From patchwork Tue Dec 5 06:52:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 844607 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yrXnD4xyDz9s74 for ; Tue, 5 Dec 2017 18:05:03 +1100 (AEDT) Received: from localhost ([::1]:46885 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eM7Hp-0002Kz-Av for incoming@patchwork.ozlabs.org; Tue, 05 Dec 2017 02:05:01 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51521) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eM77k-0000TN-Kt for qemu-devel@nongnu.org; Tue, 05 Dec 2017 01:54:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eM77f-0003u4-PT for qemu-devel@nongnu.org; Tue, 05 Dec 2017 01:54:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38252) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eM77f-0003rv-GN for qemu-devel@nongnu.org; Tue, 05 Dec 2017 01:54:31 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 68110780D0; Tue, 5 Dec 2017 06:54:28 +0000 (UTC) Received: from xz-mi.nay.redhat.com (dhcp-14-111.nay.redhat.com [10.66.14.111]) by smtp.corp.redhat.com (Postfix) with ESMTP id CCFF162668; Tue, 5 Dec 2017 06:54:21 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Tue, 5 Dec 2017 14:52:59 +0800 Message-Id: <20171205065307.21853-21-peterx@redhat.com> In-Reply-To: <20171205065307.21853-1-peterx@redhat.com> References: <20171205065307.21853-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 05 Dec 2017 06:54:28 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v5 20/28] migration: synchronize dirty bitmap for resume X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrea Arcangeli , Juan Quintela , Alexey Perevalov , peterx@redhat.com, "Dr . David Alan Gilbert" Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" This patch implements the first part of core RAM resume logic for postcopy. ram_resume_prepare() is provided for the work. When the migration is interrupted by network failure, the dirty bitmap on the source side will be meaningless, because even the dirty bit is cleared, it is still possible that the sent page was lost along the way to destination. Here instead of continue the migration with the old dirty bitmap on source, we ask the destination side to send back its received bitmap, then invert it to be our initial dirty bitmap. The source side send thread will issue the MIG_CMD_RECV_BITMAP requests, once per ramblock, to ask for the received bitmap. On destination side, MIG_RP_MSG_RECV_BITMAP will be issued, along with the requested bitmap. Data will be received on the return-path thread of source, and the main migration thread will be notified when all the ramblock bitmaps are synchronized. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Peter Xu --- migration/migration.c | 2 ++ migration/migration.h | 1 + migration/ram.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ migration/trace-events | 4 ++++ 4 files changed, 54 insertions(+) diff --git a/migration/migration.c b/migration/migration.c index 40cb9a29cf..2305a08c26 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2839,6 +2839,7 @@ static void migration_instance_finalize(Object *obj) qemu_sem_destroy(&ms->pause_sem); qemu_sem_destroy(&ms->postcopy_pause_sem); qemu_sem_destroy(&ms->postcopy_pause_rp_sem); + qemu_sem_destroy(&ms->rp_state.rp_sem); } static void migration_instance_init(Object *obj) @@ -2870,6 +2871,7 @@ static void migration_instance_init(Object *obj) qemu_sem_init(&ms->postcopy_pause_sem, 0); qemu_sem_init(&ms->postcopy_pause_rp_sem, 0); + qemu_sem_init(&ms->rp_state.rp_sem, 0); } /* diff --git a/migration/migration.h b/migration/migration.h index 11fbfebba1..82dd7d9820 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -108,6 +108,7 @@ struct MigrationState QEMUFile *from_dst_file; QemuThread rp_thread; bool error; + QemuSemaphore rp_sem; } rp_state; double mbps; diff --git a/migration/ram.c b/migration/ram.c index 601fa47754..8fa47a0353 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -49,6 +49,7 @@ #include "qemu/rcu_queue.h" #include "migration/colo.h" #include "migration/block.h" +#include "savevm.h" /***********************************************************/ /* ram save/restore */ @@ -3056,6 +3057,38 @@ static bool ram_has_postcopy(void *opaque) return migrate_postcopy_ram(); } +/* Sync all the dirty bitmap with destination VM. */ +static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs) +{ + RAMBlock *block; + QEMUFile *file = s->to_dst_file; + int ramblock_count = 0; + + trace_ram_dirty_bitmap_sync_start(); + + RAMBLOCK_FOREACH(block) { + qemu_savevm_send_recv_bitmap(file, block->idstr); + trace_ram_dirty_bitmap_request(block->idstr); + ramblock_count++; + } + + trace_ram_dirty_bitmap_sync_wait(); + + /* Wait until all the ramblocks' dirty bitmap synced */ + while (ramblock_count--) { + qemu_sem_wait(&s->rp_state.rp_sem); + } + + trace_ram_dirty_bitmap_sync_complete(); + + return 0; +} + +static void ram_dirty_bitmap_reload_notify(MigrationState *s) +{ + qemu_sem_post(&s->rp_state.rp_sem); +} + /* * Read the received bitmap, revert it as the initial dirty bitmap. * This is only used when the postcopy migration is paused but wants @@ -3130,12 +3163,25 @@ int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *block) trace_ram_dirty_bitmap_reload_complete(block->idstr); + /* + * We succeeded to sync bitmap for current ramblock. If this is + * the last one to sync, we need to notify the main send thread. + */ + ram_dirty_bitmap_reload_notify(s); + ret = 0; out: free(le_bitmap); return ret; } +static int ram_resume_prepare(MigrationState *s, void *opaque) +{ + RAMState *rs = *(RAMState **)opaque; + + return ram_dirty_bitmap_sync_all(s, rs); +} + static SaveVMHandlers savevm_ram_handlers = { .save_setup = ram_save_setup, .save_live_iterate = ram_save_iterate, @@ -3147,6 +3193,7 @@ static SaveVMHandlers savevm_ram_handlers = { .save_cleanup = ram_save_cleanup, .load_setup = ram_load_setup, .load_cleanup = ram_load_cleanup, + .resume_prepare = ram_resume_prepare, }; void ram_mig_init(void) diff --git a/migration/trace-events b/migration/trace-events index eadabf03e8..804f18d492 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -82,8 +82,12 @@ ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x" ram_postcopy_send_discard_bitmap(void) "" ram_save_page(const char *rbname, uint64_t offset, void *host) "%s: offset: 0x%" PRIx64 " host: %p" ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: 0x%zx len: 0x%zx" +ram_dirty_bitmap_request(char *str) "%s" ram_dirty_bitmap_reload_begin(char *str) "%s" ram_dirty_bitmap_reload_complete(char *str) "%s" +ram_dirty_bitmap_sync_start(void) "" +ram_dirty_bitmap_sync_wait(void) "" +ram_dirty_bitmap_sync_complete(void) "" # migration/migration.c await_return_path_close_on_source_close(void) ""