@@ -251,6 +251,7 @@ extern const VMStateInfo vmstate_info_timer;
extern const VMStateInfo vmstate_info_buffer;
extern const VMStateInfo vmstate_info_unused_buffer;
extern const VMStateInfo vmstate_info_bitmap;
+extern const VMStateInfo vmstate_info_qtailq;
#define type_check_2darray(t1,t2,n,m) ((t1(*)[n][m])0 - (t2*)0)
#define type_check_array(t1,t2,n) ((t1(*)[n])0 - (t2*)0)
@@ -662,6 +663,25 @@ extern const VMStateInfo vmstate_info_bitmap;
.offset = offsetof(_state, _field), \
}
+/* For QTAILQ that need customized handling.
+ * Target QTAILQ needs be properly initialized.
+ * _type: type of QTAILQ element
+ * _next: name of QTAILQ entry field in QTAILQ element
+ * _vmsd: VMSD for QTAILQ element
+ * size: size of QTAILQ element
+ * start: offset of QTAILQ entry in QTAILQ element
+ */
+#define VMSTATE_QTAILQ_V(_field, _state, _version, _vmsd, _type, _next) \
+{ \
+ .name = (stringify(_field)), \
+ .version_id = (_version), \
+ .vmsd = &(_vmsd), \
+ .size = sizeof(_type), \
+ .info = &vmstate_info_qtailq, \
+ .offset = offsetof(_state, _field), \
+ .start = offsetof(_type, _next), \
+}
+
/* _f : field name
_f_n : num of elements field_name
_n : num of elements
@@ -438,4 +438,65 @@ struct { \
#define QTAILQ_PREV(elm, headname, field) \
(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
+#define field_at_offset(base, offset, type) \
+ ((type) (((char *) (base)) + (offset)))
+
+typedef struct DUMMY_Q_ENTRY DUMMY_Q_ENTRY;
+typedef struct DUMMY_Q DUMMY_Q;
+
+struct DUMMY_Q_ENTRY {
+ QTAILQ_ENTRY(DUMMY_Q_ENTRY) next;
+};
+
+struct DUMMY_Q {
+ QTAILQ_HEAD(DUMMY_Q_HEAD, DUMMY_Q_ENTRY) head;
+};
+
+#define dummy_q ((DUMMY_Q *) 0)
+#define dummy_qh ((typeof(dummy_q->head) *) 0)
+#define dummy_qe ((DUMMY_Q_ENTRY *) 0)
+
+/*
+ * Offsets of layout of a tail queue head.
+ */
+#define QTAILQ_FIRST_OFFSET ((size_t) &(QTAILQ_FIRST(dummy_qh)))
+#define QTAILQ_LAST_OFFSET (offsetof(typeof(dummy_q->head), tqh_last))
+/*
+ * Raw access of elements of a tail queue
+ */
+#define QTAILQ_RAW_FIRST(head) \
+ (*field_at_offset(head, QTAILQ_FIRST_OFFSET, void **))
+#define QTAILQ_RAW_LAST(head) \
+ (*field_at_offset(head, QTAILQ_LAST_OFFSET, void ***))
+
+/*
+ * Offsets of layout of a tail queue element.
+ */
+#define QTAILQ_NEXT_OFFSET ((size_t) (&QTAILQ_NEXT(dummy_qe, next)))
+#define QTAILQ_PREV_OFFSET (offsetof(typeof(dummy_qe->next), tqe_prev))
+
+/*
+ * Raw access of elements of a tail entry
+ */
+#define QTAILQ_RAW_NEXT(elm, entry) \
+ (*field_at_offset(elm, entry + QTAILQ_NEXT_OFFSET, void **))
+#define QTAILQ_RAW_PREV(elm, entry) \
+ (*field_at_offset(elm, entry + QTAILQ_PREV_OFFSET, void ***))
+/*
+ * Tail queue tranversal using pointer arithmetic.
+ */
+#define QTAILQ_RAW_FOREACH(elm, head, entry) \
+ for ((elm) = QTAILQ_RAW_FIRST(head); \
+ (elm); \
+ (elm) = QTAILQ_RAW_NEXT(elm, entry))
+/*
+ * Tail queue insertion using pointer arithmetic.
+ */
+#define QTAILQ_RAW_INSERT_TAIL(head, elm, entry) do { \
+ QTAILQ_RAW_NEXT(elm, entry) = NULL; \
+ QTAILQ_RAW_PREV(elm, entry) = QTAILQ_RAW_LAST(head); \
+ *QTAILQ_RAW_LAST(head) = (elm); \
+ QTAILQ_RAW_LAST(head) = &QTAILQ_RAW_NEXT(elm, entry); \
+} while (/*CONSTCOND*/0)
+
#endif /* QEMU_SYS_QUEUE_H */
@@ -52,6 +52,10 @@ vmstate_n_elems(const char *name, int n_elems) "%s: %d"
vmstate_subsection_load(const char *parent) "%s"
vmstate_subsection_load_bad(const char *parent, const char *sub, const char *sub2) "%s: %s/%s"
vmstate_subsection_load_good(const char *parent) "%s"
+get_qtailq(const char *name, int version_id) "%s v%d"
+get_qtailq_end(const char *name, const char *reason, int val) "%s %s/%d"
+put_qtailq(const char *name, int version_id) "%s v%d"
+put_qtailq_end(const char *name, const char *reason) "%s %s"
# migration/qemu-file.c
qemu_file_fclose(void) ""
@@ -5,6 +5,7 @@
#include "migration/vmstate.h"
#include "qemu/bitops.h"
#include "qemu/error-report.h"
+#include "qemu/queue.h"
#include "trace.h"
#include "migration/qjson.h"
@@ -948,3 +949,69 @@ const VMStateInfo vmstate_info_bitmap = {
.get = get_bitmap,
.put = put_bitmap,
};
+
+/* get for QTAILQ
+ * meta data about the QTAILQ is encoded in a VMStateField structure
+ */
+static int get_qtailq(QEMUFile *f, void *pv, size_t unused_size,
+ VMStateField *field)
+{
+ int ret = 0;
+ const VMStateDescription *vmsd = field->vmsd;
+ /* size of a QTAILQ element */
+ size_t size = field->size;
+ /* offset of the QTAILQ entry in a QTAILQ element */
+ size_t entry_offset = field->start;
+ int version_id = field->version_id;
+ void *elm;
+
+ trace_get_qtailq(vmsd->name, version_id);
+ if (version_id > vmsd->version_id) {
+ error_report("%s %s", vmsd->name, "too new");
+ trace_get_qtailq_end(vmsd->name, "too new", -EINVAL);
+
+ return -EINVAL;
+ }
+ if (version_id < vmsd->minimum_version_id) {
+ error_report("%s %s", vmsd->name, "too old");
+ trace_get_qtailq_end(vmsd->name, "too old", -EINVAL);
+ return -EINVAL;
+ }
+
+ while (qemu_get_byte(f)) {
+ elm = g_malloc(size);
+ ret = vmstate_load_state(f, vmsd, elm, version_id);
+ if (ret) {
+ return ret;
+ }
+ QTAILQ_RAW_INSERT_TAIL(pv, elm, entry_offset);
+ }
+
+ trace_get_qtailq_end(vmsd->name, "end", ret);
+ return ret;
+}
+
+/* put for QTAILQ */
+static void put_qtailq(QEMUFile *f, void *pv, size_t unused_size,
+ VMStateField *field, QJSON *vmdesc)
+{
+ const VMStateDescription *vmsd = field->vmsd;
+ /* offset of the QTAILQ entry in a QTAILQ element*/
+ size_t entry_offset = field->start;
+ void *elm;
+
+ trace_put_qtailq(vmsd->name, vmsd->version_id);
+
+ QTAILQ_RAW_FOREACH(elm, pv, entry_offset) {
+ qemu_put_byte(f, true);
+ vmstate_save_state(f, vmsd, elm, vmdesc);
+ }
+ qemu_put_byte(f, false);
+
+ trace_put_qtailq_end(vmsd->name, "end");
+}
+const VMStateInfo vmstate_info_qtailq = {
+ .name = "qtailq",
+ .get = get_qtailq,
+ .put = put_qtailq,
+};
Currently we cannot directly transfer a QTAILQ instance because of the limitation in the migration code. Here we introduce an approach to transfer such structures. We created VMStateInfo vmstate_info_qtailq for QTAILQ. Similar VMStateInfo can be created for other data structures such as list. This approach will be used to transfer pending_events and ccs_list in spapr state. We also create some macros in qemu/queue.h to access a QTAILQ using pointer arithmetic. This ensures that we do not depend on the implementation details about QTAILQ in the migration code. Signed-off-by: Jianjun Duan <duanj@linux.vnet.ibm.com> --- include/migration/vmstate.h | 20 ++++++++++++++ include/qemu/queue.h | 61 +++++++++++++++++++++++++++++++++++++++++ migration/trace-events | 4 +++ migration/vmstate.c | 67 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 152 insertions(+)