[dpdk-dev] [PATCH 2/2] bus/fslmc: fix check for vfio_group_fd

[wangyunjian <wangyunjian@huawei.com>]

From: Yunjian Wang <wangyunjian@huawei.com>

The issue is that a file descriptor at 0 is a valid one. Currently
the file not found, the return value will be set to 0. As a result,
it is impossible to distinguish between a correct descriptor and a
failed return value. Fix it to return -ENOENT instead of 0.

Fixes: a69f79300262 ("bus/fslmc: support multi VFIO group")
Cc: stable@dpdk.org

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
---
 drivers/bus/fslmc/fslmc_vfio.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/fslmc/fslmc_vfio.c b/drivers/bus/fslmc/fslmc_vfio.c
index 970969d2b..04ccf4af6 100644
--- a/drivers/bus/fslmc/fslmc_vfio.c
+++ b/drivers/bus/fslmc/fslmc_vfio.c
@@ -448,11 +448,14 @@ fslmc_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
 
 	/* get the actual group fd */
 	vfio_group_fd = rte_vfio_get_group_fd(iommu_group_no);
-	if (vfio_group_fd < 0)
+	if (vfio_group_fd < 0 && vfio_group_fd != -ENOENT)
 		return -1;
 
-	/* if group_fd == 0, that means the device isn't managed by VFIO */
-	if (vfio_group_fd == 0) {
+	/*
+	 * if vfio_group_fd == -ENOENT, that means the device
+	 * isn't managed by VFIO
+	 */
+	if (vfio_group_fd == -ENOENT) {
 		RTE_LOG(WARNING, EAL, " %s not managed by VFIO driver, skipping\n",
 				dev_addr);
 		return 1;
-- 
2.23.0