From patchwork Tue Apr 24 06:13:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Wei W" X-Patchwork-Id: 10358723 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 4A7E360225 for ; Tue, 24 Apr 2018 06:36:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3324D28D06 for ; Tue, 24 Apr 2018 06:36:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 27B2D28D08; Tue, 24 Apr 2018 06:36:59 +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=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, 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 A0C7528D06 for ; Tue, 24 Apr 2018 06:36:58 +0000 (UTC) Received: from localhost ([::1]:56817 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fArZR-0003l0-V5 for patchwork-qemu-devel@patchwork.kernel.org; Tue, 24 Apr 2018 02:36:57 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41118) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fArVK-0000vv-1h for qemu-devel@nongnu.org; Tue, 24 Apr 2018 02:32:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fArVH-0007M4-Ef for qemu-devel@nongnu.org; Tue, 24 Apr 2018 02:32:42 -0400 Received: from mga07.intel.com ([134.134.136.100]:19343) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fArVH-0007Ky-4P for qemu-devel@nongnu.org; Tue, 24 Apr 2018 02:32:39 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Apr 2018 23:32:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,321,1520924400"; d="scan'208";a="53160552" Received: from devel-ww.sh.intel.com ([10.239.48.110]) by orsmga002.jf.intel.com with ESMTP; 23 Apr 2018 23:32:36 -0700 From: Wei Wang To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com Date: Tue, 24 Apr 2018 14:13:46 +0800 Message-Id: <1524550428-27173-4-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1524550428-27173-1-git-send-email-wei.w.wang@intel.com> References: <1524550428-27173-1-git-send-email-wei.w.wang@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.100 Subject: [Qemu-devel] [PATCH v7 3/5] migration: API to clear bits of guest free pages from the dirty bitmap 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: yang.zhang.wz@gmail.com, quan.xu0@gmail.com, liliang.opensource@gmail.com, wei.w.wang@intel.com, pbonzini@redhat.com, nilal@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP This patch adds an API to clear bits corresponding to guest free pages from the dirty bitmap. Spilt the free page block if it crosses the QEMU RAMBlock boundary. Signed-off-by: Wei Wang CC: Dr. David Alan Gilbert CC: Juan Quintela CC: Michael S. Tsirkin --- include/migration/misc.h | 2 ++ migration/ram.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) diff --git a/include/migration/misc.h b/include/migration/misc.h index 4ebf24c..113320e 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -14,11 +14,13 @@ #ifndef MIGRATION_MISC_H #define MIGRATION_MISC_H +#include "exec/cpu-common.h" #include "qemu/notify.h" /* migration/ram.c */ void ram_mig_init(void); +void qemu_guest_free_page_hint(void *addr, size_t len); /* migration/block.c */ diff --git a/migration/ram.c b/migration/ram.c index 9a72b1a..0147548 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2198,6 +2198,50 @@ static int ram_init_all(RAMState **rsp) } /* + * This function clears bits of the free pages reported by the caller from the + * migration dirty bitmap. @addr is the host address corresponding to the + * start of the continuous guest free pages, and @len is the total bytes of + * those pages. + */ +void qemu_guest_free_page_hint(void *addr, size_t len) +{ + RAMBlock *block; + ram_addr_t offset; + size_t used_len, start, npages; + + for (; len > 0; len -= used_len) { + block = qemu_ram_block_from_host(addr, false, &offset); + if (unlikely(!block)) { + return; + } + + /* + * This handles the case that the RAMBlock is resized after the free + * page hint is reported. + */ + if (unlikely(offset > block->used_length)) { + return; + } + + if (len <= block->used_length - offset) { + used_len = len; + } else { + used_len = block->used_length - offset; + addr += used_len; + } + + start = offset >> TARGET_PAGE_BITS; + npages = used_len >> TARGET_PAGE_BITS; + + qemu_mutex_lock(&ram_state->bitmap_mutex); + ram_state->migration_dirty_pages -= + bitmap_count_one_with_offset(block->bmap, start, npages); + bitmap_clear(block->bmap, start, npages); + qemu_mutex_unlock(&ram_state->bitmap_mutex); + } +} + +/* * Each of ram_save_setup, ram_save_iterate and ram_save_complete has * long-running RCU critical section. When rcu-reclaims in the code * start to become numerous it will be necessary to reduce the