Re: [Qemu-devel] ioh3420: Add a map_irq function

[Alexander Duyck <alexander.h.duyck@intel.com>]

On 10/02/2013 10:12 AM, Alex Williamson wrote:
> On Fri, 2013-09-27 at 15:10 -0700, Alexander Duyck wrote:
>> On 02/28/2013 10:49 AM, Alex Williamson wrote:
>>> Every bridge needs to know how to map IRQs from it's secondary bus to
>>> the primary bus.  We seem to be direct mapped on ioh3420.  This avoids
>>> segfaults when trying to put assigned devices behind root ports.
>>>
>>> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
>>>
>>> ---
>>> hw/ioh3420.c |    7 +++++++
>>>  1 file changed, 7 insertions(+)
>>>
>>> diff --git a/hw/ioh3420.c b/hw/ioh3420.c
>>> index 95bceb5..6ac4fe7 100644
>>> --- a/hw/ioh3420.c
>>> +++ b/hw/ioh3420.c
>>> @@ -90,6 +90,11 @@ static void ioh3420_reset(DeviceState *qdev)
>>>      pci_bridge_disable_base_limit(d);
>>>  }
>>>  
>>> +static int ioh3420_map_irq(PCIDevice *pci_dev, int irq_num)
>>> +{
>>> +    return irq_num;
>>> +}
>>> +
>>>  static int ioh3420_initfn(PCIDevice *d)
>>>  {
>>>      PCIBridge* br = DO_UPCAST(PCIBridge, dev, d);
>>> @@ -97,6 +102,8 @@ static int ioh3420_initfn(PCIDevice *d)
>>>      PCIESlot *s = DO_UPCAST(PCIESlot, port, p);
>>>      int rc;
>>>  
>>> +    pci_bridge_map_irq(br, NULL, ioh3420_map_irq);
>>> +
>>>      rc = pci_bridge_initfn(d);
>>>      if (rc < 0) {
>>>          return rc;
>>>
>> What became of this patch?  I believe I am seeing the issue described
>> when I assign a MSI-X capable virtual device to the secondary bus of an
>> ioh3420, and applying this patch seems to resolve the issue.  Was there
>> an alternate patch proposed and if so where can I find it?
> Hmm, I thought it was no longer necessary with
> pci_device_route_intx_to_irq(), especially if you're assigning a VF that
> doesn't support INTx.  Are you using the latest qemu bits?  pci-assign
> or vfio-pci?  Maybe provide a backtrace?  Thanks,
>
> Alex

I'm seeing it with an emulated interface using MSI-X, not with a VF or
assigned device.

I'll try to get you a backtrack when I have some time.  I'm currently
chasing down another issue and will try to remember to follow up on this
one.

Thanks,

Alex