[dpdk-dev] [PATCH v2] eal/bus: use RTE_IOVA_PA only if phys addresses are available

[Darek Stojaczyk <dariusz.stojaczyk@intel.com>]

When neither RTE_IOVA_VA nor RTE_IOVA_PA was explicitly
requested, DPDK would currently fallback to the default
RTE_IOVA_PA mode and possibly encounter a failure later
on if running as a non-priviledged user. Attempting to
use RTE_IOVA_VA if no phys addresses are available may
help in this case.

Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
---
Changes since v1:
 * added a missing rte_memory.h include

 lib/librte_eal/common/eal_common_bus.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
index 0943851cc..68c581b8a 100644
--- a/lib/librte_eal/common/eal_common_bus.c
+++ b/lib/librte_eal/common/eal_common_bus.c
@@ -37,6 +37,7 @@
 #include <rte_bus.h>
 #include <rte_debug.h>
 #include <rte_string_fns.h>
+#include <rte_memory.h>
 
 #include "eal_private.h"
 
@@ -236,9 +237,19 @@ rte_bus_get_iommu_class(void)
 			mode |= bus->get_iommu_class();
 	}
 
-	if (mode != RTE_IOVA_VA) {
-		/* Use default IOVA mode */
-		mode = RTE_IOVA_PA;
+	if (mode == RTE_IOVA_VA)
+		return RTE_IOVA_VA;
+
+	if (mode & RTE_IOVA_PA) {
+		/* Not all buses support RTE_IOVA_VA, fallback to RTE_IOVA_PA */
+		return RTE_IOVA_PA;
+	}
+
+	if (rte_eal_using_phys_addrs()) {
+		/* Default to RTE_IOVA_PA only if it's supported */
+		return RTE_IOVA_PA;
 	}
-	return mode;
+
+	/* Since RTE_IOVA_PA is unsupported, fallback to RTE_IOVA_VA */
+	return RTE_IOVA_VA;
 }
-- 
2.17.1