Re: [Qemu-devel] [PATCH RFC v5 14/19] s390x/virtio-ccw: enable virtio 1.0

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Dec 02, 2014 at 02:00:22PM +0100, Cornelia Huck wrote:
> virtio-ccw should now have everything in place to operate virtio 1.0
> devices, so let's enable revision 1.
> 
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

Looks like this will allow revision 1 for all devices,
we only want this for virtio 1 devices.

The following should fix it I think:

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
index d40e3be..f5a1d3e 100644
--- a/hw/s390x/virtio-ccw.h
+++ b/hw/s390x/virtio-ccw.h
@@ -69,9 +69,6 @@ typedef struct VirtIOCCWDeviceClass {
     int (*exit)(VirtioCcwDevice *dev);
 } VirtIOCCWDeviceClass;
 
-/* The maximum virtio revision we support. */
-#define VIRTIO_CCW_REV_MAX 1
-
 /* Performance improves when virtqueue kick processing is decoupled from the
  * vcpu thread using ioeventfd for some devices. */
 #define VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT 1
@@ -104,6 +101,12 @@ struct VirtioCcwDevice {
     uint64_t ind_bit;
 };
 
+/* The maximum virtio revision we support. */
+static int virtio_ccw_rev_max(VirtioCcwDevice *dev)
+{
+        return dev->host_features & (1ULL << VIRTIO_F_VERSION_1) ? 1 : 0;
+}
+
 /* virtual css bus type */
 typedef struct VirtualCssBus {
     BusState parent_obj;
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 3826074..922b021 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -693,7 +693,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
         }
         cpu_physical_memory_read(ccw.cda, &revinfo, len);
         if (dev->revision >= 0 ||
-            revinfo.revision > VIRTIO_CCW_REV_MAX) {
+            revinfo.revision > virtio_ccw_rev_max(dev)) {
             ret = -ENOSYS;
             break;
         }