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From: Rosen Xu <rosen.xu@intel.com>
To: rosen.xu@intel.com
Cc: stable@dpdk.org
Date: Wed, 16 May 2018 15:05:06 +0800
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Subject: [dpdk-stable] [PATCH v2] doc/guides/rel_notes: Add known issue for
IOMMU attributes read
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Linux kernel 4.10.0 iommu attribute read error
Cc: stable@dpdk.org
Signed-off-by: Rosen Xu <rosen.xu@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