qemu uses uefi to install the redhad6.0 VM, use the vnc connect it  which is  stuck
Description of problem:
I want to use uefi(udk2-->ovmf.fd) to install redhad6.0, but after I enter uefi and start up, I cannot use vnc to connect to it,The screen is black or often stuck, nor can I use the console of other pages, or it is a special slow to be able to use it. It's sure that the virtual machine is not crash. Anad the same operation is normal for redhad6.1 systems.
Steps to reproduce:
1.compile udk2 generate ovmf.fd
compile config: 

make -C BaseTools/Source/C

./OvmfPkg/build.sh -D DEBUG_ON_SERIAL_PORT=true   


2.run qemu with "-bios /bin/OVMF.fd"


3.use vnc to connet it

![image](/uploads/449ea89c218fe5d7e317db351271672a/image.png)

The screen is stuck can't handle it.