Is it possible to control irq allocation in QEMU?

[Hao Lee]

Hi,

I use the following options to simulate USB devices.

-drive if=none,id=usbstick,file=usb.qcow2 \
-usb -device usb-ehci,id=ehci  \
-device usb-tablet,bus=usb-bus.0 \
-device usb-storage,bus=ehci.0,drive=usbstick

The contents in /proc/interrupts are:

  0:        515   IO-APIC   2-edge      timer
  1:         63   IO-APIC   1-edge      i8042
  8:          1   IO-APIC   8-edge      rtc0
  9:          0   IO-APIC   9-fasteoi   acpi
 10:        127   IO-APIC  10-fasteoi   ehci_hcd:usb1
 11:         36   IO-APIC  11-fasteoi   uhci_hcd:usb2
 12:          5   IO-APIC  12-edge      i8042
 14:         93   IO-APIC  14-edge      ata_piix
 15:          6   IO-APIC  15-edge      ata_piix

I want to know why QEMU allocates irq-10 and irq-11 for the two USB devices.
Can I make them above irq-15? Thanks!

Regards,
Hao Lee