[PATCH v3] eal: choose IOVA mode according to compilation flags

[Viacheslav Ovsiienko]

The DPDK can be compiled to be run in IOVA VA mode with
'enable_iova_as_pa=false' meson option. If there is no
explicit EAL --iova-mode parameter specified in the command
line the rte_eal_init() tried to deduce VA or PA mode without
taking into account the above mentioned compile time option,
resulting into initialization failure.

Also, for FreeBSD and Windows EALs the IOVE mode checks were
added or moved to be after the mode selection code block for
final checking.

Signed-off-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
Reviewed-by: Morten Brørup <mb at smartsharesystems.com>
---
 lib/eal/freebsd/eal.c | 28 +++++++++++++++++++++-------
 lib/eal/linux/eal.c   |  5 ++++-
 lib/eal/windows/eal.c | 28 +++++++++++++++++++++-------
 3 files changed, 46 insertions(+), 15 deletions(-)

---
v2: - minor test message update
v3: - added the same change to FreeBSD and Windwos EALs
    - added/mode chosen IOVA mode checks in FreeBSD/Windows

diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
index 7daf22e314..ff7da2473a 100644
--- a/lib/eal/freebsd/eal.c
+++ b/lib/eal/freebsd/eal.c
@@ -694,22 +694,36 @@ rte_eal_init(int argc, char **argv)
 	 */
 	has_phys_addr = internal_conf->no_hugetlbfs == 0;
 	iova_mode = internal_conf->iova_mode;
-	if (iova_mode == RTE_IOVA_PA && !has_phys_addr) {
-		rte_eal_init_alert("Cannot use IOVA as 'PA' since physical addresses are not available");
-		rte_errno = EINVAL;
-		return -1;
-	}
 	if (iova_mode == RTE_IOVA_DC) {
 		RTE_LOG(DEBUG, EAL, "Specific IOVA mode is not requested, autodetecting\n");
 		if (has_phys_addr) {
 			RTE_LOG(DEBUG, EAL, "Selecting IOVA mode according to bus requests\n");
 			iova_mode = rte_bus_get_iommu_class();
-			if (iova_mode == RTE_IOVA_DC)
-				iova_mode = RTE_IOVA_PA;
+			if (iova_mode == RTE_IOVA_DC) {
+				if (!RTE_IOVA_IN_MBUF) {
+					iova_mode = RTE_IOVA_VA;
+					RTE_LOG(DEBUG, EAL, "IOVA as VA mode is forced by build option.\n");
+				} else	{
+					iova_mode = RTE_IOVA_PA;
+				}
+			}
 		} else {
 			iova_mode = RTE_IOVA_VA;
 		}
 	}
+
+	if (iova_mode == RTE_IOVA_PA && !has_phys_addr) {
+		rte_eal_init_alert("Cannot use IOVA as 'PA' since physical addresses are not available");
+		rte_errno = EINVAL;
+		return -1;
+	}
+
+	if (iova_mode == RTE_IOVA_PA && !RTE_IOVA_IN_MBUF) {
+		rte_eal_init_alert("Cannot use IOVA as 'PA' as it is disabled during build");
+		rte_errno = EINVAL;
+		return -1;
+	}
+
 	rte_eal_get_configuration()->iova_mode = iova_mode;
 	RTE_LOG(INFO, EAL, "Selected IOVA mode '%s'\n",
 		rte_eal_iova_mode() == RTE_IOVA_PA ? "PA" : "VA");
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index ae323cd492..9856ec9d12 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -1081,7 +1081,10 @@ rte_eal_init(int argc, char **argv)
 		if (iova_mode == RTE_IOVA_DC) {
 			RTE_LOG(DEBUG, EAL, "Buses did not request a specific IOVA mode.\n");
 
-			if (!phys_addrs) {
+			if (!RTE_IOVA_IN_MBUF) {
+				iova_mode = RTE_IOVA_VA;
+				RTE_LOG(DEBUG, EAL, "IOVA as VA mode is forced by build option.\n");
+			} else if (!phys_addrs) {
 				/* if we have no access to physical addresses,
 				 * pick IOVA as VA mode.
 				 */
diff --git a/lib/eal/windows/eal.c b/lib/eal/windows/eal.c
index 033825c14c..9c9a49fda0 100644
--- a/lib/eal/windows/eal.c
+++ b/lib/eal/windows/eal.c
@@ -362,22 +362,36 @@ rte_eal_init(int argc, char **argv)
 	}
 
 	iova_mode = internal_conf->iova_mode;
-	if (iova_mode == RTE_IOVA_PA && !has_phys_addr) {
-		rte_eal_init_alert("Cannot use IOVA as 'PA' since physical addresses are not available");
-		rte_errno = EINVAL;
-		return -1;
-	}
 	if (iova_mode == RTE_IOVA_DC) {
 		RTE_LOG(DEBUG, EAL, "Specific IOVA mode is not requested, autodetecting\n");
 		if (has_phys_addr) {
 			RTE_LOG(DEBUG, EAL, "Selecting IOVA mode according to bus requests\n");
 			iova_mode = rte_bus_get_iommu_class();
-			if (iova_mode == RTE_IOVA_DC)
-				iova_mode = RTE_IOVA_PA;
+			if (iova_mode == RTE_IOVA_DC) {
+				if (!RTE_IOVA_IN_MBUF) {
+					iova_mode = RTE_IOVA_VA;
+					RTE_LOG(DEBUG, EAL, "IOVA as VA mode is forced by build option.\n");
+				} else	{
+					iova_mode = RTE_IOVA_PA;
+				}
+			}
 		} else {
 			iova_mode = RTE_IOVA_VA;
 		}
 	}
+
+	if (iova_mode == RTE_IOVA_PA && !has_phys_addr) {
+		rte_eal_init_alert("Cannot use IOVA as 'PA' since physical addresses are not available");
+		rte_errno = EINVAL;
+		return -1;
+	}
+
+	if (iova_mode == RTE_IOVA_PA && !RTE_IOVA_IN_MBUF) {
+		rte_eal_init_alert("Cannot use IOVA as 'PA' as it is disabled during build");
+		rte_errno = EINVAL;
+		return -1;
+	}
+
 	RTE_LOG(DEBUG, EAL, "Selected IOVA mode '%s'\n",
 		iova_mode == RTE_IOVA_PA ? "PA" : "VA");
 	rte_eal_get_configuration()->iova_mode = iova_mode;
-- 
2.18.1