From: "Maciej S. Szmigiero" <maciej.szmigi...@oracle.com> These SaveVMHandlers allow device to provide its own asynchronous transmission of the remaining data at the end of a precopy phase.
In this use case the save_live_complete_precopy_begin handler is supposed to start such transmission (for example, by launching appropriate threads) while the save_live_complete_precopy_end handler is supposed to wait until such transfer has finished (for example, until the sending threads have exited). Signed-off-by: Maciej S. Szmigiero <maciej.szmigi...@oracle.com> --- include/migration/register.h | 34 ++++++++++++++++++++++++++++++++++ migration/savevm.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+) diff --git a/include/migration/register.h b/include/migration/register.h index f60e797894e5..f7b3df799991 100644 --- a/include/migration/register.h +++ b/include/migration/register.h @@ -103,6 +103,40 @@ typedef struct SaveVMHandlers { */ int (*save_live_complete_precopy)(QEMUFile *f, void *opaque); + /** + * @save_live_complete_precopy_begin + * + * Called at the end of a precopy phase, before all @save_live_complete_precopy + * handlers. The handler might, for example, arrange for device-specific + * asynchronous transmission of the remaining data. When postcopy is enabled, + * devices that support postcopy will skip this step. + * + * @f: QEMUFile where the handler can synchronously send data before returning + * @idstr: this device section idstr + * @instance_id: this device section instance_id + * @opaque: data pointer passed to register_savevm_live() + * + * Returns zero to indicate success and negative for error + */ + int (*save_live_complete_precopy_begin)(QEMUFile *f, + char *idstr, uint32_t instance_id, + void *opaque); + /** + * @save_live_complete_precopy_end + * + * Called at the end of a precopy phase, after all @save_live_complete_precopy + * handlers. The handler might, for example, wait for the asynchronous + * transmission started by the @save_live_complete_precopy_begin handler + * to complete. When postcopy is enabled, devices that support postcopy will + * skip this step. + * + * @f: QEMUFile where the handler can synchronously send data before returning + * @opaque: data pointer passed to register_savevm_live() + * + * Returns zero to indicate success and negative for error + */ + int (*save_live_complete_precopy_end)(QEMUFile *f, void *opaque); + /* This runs both outside and inside the BQL. */ /** diff --git a/migration/savevm.c b/migration/savevm.c index c621f2359ba3..56fb1c4c2563 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1494,6 +1494,27 @@ int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy) SaveStateEntry *se; int ret; + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + if (!se->ops || (in_postcopy && se->ops->has_postcopy && + se->ops->has_postcopy(se->opaque)) || + !se->ops->save_live_complete_precopy_begin) { + continue; + } + + save_section_header(f, se, QEMU_VM_SECTION_END); + + ret = se->ops->save_live_complete_precopy_begin(f, + se->idstr, se->instance_id, + se->opaque); + + save_section_footer(f, se); + + if (ret < 0) { + qemu_file_set_error(f, ret); + return -1; + } + } + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { if (!se->ops || (in_postcopy && se->ops->has_postcopy && @@ -1525,6 +1546,20 @@ int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy) end_ts_each - start_ts_each); } + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + if (!se->ops || (in_postcopy && se->ops->has_postcopy && + se->ops->has_postcopy(se->opaque)) || + !se->ops->save_live_complete_precopy_end) { + continue; + } + + ret = se->ops->save_live_complete_precopy_end(f, se->opaque); + if (ret < 0) { + qemu_file_set_error(f, ret); + return -1; + } + } + trace_vmstate_downtime_checkpoint("src-iterable-saved"); return 0;