Re: [Qemu-devel] [PATCH 19/21] pci: Don't call pci_irq_handler() for a negative intx

[Cédric Le Goater]

On 04/10/2017 07:59 AM, David Gibson wrote:
> On Wed, Apr 05, 2017 at 02:41:44PM +0200, Cédric Le Goater wrote:
>> From: Benjamin Herrenschmidt <address@hidden>
>>
>> Under some circumstances, pci_intx() can return -1 (when the interrupt
>> pin in the config space is 0 which normally means no interrupt).
>>
>> I have seen cases of pci_set_irq() being called on such devices, in
>> turn causing pci_irq_handler() to be called with "-1" as an argument
>> which doesn't seem like a terribly good idea.
>>
>> Signed-off-by: Benjamin Herrenschmidt <address@hidden>
>> [clg: updated for qemu-2.9 ]
>> Signed-off-by: Cédric Le Goater <address@hidden>
> 
> Reviewed-by: David Gibson <address@hidden>
> 
> This looks like a real bug fix which should go to Michael independent
> of the rest of the series.

Michael,

Do you want a resend or can you pick it up from this series ?

Thanks,

C.

> 
>> ---
>>  hw/pci/pci.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
>> index 817ad14ed987..bfd65461348c 100644
>> --- a/hw/pci/pci.c
>> +++ b/hw/pci/pci.c
>> @@ -1419,7 +1419,9 @@ qemu_irq pci_allocate_irq(PCIDevice *pci_dev)
>>  void pci_set_irq(PCIDevice *pci_dev, int level)
>>  {
>>      int intx = pci_intx(pci_dev);
>> -    pci_irq_handler(pci_dev, intx, level);
>> +    if (intx >= 0) {
>> +        pci_irq_handler(pci_dev, intx, level);
>> +    }
>>  }
>>  
>>  /* Special hooks used by device assignment */
>