[dpdk-dev] [PATCH] vfio: support iommu group zero

[Stephen Hemminger <stephen@networkplumber.org>]

From: Stephen Hemminger <stephen@networkplumber.org>

The implementation of VFIO is broken on some platforms and if using
the proposed VFIO without IOMMU patch.  IOMMU group zero is a valid value.

Change code to split the return value from the group value.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 lib/librte_eal/linuxapp/eal/eal_pci_vfio.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
index 0e6c48a..74f91ba 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
@@ -499,14 +499,15 @@ pci_vfio_get_group_fd(int iommu_group_no)
 }
 
 /* parse IOMMU group number for a PCI device
- * returns -1 for errors, 0 for non-existent group */
+ * returns 1 on success, -1 for errors, 0 for non-existent group
+ */
 static int
-pci_vfio_get_group_no(const char *pci_addr)
+pci_vfio_get_group_no(const char *pci_addr, int *iommu_group_no)
 {
 	char linkname[PATH_MAX];
 	char filename[PATH_MAX];
 	char *tok[16], *group_tok, *end;
-	int ret, iommu_group_no;
+	int ret;
 
 	memset(linkname, 0, sizeof(linkname));
 	memset(filename, 0, sizeof(filename));
@@ -533,13 +534,13 @@ pci_vfio_get_group_no(const char *pci_addr)
 	errno = 0;
 	group_tok = tok[ret - 1];
 	end = group_tok;
-	iommu_group_no = strtol(group_tok, &end, 10);
+	*iommu_group_no = strtol(group_tok, &end, 10);
 	if ((end != group_tok && *end != '\0') || errno != 0) {
 		RTE_LOG(ERR, EAL, "  %s error parsing IOMMU number!\n", pci_addr);
 		return -1;
 	}
 
-	return iommu_group_no;
+	return 1;
 }
 
 static void
@@ -581,16 +582,15 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
 			loc->domain, loc->bus, loc->devid, loc->function);
 
 	/* get group number */
-	iommu_group_no = pci_vfio_get_group_no(pci_addr);
-
-	/* if 0, group doesn't exist */
-	if (iommu_group_no == 0) {
+	ret = pci_vfio_get_group_no(pci_addr, &iommu_group_no);
+	if (ret == 0) {
 		RTE_LOG(WARNING, EAL, "  %s not managed by VFIO driver, skipping\n",
-				pci_addr);
+			pci_addr);
 		return 1;
 	}
+
 	/* if negative, something failed */
-	else if (iommu_group_no < 0)
+	if (ret < 0)
 		return -1;
 
 	/* get the actual group fd */
-- 
2.1.4