From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fPLE6-0000B4-2m for qemu-devel@nongnu.org; Sun, 03 Jun 2018 01:06:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fPLE5-0000qO-1u for qemu-devel@nongnu.org; Sun, 03 Jun 2018 01:06:46 -0400 Received: from mail-pl0-x242.google.com ([2607:f8b0:400e:c01::242]:42083) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fPLE4-0000qC-RC for qemu-devel@nongnu.org; Sun, 03 Jun 2018 01:06:44 -0400 Received: by mail-pl0-x242.google.com with SMTP id w17-v6so1813277pll.9 for ; Sat, 02 Jun 2018 22:06:44 -0700 (PDT) From: Zhang Chen Date: Sun, 3 Jun 2018 13:05:38 +0800 Message-Id: <20180603050546.6827-10-zhangckid@gmail.com> In-Reply-To: <20180603050546.6827-1-zhangckid@gmail.com> References: <20180603050546.6827-1-zhangckid@gmail.com> Subject: [Qemu-devel] [PATCH V8 09/17] COLO: Flush memory data from ram cache List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Paolo Bonzini , Juan Quintela , "Dr . David Alan Gilbert" , Jason Wang , Eric Blake , Markus Armbruster Cc: Zhang Chen , zhanghailiang , Li Zhijian During the time of VM's running, PVM may dirty some pages, we will transfer PVM's dirty pages to SVM and store them into SVM's RAM cache at next checkpoint time. So, the content of SVM's RAM cache will always be same with PVM's memory after checkpoint. Instead of flushing all content of PVM's RAM cache into SVM's MEMORY, we do this in a more efficient way: Only flush any page that dirtied by PVM since last checkpoint. In this way, we can ensure SVM's memory same with PVM's. Besides, we must ensure flush RAM cache before load device state. Signed-off-by: zhanghailiang Signed-off-by: Li Zhijian Reviewed-by: Dr. David Alan Gilbert --- migration/ram.c | 37 +++++++++++++++++++++++++++++++++++++ migration/trace-events | 2 ++ 2 files changed, 39 insertions(+) diff --git a/migration/ram.c b/migration/ram.c index dd86eeba87..927436bd12 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3332,6 +3332,39 @@ static bool postcopy_is_running(void) return ps >= POSTCOPY_INCOMING_LISTENING && ps < POSTCOPY_INCOMING_END; } +/* + * Flush content of RAM cache into SVM's memory. + * Only flush the pages that be dirtied by PVM or SVM or both. + */ +static void colo_flush_ram_cache(void) +{ + RAMBlock *block = NULL; + void *dst_host; + void *src_host; + unsigned long offset = 0; + + trace_colo_flush_ram_cache_begin(ram_state->migration_dirty_pages); + rcu_read_lock(); + block = QLIST_FIRST_RCU(&ram_list.blocks); + + while (block) { + offset = migration_bitmap_find_dirty(ram_state, block, offset); + + if (offset << TARGET_PAGE_BITS >= block->used_length) { + offset = 0; + block = QLIST_NEXT_RCU(block, next); + } else { + migration_bitmap_clear_dirty(ram_state, block, offset); + dst_host = block->host + (offset << TARGET_PAGE_BITS); + src_host = block->colo_cache + (offset << TARGET_PAGE_BITS); + memcpy(dst_host, src_host, TARGET_PAGE_SIZE); + } + } + + rcu_read_unlock(); + trace_colo_flush_ram_cache_end(); +} + static int ram_load(QEMUFile *f, void *opaque, int version_id) { int flags = 0, ret = 0, invalid_flags = 0; @@ -3504,6 +3537,10 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) ret |= wait_for_decompress_done(); rcu_read_unlock(); trace_ram_load_complete(ret, seq_iter); + + if (!ret && migration_incoming_in_colo_state()) { + colo_flush_ram_cache(); + } return ret; } diff --git a/migration/trace-events b/migration/trace-events index 20accb5b80..9cc80075ca 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -90,6 +90,8 @@ ram_dirty_bitmap_sync_start(void) "" ram_dirty_bitmap_sync_wait(void) "" ram_dirty_bitmap_sync_complete(void) "" ram_state_resume_prepare(uint64_t v) "%" PRId64 +colo_flush_ram_cache_begin(uint64_t dirty_pages) "dirty_pages %" PRIu64 +colo_flush_ram_cache_end(void) "" # migration/migration.c await_return_path_close_on_source_close(void) "" -- 2.17.GIT