[dpdk-dev] [PATCH v3 2/3] eal: force IOVA to a particular mode

[eric zhang]

This patch uses EAL option "--iova-mode" to force the IOVA mode to a
particular value. There exists virtual devices that are not directly
attached to the PCI bus, and therefore the auto detectioni of the IOVA
mode based on probing the PCI bus and IOMMU configuration may not
report the required addressing mode. Using the EAL option permits the
mode to be explicitly configured in this scenario.

Signed-off-by: eric zhang <eric.zh...@windriver.com>
---
 lib/librte_eal/bsdapp/eal/eal.c   | 11 +++++++++--
 lib/librte_eal/linuxapp/eal/eal.c | 27 +++++++++++++++++----------
 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c
index 369a682..5392f06 100644
--- a/lib/librte_eal/bsdapp/eal/eal.c
+++ b/lib/librte_eal/bsdapp/eal/eal.c
@@ -569,8 +569,15 @@ static void rte_eal_init_alert(const char *msg)
                return -1;
        }
 
-       /* autodetect the iova mapping mode (default is iova_pa) */
-       rte_eal_get_configuration()->iova_mode = rte_bus_get_iommu_class();
+       /* if no eal option "--iova-mode=<pa|va>", use bus iova scheme */
+       if (internal_config.iova_mode == RTE_IOVA_DC) {
+               /* autodetect the iova mapping mode (default is iova_pa) */
+               rte_eal_get_configuration()->iova_mode =
+                       rte_bus_get_iommu_class();
+       } else {
+               rte_eal_get_configuration()->iova_mode =
+                       internal_config.iova_mode;
+       }
 
        if (internal_config.no_hugetlbfs == 0 &&
                        internal_config.process_type != RTE_PROC_SECONDARY &&
diff --git a/lib/librte_eal/linuxapp/eal/eal.c 
b/lib/librte_eal/linuxapp/eal/eal.c
index e0b5ae1..1af9458 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -805,16 +805,23 @@ static void rte_eal_init_alert(const char *msg)
                return -1;
        }
 
-       /* 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 no eal option "--iova-mode=<pa|va>", use bus iova scheme */
+       if (internal_config.iova_mode == RTE_IOVA_DC) {
+               /* 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");
+               }
+       } else {
+               rte_eal_get_configuration()->iova_mode =
+                       internal_config.iova_mode;
        }
 
        if (internal_config.no_hugetlbfs == 0 &&
-- 
1.8.3.1