From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Perform a check on vmsd structures during test runs in the hope
of catching any missing terminators and other simple screwups.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/savevm.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/migration/savevm.c b/migration/savevm.c
index 8077393d11..97a4471220 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -66,6 +66,7 @@
 #include "net/announce.h"
 #include "qemu/yank.h"
 #include "yank_functions.h"
+#include "sysemu/qtest.h"
 
 const unsigned int postcopy_ram_discard_version;
 
@@ -839,6 +840,39 @@ void unregister_savevm(VMStateIf *obj, const char *idstr, void *opaque)
     }
 }
 
+/*
+ * Perform some basic checks on vmsd's at registration
+ * time.
+ */
+static void vmstate_check(const VMStateDescription *vmsd)
+{
+    const VMStateField *field = vmsd->fields;
+    const VMStateDescription **subsection = vmsd->subsections;
+
+    if (field) {
+        while (field->name) {
+            if (field->flags & (VMS_STRUCT | VMS_VSTRUCT)) {
+                /* Recurse to sub structures */
+                vmstate_check(field->vmsd);
+            }
+            /* Carry on */
+            field++;
+        }
+        /* Check for the end of field list canary */
+        assert(field->flags == VMS_END);
+    }
+
+    while (subsection && *subsection) {
+        /*
+         * The name of a subsection should start with the name of the
+         * current object.
+         */
+        assert(!strncmp(vmsd->name, (*subsection)->name, strlen(vmsd->name)));
+        vmstate_check(*subsection);
+        subsection++;
+    }
+}
+
 int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id,
                                    const VMStateDescription *vmsd,
                                    void *opaque, int alias_id,
@@ -884,6 +918,11 @@ int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id,
     } else {
         se->instance_id = instance_id;
     }
+
+    /* Perform a recursive sanity check during the test runs */
+    if (qtest_enabled()) {
+        vmstate_check(vmsd);
+    }
     assert(!se->compat || se->instance_id == 0);
     savevm_state_handler_insert(se);
     return 0;
-- 
2.34.1

On Thu, 13 Jan 2022 at 19:45, Dr. David Alan Gilbert (git)
<dgilbert@redhat.com> wrote:
>
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> Perform a check on vmsd structures during test runs in the hope
> of catching any missing terminators and other simple screwups.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  migration/savevm.c | 39 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> Perform a check on vmsd structures during test runs in the hope
> of catching any missing terminators and other simple screwups.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>

queued.

* Juan Quintela (quintela@redhat.com) wrote:
> "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >
> > Perform a check on vmsd structures during test runs in the hope
> > of catching any missing terminators and other simple screwups.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> 
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> 
> queued.

Careful; I think that'll break with slirp until libslirp gets updated
first.

Dave

-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
>> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>> >
>> > Perform a check on vmsd structures during test runs in the hope
>> > of catching any missing terminators and other simple screwups.
>> >
>> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> 
>> Reviewed-by: Juan Quintela <quintela@redhat.com>
>> 
>> queued.
>
> Careful; I think that'll break with slirp until libslirp gets updated
> first.

As expected, it broke it.

I resend the PULL request wihtout that two patches.

Once that we are here, how it is that make check didn't catch this?

Later, Juan.