From patchwork Tue Apr 28 06:23:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 11513885 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E01214DD for ; Tue, 28 Apr 2020 06:23:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 851C6206D6 for ; Tue, 28 Apr 2020 06:23:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bT0f3Lxw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726338AbgD1GXk (ORCPT ); Tue, 28 Apr 2020 02:23:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726042AbgD1GXk (ORCPT ); Tue, 28 Apr 2020 02:23:40 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E0A0C03C1A9; Mon, 27 Apr 2020 23:23:40 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id w65so10167644pfc.12; Mon, 27 Apr 2020 23:23:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=Rg/qLxiNVWfFmoRhGooaCspQ06LzLm65xMpP+49aITo=; b=bT0f3LxwO8Wi5DI7F28YPePPQo3wDrPpjG6Z7eWzzlW/9SesYyzKkuW37K9Au8//he TJydnm3o0UhAtfOXKz+cx0hcQ/z6U2WJjWrGTvkX4fdfdIGH3NEg6JMIlwGW6nZtD2/I fVRRAkox95aPwbuubMx74r+vjBUspp77S7AMj3mYFzzd0PYf3o+kHkcxleB7oJeU26NV yztRJNbOwq+j/3VsdsxLt/qzuyHTnGH3xj+rZJgbR2QMk2TpVjMqcKF2M+8HKMNmWPzB vNOcOew2+OqmKPHvcKdAD788A8XoYm404jF82NdVvWnwGTUJUT7QmR7jzQyNoNJD2LR2 KQhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Rg/qLxiNVWfFmoRhGooaCspQ06LzLm65xMpP+49aITo=; b=U7kslQhYc31FKrp9SenphdbWtkb5gwcz4pURCzQMAW8+FNud2L9rhJw8O9Mp8n4LSe 6p6n84dOnbqcSo/m6iqn/aSHEmibHd1KiWzOgB68gHc2pP80pJ3OI4fJZ2qv+kPUqopq Ef/LxRck+L4UzHvgHS1340py2Vi1ELAnB3EpWlXdb1dq+NXwrbsgz6W6oeForpe15C+8 AG0q36iCL0cQrJxMbr/IRVYB30TCfMKTRhONZOtNNXOfBEaVTEauAlWeEe49tseR2jPk 47Nhe09me+CWSSlklzitzWOBEMi+OzfAP9tBP75Kgya1UtaVaCRV1YiA3mt4qwCTOfEY zCjA== X-Gm-Message-State: AGi0PuaKwRk5cF3IEUS36AX5iA38EI+ZS9zz/QNkkQudtQVAvPVj1EIM xpMvSNDdWBF7bwiV7O3Qz52b0Php X-Google-Smtp-Source: APiQypKx447iCNYPNvDT17BVFLgzVIFOyg3nZ+i5OqMFjvdBwiERmw/EydV78/66W3kQT5sqS2DBWQ== X-Received: by 2002:a62:e80e:: with SMTP id c14mr27294464pfi.83.1588055019397; Mon, 27 Apr 2020 23:23:39 -0700 (PDT) Received: from localhost.localdomain ([103.7.29.6]) by smtp.googlemail.com with ESMTPSA id u188sm14183071pfu.33.2020.04.27.23.23.36 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Apr 2020 23:23:38 -0700 (PDT) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Haiwei Li Subject: [PATCH v4 0/7] KVM: VMX: Tscdeadline timer emulation fastpath Date: Tue, 28 Apr 2020 14:23:22 +0800 Message-Id: <1588055009-12677-1-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org IPI and Timer cause the main vmexits in cloud environment observation, after single target IPI fastpath, let's optimize tscdeadline timer latency by introducing tscdeadline timer emulation fastpath, it will skip various KVM related checks when possible. i.e. after vmexit due to tscdeadline timer emulation, handle it and vmentry immediately without checking various kvm stuff when possible. Testing on SKX Server. cyclictest in guest(w/o mwait exposed, adaptive advance lapic timer is default -1): 5540.5ns -> 4602ns 17% kvm-unit-test/vmexit.flat: w/o avanced timer: tscdeadline_immed: 3028.5 -> 2494.75 17.6% tscdeadline: 5765.7 -> 5285 8.3% w/ adaptive advance timer default -1: tscdeadline_immed: 3123.75 -> 2583 17.3% tscdeadline: 4663.75 -> 4537 2.7% Tested-by: Haiwei Li Cc: Haiwei Li v3 -> v4: * fix bad indentation * rename CONT_RUN to REENTER_GUEST * rename kvm_need_cancel_enter_guest to kvm_vcpu_exit_request * rename EXIT_FASTPATH_CONT_RUN to EXIT_FASTPATH_REENTER_GUEST * introduce EXIT_FASTPATH_NOP * don't squish several stuffs to one patch * REENTER_GUEST be introduced with its first usage * introduce __handle_preemption_timer subfunction v2 -> v3: * skip interrupt notify and use vmx_sync_pir_to_irr before each cont_run * add from_timer_fn argument to apic_timer_expired * remove all kinds of duplicate codes v1 -> v2: * move more stuff from vmx.c to lapic.c * remove redundant checking * check more conditions to bail out CONT_RUN * not break AMD * not handle LVTT sepecial * cleanup codes Wanpeng Li (7): KVM: VMX: Introduce generic fastpath handler KVM: X86: Enable fastpath when APICv is enabled KVM: X86: Introduce more exit_fastpath_completion enum values KVM: X86: Introduce kvm_vcpu_exit_request() helper KVM: VMX: Optimize posted-interrupt delivery for timer fastpath KVM: X86: TSCDEADLINE MSR emulation fastpath KVM: VMX: Handle preemption timer fastpath arch/x86/include/asm/kvm_host.h | 3 ++ arch/x86/kvm/lapic.c | 18 +++++++---- arch/x86/kvm/svm/svm.c | 11 ++++--- arch/x86/kvm/vmx/vmx.c | 66 +++++++++++++++++++++++++++++++++-------- arch/x86/kvm/x86.c | 44 ++++++++++++++++++++------- arch/x86/kvm/x86.h | 3 +- virt/kvm/kvm_main.c | 1 + 7 files changed, 110 insertions(+), 36 deletions(-)