| Message ID | 1477607317-27817-3-git-send-email-duanj@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Jianjun Duan (duanj@linux.vnet.ibm.com) wrote: > 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(+) > > diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h > index d0e37b5..318a6f1 100644 > --- a/include/migration/vmstate.h > +++ b/include/migration/vmstate.h > @@ -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 > diff --git a/include/qemu/queue.h b/include/qemu/queue.h > index 342073f..16af127 100644 > --- a/include/qemu/queue.h > +++ b/include/qemu/queue.h > @@ -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 DUMB_Q_ENTRY DUMB_Q_ENTRY; > +typedef struct DUMB_Q DUMB_Q; > + > +struct DUMB_Q_ENTRY { > + QTAILQ_ENTRY(DUMB_Q_ENTRY) next; > +}; > + > +struct DUMB_Q { > + QTAILQ_HEAD(DUMB_Q_HEAD, DUMB_Q_ENTRY) head; > +}; OK, good we've got rid of the hard coded offsets; thanks! > +#define dumb_q ((DUMB_Q *) 0) > +#define dumb_qh ((typeof(dumb_q->head) *) 0) > +#define dumb_qe ((DUMB_Q_ENTRY *) 0) Note that 'dumb' and 'dummy' are completely different words; this is a dummy not a dumb. > +/* > + * Offsets of layout of a tail queue head. > + */ > +#define QTAILQ_FIRST_OFFSET ((size_t) &(QTAILQ_FIRST(dumb_qh))) Isn't that just offsetof(dumb_qh, tqh_first) ? > +#define QTAILQ_LAST_OFFSET (offsetof(typeof(dumb_q->head), tqh_last)) Similarly isnt't that just offsetof(DUMB_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(dumb_qe, next))) > +#define QTAILQ_PREV_OFFSET (offsetof(typeof(dumb_qe->next), tqe_prev)) Similar comments to the pair above. Dave P.S. I'm out next week, so please someone else jump in. > +/* > + * 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 */ > diff --git a/migration/trace-events b/migration/trace-events > index dfee75a..9a6ec59 100644 > --- a/migration/trace-events > +++ b/migration/trace-events > @@ -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) "" > diff --git a/migration/vmstate.c b/migration/vmstate.c > index d188afa..70e0472 100644 > --- a/migration/vmstate.c > +++ b/migration/vmstate.c > @@ -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, > +}; > -- > 1.9.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 10/28/2016 12:06 PM, Dr. David Alan Gilbert wrote: > * Jianjun Duan (duanj@linux.vnet.ibm.com) wrote: >> 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(+) >> >> diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h >> index d0e37b5..318a6f1 100644 >> --- a/include/migration/vmstate.h >> +++ b/include/migration/vmstate.h >> @@ -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 >> diff --git a/include/qemu/queue.h b/include/qemu/queue.h >> index 342073f..16af127 100644 >> --- a/include/qemu/queue.h >> +++ b/include/qemu/queue.h >> @@ -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 DUMB_Q_ENTRY DUMB_Q_ENTRY; >> +typedef struct DUMB_Q DUMB_Q; >> + >> +struct DUMB_Q_ENTRY { >> + QTAILQ_ENTRY(DUMB_Q_ENTRY) next; >> +}; >> + >> +struct DUMB_Q { >> + QTAILQ_HEAD(DUMB_Q_HEAD, DUMB_Q_ENTRY) head; >> +}; > > OK, good we've got rid of the hard coded offsets; thanks! > >> +#define dumb_q ((DUMB_Q *) 0) >> +#define dumb_qh ((typeof(dumb_q->head) *) 0) >> +#define dumb_qe ((DUMB_Q_ENTRY *) 0) > > Note that 'dumb' and 'dummy' are completely different words; > this is a dummy not a dumb. > OK. >> +/* >> + * Offsets of layout of a tail queue head. >> + */ >> +#define QTAILQ_FIRST_OFFSET ((size_t) &(QTAILQ_FIRST(dumb_qh))) > > Isn't that just offsetof(dumb_qh, tqh_first) ? Yes. But I don't want to depend on the inside of the type if it is possible. QTAILQ_FIRST is a defined access macro. > >> +#define QTAILQ_LAST_OFFSET (offsetof(typeof(dumb_q->head), tqh_last)) > > Similarly isnt't that just offsetof(DUMB_Q_HEAD, tqh_last) ? > Similarly, DUMB_Q_HEAD may not be a type name in the future. Thanks, Jianjun >> +/* >> + * 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(dumb_qe, next))) >> +#define QTAILQ_PREV_OFFSET (offsetof(typeof(dumb_qe->next), tqe_prev)) > > Similar comments to the pair above. > > Dave > P.S. I'm out next week, so please someone else jump in. > >> +/* >> + * 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 */ >> diff --git a/migration/trace-events b/migration/trace-events >> index dfee75a..9a6ec59 100644 >> --- a/migration/trace-events >> +++ b/migration/trace-events >> @@ -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) "" >> diff --git a/migration/vmstate.c b/migration/vmstate.c >> index d188afa..70e0472 100644 >> --- a/migration/vmstate.c >> +++ b/migration/vmstate.c >> @@ -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, >> +}; >> -- >> 1.9.1 >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index d0e37b5..318a6f1 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -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 diff --git a/include/qemu/queue.h b/include/qemu/queue.h index 342073f..16af127 100644 --- a/include/qemu/queue.h +++ b/include/qemu/queue.h @@ -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 DUMB_Q_ENTRY DUMB_Q_ENTRY; +typedef struct DUMB_Q DUMB_Q; + +struct DUMB_Q_ENTRY { + QTAILQ_ENTRY(DUMB_Q_ENTRY) next; +}; + +struct DUMB_Q { + QTAILQ_HEAD(DUMB_Q_HEAD, DUMB_Q_ENTRY) head; +}; + +#define dumb_q ((DUMB_Q *) 0) +#define dumb_qh ((typeof(dumb_q->head) *) 0) +#define dumb_qe ((DUMB_Q_ENTRY *) 0) + +/* + * Offsets of layout of a tail queue head. + */ +#define QTAILQ_FIRST_OFFSET ((size_t) &(QTAILQ_FIRST(dumb_qh))) +#define QTAILQ_LAST_OFFSET (offsetof(typeof(dumb_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(dumb_qe, next))) +#define QTAILQ_PREV_OFFSET (offsetof(typeof(dumb_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 */ diff --git a/migration/trace-events b/migration/trace-events index dfee75a..9a6ec59 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -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) "" diff --git a/migration/vmstate.c b/migration/vmstate.c index d188afa..70e0472 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -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(+)