From fc552cfb14b9a50ccbf8055d9bab2feb55a8e40c Mon Sep 17 00:00:00 2001 From: Anatoly Burakov Date: Wed, 1 Jun 2016 15:51:57 +0100 Subject: [PATCH] ivshmem: document a potential crash in rte_ring Commit 4768c475 added a pointer to the memzone in rte_ring. However, all memzones are residing in local mem_config, therefore accessing the memzone pointer inside the guest in an IVSHMEM-shared rte_ring will cause segmentation fault. This issue is unlikely to ever get fixed, as this would require lots of changes for very little benefit, therefore we're documenting this limitation instead. Signed-off-by: Anatoly Burakov --- doc/guides/prog_guide/ivshmem_lib.rst | 2 ++ 1 file changed, 2 insertions(+) diff --git a/doc/guides/prog_guide/ivshmem_lib.rst b/doc/guides/prog_guide/ivshmem_lib.rst index 9401ccf251..b8a32e4c6c 100644 --- a/doc/guides/prog_guide/ivshmem_lib.rst +++ b/doc/guides/prog_guide/ivshmem_lib.rst @@ -79,6 +79,8 @@ The following is a simple guide to using the IVSHMEM Library API: Only data structures fully residing in DPDK hugepage memory work correctly. Supported data structures created by malloc(), mmap() or otherwise using non-DPDK memory cause undefined behavior and even a segmentation fault. + Specifically, because the memzone field in an rte_ring refers to a memzone structure residing in local memory, + accessing the memzone field in a shared rte_ring will cause an immediate segmentation fault. IVSHMEM Environment Configuration --------------------------------- -- 2.20.1