[Qemu-stable] [PATCH 079/108] virtio-scsi: define dummy handle_output for vhost-scsi vqs

[Michael Roth]

From: Ming Lei <address@hidden>

vhost userspace needn't to handle vq's notification from guest,
so define dummy handle_output callback for all vqs of vhost-scsi.

In some corner cases(such as when handling vq's reset from VM), virtio-pci
still trys to handle pending virtio-scsi events, then object check failure
inside virtio_scsi_handle_event() for vhost-scsi can be triggered.

The issue can be reproduced by 'rmmod virtio-scsi', 'system sleep' or reboot
inside VM.

Cc: address@hidden
Cc: Anthony Liguori <address@hidden>
Cc: "Michael S. Tsirkin" <address@hidden>
Cc: Paolo Bonzini <address@hidden>
Signed-off-by: Ming Lei <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
(cherry picked from commit 91d670fbf9945ca4ecbd123affb36889e7fe8a5d)
Signed-off-by: Michael Roth <address@hidden>
---
 hw/scsi/vhost-scsi.c            |  8 +++++++-
 hw/scsi/virtio-scsi.c           | 14 +++++++++-----
 include/hw/virtio/virtio-scsi.h |  7 ++++++-
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 3983a5b..9099192 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -196,6 +196,10 @@ static void vhost_scsi_set_status(VirtIODevice *vdev, 
uint8_t val)
     }
 }
 
+static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+}
+
 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 {
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
@@ -217,7 +221,9 @@ static void vhost_scsi_realize(DeviceState *dev, Error 
**errp)
         }
     }
 
-    virtio_scsi_common_realize(dev, &err);
+    virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
+                               vhost_dummy_handle_output,
+                               vhost_dummy_handle_output);
     if (err != NULL) {
         error_propagate(errp, err);
         return;
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 14261fb..d183cd0 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -605,7 +605,9 @@ static struct SCSIBusInfo virtio_scsi_scsi_info = {
     .load_request = virtio_scsi_load_request,
 };
 
-void virtio_scsi_common_realize(DeviceState *dev, Error **errp)
+void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
+                                HandleOutput ctrl, HandleOutput evt,
+                                HandleOutput cmd)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
@@ -619,12 +621,12 @@ void virtio_scsi_common_realize(DeviceState *dev, Error 
**errp)
     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 
     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
-                                  virtio_scsi_handle_ctrl);
+                                  ctrl);
     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
-                                   virtio_scsi_handle_event);
+                                   evt);
     for (i = 0; i < s->conf.num_queues; i++) {
         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
-                                         virtio_scsi_handle_cmd);
+                                         cmd);
     }
 }
 
@@ -635,7 +637,9 @@ static void virtio_scsi_device_realize(DeviceState *dev, 
Error **errp)
     static int virtio_scsi_id;
     Error *err = NULL;
 
-    virtio_scsi_common_realize(dev, &err);
+    virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
+                               virtio_scsi_handle_event,
+                               virtio_scsi_handle_cmd);
     if (err != NULL) {
         error_propagate(errp, err);
         return;
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index 42b1024..e81a643 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -186,7 +186,12 @@ typedef struct {
     DEFINE_PROP_BIT("param_change", _state, _feature_field,                    
\
                                             VIRTIO_SCSI_F_CHANGE, true)
 
-void virtio_scsi_common_realize(DeviceState *dev, Error **errp);
+typedef void (*HandleOutput)(VirtIODevice *, VirtQueue *);
+
+void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
+                                HandleOutput ctrl, HandleOutput evt,
+                                HandleOutput cmd);
+
 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp);
 
 #endif /* _QEMU_VIRTIO_SCSI_H */
-- 
1.9.1