From patchwork Thu Nov 15 10:08:00 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: 10684109 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4ED88109C for ; Thu, 15 Nov 2018 10:42:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3DCB52BEF4 for ; Thu, 15 Nov 2018 10:42:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 31DF42BF04; Thu, 15 Nov 2018 10:42:36 +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 B48672BEF4 for ; Thu, 15 Nov 2018 10:42:35 +0000 (UTC) Received: from localhost ([::1]:37973 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gNF6Z-0004ul-1u for patchwork-qemu-devel@patchwork.kernel.org; Thu, 15 Nov 2018 05:42:35 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57619) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gNF5E-0003jJ-Eu for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:41:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gNF5D-0000ro-Gp for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:41:12 -0500 Received: from mga03.intel.com ([134.134.136.65]:14567) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gNF5D-0000oM-9O for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:41:11 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Nov 2018 02:41:11 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,236,1539673200"; d="scan'208";a="106467288" Received: from devel-ww.sh.intel.com ([10.239.48.119]) by fmsmga004.fm.intel.com with ESMTP; 15 Nov 2018 02:41:09 -0800 From: Wei Wang To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com Date: Thu, 15 Nov 2018 18:08:00 +0800 Message-Id: <1542276484-25508-5-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1542276484-25508-1-git-send-email-wei.w.wang@intel.com> References: <1542276484-25508-1-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: 134.134.136.65 Subject: [Qemu-devel] [PATCH v9 4/8] 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: liliang.opensource@gmail.com, peterx@redhat.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 CC: Peter Xu --- include/migration/misc.h | 2 ++ migration/ram.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 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 ef69dbe..229b791 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3131,6 +3131,54 @@ static void ram_state_resume_prepare(RAMState *rs, QEMUFile *out) } /* + * 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; + MigrationState *s = migrate_get_current(); + + /* This function is currently expected to be used during live migration */ + if (!migration_is_setup_or_active(s->state)) { + return; + } + + for (; len > 0; len -= used_len) { + block = qemu_ram_block_from_host(addr, false, &offset); + assert(block); + + /* + * 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