[Users] Can I delay boot of VM so to interact with grub?

Hello, in VMware I can choose two things that sometimes are useful 1) boot directly in bios I choose this when I want to attach an iso image to the VM In oVirt probably could be obtained with run once and attach cd. But in general it could be interesting this opportunity 2) choose a delay in boot This way I can use the VM console befaore OS starts and if needed I can interact with boot loader (grub in Linux VM for example). When I open a spice console I'm not able to get usability before os already in start after grub. I see to options: - create a delay in boot as in VMware - give spice console the "-w" (for wait) option that already existed in virt-viewer and not in remote-viewer so that one can spawn a console window before the VM ha already been started. What do you think? Is there anything already in place to jump into a vm before grub completes (other than setting a long delay in grub itself)? Thanks Gianluca