On Wed, Oct 18, 2017 at 09:24:33PM +0200, Paolo Bonzini wrote: > On 18/10/2017 19:49, Andi Kleen wrote: > > > > The ioctl appears to be the PIC timer > > > > - 6.36% __GI___ioctl ▒ > > kvm_vm_ioctl ▒ > > kvm_set_irq ▒ > > kvm_pic_set_irq > > PIC is the interrupt controller, why do you say the timer? What is the > QEMU side of the call stack? I did some more sampling in gdb this time. All the timer call backs I caught are rtc_period_timer. Perhaps that needs to be stopped when the guest is stopped? It also calls the ioctl: #0 0x00007f73d97175e0 in ioctl () from target:/lib64/libc.so.6 #1 0x000055ed03c7ec82 in kvm_vm_ioctl (s=s@entry=0x55ed06ba2000, type=<optimized out>) at /usr/src/debug/qemu-2.9.1/kvm-all.c:2136 #2 0x000055ed03c7fb15 in kvm_set_irq (s=0x55ed06ba2000, irq=<optimized out>, level=<optimized out>) at /usr/src/debug/qemu-2.9.1/kvm-all.c:1001 #3 0x000055ed03cef2c0 in kvm_pic_set_irq (opaque=<optimized out>, irq=<optimized out>, level=<optimized out>) at /usr/src/debug/qemu-2.9.1/hw/i386/kvm/i8259.c:114 #4 0x000055ed03cba196 in qemu_irq_raise (irq=<optimized out>) at /usr/src/debug/qemu-2.9.1/include/hw/irq.h:16 #5 rtc_periodic_timer (opaque=0x55ed06f88580) at /usr/src/debug/qemu-2.9.1/hw/timer/mc146818rtc.c:198 #6 0x000055ed03faf1f0 in timerlist_run_timers (timer_list=0x55ed06aafa40) at /usr/src/debug/qemu-2.9.1/util/qemu-timer.c:536 #7 0x000055ed03faf3f7 in qemu_clock_run_timers (type=QEMU_CLOCK_HOST) at /usr/src/debug/qemu-2.9.1/util/qemu-timer.c:547 #8 qemu_clock_run_all_timers () at /usr/src/debug/qemu-2.9.1/util/qemu-timer.c:662 #9 0x000055ed03faf8da in main_loop_wait (nonblocking=<optimized out>) at /usr/src/debug/qemu-2.9.1/util/main-loop.c:525 #10 0x000055ed03c2f0e3 in main_loop () at /usr/src/debug/qemu-2.9.1/vl.c:1898 -Andi