2 files changed, 32 insertions, 1 deletions

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index a7cf726bc747..595af1ae4421 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -279,6 +279,31 @@ static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
         }
 }
 
+static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
+                                         struct virtio_scsi_event *event)
+{
+        struct scsi_device *sdev;
+        struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+        unsigned int target = event->lun[1];
+        unsigned int lun = (event->lun[2] << 8) | event->lun[3];
+        u8 asc = event->reason & 255;
+        u8 ascq = event->reason >> 8;
+
+        sdev = scsi_device_lookup(shost, 0, target, lun);
+        if (!sdev) {
+                pr_err("SCSI device %d 0 %d %d not found\n",
+                        shost->host_no, target, lun);
+                return;
+        }
+
+        /* Handle "Parameters changed", "Mode parameters changed", and
+           "Capacity data has changed".  */
+        if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
+                scsi_rescan_device(&sdev->sdev_gendev);
+
+        scsi_device_put(sdev);
+}
+
 static void virtscsi_handle_event(struct work_struct *work)
 {
         struct virtio_scsi_event_node *event_node =
@@ -297,6 +322,9 @@ static void virtscsi_handle_event(struct work_struct *work)
         case VIRTIO_SCSI_T_TRANSPORT_RESET:
                 virtscsi_handle_transport_reset(vscsi, event);
                 break;
+        case VIRTIO_SCSI_T_PARAM_CHANGE:
+                virtscsi_handle_param_change(vscsi, event);
+                break;
         default:
                 pr_err("Unsupport virtio scsi event %x\n", event->event);
         }
@@ -737,7 +765,8 @@ static struct virtio_device_id id_table[] = {
 };
 
 static unsigned int features[] = {
-        VIRTIO_SCSI_F_HOTPLUG
+        VIRTIO_SCSI_F_HOTPLUG,
+        VIRTIO_SCSI_F_CHANGE,
 };
 
 static struct virtio_driver virtio_scsi_driver = {
diff --git a/include/linux/virtio_scsi.h b/include/linux/virtio_scsi.h
index dc8d305b0e05..d6b4440387b7 100644
--- a/include/linux/virtio_scsi.h
+++ b/include/linux/virtio_scsi.h
@@ -72,6 +72,7 @@ struct virtio_scsi_config {
 /* Feature Bits */
 #define VIRTIO_SCSI_F_INOUT                    0
 #define VIRTIO_SCSI_F_HOTPLUG                  1
+#define VIRTIO_SCSI_F_CHANGE                   2
 
 /* Response codes */
 #define VIRTIO_SCSI_S_OK                       0
@@ -108,6 +109,7 @@ struct virtio_scsi_config {
 #define VIRTIO_SCSI_T_NO_EVENT                 0
 #define VIRTIO_SCSI_T_TRANSPORT_RESET          1
 #define VIRTIO_SCSI_T_ASYNC_NOTIFY             2
+#define VIRTIO_SCSI_T_PARAM_CHANGE             3
 
 /* Reasons of transport reset event */
 #define VIRTIO_SCSI_EVT_RESET_HARD             0