From: Rosen Xu <rosen.xu@intel.com>
Date: Wed, 16 May 2018 07:29:12 +0000 (+0800)
Subject: doc: add Linux 4.10.0 known issue in release notes
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=b667029e9096964971962fd627bd9c1d8e957b79;p=dpdk.git

doc: add Linux 4.10.0 known issue in release notes

Linux kernel 4.10.0 IOMMU attribute read error.

Cc: stable@dpdk.org

Signed-off-by: Rosen Xu <rosen.xu@intel.com>
Acked-by: John McNamara <john.mcnamara@intel.com>
---

diff --git a/doc/guides/rel_notes/known_issues.rst b/doc/guides/rel_notes/known_issues.rst
index afcc2c445d..716bd73609 100644
--- a/doc/guides/rel_notes/known_issues.rst
+++ b/doc/guides/rel_notes/known_issues.rst
@@ -714,3 +714,28 @@ igb_uio can not be used when running l3fwd-power
 
 **Driver/Module**:
    ``igb_uio`` module.
+
+
+Linux kernel 4.10.0 iommu attribute read error
+----------------------------------------------
+
+**Description**:
+   When VT-d is enabled (``iommu=pt intel_iommu=on``), reading IOMMU attributes from
+   /sys/devices/virtual/iommu/dmarXXX/intel-iommu/cap on Linux kernel 4.10.0 error.
+   This bug is fixed in `Linux commmit a7fdb6e648fb
+   <https://patchwork.kernel.org/patch/9595727/>`_,
+   This bug is introduced in `Linux commmit 39ab9555c241
+   <https://patchwork.kernel.org/patch/9554403/>`_,
+
+**Implication**:
+   When binding devices to VFIO and attempting to run testpmd application,
+   testpmd (and other DPDK applications) will not initialize.
+
+**Resolution/Workaround**:
+   Use other linux kernel version. It only happens in linux kernel 4.10.0.
+
+**Affected Environment/Platform**:
+   ALL OS of linux kernel 4.10.0.
+
+**Driver/Module**:
+   ``vfio-pci`` module.