Re: [PATCH] xen-pciback: Use pci_enable_msix_range() instead of pci_enable_msix()

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 02/19/2014 10:22 AM, Boris Ostrovsky wrote:
> On 02/19/2014 05:15 AM, Alexander Gordeev wrote:
>> As result of deprecation of MSI-X/MSI enablement functions
>> pci_enable_msix() and pci_enable_msi_block() all drivers
>> using these two interfaces need to be updated to use the
>> new pci_enable_msi_range() and pci_enable_msix_range()
>> interfaces.
>>
>> Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
>> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>> Cc: David Vrabel <david.vrabel@citrix.com>
>> Cc: linux-pci@vger.kernel.org
>> ---
>>   drivers/xen/xen-pciback/pciback_ops.c |   16 ++++++++++------
>>   1 files changed, 10 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/xen/xen-pciback/pciback_ops.c 
>> b/drivers/xen/xen-pciback/pciback_ops.c
>> index 64eb0cd..f5b4c3e 100644
>> --- a/drivers/xen/xen-pciback/pciback_ops.c
>> +++ b/drivers/xen/xen-pciback/pciback_ops.c
>> @@ -213,9 +213,15 @@ int xen_pcibk_enable_msix(struct 
>> xen_pcibk_device *pdev,
>>           entries[i].vector = op->msix_entries[i].vector;
>>       }
>>   -    result = pci_enable_msix(dev, entries, op->value);
>> +    result = pci_enable_msix_range(dev, entries, op->value, op->value);
>> +    if (result < op->value) {
>
>
> I think it would be better to have 'if (result != op->value)', in case 
> op->value is negative (which presumably it should never be).


Better yet, at the top of the routine we check 'if (op->value > 
SH_INFO_MAX_VEC)'. If you add '|| op->value < 0' we'd be all set.

-boris

>
>
> -boris
>
>
>> +        if (result > 0)
>> +            pci_disable_msix(dev);
>>   -    if (result == 0) {
>> +        pr_warn_ratelimited("%s: error enabling MSI-X for guest %u: 
>> err %d!\n",
>> +                    pci_name(dev), pdev->xdev->otherend_id,
>> +                    result);
>> +    } else {
>>           for (i = 0; i < op->value; i++) {
>>               op->msix_entries[i].entry = entries[i].entry;
>>               if (entries[i].vector)
>> @@ -227,10 +233,8 @@ int xen_pcibk_enable_msix(struct 
>> xen_pcibk_device *pdev,
>>                           pci_name(dev), i,
>>                           op->msix_entries[i].vector);
>>           }
>> -    } else
>> -        pr_warn_ratelimited("%s: error enabling MSI-X for guest %u: 
>> err %d!\n",
>> -                    pci_name(dev), pdev->xdev->otherend_id,
>> -                    result);
>> +    }
>> +
>>       kfree(entries);
>>         op->value = result;
>