On 15/3/18 2:02 pm, Alex Williamson wrote:
> On Tue, 13 Mar 2018 13:38:46 +1100
> Alexey Kardashevskiy <aik@xxxxxxxxx> wrote:
>
>> On 13/3/18 9:44 am, Alex Williamson wrote:
>>> On Fri, 9 Mar 2018 12:17:36 +1100
>>> Alexey Kardashevskiy <aik@xxxxxxxxx> wrote:
>>>
>>>> Commit 2170dd04316e ("vfio-pci: Mask INTx if a device is not capabable
>>>> of enabling it") is causing 'Masking broken INTx support' messages
>>>> every time when a PCI without INTx support is enabled. This message is
>>>> intended to appear when a device known for broken INTx is being enabled.
>>>> However the message also appears on IOV virtual functions where INTx
>>>> cannot possibly be enabled so saying that the "broken" support is masked
>>>> is not correct.
>>>>
>>>> This changes the message to only appear when the device advertises INTx
>>>> (via PCI_INTERRUPT_PIN != 0) but does not implement PCI 2.3 INTx masking.
>>>>
>>>> Fixes: 2170dd04316e ("vfio-pci: Mask INTx if a device is not capabable of enabling it")
>>>> Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
>>>> ---
>>>> drivers/vfio/pci/vfio_pci.c | 8 +++++++-
>>>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
>>>> index b0f7594..7f2ec47 100644
>>>> --- a/drivers/vfio/pci/vfio_pci.c
>>>> +++ b/drivers/vfio/pci/vfio_pci.c
>>>> @@ -245,7 +245,13 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
>>>>
>>>> if (likely(!nointxmask)) {
>>>> if (vfio_pci_nointx(pdev)) {
>>>> - dev_info(&pdev->dev, "Masking broken INTx support\n");
>>>> + u8 pin = 0;
>>>> +
>>>> + pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN,
>>>> + &pin);
>>>> + if (pin)
>>>> + dev_info(&pdev->dev,
>>>> + "Masking broken INTx support\n");
>>>> vdev->nointx = true;
>>>> pci_intx(pdev, 0);
>>>> } else
>>>
> Should we only be invoking the nointx path
> if a) the device supports intx (pin reg), b) pdev->irq is null, and c)
> the device passes the v2.3 masking test (which is cached, not retested
> now, btw)?
Yes we should, and yes I missed that last bit about caching the result of
the test which is performed anyway in the common pci code. Thanks,
--
Alexey
