From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50163) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5GEH-0001Wi-7c for qemu-devel@nongnu.org; Wed, 17 Jun 2015 12:30:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5GEF-0006dp-SW for qemu-devel@nongnu.org; Wed, 17 Jun 2015 12:30:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46452) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5GEF-0006cs-Ie for qemu-devel@nongnu.org; Wed, 17 Jun 2015 12:30:19 -0400 From: Juan Quintela In-Reply-To: <1434450415-11339-15-git-send-email-dgilbert@redhat.com> (David Alan Gilbert's message of "Tue, 16 Jun 2015 11:26:27 +0100") References: <1434450415-11339-1-git-send-email-dgilbert@redhat.com> <1434450415-11339-15-git-send-email-dgilbert@redhat.com> Date: Wed, 17 Jun 2015 18:30:16 +0200 Message-ID: <877fr247s7.fsf@neno.neno> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH v7 14/42] Return path: Send responses from destination to source Reply-To: quintela@redhat.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" 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 "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? > + 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