vfio: check if group fd is already open

Always attempt to find already opened fd for an iommu
group as subsequent attempts to open it will fail.

There's no public API to check if a group was already
bound and has a container, so rte_vfio_container_group_bind()
shouldn't fail in such case.

Fixes: ea2dc1066870 ("vfio: add multi container support")
Cc: stable@dpdk.org
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Acked-by: Xiao Wang <xiao.w.wang@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/librte_eal/linuxapp/eal/eal_vfio.c
index ebecde1..04c8f2e 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
@@ -1702,6 +1702,11 @@ rte_vfio_container_group_bind(int container_fd, int iommu_group_num)
                return -1;
        }
 
+       /* check if we already have the group descriptor open */
+       for (i = 0; i < VFIO_MAX_GROUPS; i++)
+               if (vfio_cfg->vfio_groups[i].group_num == iommu_group_num)
+                       return vfio_cfg->vfio_groups[i].fd;
+
        /* Check room for new group */
        if (vfio_cfg->vfio_active_groups == VFIO_MAX_GROUPS) {
                RTE_LOG(ERR, EAL, "Maximum number of VFIO groups reached!\n");