[dpdk-dev] [PATCH v2] doc: Malicious Driver Detection not supported by ixgbe

[Wenzhuo Lu <wenzhuo.lu@intel.com>]

Announce that Malicious Driver Detection is not supported.

V2:
 *Rework the words.

Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
---
 doc/guides/nics/ixgbe.rst              | 20 ++++++++++++++++++++
 doc/guides/rel_notes/release_16_04.rst | 23 +++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/doc/guides/nics/ixgbe.rst b/doc/guides/nics/ixgbe.rst
index 8cae299..7218cdd 100644
--- 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
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+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.)
+
+
 API Changes
 -----------
 
-- 
1.9.3