From 9372cd814782d3ffdf2464b64fc6aa67a0bf117c Mon Sep 17 00:00:00 2001
From: Alejandro Lucero <alejandro.lucero@netronome.com>
Date: Tue, 10 Jul 2018 18:25:49 +0100
Subject: [2/5] bus/pci: use IOVAs check when setting IOVA mode

Although VT-d emulation currently only supports 39 bits, it could
be iovas being within that supported range. This patch allows
IOVA mode in such a case.

Indeed, memory initialization code can be modified for using lower
virtual addresses than those used by the kernel for 64 bits processes
by default, and therefore memsegs iovas can use 39 bits or less for
most system. And this is likely 100% true for VMs.

Applicable to v17.11.3 only.

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
---
 drivers/bus/pci/linux/pci.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index 74deef3..c81ed50 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -43,6 +43,7 @@
 #include <rte_devargs.h>
 #include <rte_memcpy.h>
 #include <rte_vfio.h>
+#include <rte_memory.h>
 
 #include "eal_private.h"
 #include "eal_filesystem.h"
@@ -613,10 +614,12 @@ pci_one_device_iommu_support_va(struct rte_pci_device *dev)
 	fclose(fp);
 
 	mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1;
-	if (mgaw < X86_VA_WIDTH)
+
+	if (!rte_eal_check_dma_mask(mgaw))
+		return true;
+	else
 		return false;
 
-	return true;
 }
 #elif defined(RTE_ARCH_PPC_64)
 static bool
@@ -640,13 +643,17 @@ pci_devices_iommu_support_va(void)
 {
 	struct rte_pci_device *dev = NULL;
 	struct rte_pci_driver *drv = NULL;
+	int iommu_dma_mask_check_done = 0;
 
 	FOREACH_DRIVER_ON_PCIBUS(drv) {
 		FOREACH_DEVICE_ON_PCIBUS(dev) {
 			if (!rte_pci_match(drv, dev))
 				continue;
-			if (!pci_one_device_iommu_support_va(dev))
-				return false;
+			if (!iommu_dma_mask_check_done) {
+				if (!pci_one_device_iommu_support_va(dev))
+					return false;
+				iommu_dma_mask_check_done  = 1;
+			}
 		}
 	}
 	return true;
-- 
1.8.3.1