From b667029e9096964971962fd627bd9c1d8e957b79 Mon Sep 17 00:00:00 2001 From: Rosen Xu Date: Wed, 16 May 2018 15:29:12 +0800 Subject: [PATCH] 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 Acked-by: John McNamara --- 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 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 + `_, + This bug is introduced in `Linux commmit 39ab9555c241 + `_, + +**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. -- 2.20.1