[dpdk-dev] [PATCH 02/10] vdpa/sfc: add support for device initialization

[Vijay Kumar Srivastava]

Hi Chenbo, 

>-----Original Message-----
>From: Xia, Chenbo <chenbo.xia at intel.com>
>Sent: Tuesday, October 19, 2021 7:47 AM
>To: Vijay Kumar Srivastava <vsrivast at xilinx.com>; dev at dpdk.org
>Cc: maxime.coquelin at redhat.com; andrew.rybchenko at oktetlabs.ru; Harpreet
>Singh Anand <hanand at xilinx.com>; Praveen Kumar Jain <praveenj at xilinx.com>
>Subject: RE: [PATCH 02/10] vdpa/sfc: add support for device initialization

[Snip]

>> Rx packet will carry headers making highly unlikely any proper MCDI
>> data can be written to the IOVA address (for MCDI buffer) to work with by the
>FW.
>> Writing to the buffer does not imply to issue the MCDI message. Even
>> if MCDI is sent then FW is resilient enough to identify the incorrect
>> MCDI and will reject the message.
>>
>> This is going to affect only to VF on which malicious guest is
>> present, as this MCDI buffer is specific to the corresponding VF.
>> So it won't affect any control path operation on the any other VF or host.
>
>OK. So it's very hard to do attack with the FW detection. But about 'won't affect
>host', I think it depends on how you handle the DMA-ed control messages. Take
>a bad
>example: if one DMA address saves a pointer and the malicious DMA makes the
>pointer be NULL, it will segfaults the program (But I don't think this will happen
>in your driver, just help you understand my point). So please check the control
>messages handling is robust.
Yes, It is highly unlikely that it can affect the host. 

>And in the future, I would like to see this problem solved by PASID when your
>HW has the support.
Yes. Sure.

Regards,
Vijay