* Juan Quintela (quint...@redhat.com) wrote: > "Dr. David Alan Gilbert" <dgilb...@redhat.com> wrote: > > * Juan Quintela (quint...@redhat.com) wrote: > >> "Dr. David Alan Gilbert (git)" <dgilb...@redhat.com> wrote: > >> > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > >> > > >> > Add migrate_send_rp_message to send a message from destination to source > >> > along the return path. > >> > (It uses a mutex to let it be called from multiple threads) > >> > Add migrate_send_rp_shut to send a 'shut' message to indicate > >> > the destination is finished with the RP. > >> > Add migrate_send_rp_ack to send a 'PONG' message in response to a PING > >> > Use it in the MSG_RP_PING handler > >> > > >> > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > >> > --- > >> > include/migration/migration.h | 17 ++++++++++++++++ > >> > migration/migration.c | 45 > >> > +++++++++++++++++++++++++++++++++++++++++++ > >> > migration/savevm.c | 2 +- > >> > trace-events | 1 + > >> > 4 files changed, 64 insertions(+), 1 deletion(-) > >> > > >> > diff --git a/include/migration/migration.h > >> > b/include/migration/migration.h > >> > index 65fe5db..36caab9 100644 > >> > --- a/include/migration/migration.h > >> > +++ b/include/migration/migration.h > >> > @@ -42,12 +42,20 @@ struct MigrationParams { > >> > bool shared; > >> > }; > >> > > >> > +/* Messages sent on the return path from destination to source */ > >> > +enum mig_rp_message_type { > >> > + MIG_RP_MSG_INVALID = 0, /* Must be 0 */ > >> > + MIG_RP_MSG_SHUT, /* sibling will not send any more RP > >> > messages */ > >> > + MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */ > >> > +}; > >> > + > >> > typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head; > >> > /* State for the incoming migration */ > >> > struct MigrationIncomingState { > >> > QEMUFile *file; > >> > > >> > QEMUFile *return_path; > >> > + QemuMutex rp_mutex; /* We send replies from multiple > >> > threads */ > >> > > >> > /* See savevm.c */ > >> > LoadStateEntry_Head loadvm_handlers; > >> > @@ -179,6 +187,15 @@ int migrate_compress_level(void); > >> > int migrate_compress_threads(void); > >> > int migrate_decompress_threads(void); > >> > > >> > +/* Sending on the return path - generic and then for each message type > >> > */ > >> > +void migrate_send_rp_message(MigrationIncomingState *mis, > >> > + enum mig_rp_message_type message_type, > >> > + uint16_t len, void *data); > >> > +void migrate_send_rp_shut(MigrationIncomingState *mis, > >> > + uint32_t value); > >> > +void migrate_send_rp_pong(MigrationIncomingState *mis, > >> > + uint32_t value); > >> > + > >> > void ram_control_before_iterate(QEMUFile *f, uint64_t flags); > >> > void ram_control_after_iterate(QEMUFile *f, uint64_t flags); > >> > void ram_control_load_hook(QEMUFile *f, uint64_t flags); > >> > diff --git a/migration/migration.c b/migration/migration.c > >> > index 295f15a..afb19a1 100644 > >> > --- a/migration/migration.c > >> > +++ b/migration/migration.c > >> > @@ -85,6 +85,7 @@ MigrationIncomingState > >> > *migration_incoming_state_new(QEMUFile* f) > >> > mis_current = g_malloc0(sizeof(MigrationIncomingState)); > >> > mis_current->file = f; > >> > QLIST_INIT(&mis_current->loadvm_handlers); > >> > + qemu_mutex_init(&mis_current->rp_mutex); > >> > > >> > return mis_current; > >> > } > >> > @@ -182,6 +183,50 @@ void process_incoming_migration(QEMUFile *f) > >> > qemu_coroutine_enter(co, f); > >> > } > >> > > >> > +/* > >> > + * Send a message on the return channel back to the source > >> > + * of the migration. > >> > + */ > >> > +void migrate_send_rp_message(MigrationIncomingState *mis, > >> > + enum mig_rp_message_type message_type, > >> > + uint16_t len, void *data) > >> > +{ > >> > + trace_migrate_send_rp_message((int)message_type, len); > >> > + qemu_mutex_lock(&mis->rp_mutex); > >> > + qemu_put_be16(mis->return_path, (unsigned int)message_type); > >> > + qemu_put_be16(mis->return_path, len); > >> if (len) { > >> > >> > + qemu_put_buffer(mis->return_path, data, len); > >> } > >> > >> > >> ? > >> > >> We check for zero sized command on control commands but not on > >> responses? > > > > Or should I remove the check in the control commands case? > > qemu_put_buffer looks like it's safe for size == 0 > > I would go for this just for consistence?
OK, check removed in both cases. Dave (Resend: I dropped the list off the first message) -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK