Question about edge-triggered interrupt

[LIU Zhiwei]

    Hi folks,
    
    Currently, I am writing an interrupt controller (CLIC) for RISC-V. 
    I can't find a good way to process edge-triggered interrupt.
    
    According to edge-triggered definition, if I select an
    edge-triggered  interrupt to serve , it will clean its pending
    status. However after serving the interrupt,  there is no chance to
    select other pending interrupts.
    
    I have two methods.

1. One is to add a timer for interrupt controller, so that every pending interrupt can be served at some point.
2. The other is that  always pull a pending interrupt to serve at the interrupt return instruction.

    But both are not so good. The first one we can not server the
    interrupts immediately. The second one we have to add some
    code when executing the guest code.
    
    I want to know if there is a better way to handle edge-triggered
    interrupt on QEMU.
    
    Thanks very much for your reading and look forward to your 
    response.
    
    Zhiwei