From nobody Sat Oct 25 21:42:30 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 15211985959811018.926407837478; Fri, 16 Mar 2018 04:09:55 -0700 (PDT) Received: from localhost ([::1]:56074 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ewnFA-0001Ir-Ge for importer@patchew.org; Fri, 16 Mar 2018 07:09:55 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51164) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ewnCt-0008NP-8w for qemu-devel@nongnu.org; Fri, 16 Mar 2018 07:07:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ewnCp-00076j-N8 for qemu-devel@nongnu.org; Fri, 16 Mar 2018 07:07:31 -0400 Received: from mga02.intel.com ([134.134.136.20]:53872) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ewnCp-00070R-Er for qemu-devel@nongnu.org; Fri, 16 Mar 2018 07:07:27 -0400 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Mar 2018 04:07:23 -0700 Received: from devel-ww.sh.intel.com ([10.239.48.110]) by fmsmga001.fm.intel.com with ESMTP; 16 Mar 2018 04:07:21 -0700 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,315,1517904000"; d="scan'208";a="38522162" From: Wei Wang To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com Date: Fri, 16 Mar 2018 18:48:27 +0800 Message-Id: <1521197309-13544-4-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521197309-13544-1-git-send-email-wei.w.wang@intel.com> References: <1521197309-13544-1-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: 134.134.136.20 Subject: [Qemu-devel] [PATCH v5 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 77fd4f5..fae1acf 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -14,11 +14,13 @@ #ifndef MIGRATION_MISC_H #define MIGRATION_MISC_H =20 +#include "exec/cpu-common.h" #include "qemu/notify.h" =20 /* migration/ram.c */ =20 void ram_mig_init(void); +void qemu_guest_free_page_hint(void *addr, size_t len); =20 /* migration/block.c */ =20 diff --git a/migration/ram.c b/migration/ram.c index 38c991d..2e82181 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2193,6 +2193,50 @@ static int ram_init_all(RAMState **rsp) } =20 /* + * 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 -=3D used_len) { + block =3D qemu_ram_block_from_host(addr, false, &offset); + if (unlikely(!block)) { + return; + } + + /* + * This handles the case that the RAMBlock is resized after the fr= ee + * page hint is reported. + */ + if (unlikely(offset > block->used_length)) { + return; + } + + if (len <=3D block->used_length - offset) { + used_len =3D len; + } else { + used_len =3D block->used_length - offset; + addr +=3D used_len; + } + + start =3D offset >> TARGET_PAGE_BITS; + npages =3D used_len >> TARGET_PAGE_BITS; + + qemu_mutex_lock(&ram_state->bitmap_mutex); + ram_state->migration_dirty_pages -=3D + bitmap_count_one_with_offset(block->bmap, start, npa= ges); + 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 --=20 1.8.3.1