired OS, it added its EFI stub to every storage device, and reordered my EFI boot order. It does this after most feature updates.

I merely want to reinstall because:

1. As reddit.com/r/techsupport/comments/1l1wwsj/comment/nlbi86c cites, Windows Update always somehow becomes inoperative for me, despite me never touching the preinstalled MSIX/AppX packages, or the WU service.

2. When I last installed the desired OS, it would not exceed a 300 by 600-pixel display resolution, because the Basic Display Adapter failed to load, requiring a reinstallation.

Fedora is my primary OS, so I prioritise it.

(Lack Of) Duplicates

posts/search?search=gpu+passthrough returned 0 relevant results at +2025-010-25T22:29:23+01:00.

Reposts

1. discussion.fedoraproject.org/t/169986