From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59044) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ddECO-0007lR-TK for qemu-devel@nongnu.org; Thu, 03 Aug 2017 07:21:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ddECL-0008NS-4V for qemu-devel@nongnu.org; Thu, 03 Aug 2017 07:21:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52376) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ddECK-0008Md-Rs for qemu-devel@nongnu.org; Thu, 03 Aug 2017 07:21:49 -0400 Date: Thu, 3 Aug 2017 12:21:41 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170803112141.GF2076@work-vm> References: <1501229198-30588-1-git-send-email-peterx@redhat.com> <1501229198-30588-25-git-send-email-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1501229198-30588-25-git-send-email-peterx@redhat.com> Subject: Re: [Qemu-devel] [RFC 24/29] migration: new message MIG_RP_MSG_RESUME_ACK List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, Laurent Vivier , Alexey Perevalov , Juan Quintela , Andrea Arcangeli * Peter Xu (peterx@redhat.com) wrote: > Creating new message to reply for MIG_CMD_POSTCOPY_RESUME. One uint32_t > is used as payload to let the source know whether destination is ready > to continue the migration. > > Signed-off-by: Peter Xu > --- > migration/migration.c | 37 +++++++++++++++++++++++++++++++++++++ > migration/migration.h | 1 + > migration/savevm.c | 3 ++- > migration/trace-events | 1 + > 4 files changed, 41 insertions(+), 1 deletion(-) > > diff --git a/migration/migration.c b/migration/migration.c > index c2b85ac..62f91ce 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -93,6 +93,7 @@ enum mig_rp_message_type { > MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */ > MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */ > MIG_RP_MSG_RECV_BITMAP, /* send recved_bitmap back to source */ > + MIG_RP_MSG_RESUME_ACK, /* tell source that we are ready to resume */ > > MIG_RP_MSG_MAX > }; > @@ -484,6 +485,14 @@ void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis, > trace_migrate_send_rp_recv_bitmap(block_name, res); > } > > +void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value) > +{ > + uint32_t buf; > + > + buf = cpu_to_be32(value); > + migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf); > +} > + > MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) > { > MigrationCapabilityStatusList *head = NULL; > @@ -1595,6 +1604,7 @@ static struct rp_cmd_args { > [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, > [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, > [MIG_RP_MSG_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" }, > + [MIG_RP_MSG_RESUME_ACK] = { .len = 4, .name = "RESUME_ACK" }, > [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, > }; > > @@ -1652,6 +1662,25 @@ static int migrate_handle_rp_recv_bitmap(MigrationState *s, char *block_name) > return ram_dirty_bitmap_reload(s, block); > } > > +static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value) > +{ > + trace_source_return_path_thread_resume_ack(value); > + > + /* > + * Currently value will always be one. It can be used in the > + * future to notify source that destination cannot continue. > + */ > + assert(value == 1); Again I prefer the routine to fail than to assert. Maybe it's worth having a constant rather than the magic 1. > + /* Now both sides are active. */ > + migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_RECOVER, > + MIGRATION_STATUS_POSTCOPY_ACTIVE); > + > + /* TODO: notify send thread that time to continue send pages */ > + > + return 0; > +} > + > /* > * Handles messages sent on the return path towards the source VM > * > @@ -1771,6 +1800,14 @@ retry: > } > break; > > + case MIG_RP_MSG_RESUME_ACK: > + tmp32 = ldl_be_p(buf); > + if (migrate_handle_rp_resume_ack(ms, tmp32)) { > + mark_source_rp_bad(ms); > + goto out; > + } > + break; > + > default: > break; > } > diff --git a/migration/migration.h b/migration/migration.h > index 4d38308..2a3f905 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -206,5 +206,6 @@ int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname, > ram_addr_t start, size_t len); > void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis, > char *block_name); > +void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value); > > #endif > diff --git a/migration/savevm.c b/migration/savevm.c > index 2e330bc..02a67ac 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -1690,7 +1690,8 @@ static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis) > MIGRATION_STATUS_POSTCOPY_ACTIVE); > qemu_sem_post(&mis->postcopy_pause_sem_fault); > > - /* TODO: Tell source that "we are ready" */ > + /* Tell source that "we are ready" */ > + migrate_send_rp_resume_ack(mis, 1); > > return 0; > } > diff --git a/migration/trace-events b/migration/trace-events > index 04dd9d8..0b43fec 100644 > --- a/migration/trace-events > +++ b/migration/trace-events > @@ -116,6 +116,7 @@ source_return_path_thread_entry(void) "" > source_return_path_thread_loop_top(void) "" > source_return_path_thread_pong(uint32_t val) "%x" > source_return_path_thread_shut(uint32_t val) "%x" > +source_return_path_thread_resume_ack(uint32_t v) "%"PRIu32 > migrate_global_state_post_load(const char *state) "loaded state: %s" > migrate_global_state_pre_save(const char *state) "saved state: %s" > migration_thread_low_pending(uint64_t pending) "%" PRIu64 > -- > 2.7.4 Dave > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK