On Tue, Sep 20, 2016 at 06:42:02PM +0000, Dey, Souvik wrote:
> I have already taken care of this in v5 of the patch , If possible please
> review the same .
I don't think so, otherwise I would not comment here.
BTW, there is a format error: you used white space instead of TAB for
indention.
You might want to send another version, to fix above two issues. Or,
if you don't mind, I could fix them for you and apply it.
--yliu
>
> -----Original Message-----
> From: Yuanhan Liu [mailto:yuanhan.liu at linux.intel.com]
> Sent: Tuesday, September 20, 2016 3:12 AM
> To: Kavanagh, Mark B <mark.b.kavanagh at intel.com>
> Cc: Dey, Souvik <sodey at sonusnet.com>; dev at dpdk.org; stephen at
> networkplumber.org
> Subject: Re: [PATCH v4]net/virtio: add mtu set in virtio
>
> On Wed, Sep 14, 2016 at 12:15:37PM +0000, Kavanagh, Mark B wrote:
> > >
> > >>+{
> > >>+?????? struct rte_eth_dev_info dev_info;
> > >>+?????? uint32_t ether_hdr_len = ETHER_HDR_LEN + ETHER_CRC_LEN +
> > >>+VLAN_TAG_LEN;
> > >>+?????? uint32_t frame_size = mtu + ether_hdr_len;
> > >>+
> > >>+?????? virtio_dev_info_get(dev, &dev_info);
> > >>+
> > >>+?????? if (mtu < dev_info.min_rx_bufsize || frame_size >
> > >>+dev_info.max_rx_pktlen) {
> > >
> > >It's not clear to me whether 'mtu' in this case should be compared
> > >with ETHER_MIN_MTU, as per other DPDK drivers, or alternatively
> > >whether 'frame_size' should be compared with dev_info.min_rx_bufsize.
> > >Any thoughts?
> > >[Dey, Souvik] I am not sure why virtio min_rx_bufsize is less than
> > >ETHER_MIN_MTU, i think it will be good to have the compare statement
> > >as If(frame_size < ETHER_MIN_MTU || frame_size >
> > >dev_info.max_rx_pktlen) , then error. What do you suggest ?
> >
> > Again, this all depends on what 'mtu' means in this context.
> >
> > Since you mentioned previously that it relates to the packet (i.e. L3)
> > length, and not the frame (i.e. L2) length, I would suggest that the
> > comparison should be:
> >
> > if (mtu < ETHER_MIN_MTU || frame_size > dev_info.max_rx_pktlen)
> >
> > Yuanhan, any thoughts on this?
>
> I think you are right. At least, that's how the ixgbe PMD driver code looks
> like.
>
> --yliu
