iotests: Skip 211 on insufficient memory

VDI keeps the whole bitmap in memory, and the maximum size (which is
tested here) is 2 GB.  This may not be available on all machines, and it
rarely is available when running a 32 bit build.

Fix this by making VM.run_job() return the error string if an error
occurred, and checking whether that contains "Could not allocate bmap"
in 211.  If so, the test is skipped.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190218180646.30282-1-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

tests/qemu-iotests/211

@@ -32,7 +32,9 @@ def blockdev_create(vm, options):
 
     if 'return' in result:
         assert result['return'] == {}
-        vm.run_job('job0')
+        error = vm.run_job('job0')
+        if error and 'Could not allocate bmap' in error:
+            iotests.notrun('Insufficient memory')
     iotests.log("")
 
 with iotests.FilePath('t.vdi') as disk_path, \

tests/qemu-iotests/iotests.py

@@ -532,7 +532,9 @@ class VM(qtest.QEMUQtestMachine):
         log(result, filters, indent=indent)
         return result
 
+    # Returns None on success, and an error string on failure
     def run_job(self, job, auto_finalize=True, auto_dismiss=False):
+        error = None
         while True:
             for ev in self.get_qmp_events_filtered(wait=True):
                 if ev['event'] == 'JOB_STATUS_CHANGE':
@@ -541,13 +543,14 @@ class VM(qtest.QEMUQtestMachine):
                         result = self.qmp('query-jobs')
                         for j in result['return']:
                             if j['id'] == job:
+                                error = j['error']
                                 log('Job failed: %s' % (j['error']))
                     elif status == 'pending' and not auto_finalize:
                         self.qmp_log('job-finalize', id=job)
                     elif status == 'concluded' and not auto_dismiss:
                         self.qmp_log('job-dismiss', id=job)
                     elif status == 'null':
-                        return
+                        return error
                 else:
                     iotests.log(ev)