vfio: Pass an error object to vfio_get_device

Pass an error object to prepare for migration to VFIO-PCI realize.

In vfio platform vfio_base_device_init we currently just report the
error. Subsequent patches will propagate the error up to the realize
function.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

hw/vfio/common.c

@@ -1211,23 +1211,24 @@ void vfio_put_group(VFIOGroup *group)
 }
 
 int vfio_get_device(VFIOGroup *group, const char *name,
-                       VFIODevice *vbasedev)
+                    VFIODevice *vbasedev, Error **errp)
 {
     struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
     int ret, fd;
 
     fd = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
     if (fd < 0) {
-        error_report("vfio: error getting device %s from group %d: %m",
-                     name, group->groupid);
-        error_printf("Verify all devices in group %d are bound to vfio-<bus> "
-                     "or pci-stub and not already in use\n", group->groupid);
+        error_setg_errno(errp, errno, "error getting device from group %d",
+                         group->groupid);
+        error_append_hint(errp,
+                      "Verify all devices in group %d are bound to vfio-<bus> "
+                      "or pci-stub and not already in use\n", group->groupid);
         return fd;
     }
 
     ret = ioctl(fd, VFIO_DEVICE_GET_INFO, &dev_info);
     if (ret) {
-        error_report("vfio: error getting device info: %m");
+        error_setg_errno(errp, errno, "error getting device info");
         close(fd);
         return ret;
     }

hw/vfio/pci.c

@@ -2578,9 +2578,8 @@ static int vfio_initfn(PCIDevice *pdev)
         }
     }
 
-    ret = vfio_get_device(group, vdev->vbasedev.name, &vdev->vbasedev);
+    ret = vfio_get_device(group, vdev->vbasedev.name, &vdev->vbasedev, &err);
     if (ret) {
-        error_setg_errno(&err, -ret, "failed to get device");
         vfio_put_group(group);
         goto error;
     }

hw/vfio/platform.c

@@ -607,11 +607,10 @@ static int vfio_base_device_init(VFIODevice *vbasedev)
             return -EBUSY;
         }
     }
-    ret = vfio_get_device(group, vbasedev->name, vbasedev);
+    ret = vfio_get_device(group, vbasedev->name, vbasedev, &err);
     if (ret) {
-        error_report("vfio: failed to get device %s", vbasedev->name);
         vfio_put_group(group);
-        return ret;
+        goto error;
     }
 
     ret = vfio_populate_device(vbasedev);

include/hw/vfio/vfio-common.h

@@ -158,7 +158,7 @@ void vfio_reset_handler(void *opaque);
 VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp);
 void vfio_put_group(VFIOGroup *group);
 int vfio_get_device(VFIOGroup *group, const char *name,
-                    VFIODevice *vbasedev);
+                    VFIODevice *vbasedev, Error **errp);
 
 extern const MemoryRegionOps vfio_region_ops;
 extern QLIST_HEAD(vfio_group_head, VFIOGroup) vfio_group_list;