From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51003) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z61Fd-0004rD-Jc for qemu-devel@nongnu.org; Fri, 19 Jun 2015 14:42:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z61FZ-00014I-AW for qemu-devel@nongnu.org; Fri, 19 Jun 2015 14:42:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44333) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z61FZ-000141-3h for qemu-devel@nongnu.org; Fri, 19 Jun 2015 14:42:49 -0400 Date: Fri, 19 Jun 2015 19:42:42 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20150619184241.GM2147@work-vm> References: <1434450415-11339-1-git-send-email-dgilbert@redhat.com> <1434450415-11339-15-git-send-email-dgilbert@redhat.com> <877fr247s7.fsf@neno.neno> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <877fr247s7.fsf@neno.neno> Subject: Re: [Qemu-devel] [PATCH v7 14/42] Return path: Send responses from destination to source List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juan Quintela Cc: aarcange@redhat.com, yamahata@private.email.ne.jp, liang.z.li@intel.com, qemu-devel@nongnu.org, luis@cs.umu.se, amit.shah@redhat.com, pbonzini@redhat.com, david@gibson.dropbear.id.au * Juan Quintela (quintela@redhat.com) wrote: > "Dr. David Alan Gilbert (git)" wrote: > > From: "Dr. David Alan Gilbert" > > > > 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 > > --- > > 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 Dave > > > + 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. 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 a995014..d424c2a 100644 > > --- a/migration/savevm.c > > +++ b/migration/savevm.c > > @@ -1071,7 +1071,7 @@ 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 5967fdf..5738e3f 100644 > > --- a/trace-events > > +++ b/trace-events > > @@ -1399,6 +1399,7 @@ 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 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK