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Date: Mon, 21 May 2012 22:05:47 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
Message-ID: <20120521190546.GA14642@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 1/2] pci: Add pci_device_get_host_irq
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To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Alex Williamson <alex.williamson@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, qemu-devel <qemu-devel@nongnu.org>, Avi Kivity <avi@redhat.com>

On Mon, May 21, 2012 at 10:13:47AM -0300, Jan Kiszka wrote:
> @@ -386,6 +387,14 @@ static void piix3_set_irq(void *opaque, int pirq, int level)
>      piix3_set_irq_level(piix3, pirq, level);
>  }
>  
> +static int piix3_map_host_irq(void *opaque, int pci_intx)
> +{
> +    PIIX3State *piix3 = opaque;
> +    int host_irq = piix3->dev.config[PIIX_PIRQC + pci_intx];
> +
> +    return host_irq < PIIX_NUM_PIC_IRQS ? host_irq : -1;
> +}
> +
>  /* irq routing is changed. so rebuild bitmap */
>  static void piix3_update_irq_levels(PIIX3State *piix3)
>  {


So, instead of special API just for assignment,
I would like to see map_irq in piix being reworked
to take dev config into account.
I think piix is almost unique in this but need to check,
if not fix other host buses that are programmable.
PCI bridges are all fixed routing.

Then we can drop set_irq callback.

Finally all devices can cache the irq#,
and piix would scan devices behind it
and update the irq.

Assignment then just needs a notifier, since
it owns the device just a pointer in device is
enough.

Could you look at doing this please?
If no I can give it a stub.

-- 
MST