[dpdk-dev] [PATCH v2] doc/guides/rel_notes: Add known issue for IOMMU attributes read

[Rosen Xu]

Linux kernel 4.10.0 iommu attribute read error

Cc: stable at dpdk.org

Signed-off-by: Rosen Xu <rosen.xu at intel.com>

v2 updates:
===========
 - Fixed Anatoly comments
---
 doc/guides/rel_notes/known_issues.rst | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/doc/guides/rel_notes/known_issues.rst b/doc/guides/rel_notes/known_issues.rst
index afcc2c4..716bd73 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.
-- 
1.8.3.1