vfio: fix device unplug when several devices per group

VFIO allows a secure way of assigning devices to user space and those
devices which can not be isolated from other ones are set in same VFIO
group. Releasing or unplugging a device should be aware of remaining
devices is the same group for avoiding to close such a group.

Fixes: 94c0776b1bad ("vfio: support hotplug")

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.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 dd59c1c..d3eae20 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
@@ -184,6 +184,7 @@ clear_group(int vfio_group_fd)
                        if (vfio_cfg.vfio_groups[i].fd == vfio_group_fd) {
                                vfio_cfg.vfio_groups[i].group_no = -1;
                                vfio_cfg.vfio_groups[i].fd = -1;
+                               vfio_cfg.vfio_groups[i].devices = 0;
                                vfio_cfg.vfio_active_groups--;
                                return 0;
                        }
@@ -357,6 +358,7 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                clear_group(vfio_group_fd);
                return -1;
        }
+       vfio_cfg.vfio_groups[vfio_group_fd].devices++;
 
        return 0;
 }
@@ -394,17 +396,30 @@ vfio_release_device(const char *sysfs_base, const char *dev_addr,
         * code will unset the container and the IOMMU mappings.
         */
 
-       if (close(vfio_group_fd) < 0)
-               RTE_LOG(INFO, EAL, "Error when closing vfio_group_fd for %s\n",
-                                  dev_addr);
-
-       if (close(vfio_dev_fd) < 0)
+       /* Closing a device */
+       if (close(vfio_dev_fd) < 0) {
                RTE_LOG(INFO, EAL, "Error when closing vfio_dev_fd for %s\n",
                                   dev_addr);
+               return -1;
+       }
 
-       if (clear_group(vfio_group_fd) < 0)
-               RTE_LOG(INFO, EAL, "Error when clearing group for %s\n",
-                                  dev_addr);
+       /* An VFIO group can have several devices attached. Just when there is
+        * no devices remaining should the group be closed.
+        */
+       if (--vfio_cfg.vfio_groups[vfio_group_fd].devices == 0) {
+
+               if (close(vfio_group_fd) < 0) {
+                       RTE_LOG(INFO, EAL, "Error when closing vfio_group_fd for %s\n",
+                               dev_addr);
+                       return -1;
+               }
+
+               if (clear_group(vfio_group_fd) < 0) {
+                       RTE_LOG(INFO, EAL, "Error when clearing group for %s\n",
+                                          dev_addr);
+                       return -1;
+               }
+       }
 
        return 0;
 }
@@ -419,6 +434,7 @@ vfio_enable(const char *modname)
        for (i = 0; i < VFIO_MAX_GROUPS; i++) {
                vfio_cfg.vfio_groups[i].fd = -1;
                vfio_cfg.vfio_groups[i].group_no = -1;
+               vfio_cfg.vfio_groups[i].devices = 0;
        }
 
        /* inform the user that we are probing for VFIO */

diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.h b/lib/librte_eal/linuxapp/eal/eal_vfio.h
index 239ac4d..429d625 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.h
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.h
@@ -126,6 +126,7 @@ int vfio_mp_sync_connect_to_primary(void);
 struct vfio_group {
        int group_no;
        int fd;
+       int devices;
 };
 
 struct vfio_config {