[Qemu-devel] Re: gui application

[Charles Duffy]

You should not need to change the bootloader to modify your screen 
resolution for a graphical application. Simply modify the guest's X11 
configuration to change the size, as you would were the system not a 
virtual machine.

That said, unless you configure qemu to use the vmwarevga adapter (which 
isn't necessarily fully stable yet), only fairly standard resolutions 
are available; if you really intend to use 600x800 rather than the more 
standard 800x600, you may not be able to do that.

One failproof approach would be to start an Xvnc instance in the guest, 
and connect to that using a VNC client; this way, you can configure the 
Xvnc instance to any arbitrary screen resolution you like. If you use 
tap-based networking and are virtualized rather than emulated, it should 
also be quite a bit faster than other approaches.