Re: [PATCH v4] ixgbe: Drop flow control frames from VFs

[Vlad Zolotarov <vladz@cloudius-systems.com>]

On 10/23/15 10:14, Zhang, Helin wrote:
>
> From: Vladislav Zolotarov [mailto:vladz@cloudius-systems.com]
> Sent: Friday, October 23, 2015 2:57 PM
> To: Zhang, Helin
> Cc: Lu, Wenzhuo; dev@dpdk.org
> Subject: RE: [dpdk-dev] [PATCH v4] ixgbe: Drop flow control frames from VFs
>
>
> On Oct 23, 2015 9:30 AM, "Zhang, Helin" <helin.zhang@intel.com> wrote:
>>
>>
>> From: Vladislav Zolotarov [mailto:vladz@cloudius-systems.com]
>> Sent: Friday, October 23, 2015 2:24 PM
>> To: Zhang, Helin
>> Cc: Lu, Wenzhuo; dev@dpdk.org
>> Subject: Re: [dpdk-dev] [PATCH v4] ixgbe: Drop flow control frames from VFs
>>
>>
>> On Oct 23, 2015 9:02 AM, "Zhang, Helin" <helin.zhang@intel.com> wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: Lu, Wenzhuo
>>>> Sent: Friday, October 23, 2015 1:52 PM
>>>> To: dev@dpdk.org
>>>> Cc: Zhang, Helin; Lu, Wenzhuo
>>>> Subject: [PATCH v4] ixgbe: Drop flow control frames from VFs
>>>>
>>>> This patch will drop flow control frames from being transmitted from VSIs.
>>>> With this patch in place a malicious VF cannot send flow control or PFC packets
>>>> out on the wire.
>> The whole idea of this (and similar i40e patches sent before) is really confusing.
>> If u want to disable FC feature for VFs then go and disable the feature. Why keep (not malicious) user think that he/she has enabled the feature while u silently block it?
>>
>> Helin: I don't think disabling FC is equal to filtering out any pause frames. How about the software application constructs a pause frame and then tries to send it out?
> But not disabling FC for the user and silently preventing it is bogus. First, the conventional user should not be affected. I think this patch (and all its clones) should be extended to, first, disable the FC Tx feature for the relevant devices and only then adding any anti malicious filtering.
>   
> Helin: Disabling FC will disable both PF and VF FC, I don't find out where can disable VF FC only. Am I wrong?

There are flow_ctrl_get/set callbacks in eth_dev_ops which are used for 
configuring FC.
I see that they are not set for either ixgbevf or i40evf, so here we are 
all set for these.

>
>>>> V2:
>>>> Reword the comments.
>>>>
>>>> V3:
>>>> Move the check of set_ethertype_anti_spoofing to the top of the function, to
>>>> avoid occupying an ethertype_filter entity without using it.
>>>>
>>>> V4:
>>>> Remove the useless braces and return.
>>>>
>>>> Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
>>> Acked-by: Helin Zhang <helin.zhang@intel.com>
>>>