[v2,3/6] bus/pci: use IOVAs check when setting IOVA mode

Message ID 1530619789-33337-4-git-send-email-alejandro.lucero@netronome.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series use IOVAs check based on DMA mask |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Alejandro Lucero July 3, 2018, 12:09 p.m. UTC
  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.

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

Patch

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index 74deef3..792c819 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 @@ 
 	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 @@ 
 {
 	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) < 0)
+					return false;
+				iommu_dma_mask_check_done  = 1;
+			}
 		}
 	}
 	return true;