From 6decec931149ae50d84e2b264bf93f3676d5b3f9 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Thu, 5 Nov 2015 18:10:47 +0000 Subject: [PATCH] Return path: Send responses from destination to source 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 Reviewed-by: Amit Shah Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- include/migration/migration.h | 19 +++++++++++++++ migration/migration.c | 45 +++++++++++++++++++++++++++++++++++ migration/savevm.c | 2 +- trace-events | 1 + 4 files changed, 66 insertions(+), 1 deletion(-) diff --git a/include/migration/migration.h b/include/migration/migration.h index 98a6d079fd..3ce3fda6b7 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -43,12 +43,22 @@ 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 ) */ + + MIG_RP_MSG_MAX +}; + typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head; /* State for the incoming migration */ struct MigrationIncomingState { QEMUFile *from_src_file; QEMUFile *to_src_file; + QemuMutex rp_mutex; /* We send replies from multiple threads */ /* See savevm.c */ LoadStateEntry_Head loadvm_handlers; @@ -181,6 +191,15 @@ int migrate_compress_threads(void); int migrate_decompress_threads(void); bool migrate_use_events(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, void *data); diff --git a/migration/migration.c b/migration/migration.c index bb7dcb9b06..8380e2f2d1 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -97,6 +97,7 @@ MigrationIncomingState *migration_incoming_state_new(QEMUFile* f) mis_current = g_new0(MigrationIncomingState, 1); mis_current->from_src_file = f; QLIST_INIT(&mis_current->loadvm_handlers); + qemu_mutex_init(&mis_current->rp_mutex); return mis_current; } @@ -344,6 +345,50 @@ 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->to_src_file, (unsigned int)message_type); + qemu_put_be16(mis->to_src_file, len); + qemu_put_buffer(mis->to_src_file, data, len); + qemu_fflush(mis->to_src_file); + qemu_mutex_unlock(&mis->rp_mutex); +} + +/* + * Send a 'SHUT' message on the return channel with the given value + * to indicate that we've finished with the RP. Non-0 value indicates + * error. + */ +void migrate_send_rp_shut(MigrationIncomingState *mis, + uint32_t value) +{ + uint32_t buf; + + buf = cpu_to_be32(value); + migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf); +} + +/* + * Send a 'PONG' message on the return channel with the given value + * (normally in response to a 'PING') + */ +void migrate_send_rp_pong(MigrationIncomingState *mis, + uint32_t value) +{ + uint32_t buf; + + buf = cpu_to_be32(value); + migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf); +} + /* amount of nanoseconds we are willing to wait for migration to be down. * the choice of nanoseconds is because it is the maximum resolution that * get_clock() can achieve. It is an internal measure. All user-visible diff --git a/migration/savevm.c b/migration/savevm.c index d47c55b61c..1ffe7b0a57 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1103,7 +1103,7 @@ static int loadvm_process_command(QEMUFile *f) tmp32); return -1; } - /* migrate_send_rp_pong(mis, tmp32); TODO: gets added later */ + migrate_send_rp_pong(mis, tmp32); break; } diff --git a/trace-events b/trace-events index 500f1e3936..ca5909bd08 100644 --- a/trace-events +++ b/trace-events @@ -1431,6 +1431,7 @@ migrate_fd_cleanup(void) "" migrate_fd_error(void) "" migrate_fd_cancel(void) "" migrate_pending(uint64_t size, uint64_t max) "pending size %" PRIu64 " max %" PRIu64 +migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d" migrate_transferred(uint64_t tranferred, uint64_t time_spent, double bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %g max_size %" PRId64 migrate_state_too_big(void) "" migrate_global_state_post_load(const char *state) "loaded state: %s"