From: Jerin Jacob <jer...@marvell.com>
When bus layer selected the preferred mode as RTE_IOVA_DC then
select the IOVA mode as RTE_IOVA_VA.
The RTE_IOVA_VA selected as the default because,
1) All drivers work in RTE_IOVA_VA mode, irrespective of physical
address availability.
2) By default, the mempool, first asks for IOVA-contiguous memory
using RTE_MEMZONE_IOVA_CONTIG and this is slow in IOVA as PA mode
and it may affect the application boot time.
Signed-off-by: Jerin Jacob <jer...@marvell.com>
---
doc/guides/prog_guide/env_abstraction_layer.rst | 10 ++++++++--
lib/librte_eal/linux/eal/eal.c | 6 ++----
2 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/doc/guides/prog_guide/env_abstraction_layer.rst
b/doc/guides/prog_guide/env_abstraction_layer.rst
index 77307e3a6..1b0343eee 100644
--- a/doc/guides/prog_guide/env_abstraction_layer.rst
+++ b/doc/guides/prog_guide/env_abstraction_layer.rst
@@ -445,8 +445,14 @@ kernels.
- if the preferred mode is RTE_IOVA_PA but there is no access to Physical
Addresses, then EAL init will fail early, since later probing of the devices
would fail anyway,
-- if the preferred mode is RTE_IOVA_DC then based on the Physical Addresses
- availability, the preferred mode is adjusted to RTE_IOVA_PA or RTE_IOVA_VA.
+- if the preferred mode is RTE_IOVA_DC then select the IOVA mode as
RTE_IOVA_VA.
+ The RTE_IOVA_VA selected as the default because,
+
+#. All drivers work in RTE_IOVA_VA mode, irrespective of physical address
availability.
+
+#. By default, the mempool, first asks for IOVA-contiguous memory using
``RTE_MEMZONE_IOVA_CONTIG``,
+ and this is slow in IOVA as PA mode and it may affect the application boot
time.
+
In the case when the buses had disagreed on the IOVA Mode at the first step,
part of the buses won't work because of this decision.
diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
index 2e5499f9b..34db78753 100644
--- a/lib/librte_eal/linux/eal/eal.c
+++ b/lib/librte_eal/linux/eal/eal.c
@@ -1061,10 +1061,8 @@ rte_eal_init(int argc, char **argv)
enum rte_iova_mode iova_mode = rte_bus_get_iommu_class();
if (iova_mode == RTE_IOVA_DC) {
- iova_mode = phys_addrs ? RTE_IOVA_PA : RTE_IOVA_VA;
- RTE_LOG(DEBUG, EAL,
- "Buses did not request a specific IOVA mode,
using '%s' based on physical addresses availability.\n",
- phys_addrs ? "PA" : "VA");
+ iova_mode = RTE_IOVA_VA;
+ RTE_LOG(DEBUG, EAL, "Buses did not request a specific
IOVA mode, select IOVA as VA mode.\n");
}
#ifdef RTE_LIBRTE_KNI
/* Workaround for KNI which requires physical address to work */
--
2.22.0
