[dpdk-dev] [PATCH] vfio: noiommu check error handling

[Jonas Pfefferle <jpf@zurich.ibm.com>]

Check and report errors on open/read in noiommu check.

Signed-off-by: Jonas Pfefferle <jpf@zurich.ibm.com>
---
 lib/librte_eal/linuxapp/eal/eal_vfio.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/librte_eal/linuxapp/eal/eal_vfio.c
index 5bbcdf9..8f9d043 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
@@ -843,20 +843,34 @@ vfio_noiommu_dma_map(int __rte_unused vfio_container_fd)
 int
 vfio_noiommu_is_enabled(void)
 {
-	int fd, ret, cnt __rte_unused;
+	int fd;
+	ssize_t cnt;
 	char c;
 
-	ret = -1;
+	if (access(VFIO_NOIOMMU_MODE, R_OK) == -1) {
+		/*
+		 * file does not exist assume noiommu mode
+		 * is not available i.e. not enabled
+		 */
+		return 0;
+	}
+
 	fd = open(VFIO_NOIOMMU_MODE, O_RDONLY);
-	if (fd < 0)
+	if (fd < 0) {
+		RTE_LOG(ERR, EAL, "  cannot open vfio noiommu file %i (%s)\n",
+				errno, strerror(errno));
 		return -1;
+	}
 
 	cnt = read(fd, &c, 1);
-	if (c == 'Y')
-		ret = 1;
-
 	close(fd);
-	return ret;
+	if (cnt != 1) {
+		RTE_LOG(ERR, EAL, "  unable to read from vfio noiommu "
+				"file %i (%s)\n", errno, strerror(errno));
+		return -1;
+	}
+
+	return c == 'Y';
 }
 
 #endif
-- 
2.7.4