Re: [Qemu-devel] [PATCH 1/2] pci: Add pci_device_get_host_irq

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

On Mon, May 21, 2012 at 03:58:57PM -0300, Jan Kiszka wrote:
> On 2012-05-21 14:34, Michael S. Tsirkin wrote:
> > On Mon, May 21, 2012 at 10:13:47AM -0300, Jan Kiszka wrote:
> >> Add a PCI IRQ path discovery function that walks from a given device to
> >> the host bridge, returning the IRQ number that is reported to the
> >> attached interrupt controller. For this purpose, another PCI bridge
> >> callback function is introduced: map_host_irq. It is so far only
> >> implemented by the PIIX3, other host bridges can be added later on as
> >> required.
> >>
> >> Will be used for KVM PCI device assignment.
> >>
> >> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > 
> > interrupt injection is data path even for emulated devices.
> > So instead of special casing device assignment I would like to see all
> > devices converted to an API that caches irqs.
> > 
> > This will likely mean that we can maintain the final
> > irq as part of the pci device structure, and
> > this api will simply return it.
> 
> Yep, I definitely agree. It's just that such a design has to please even
> more users than PCI devices, thus will likely take longer to settle than
> the device assignment effort. Therefore I decided to rush forward with
> an intermediate approach first.
> 
> Jan

I think it's easy, will try to do it soon.

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