[PATCH 7/7] migration: Provide explicit error message for file shutdowns

[Peter Xu <peterx@redhat.com>]

Provide an explicit reason for qemu_file_shutdown()s, which can be
displayed in query-migrate when used.

This will make e.g. migrate-pause to display explicit error descriptions,
from:

"error-desc": "Channel error: Input/output error"

To:

"error-desc": "Channel is explicitly shutdown by the user"

in query-migrate.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/qemu-file.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 419b4092e7..ff605027de 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -87,7 +87,10 @@ int qemu_file_shutdown(QEMUFile *f)
      *      --> guest crash!
      */
     if (!f->last_error) {
-        qemu_file_set_error(f, -EIO);
+        Error *err = NULL;
+
+        error_setg(&err, "Channel is explicitly shutdown by the user");
+        qemu_file_set_error_obj(f, -EIO, err);
     }
 
     if (!qio_channel_has_feature(f->ioc,
-- 
2.41.0