2016-02-26 12:48, Wenzhuo Lu: > --- a/doc/guides/nics/ixgbe.rst > +++ b/doc/guides/nics/ixgbe.rst > @@ -147,6 +147,26 @@ The following MACROs are used for these three features: > > * ETH_TXQ_FLAGS_NOXSUMTCP > > +Malicious Driver Detection not Supported by ixgbe > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Why is it in the vector PMD section? > + > +The Intel x550 series NICs support a feature called MDD (Malcicious > +Driver Detection) which checks the behavior of the VF driver. > +If this feature is enabled, the VF must use the advanced context descriptor > +correctly and set the CC (Check Context) bit. > +DPDK PF doesn't support MDD, but kernel PF does. We may hit problem in this > +scenario kernel PF + DPDK VF. If user enables MDD in kernel PF, DPDK VF will > +not work. Because kernel PF thinks the VF is malicious. But actually it's > not. > +The only reason is the VF doesn't act as MDD required. > +There's significant performance impact to support MDD. DPDK should check if > +the advanced context descriptor should be set and set it. And DPDK has to ask > +the info about the header length from the upper layer, because parsing the > +packet itself is not acceptale. So, it's too expensive to support MDD. > +When using kernel PF + DPDK VF on x550, please make sure using the kernel > +driver that disables MDD or can disable MDD. (Some kernel driver can use > +this CLI 'insmod ixgbe.ko MDD=0,0' to disable MDD. Some kernel driver > disables > +it by default.) > + > > Sample Application Notes > ~~~~~~~~~~~~~~~~~~~~~~~~ > diff --git a/doc/guides/rel_notes/release_16_04.rst > b/doc/guides/rel_notes/release_16_04.rst > index 5786f74..0647896 100644 > --- a/doc/guides/rel_notes/release_16_04.rst > +++ b/doc/guides/rel_notes/release_16_04.rst > @@ -90,6 +90,29 @@ This section should contain new known issues in this > release. Sample format: > tense. Add information on any known workarounds. > > > +Restriction > +----------- > + > +* **Malicious Driver Detection is not supported by ixgbe** > + > + The Intel x550 series NICs support a feature called MDD (Malcicious > + Driver Detection) which checks the behavior of the VF driver. > + If this feature is enabled, the VF must use the advanced context descriptor > + correctly and set the CC (Check Context) bit. > + DPDK PF doesn't support MDD, but kernel PF does. We may hit problem in this > + scenario kernel PF + DPDK VF. If user enables MDD in kernel PF, DPDK VF > will > + not work. Because kernel PF thinks the VF is malicious. But actually it's > not. > + The only reason is the VF doesn't act as MDD required. > + There's significant performance impact to support MDD. DPDK should check if > + the advanced context descriptor should be set and set it. And DPDK has to > ask > + the info about the header length from the upper layer, because parsing the > + packet itself is not acceptale. So, it's too expensive to support MDD. > + When using kernel PF + DPDK VF on x550, please make sure using the kernel > + driver that disables MDD or can disable MDD. (Some kernel driver can use > + this CLI 'insmod ixgbe.ko MDD=0,0' to disable MDD. Some kernel driver > disables > + it by default.) Why repeating the whole explanation in the release notes? I think the ixgbe doc is enough to say that a kernel option is required.
