net/nbl: check IOVA mode in Linux coexistence

Add IOVA mode check in Coexistence.

Signed-off-by: Dimon Zhao <[email protected]>

Author: Dimon-Zhao

doc/guides/nics/nbl.rst

@@ -70,6 +70,15 @@ Anolis community:
 Alternatively, you can contact us to obtain the `nbl_core` code and installation package.
 
 
+Coexistence Between DPDK And Kernel Driver
+------------------------------------------
+
+When the device is bound to the `nbl_core` driver and IOMMU is in passthrough mode,
+it is necessary to force I/O virtual address (IOVA)
+to be mapped to physical address (PA)
+with the EAL command line option ``--iova-mode=pa``.
+
+
 Prerequisites
 -------------
 

drivers/net/nbl/nbl_common/nbl_userdev.c

@@ -679,11 +679,20 @@ int nbl_pci_map_device(struct nbl_adapter *adapter)
 
 	NBL_USERDEV_INIT_COMMON(common);
 	iova_mode = rte_eal_iova_mode();
+
+	snprintf(pathname, sizeof(pathname), "/dev/nbl_userdev/" PCI_PRI_FMT, loc->domain,
+		 loc->bus, loc->devid, loc->function);
+
+	/* check iommu passthrough mode */
+	if (!access(pathname, F_OK) && iova_mode != RTE_IOVA_PA) {
+		NBL_LOG(ERR, "%s IOMMU is in passthrough mode, must select IOVA as PA"
+			" with --iova-mode=pa", pci_dev->device.name);
+		ret = -1;
+		return ret;
+	}
+
 	if (iova_mode == RTE_IOVA_PA) {
 		/* check iommu disable */
-		snprintf(pathname, sizeof(pathname),
-			 "/dev/nbl_userdev/" PCI_PRI_FMT, loc->domain,
-			 loc->bus, loc->devid, loc->function);
 		common->devfd = open(pathname, O_RDWR);
 		if (common->devfd >= 0)
 			goto mmap;