[3/5] bus/pci: use IOVAs check when setting IOVA mode
diff mbox series

Message ID 1535642492-21831-4-git-send-email-alejandro.lucero@netronome.com
State Not Applicable, archived
Headers show
Series
  • use IOVAs check based on DMA mask
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Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation fail Compilation issues

Commit Message

Alejandro Lucero Aug. 30, 2018, 3:21 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, 10 insertions(+), 5 deletions(-)

Patch
diff mbox series

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index 04648ac..215dc10 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -588,10 +588,11 @@ 
 	fclose(fp);
 
 	mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1;
-	if (mgaw < X86_VA_WIDTH)
-		return false;
 
-	return true;
+	if (!rte_eal_check_dma_mask(mgaw))
+		return true;
+	else
+		return false;
 }
 #elif defined(RTE_ARCH_PPC_64)
 static bool
@@ -615,13 +616,17 @@ 
 {
 	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))
+					return false;
+				iommu_dma_mask_check_done  = 1;
+			}
 		}
 	}
 	return true;