From patchwork Wed Feb 7 07:33:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haozhong Zhang X-Patchwork-Id: 10204697 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0A831602D8 for ; Wed, 7 Feb 2018 07:38:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE32728DC4 for ; Wed, 7 Feb 2018 07:38:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E2C0B28DCF; Wed, 7 Feb 2018 07:38:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id ACD9A28E3E for ; Wed, 7 Feb 2018 07:38:49 +0000 (UTC) Received: from localhost ([::1]:58639 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejKJc-0001Uo-Rn for patchwork-qemu-devel@patchwork.kernel.org; Wed, 07 Feb 2018 02:38:48 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43921) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejKFG-0004tt-M7 for qemu-devel@nongnu.org; Wed, 07 Feb 2018 02:34:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ejKFF-0000bZ-H4 for qemu-devel@nongnu.org; Wed, 07 Feb 2018 02:34:18 -0500 Received: from mga09.intel.com ([134.134.136.24]:13680) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ejKFF-0000Td-5R for qemu-devel@nongnu.org; Wed, 07 Feb 2018 02:34:17 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Feb 2018 23:34:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,471,1511856000"; d="scan'208";a="17873997" Received: from hz-desktop.sh.intel.com (HELO localhost) ([10.239.13.35]) by fmsmga002.fm.intel.com with ESMTP; 06 Feb 2018 23:34:14 -0800 From: Haozhong Zhang To: qemu-devel@nongnu.org Date: Wed, 7 Feb 2018 15:33:28 +0800 Message-Id: <20180207073331.14158-6-haozhong.zhang@intel.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180207073331.14158-1-haozhong.zhang@intel.com> References: <20180207073331.14158-1-haozhong.zhang@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.24 Subject: [Qemu-devel] [PATCH v2 5/8] migration/ram: ensure write persistence on loading zero pages to PMEM 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: Haozhong Zhang , Xiao Guangrong , mst@redhat.com, Juan Quintela , dgilbert@redhat.com, Stefan Hajnoczi , Paolo Bonzini , Igor Mammedov , Dan Williams , Eduardo Habkost Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP When loading a zero page, check whether it will be loaded to persistent memory If yes, load it by libpmem function pmem_memset_nodrain(). Combined with a call to pmem_drain() at the end of RAM loading, we can guarantee all those zero pages are persistently loaded. Depending on the host HW/SW configurations, pmem_drain() can be "sfence". Therefore, we do not call pmem_drain() after each pmem_memset_nodrain(), or use pmem_memset_persist() (equally pmem_memset_nodrain() + pmem_drain()), in order to avoid unnecessary overhead. Signed-off-by: Haozhong Zhang --- include/qemu/pmem.h | 9 +++++++++ migration/ram.c | 34 +++++++++++++++++++++++++++++----- 2 files changed, 38 insertions(+), 5 deletions(-) diff --git a/include/qemu/pmem.h b/include/qemu/pmem.h index 9017596ff0..861d8ecc21 100644 --- a/include/qemu/pmem.h +++ b/include/qemu/pmem.h @@ -26,6 +26,15 @@ pmem_memcpy_persist(void *pmemdest, const void *src, size_t len) return memcpy(pmemdest, src, len); } +static inline void *pmem_memset_nodrain(void *pmemdest, int c, size_t len) +{ + return memset(pmemdest, c, len); +} + +static inline void pmem_drain(void) +{ +} + #endif /* CONFIG_LIBPMEM */ #endif /* !QEMU_PMEM_H */ diff --git a/migration/ram.c b/migration/ram.c index cb1950f3eb..5a0e503818 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 "qemu/pmem.h" /***********************************************************/ /* ram save/restore */ @@ -2467,6 +2468,20 @@ static inline void *host_from_ram_block_offset(RAMBlock *block, return block->host + offset; } +static void ram_handle_compressed_common(void *host, uint8_t ch, uint64_t size, + bool is_pmem) +{ + if (!ch && is_zero_range(host, size)) { + return; + } + + if (!is_pmem) { + memset(host, ch, size); + } else { + pmem_memset_nodrain(host, ch, size); + } +} + /** * ram_handle_compressed: handle the zero page case * @@ -2479,9 +2494,7 @@ static inline void *host_from_ram_block_offset(RAMBlock *block, */ void ram_handle_compressed(void *host, uint8_t ch, uint64_t size) { - if (ch != 0 || !is_zero_range(host, size)) { - memset(host, ch, size); - } + return ram_handle_compressed_common(host, ch, size, false); } static void *do_data_decompress(void *opaque) @@ -2823,6 +2836,7 @@ 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_pmem_drain = false; seq_iter++; @@ -2848,6 +2862,8 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) ram_addr_t addr, total_ram_bytes; void *host = NULL; uint8_t ch; + RAMBlock *block = NULL; + bool is_pmem = false; addr = qemu_get_be64(f); flags = addr & ~TARGET_PAGE_MASK; @@ -2864,7 +2880,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE | RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) { - RAMBlock *block = ram_block_from_stream(f, flags); + block = ram_block_from_stream(f, flags); host = host_from_ram_block_offset(block, addr); if (!host) { @@ -2874,6 +2890,9 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) } ramblock_recv_bitmap_set(block, host); trace_ram_load_loop(block->idstr, (uint64_t)addr, flags, host); + + is_pmem = ramblock_is_pmem(block); + need_pmem_drain = need_pmem_drain || is_pmem; } switch (flags & ~RAM_SAVE_FLAG_CONTINUE) { @@ -2927,7 +2946,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) case RAM_SAVE_FLAG_ZERO: ch = qemu_get_byte(f); - ram_handle_compressed(host, ch, TARGET_PAGE_SIZE); + ram_handle_compressed_common(host, ch, TARGET_PAGE_SIZE, is_pmem); break; case RAM_SAVE_FLAG_PAGE: @@ -2970,6 +2989,11 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) } wait_for_decompress_done(); + + if (need_pmem_drain) { + pmem_drain(); + } + rcu_read_unlock(); trace_ram_load_complete(ret, seq_iter); return ret;