Re: gicv3 maintenance interrupt not triggering

[Jose Martins]

Hey Peter, thank you for the prompt response.

In reverse order:

> (You don't say what QEMU version you're using or what command line
> you use to start QEMU -- those are both always useful information
> for "I'm trying to do something with QEMU and it's not working"
> queries...)

I've compiled QEMU 5.1.0 which I configured using: ./configure
--target-list=aarch64-softmmu
This is how invoke QEMU: qemu-system-aarch64 -nographic -M
virt,secure=on,virtualization=on,gic-version=3 -cpu cortex-a53 -smp 4
-m 4G -bios systemimage.bin

> Given the MISR and HCR values you quote I would also check that
> you've set up the maintenance interrupt itself correctly, ie that
> it isn't disabled or similar such that the GIC asserts it but
> nothing happens.

If that was the case, the pending bit in the gicr.ispendr0 would still
be set, but it would just not raise the irq line to the cpu.
Nevertheless, I know the interrupt is correctly setup because if I set
it pending by writing to gicr.ispendr0, the interrupt is triggered and
the final handler executes.

> You might like to (a) enable some or all the QEMU gicv3 trace events to
> see if they provide any insight into what the emulated GIC is doing when
> your guest prods it, and/or (b) run QEMU under a debugger and look at what
> it is doing in gicv3_cpuif_virt_update() (and in particular when it
> calls maintenance_interrupt_state()) to see what it thinks it
> is setting the maintenance interrupt line to.

I'll try to dig deeper tomorrow. But just now doing some basic printf
debugging, I've noticed that cs->maintenance_irq is NULL which results
in the call to qemu_set_irq returning without calling the
irq->handler.

Thanks,
Jose