"Skidmore, Donald C" <donald.c.skidm...@intel.com> writes:
> My hang up is more related to: without the nob to enable it (off by
> default) we are letting one VF dictate policy for all the other VFs
> and the PF. If one VF needs to be in promiscuous multicast so is
> everyone else. Their stacks now needs to deal with all the extra
> multicast packets. As you point out this might not be a direct
> concern for isolation in that the VM could have 'chosen' to join any
> Multicast group and seen this traffic. My concern over isolation is
> one VF has chosen that all the other VM now have to see this multicast
> traffic.
Apologies if this question is stupid, but I just have to ask about stuff
I don't understand...
Looking at the proposed implementation, the promiscous multicast flag
seems to be a per-VF flag:
+int ixgbe_ndo_set_vf_mc_promisc(struct net_device *netdev, int vf, bool
setting)
+{
+ struct ixgbe_adapter *adapter = netdev_priv(netdev);
+ struct ixgbe_hw *hw = &adapter->hw;
+ u32 vmolr;
+
+ if (vf >= adapter->num_vfs)
+ return -EINVAL;
+
+ adapter->vfinfo[vf].mc_promisc_enabled = setting;
+
+ vmolr = IXGBE_READ_REG(hw, IXGBE_VMOLR(vf));
+ if (setting) {
+ e_info(drv, "VF %u: enabling multicast promiscuous\n", vf);
+ vmolr |= IXGBE_VMOLR_MPE;
+ } else {
+ e_info(drv, "VF %u: disabling multicast promiscuous\n", vf);
+ vmolr &= ~IXGBE_VMOLR_MPE;
+ }
+
+ IXGBE_WRITE_REG(hw, IXGBE_VMOLR(vf), vmolr);
+
+ return 0;
+}
+
I haven't read the data sheet, but I took a quick look at the excellent
high level driver docs:
http://www.intel.com/content/dam/doc/design-guide/82599-sr-iov-driver-companion-guide.pdf
It mentions "Multicast Promiscuous Enable" in its "Thoughts for
Customization" section:
7.1 Multicast Promiscuous Enable
The controller has provisions to allow each VF to be put into Multicast
Promiscuous mode. The Intel reference driver does not configure this
option .
The capability can be enabled/disabled by manipulating the MPE field
(bit 28) of the PF VF L2 Control Register (PFVML2FLT – 0x0F000)
and showing a section from the data sheet describing the
"PF VM L2 Control Register - PFVML2FLT[n] (0x0F000 + 4 * n, n=0...63; RW)"
To me it looks like enabling Promiscuos Multicast for a VF won't affect
any other VF at all. Is this really not the case?
Bjørn
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