[PATCH v2] vfio: noiommu check error handling

* [PATCH v2] vfio: noiommu check error handling
@ 2017-10-31 15:59 Jonas Pfefferle
  2017-11-06 20:25 ` Thomas Monjalon
                   ` (2 more replies)
  0 siblings, 3 replies; 20+ messages in thread
From: Jonas Pfefferle @ 2017-10-31 15:59 UTC (permalink / raw)
  To: dev; +Cc: anatoly.burakov, Jonas Pfefferle

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 | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/librte_eal/linuxapp/eal/eal_vfio.c
index 5bbcdf9..80afdb3 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
@@ -843,20 +843,33 @@ 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;
 	fd = open(VFIO_NOIOMMU_MODE, O_RDONLY);
-	if (fd < 0)
-		return -1;
+	if (fd < 0) {
+		if (errno != ENOENT) {
+			RTE_LOG(ERR, EAL, "  cannot open vfio noiommu file %i (%s)\n",
+					errno, strerror(errno));
+			return -1;
+		}
+		/*
+		 * else the file does not exists
+		 * i.e. noiommu is not enabled
+		 */
+		return 0;
+	}
 
 	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

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