vhost-scsi: init backend features earlier

As vhost core can use backend_features during init, clear it earlier to
avoid using uninitialized memory.
This use would be harmless since vhost scsi ignores the result
anyway, but initializing earlier will help prevent valgrind errors,
and make scsi and net behave similarly.

Cc: qemu-stable@nongnu.org
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 3a1655fc53a2d0375dc0b8cd358405c2cae288e3)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index ddfe76aed01b0a2ed5fa709ade3badba753ac854..7146e0ec49b392834a4a1320dcae72a5ba468c9b 100644 (file)
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -238,6 +238,7 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp)
     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
     s->dev.vq_index = 0;
+    s->dev.backend_features = 0;
 
     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
                          VHOST_BACKEND_TYPE_KERNEL, true);
@@ -246,7 +247,6 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp)
                    strerror(-ret));
         return;
     }
-    s->dev.backend_features = 0;
 
     error_setg(&s->migration_blocker,
             "vhost-scsi does not support migration");