I had a little hickup when I installed Fedora 34 on a machine with an AMD Radeon RX 6700 XT graphics adapter: the boot process got stuck after mounting /tmp. I assume this was caused by KVM, because booting in basic graphics mode worked flawlessly.
This is nothing to be worried about. The bootstick obviously just didn’t include the necessary microcode for this rather new GPU.
Since Fedora is known for including such microcode in the update cycle of their current releases, I assumed a simple # dnf update might fix this after the installation.
However, after I booted the freshly installed system and fully updated system, the resolution was still locked to 1024x768.
Turns out that installing Fedora in basic graphics mode adds nomodeset as a parameter to all Grub entries.
This seems like a smart idea, considering you might not be able to boot in your new system after the installation otherwise. However, you have to run # grubby --remove-args=nomodeset --update-kernel=ALL after updating your system. This re-enables KVM and everything works as expected.