Re: [PATCH for qemu-kvm-1.2] pci-assign: Use proper pin number for INTx-to-IRQ routing

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

On Wed, Aug 29, 2012 at 01:27:52PM +0200, Jan Kiszka wrote:
> Broken by commit e21f28b497.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  hw/kvm/pci-assign.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/hw/kvm/pci-assign.c b/hw/kvm/pci-assign.c
> index 9cce02c..fea05b4 100644
> --- a/hw/kvm/pci-assign.c
> +++ b/hw/kvm/pci-assign.c
> @@ -892,7 +892,7 @@ static int assign_intx(AssignedDevice *dev)
>      pci_device_set_intx_routing_notifier(&dev->dev,
>                                           assigned_dev_update_irq_routing);
>  
> -    intx_route = pci_device_route_intx_to_irq(&dev->dev, 0);
> +    intx_route = pci_device_route_intx_to_irq(&dev->dev, dev->intpin);
>      assert(intx_route.mode != PCI_INTX_INVERTED);
>  
>      if (dev->intx_route.mode == intx_route.mode &&


Hmm but looking at it, I see a different problem:

   /* handle interrupt routing */
    e_intx = dev->dev.config[0x3d] - 1;
    dev->intpin = e_intx;

PCI spec however says:

PCI defines one interrupt line for a single function device and up to
four interrupt lines for a multi-function6 device or connector. For a
single function device, only INTA# may be used while the other three
interrupt lines have no meaning.

And:
	When several independent functions are integrated into a single
	device, it will be referred to as a multi-
	function device. Each function on a multi-function device has its own
	configuration space.

So this is not easily virtualizeable.
I think in practice it should be only legal to assign
VFs or all functions of a physical device in one go.

In last case, we can then make sure function numbers match.

Alex?

> -- 
> 1.7.3.4