RE: Why my interrupt is not connected? qemu_irq_is_connected( ) returns false.

[Chan Kim]

Hello Peter Maydell, and all,

> > If the device does try to raise its interrupt, then either you've
> > wired the interrupt wrongly or else perhaps the guest never unmasked
> > the interrupt in the GIC. You can singlestep into the qemu_raise_irq()
> > function to see where it takes you.
> >
I've set breakpoint at qemu_irq_raise() just before qemu does 
qemu_set_irq(s->irq, 1) following a specific condition of register write. But 
after the mmio write is finished, it crashes before reaching qemu_irq_raise(). 
The log looks like this.

start of main!
interupt test!
[  511.538838] addr axpu_es = ffff000068300000, I got 524288 bytes
writing 1 at dev reg. 0x1604
app: calling ioctl with reqcmd = 1074291031
[  511.547039] driver : ioctl CallWrite called!
[  584.800415] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[  584.805766] rcu:     0-...!: (2 ticks this GP) idle=23a/1/0x4000000000000002 
softirq=50739/50739 fqs=0 
[  584.808996] rcu:     1-...!: (1 GPs behind) idle=3ce/1/0x4000000000000000 
softirq=55180/55182 fqs=0 
[  584.812235]  (detected by 2, t=18317 jiffies, g=112541, q=0)
[  584.819408] Call trace:
[  584.823551]  __switch_to+0x134/0x190
[  584.824383]  __schedule+0x31c/0x7e0
[  584.825057]  schedule+0x40/0xb8
[  584.825615]  do_nanosleep+0x98/0x188
[  584.826448]  hrtimer_nanosleep+0xcc/0x198
[  584.827386]  common_nsleep+0x3c/0x50
[  584.828356]  __arm64_sys_clock_nanosleep+0xcc/0x148
[  584.829230]  el0_svc_common.constprop.0+0xe4/0x1f0
[  584.829972]  el0_svc_handler+0x38/0xa8
[  584.830589]  el0_svc+0x10/0x2c8
[  584.832102] Call trace:
[  584.832595]  __switch_to+0x134/0x190
[  584.834134]  0xffff000075307480
did you see it?
[  584.885964] Unable to handle kernel NULL pointer dereference at virtual 
address 0000000000000000
[  584.886735] Mem abort info:

If you have any idea where I should check, please tell me.
Thank you.

Chan Kim