Message ID | 1548327746-20484-1-git-send-email-ann.zhuangyanying@huawei.com (mailing list archive) |
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Return-Path: <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org> 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 2B16891E for <patchwork-qemu-devel@patchwork.kernel.org>; Thu, 24 Jan 2019 11:08:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1785D2E5B2 for <patchwork-qemu-devel@patchwork.kernel.org>; Thu, 24 Jan 2019 11:08:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0873E2E948; Thu, 24 Jan 2019 11:08:37 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A75732E5B2 for <patchwork-qemu-devel@patchwork.kernel.org>; Thu, 24 Jan 2019 11:08:36 +0000 (UTC) Received: from localhost ([127.0.0.1]:51501 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org>) id 1gmcs7-0003xV-IO for patchwork-qemu-devel@patchwork.kernel.org; Thu, 24 Jan 2019 06:08:35 -0500 Received: from eggs.gnu.org ([209.51.188.92]:48659) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from <ann.zhuangyanying@huawei.com>) id 1gmcqy-00039r-Sb for qemu-devel@nongnu.org; Thu, 24 Jan 2019 06:07:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from <ann.zhuangyanying@huawei.com>) id 1gmcqy-0003E5-0U for qemu-devel@nongnu.org; Thu, 24 Jan 2019 06:07:24 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:2236 helo=huawei.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from <ann.zhuangyanying@huawei.com>) id 1gmcqx-00030B-BT for qemu-devel@nongnu.org; Thu, 24 Jan 2019 06:07:23 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id E2EEFFB87B24D7674BFA; Thu, 24 Jan 2019 19:07:17 +0800 (CST) Received: from localhost (10.177.21.2) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.408.0; Thu, 24 Jan 2019 19:07:09 +0800 From: Zhuangyanying <ann.zhuangyanying@huawei.com> To: <xiaoguangrong@tencent.com>, <sean.j.christopherson@intel.com>, <arei.gonglei@huawei.com>, <liu.jinsong@huawei.com> Date: Thu, 24 Jan 2019 11:02:23 +0000 Message-ID: <1548327746-20484-1-git-send-email-ann.zhuangyanying@huawei.com> X-Mailer: git-send-email 2.6.4.windows.1 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-Originating-IP: [10.177.21.2] X-CFilter-Loop: Reflected Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 45.249.212.191 Subject: [Qemu-devel] [PATCH v2 0/3] KVM: MMU: fast cleanup D bit based on fast write protect X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: <qemu-devel.nongnu.org> List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>, <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe> List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/> List-Post: <mailto:qemu-devel@nongnu.org> List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help> List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>, <mailto:qemu-devel-request@nongnu.org?subject=subscribe> Cc: kvm@vger.kernel.org, wangxinxin.wang@huawei.com, qemu-devel@nongnu.org, Zhuang yanying <ann.zhuangyanying@huawei.com>, jianjay.zhou@huawei.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org> X-Virus-Scanned: ClamAV using ClamSMTP |
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KVM: MMU: fast cleanup D bit based on fast write protect
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From: Zhuang yanying <ann.zhuangyanying@huawei.com> When live-migration with large-memory guests, vcpu may hang for a long time while starting migration, such as 9s for 2T (linux-5.0.0-rc2+qemu-3.1.0). The reason is memory_global_dirty_log_start() taking too long, and the vcpu is waiting for BQL. The page-by-page D bit clearup is the main time consumption. I think that the idea of "KVM: MMU: fast write protect" by xiaoguangrong, especially the function kvm_mmu_write_protect_all_pages(), is very helpful. After a little modifcation, on his patch, can solve this problem, 9s to 0.5s. At the beginning of live migration, write protection is only applied to the top-level SPTE. Then the write from vm trigger the EPT violation, with for_each_shadow_entry write protection is performed at dirct_map. Finally the Dirty bit of the target page(at level 1 page table) is cleared, and the dirty page tracking is started. The page where GPA is located is marked dirty when mmu_set_spte. A similar implementation on xen, just emt instead of write protection. Xiao Guangrong (2): KVM: MMU: introduce possible_writable_spte_bitmap KVM: MMU: introduce kvm_mmu_write_protect_all_pages Zhuang Yanying (1): KVM: MMU: fast cleanup D bit based on fast write protect arch/x86/include/asm/kvm_host.h | 24 ++++- arch/x86/kvm/mmu.c | 229 ++++++++++++++++++++++++++++++++++++++-- arch/x86/kvm/mmu.h | 1 + arch/x86/kvm/paging_tmpl.h | 13 ++- arch/x86/kvm/vmx/vmx.c | 5 +- 5 files changed, 257 insertions(+), 15 deletions(-) -- v1 -> v2: - drop "KVM: MMU: correct the behavior of mmu_spte_update_no_track" - mmu_write_protect_all_indicator is no longer an atomic variable, protected by mmu_lock - Implement kvm_mmu_slot_set_dirty with kvm_mmu_write_protect_all_pages - some modification on the commit messages -- 1.8.3.1