Re: [PATCH net-next 1/4] net: Add SRIOV VGT+ support

On Mon, Aug 28, 2017 at 6:52 PM, Sabrina Dubroca [off-list ref] wrote:

2017-08-27, 14:06:15 +0300, Saeed Mahameed wrote:
[...]

quoted

+#define VF_VLAN_BITMAP       DIV_ROUND_UP(VF_VLAN_N_VID, sizeof(__u64) * BITS_PER_BYTE)
+struct ifla_vf_vlan_trunk {
+     __u32 vf;
+     __u64 allowed_vlans_8021q_bm[VF_VLAN_BITMAP];
+     __u64 allowed_vlans_8021ad_bm[VF_VLAN_BITMAP];
+};

This is huge (1032B). And you put one of these in the netlink message
for each VF.  This means that with 51 VF (at least in my environment,
where each VF takes 1296B), you're going to overflow the u16 size of a
single attribute (IFLA_VFINFO_LIST), and you cannot dump the device
anymore. I'm afraid this is going to break existing setups.

Yes ! We will fix this,
we are considering to report only a boolean in VFINFO which indecates
if VGT+ is enable or not
and provide a new attribute per VF to report only the vlan list of specific VF.

Thanks for the input,
we will handle this.

--
Sabrina