Hi Ard,

 

I notice that you had ever worked on VirtNorFlashDxe, and maybe can help me on the following trouble.

 

I am trying to boot kvm VM on aarch64(arm-v8) with preempt-rt kernel host,

the UpdateVariable is very very slow, and the uefi boot take about ~80s to get to phase,

while it takes only about ~15s on a normal linux kernel or on x86 hardware.

 

This only happen when the VM is first defined, or redefine the VM:

virsh destroy VM;      

virsh undefine VM --nvram

virsh define VM.xml ; 

virsh start VM

It seems the most time spending when VirtNorFlash write operation at MmioWrite32();

On X64 platform，it seems use EmuVariableFvbRuntimeDxe driver，not really write the NorFlash device，

Is it possible for arm to use the similar way as X64 ?

 

Could you give any suggestion?

 

Best Regards.

Limin Wang