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

[Jonas Pfefferle]

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

Signed-off-by: Jonas Pfefferle <j...@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