From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v2] doc: Malicious Driver Detection not supported by ixgbe Date: Sun, 06 Mar 2016 23:24:44 +0100 Message-ID: <3090594.zNmFQBUITj@xps13> References: <1456291984-7309-1-git-send-email-wenzhuo.lu@intel.com> <1456462117-29522-1-git-send-email-wenzhuo.lu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev@dpdk.org To: Wenzhuo Lu Return-path: Received: from mail-wm0-f44.google.com (mail-wm0-f44.google.com [74.125.82.44]) by dpdk.org (Postfix) with ESMTP id 82E622C50 for ; Sun, 6 Mar 2016 23:26:22 +0100 (CET) Received: by mail-wm0-f44.google.com with SMTP id p65so86118770wmp.1 for ; Sun, 06 Mar 2016 14:26:22 -0800 (PST) In-Reply-To: <1456462117-29522-1-git-send-email-wenzhuo.lu@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 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.