[Qemu-devel] [PATCH 2/2] virtio-ccw: assure be accesses for set-revision

[Cornelia Huck <cornelia.huck@de.ibm.com>]

All fields in structures transmitted by ccws are big endian; assure
we handle them as such for the set-revision ccw as well.

Should be merged into "s390x/virtio-ccw: add virtio set-revision call".

CC: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 hw/s390x/virtio-ccw.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 60f8a14..a64f116 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -687,7 +687,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
         break;
     case CCW_CMD_SET_VIRTIO_REV:
         len = sizeof(revinfo);
-        if (ccw.count < len || (check_len && ccw.count > len)) {
+        if (ccw.count < sizeof(revinfo)) {
             ret = -EINVAL;
             break;
         }
@@ -695,7 +695,18 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
             ret = -EFAULT;
             break;
         }
-        cpu_physical_memory_read(ccw.cda, &revinfo, len);
+        revinfo.revision = lduw_be_phys(&address_space_memory, ccw.cda);
+        revinfo.length = lduw_be_phys(&address_space_memory,
+                                   ccw.cda + sizeof(revinfo.revision));
+        if (ccw.count < len + revinfo.length ||
+            (check_len && ccw.count > len + revinfo.length)) {
+            ret = -EINVAL;
+            break;
+        }
+        /*
+         * Once we start to support revisions with additional data, we'll
+         * need to fetch it here. Nothing to do for now, though.
+         */
         if (dev->revision >= 0 ||
             revinfo.revision > virtio_ccw_rev_max(dev)) {
             ret = -ENOSYS;
-- 
2.1.4