Re: [Qemu-devel] [PATCH v4 5/5] i8259: fix dynamically masking slave IRQs with IMR register

[Paolo Bonzini]

Il 03/09/2012 04:56, Matthew Ogilvie ha scritto:
> Although I haven't found any specs that say so, on real hardware
> I have a test program that shows if you mask off the slave
> interrupt (say IRQ14) in the IMR after it has already been raised,
> the master (IRQ2) gets canceled (that is, IRQ2 acts like it is level
> triggered).  Without this patch, qemu delivers a
> spurious interrupt (IRQ15) instead when running the test program.
> 
> Signed-off-by: Matthew Ogilvie <address@hidden>

Nice testing, thanks!

KVM's i8259 emulation can be patched at arch/x86/kvm/i8259.c in the
Linux tree.

You can write a test for kvm-unit-tests.  These tests can be written in
C, including interrupt handlers (see lib/x86/isr.h).  The git tree is at
git://git.kernel.org/pub/scm/virt/kvm/kvm-unit-tests.git.

Paolo