X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=doc%2Fguides%2Frel_notes%2Fknown_issues.rst;h=ee3ed1e6587772079feabcd874a4655f25359613;hb=6a951567c1595203597de7a5736e0dddb5b8dc33;hp=a1face9c1d7a1cc90411793ed36689a0fed33438;hpb=a2e97ef700f396fa086c72f24be331599cfed401;p=dpdk.git

diff --git a/doc/guides/rel_notes/known_issues.rst b/doc/guides/rel_notes/known_issues.rst
index a1face9c1d..ee3ed1e658 100644
--- a/doc/guides/rel_notes/known_issues.rst
+++ b/doc/guides/rel_notes/known_issues.rst
@@ -118,8 +118,8 @@ HPET timers do not work on the Osage customer reference platform
    On Osage boards, the implementation of the ``rte_delay_us()`` function must be changed to not use the HPET timer.
 
 **Resolution/Workaround**:
-   This can be addressed by building the system with the ``CONFIG_RTE_LIBEAL_USE_HPET=n``
-   configuration option or by using the ``--no-hpet`` EAL option.
+   This can be addressed by building the system with ``RTE_LIBEAL_USE_HPET`` unset
+   or by using the ``--no-hpet`` EAL option.
 
 **Affected Environment/Platform**:
    The Osage customer reference platform.
@@ -127,7 +127,7 @@ HPET timers do not work on the Osage customer reference platform
    work correctly, provided the BIOS supports HPET.
 
 **Driver/Module**:
-   ``lib/librte_eal/common/include/rte_cycles.h``
+   ``lib/librte_eal/include/rte_cycles.h``
 
 
 Not all variants of supported NIC types have been used in testing
@@ -676,7 +676,7 @@ igb uio legacy mode can not be used in X710/XL710/XXV710
 
 **Description**:
    X710/XL710/XXV710 NICs lack support for indicating INTx is asserted via the interrupt
-   bit in the PCI status register. Linux delected them from INTx support table. The related
+   bit in the PCI status register. Linux deleted them from INTx support table. The related
    `commit <https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/drivers/pci/quirks.c?id=8bcf4525c5d43306c5fd07e132bc8650e3491aec>`_.
 
 **Implication**:
@@ -722,9 +722,9 @@ 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 fixed in `Linux commit a7fdb6e648fb
    <https://patchwork.kernel.org/patch/9595727/>`_,
-   This bug is introduced in `Linux commmit 39ab9555c241
+   This bug is introduced in `Linux commit 39ab9555c241
    <https://patchwork.kernel.org/patch/9554403/>`_,
 
 **Implication**:
@@ -826,3 +826,82 @@ Kernel crash when hot-unplug igb_uio device while DPDK application is running
 
 **Driver/Module**:
    ``igb_uio`` module.
+
+
+AVX-512 support disabled
+------------------------
+
+**Description**:
+   ``AVX-512`` support has been disabled on some conditions.
+
+   On DPDK v18.11 ``AVX-512`` is disabled for all ``GCC`` builds which reported to cause a performance
+   drop.
+
+   On DPDK v19.02 ``AVX-512`` disable scope is reduced to ``GCC`` and ``binutils version 2.30`` based
+   on information accrued from the GCC community defect.
+
+**Reason**:
+   Generated ``AVX-512`` code cause crash:
+   https://bugs.dpdk.org/show_bug.cgi?id=97
+   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88096
+
+**Resolution/Workaround**:
+   * Update ``binutils`` to newer version than ``2.30``.
+
+   OR
+
+   * Use different compiler, like ``clang`` for this case.
+
+**Affected Environment/Platform**:
+    ``GCC`` and ``binutils version 2.30``.
+
+**Driver/Module**:
+    ALL.
+
+
+Unsuitable IOVA mode may be picked as the default
+-------------------------------------------------
+
+**Description**
+   Not all kernel drivers and not all devices support all IOVA modes. EAL will
+   attempt to pick a reasonable default based on a number of factors, but there
+   may be cases where the default may be unsuitable (for example, hotplugging
+   devices using `igb_uio` driver while having picked IOVA as VA mode on EAL
+   initialization).
+
+**Implication**
+   Some devices (hotplugged or otherwise) may not work due to incompatible IOVA
+   mode being automatically picked by EAL.
+
+**Resolution/Workaround**:
+   It is possible to force EAL to pick a particular IOVA mode by using the
+   `--iova-mode` command-line parameter. If conflicting requirements are present
+   (such as one device requiring IOVA as PA and one requiring IOVA as VA mode),
+   there is no workaround.
+
+**Affected Environment/Platform**:
+   Linux.
+
+**Driver/Module**:
+   ALL.
+
+Vhost multi-queue reconnection failed with QEMU version >= 4.2.0
+----------------------------------------------------------------
+
+**Description**
+   It's a QEMU regression bug (bad commit: c6beefd674ff). QEMU only saves
+   acked features for one vhost-net when vhost quits. When vhost reconnects
+   to virtio-net/virtio-pmd in multi-queue situations, the features been
+   set multiple times are not consistent.
+
+**Implication**
+   Vhost cannot reconnect back to virtio-net/virtio-pmd normally.
+
+**Resolution/Workaround**:
+   It is possible to filter the incorrect acked features at vhost-user side.
+
+**Affected Environment/Platform**:
+   ALL.
+
+**Driver/Module**:
+   Virtual Device Poll Mode Driver (PMD).