diff mbox

virtio-scsi: fix object check failure

Message ID CACVXFVM64qEYhh5nMZqViz5nHxVrkquKjjTfEMgUTDGzwUtw4g@mail.gmail.com
State New
Headers show

Commit Message

Ming Lei June 18, 2014, 2:43 p.m. UTC 
On Wed, Jun 18, 2014 at 10:23 PM, Andreas Färber <afaerber@suse.de> wrote:
> Am 18.06.2014 14:13, schrieb Ming Lei:
>> In case of vhost-scsi, the object type of VirtIODevice isn't
>> VirtIOSCSI, so use the cast trick to fix the problem like
>> in virtio_scsi_handle_cmd()
>>
>> Cc: qemu-stable@nongnu.org
>> Cc: Anthony Liguori <aliguori@amazon.com>
>> Cc: "Michael S. Tsirkin" <mst@redhat.com>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Signed-off-by: Ming Lei <ming.lei@canonical.com>
>> ---
>>  hw/scsi/virtio-scsi.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
>> index b0d7517..13700f5 100644
>> --- a/hw/scsi/virtio-scsi.c
>> +++ b/hw/scsi/virtio-scsi.c
>> @@ -538,7 +538,7 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
>>
>>  static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
>>  {
>> -    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
>> +    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
>>
>>      if (s->events_dropped) {
>
> If s is not of type VirtIOSCSI as you indicate, then you shouldn't be
> accessing its fields here either. You're basically disabling the safety
> mechanism to avoid just that.

Yes, you are right, and the correct approach should let VirtIOSCSI
as parent of VHostSCSI, so how about attached patch?

>
> If you see a direct cast used elsewhere, it is most likely for
> performance reasons, not for correctness.

The other two places aren't for performance reason, and it is
designed as so.


Thanks,
--
Ming Lei
diff mbox

Patch

From b1e09246ee961a67a301dd0591a2919cd9b5bab3 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@canonical.com>
Date: Wed, 18 Jun 2014 20:06:55 +0800
Subject: [PATCH] virtio-scsi: fix object check failure

In case of vhost-scsi, the object type of VirtIODevice isn't
VirtIOSCSI, so use the cast trick to fix the problem like
in virtio_scsi_handle_cmd()

Cc: qemu-stable@nongnu.org
Cc: Anthony Liguori <aliguori@amazon.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
---
 hw/scsi/vhost-scsi.c           |    2 +-
 hw/scsi/virtio-scsi.c          |    2 +-
 hw/virtio/virtio-pci.c         |    2 +-
 include/hw/virtio/vhost-scsi.h |    2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 3983a5b..76985a7 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -257,7 +257,7 @@  static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 }
 
 static Property vhost_scsi_properties[] = {
-    DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
+    DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent.parent_obj.conf),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index b0d7517..13700f5 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -538,7 +538,7 @@  static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 
 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 {
-    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 
     if (s->events_dropped) {
         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index af2e1c3..b428898 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1199,7 +1199,7 @@  static const TypeInfo virtio_scsi_pci_info = {
 static Property vhost_scsi_pci_properties[] = {
     DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
                        DEV_NVECTORS_UNSPECIFIED),
-    DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSIPCI, vdev.parent_obj.conf),
+    DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSIPCI, vdev.parent.parent_obj.conf),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/virtio/vhost-scsi.h b/include/hw/virtio/vhost-scsi.h
index 85cc031..62fc820 100644
--- a/include/hw/virtio/vhost-scsi.h
+++ b/include/hw/virtio/vhost-scsi.h
@@ -55,7 +55,7 @@  enum vhost_scsi_vq_list {
         OBJECT_CHECK(VHostSCSI, (obj), TYPE_VHOST_SCSI)
 
 typedef struct VHostSCSI {
-    VirtIOSCSICommon parent_obj;
+    VirtIOSCSI parent;
 
     Error *migration_blocker;
 
-- 
1.7.9.5