Re: [PATCH V4 07/11] vfio/pci: Update stale comment

[Reinette Chatre]

Hi Kevin,

On 4/27/2023 11:42 PM, Tian, Kevin wrote:
>> From: Chatre, Reinette <reinette.chatre@xxxxxxxxx>
>> Sent: Friday, April 28, 2023 1:36 AM
>>
>> @@ -419,11 +419,9 @@ static int vfio_msi_set_vector_signal(struct
>> vfio_pci_core_device *vdev,
>>  	}
>>
>>  	/*
>> -	 * The MSIx vector table resides in device memory which may be
>> cleared
>> -	 * via backdoor resets. We don't allow direct access to the vector
>> -	 * table so even if a userspace driver attempts to save/restore
>> around
>> -	 * such a reset it would be unsuccessful. To avoid this, restore the
>> -	 * cached value of the message prior to enabling.
>> +	 * If the vector was previously allocated, refresh the on-device
>> +	 * message data before enabling in case it had been cleared or
>> +	 * corrupted since writing.
>>  	 */
>>  	cmd = vfio_pci_memory_lock_and_enable(vdev);
>>  	if (msix) {
> 
> What about keeping backdoor reset as an example, e.g.
> 
> "in case it had been cleared or corrupted (e.g. due to backdoor resets) ..."
> 
> otherwise one may doubt whether it is a more severe problem causing
> the corruption inadvertently w/o userspace driver's awareness and then
> whether just restoring the data is sufficient to move on.

Will do. Thank you very much.

Reinette