* [PATCH 1/2] migration: Add canary to VMSTATE_END_OF_LIST
2022-11-28 13:08 [PATCH 0/2] Put Canary End of List in VMSTATE Juan Quintela
@ 2022-11-28 13:08 ` Juan Quintela
2022-11-28 13:08 ` [PATCH 2/2] migration: Perform vmsd structure check during tests Juan Quintela
1 sibling, 0 replies; 4+ messages in thread
From: Juan Quintela @ 2022-11-28 13:08 UTC (permalink / raw)
To: qemu-devel
Cc: Juan Quintela, Dr. David Alan Gilbert, Peter Maydell,
Philippe Mathieu-Daudé
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
We fairly regularly forget VMSTATE_END_OF_LIST markers off descriptions;
given that the current check is only for ->name being NULL, sometimes
we get unlucky and the code apparently works and no one spots the error.
Explicitly add a flag, VMS_END that should be set, and assert it is
set during the traversal.
Note: This can't go in until we update the copy of vmstate.h in slirp.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/vmstate.h | 7 ++++++-
migration/savevm.c | 1 +
migration/vmstate.c | 2 ++
3 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index ad24aa1934..527ead2831 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -147,6 +147,9 @@ enum VMStateFlags {
* VMStateField.struct_version_id to tell which version of the
* structure we are referencing to use. */
VMS_VSTRUCT = 0x8000,
+
+ /* Marker for end of list */
+ VMS_END = 0x10000
};
typedef enum {
@@ -1161,7 +1164,9 @@ extern const VMStateInfo vmstate_info_qlist;
VMSTATE_UNUSED_BUFFER(_test, 0, _size)
#define VMSTATE_END_OF_LIST() \
- {}
+ { \
+ .flags = VMS_END, \
+ }
int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque, int version_id);
diff --git a/migration/savevm.c b/migration/savevm.c
index a0cdb714f7..3ad81359ab 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -585,6 +585,7 @@ static void dump_vmstate_vmsd(FILE *out_file,
field++;
first = false;
}
+ assert(field->flags == VMS_END);
fprintf(out_file, "\n%*s]", indent, "");
}
if (vmsd->subsections != NULL) {
diff --git a/migration/vmstate.c b/migration/vmstate.c
index 924494bda3..83ca4c7d3e 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -154,6 +154,7 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
}
field++;
}
+ assert(field->flags == VMS_END);
ret = vmstate_subsection_load(f, vmsd, opaque);
if (ret != 0) {
return ret;
@@ -408,6 +409,7 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
}
field++;
}
+ assert(field->flags == VMS_END);
if (vmdesc) {
json_writer_end_array(vmdesc);
--
2.38.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] migration: Perform vmsd structure check during tests
2022-11-28 13:08 [PATCH 0/2] Put Canary End of List in VMSTATE Juan Quintela
2022-11-28 13:08 ` [PATCH 1/2] migration: Add canary to VMSTATE_END_OF_LIST Juan Quintela
@ 2022-11-28 13:08 ` Juan Quintela
2022-11-28 13:38 ` Peter Maydell
1 sibling, 1 reply; 4+ messages in thread
From: Juan Quintela @ 2022-11-28 13:08 UTC (permalink / raw)
To: qemu-devel; +Cc: Juan Quintela, Dr. David Alan Gilbert, Peter Maydell
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/savevm.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/migration/savevm.c b/migration/savevm.c
index 3ad81359ab..653087f0bb 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;
@@ -804,6 +805,42 @@ 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 */
+ if (field->flags != VMS_END) {
+ error_report("VMSTATE not ending with VMS_END: %s", vmsd->name);
+ exit(-1);
+ }
+ }
+
+ 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,
@@ -849,6 +886,11 @@ 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;
--
2.38.1
^ permalink raw reply related [flat|nested] 4+ messages in thread