virtio-scsi: Move DEFINE_VIRTIO_SCSI_FEATURES to virtio-scsi

So far virtio-scsi-device can't expose host features to guest while
using virtio-mmio because it doesn't set DEFINE_VIRTIO_SCSI_FEATURES on
backend or transport.

The host features belong to the backends while virtio-scsi-pci,
virtio-scsi-s390 and virtio-scsi-ccw set the DEFINE_VIRTIO_SCSI_FEATURES
on transports. But they already have the ability to forward property
accesses to the backend child. So if we move the host features to
backends, it doesn't break the backwards compatibility for them and
make host features work while using virtio-mmio.

Move DEFINE_VIRTIO_SCSI_FEATURES to the backend virtio-scsi. The
transports just sync the host features from backends.

Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 6 insertions, 3 deletions

diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index b893e02..c8a78ba 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -622,7 +622,6 @@ static const TypeInfo virtio_s390_device_info = {
 
 static Property s390_virtio_scsi_properties[] = {
     DEFINE_VIRTIO_COMMON_FEATURES(VirtIOS390Device, host_features),
-    DEFINE_VIRTIO_SCSI_FEATURES(VirtIOS390Device, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index e6e9f9d..db798a8 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1506,7 +1506,6 @@ static const TypeInfo virtio_ccw_balloon = {
 
 static Property virtio_ccw_scsi_properties[] = {
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
-    DEFINE_VIRTIO_SCSI_FEATURES(VirtioCcwDevice, host_features[0]),
     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_END_OF_LIST(),
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index c9bea06..e242fef 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -631,6 +631,10 @@ static void virtio_scsi_set_config(VirtIODevice *vdev,
 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
                                          uint32_t requested_features)
 {
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+
+    /* Firstly sync all virtio-scsi possible supported features */
+    requested_features |= s->host_features;
     return requested_features;
 }
 
@@ -945,6 +949,7 @@ static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 
 static Property virtio_scsi_properties[] = {
     DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOSCSI, parent_obj.conf),
+    DEFINE_VIRTIO_SCSI_FEATURES(VirtIOSCSI, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 07b2a67..867c9d1 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1087,7 +1087,6 @@ static Property virtio_scsi_pci_properties[] = {
                     VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
                        DEV_NVECTORS_UNSPECIFIED),
-    DEFINE_VIRTIO_SCSI_FEATURES(VirtIOPCIProxy, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index f93b57d..b42e7f1 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -98,6 +98,7 @@ typedef struct VirtIOSCSI {
     bool dataplane_fenced;
     Error *blocker;
     Notifier migration_state_notifier;
+    uint32_t host_features;
 } VirtIOSCSI;
 
 typedef struct VirtIOSCSIReq {