Re: [PATCH 0/3] Resolve vt82c686 and piix4 qemu_irq memory leaks

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Jul 04, 2024 at 10:58:51PM +0200, Bernhard Beschow wrote:
> This series first turns vt82c686's "INTR" pin into a named GPIO for better
> comprehensibility. It then continues fixing qemu_irq memory leaks in vt82c686
> and piix4 by connecting out IRQs of the south bridges before they get realized.
> This approach is already used in the pc machines after it had been discussed at
> KVM forum `23.
> 
> Observe that out IRQs are callbacks such as an INTR IRQ handler in a CPU which a
> south bridge wants to trigger. If, as an implementation detail, the south bridge
> wants to pass this callback to a child device, such as the PIC, then this
> callback must be known to the south bridge before it gets realized. Otherwise
> board code had to wire the PIC device itself, breaking encapsulation. This means
> that qdev_connect_gpio_out*() has to be called before realize() which this
> series implements. Another way to look at it is that callbacks apparently are
> resouces such as memory regions which are also populated before realize().
> 
> Please check if above paragraph makes sense.
> 
> Best regards,
> Bernhard


Bernhard, do you intend to resolve Zoltan's comments on this
patchset?

Thanks!


> See also:
> * https://lore.kernel.org/qemu-devel/0FFB5FD2-08CE-4CEC-9001-E7AC24407A44@gmail.
> com/
> * "Remove intermediate IRQ forwarder" patches in
> https://lore.kernel.org/qemu-devel/20230210163744.32182-1-philmd@linaro.org/
> 
> Testing done:
> * Boot amigaone machine into Linux
> * Boot pegasos2 machine into MorphOS
> * Start fuloong2e machine and check that it doesn't abort
> * Boot malta machine with https://people.debian.org/~gio/dqib/
> 
> Bernhard Beschow (3):
>   hw/isa/vt82c686: Turn "intr" irq into a named gpio
>   hw/isa/vt82c686: Resolve intermediate IRQ forwarder
>   hw/isa/piix: Resolve intermediate IRQ forwarder
> 
>  hw/isa/piix.c       | 13 ++-----------
>  hw/isa/vt82c686.c   | 12 ++----------
>  hw/mips/fuloong2e.c |  2 +-
>  hw/mips/malta.c     |  4 +---
>  hw/ppc/amigaone.c   |  8 ++++----
>  hw/ppc/pegasos2.c   |  4 ++--
>  6 files changed, 12 insertions(+), 31 deletions(-)
> 
> -- 
> 2.45.2
>