[dpdk-dev] [PATCH] eal: force IOVA PA mode if KNI module inserted

[Ferruh Yigit]

Fix kernel crash with KNI because KNI requires physical addresses.

When IOVA VA mode used, memzones and mbufs physical address fields
contain virtual addresses. But KNI relies on these fields to enable
kernel access for buffers. Those fields having virtual address cause
crash in kernel.

This is a workaround until KNI fixed properly to work with virtual
addresses.

Fixes: 72d013644bd6 ("mem: honor IOVA mode in malloc virt2phy")

Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
---
Cc: Jianfeng Tan <jianfeng.tan at intel.com>
Cc: Jerin Jacob <jerin.jacob at caviumnetworks.com>
Cc: Santosh Shukla <santosh.shukla at caviumnetworks.com>
Cc: Thomas Monjalon <thomas at monjalon.net>

This patch superseded following one:
http://dpdk.org/dev/patchwork/patch/31071/
---
 lib/librte_eal/linuxapp/eal/eal.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 017c402ed..29912a4e5 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -808,6 +808,15 @@ rte_eal_init(int argc, char **argv)
 	/* autodetect the iova mapping mode (default is iova_pa) */
 	rte_eal_get_configuration()->iova_mode = rte_bus_get_iommu_class();
 
+	/* Workaround for KNI which requires physical address to work */
+	if (rte_eal_get_configuration()->iova_mode == RTE_IOVA_VA &&
+			rte_eal_check_module("rte_kni") == 1) {
+		rte_eal_get_configuration()->iova_mode = RTE_IOVA_PA;
+		RTE_LOG(WARNING, EAL,
+			"Some devices want iova as va but pa will be used because.. "
+			"KNI module inserted\n");
+	}
+
 	if (internal_config.no_hugetlbfs == 0 &&
 			internal_config.process_type != RTE_PROC_SECONDARY &&
 			eal_hugepage_info_init() < 0) {
-- 
2.13.6