GRUB menu actions set video resolution
While debugging QEMU resolution changes in the QEMU port, I noticed that every time I did anything on the GRUB menu, the virtual machine got a request to set the resolution to the current resolution. That includes just using the arrow keys on the menu. If GRUB is doing a lot of stuff like that, it would explain why the GRUB menu has that much latency. This should be fixed. Rumors on IRC has it GRUB reloads the configuration every time.