[Qemu-devel] [PATCH STABLE 0.14 7/9] qed: Report error for unsupported features

[Kevin Wolf <kwolf@redhat.com>]

Instead of just returning -ENOTSUP, generate a more detailed error.

Unfortunately we don't have a helpful text for features that we don't know yet,
so just print the feature mask. It might be useful at least if someone asks for
help.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
(cherry picked from commit 10b758e85c9b38b4b370cff81435f6ed26024a26)
---
 block/qed.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/block/qed.c b/block/qed.c
index 3273448..75ae244 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -14,6 +14,7 @@
 
 #include "trace.h"
 #include "qed.h"
+#include "qerror.h"
 
 static void qed_aio_cancel(BlockDriverAIOCB *blockacb)
 {
@@ -311,7 +312,13 @@ static int bdrv_qed_open(BlockDriverState *bs, int flags)
         return -EINVAL;
     }
     if (s->header.features & ~QED_FEATURE_MASK) {
-        return -ENOTSUP; /* image uses unsupported feature bits */
+        /* image uses unsupported feature bits */
+        char buf[64];
+        snprintf(buf, sizeof(buf), "%" PRIx64,
+            s->header.features & ~QED_FEATURE_MASK);
+        qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+            bs->device_name, "QED", buf);
+        return -ENOTSUP;
     }
     if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
         return -EINVAL;
-- 
1.7.2.3