From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46743) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecX0C-0003s5-Fb for qemu-devel@nongnu.org; Fri, 19 Jan 2018 08:46:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecX0B-0003Js-BF for qemu-devel@nongnu.org; Fri, 19 Jan 2018 08:46:40 -0500 Received: from mail-pg0-x242.google.com ([2607:f8b0:400e:c05::242]:34461) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1ecX0B-0003Ja-61 for qemu-devel@nongnu.org; Fri, 19 Jan 2018 08:46:39 -0500 Received: by mail-pg0-x242.google.com with SMTP id r19so1478952pgn.1 for ; Fri, 19 Jan 2018 05:46:39 -0800 (PST) From: Zhang Chen Date: Fri, 19 Jan 2018 21:44:38 +0800 Message-Id: <1516369485-5374-10-git-send-email-zhangckid@gmail.com> In-Reply-To: <1516369485-5374-1-git-send-email-zhangckid@gmail.com> References: <1516369485-5374-1-git-send-email-zhangckid@gmail.com> Subject: [Qemu-devel] [PATCH V4 09/16] COLO: Flush memory data from ram cache List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , zhanghailiang , Juan Quintela , "Dr . David Alan Gilbert" , Jason Wang , Eric Blake , Markus Armbruster , Zhang Chen , Li Zhijian From: zhanghailiang 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 | 39 +++++++++++++++++++++++++++++++++++++++ migration/trace-events | 2 ++ 2 files changed, 41 insertions(+) diff --git a/migration/ram.c b/migration/ram.c index d916da0..faee086 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2909,6 +2909,40 @@ 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); + migration_bitmap_clear_dirty(ram_state, block, offset); + + if (offset << TARGET_PAGE_BITS >= block->used_length) { + offset = 0; + block = QLIST_NEXT_RCU(block, next); + } else { + 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(); + assert(ram_state->migration_dirty_pages == 0); +} + static int ram_load(QEMUFile *f, void *opaque, int version_id) { int flags = 0, ret = 0, invalid_flags = 0; @@ -2921,6 +2955,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) bool postcopy_running = postcopy_is_running(); /* ADVISE is earlier, it shows the source has the postcopy capability on */ bool postcopy_advised = postcopy_is_advised(); + bool need_flush = false; seq_iter++; @@ -3096,6 +3131,10 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) wait_for_decompress_done(); rcu_read_unlock(); trace_ram_load_complete(ret, seq_iter); + + if (!ret && migration_incoming_in_colo_state() && need_flush) { + colo_flush_ram_cache(); + } return ret; } diff --git a/migration/trace-events b/migration/trace-events index 59c7e3e..eb56cc6 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -78,6 +78,8 @@ 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" +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) "" -- 2.7.4