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 +++++++++++++++++++++++++++++++++++++++++++
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 e2e251d..6300ec1 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -41,6 +41,13 @@ 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 struct MigrationState MigrationState;
/* State for the incoming migration */
@@ -48,6 +55,7 @@ struct MigrationIncomingState {
QEMUFile *file;
QEMUFile *return_path;
+ QemuMutex rp_mutex; /* We send replies from multiple threads */
};
MigrationIncomingState *migration_incoming_get_current(void);
@@ -164,6 +172,15 @@ int64_t migrate_xbzrle_cache_size(void);
int64_t xbzrle_cache_resize(int64_t new_size);
+/* 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 872d1e1..db9471d 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -70,6 +70,7 @@ MigrationIncomingState
*migration_incoming_state_new(QEMUFile* f)
{
mis_current = g_malloc0(sizeof(MigrationIncomingState));
mis_current->file = f;
+ qemu_mutex_init(&mis_current->rp_mutex);
return mis_current;
}
@@ -162,6 +163,50 @@ 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);
+ qemu_put_buffer(mis->return_path, data, len);
+ qemu_fflush(mis->return_path);
+ 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. None-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/savevm.c b/savevm.c
index 4dc8f06..f6b8b90 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1016,7 +1016,7 @@ 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;
default:
diff --git a/trace-events b/trace-events
index 0f74836..9f0a071 100644
--- a/trace-events
+++ b/trace-events
@@ -1383,6 +1383,7 @@ 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
# migration/rdma.c
--
2.1.0
