From patchwork Fri Apr 24 06:22:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 11507171 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 4AD8315AB for ; Fri, 24 Apr 2020 06:23:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33B1920767 for ; Fri, 24 Apr 2020 06:23:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="WCZQnwIu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726522AbgDXGW5 (ORCPT ); Fri, 24 Apr 2020 02:22:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726078AbgDXGW4 (ORCPT ); Fri, 24 Apr 2020 02:22:56 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A760DC09B045; Thu, 23 Apr 2020 23:22:56 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id s18so1490320pgl.12; Thu, 23 Apr 2020 23:22:56 -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=b4QeW0VDRqbvEETBZ13QetaInWr2btitEZOC+VxZd+E=; b=WCZQnwIuKhUUloQh2c8VR7QuGYr40YhAxbYbxnj9MafTQWfH98agLefwnFk+dwwLBF 9fqNuPM3rPdotc1tcGf3gXl1rGWH3Cr0/F+hNpopsTyz3JwOFombvtTce/7PW7xHxR0K x9xKvc/QOQlFovYUHuamprejDWRPfZHweqsKzRPs/ADFzI2Go4c33+TXAfC6k56NvR+r m7uJdzzKttWWeLZDSArEHhGRSf4XEIAP2qh9EwNKW5vZ3z4AoM0W7iO9U3ywmchGXpZ/ YfwC4hXtwJkAvMS3ax+Z8qgiIvo220y4wtXahG67ff/a2uL7Qpz36YCUVtIKbDdqywWz 4gkw== 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=b4QeW0VDRqbvEETBZ13QetaInWr2btitEZOC+VxZd+E=; b=bgGlorhAzxlJwehLCbNH9pFxM7q6GfdAYX7GpS6rNDs2wTAvheIJDCN4XOp4ehjFSk 5rb7vMP3g6IHwcpXo5Wff66kgZT2c0d7NpG7hd3PYHoSX4t/FOF1x9ZPdVWx/x1rS0Aj 0LxyeW+aDzU/JL6sa/ke1+ABE2SL7hhZVS8LXVmtK3pUjqrTIfvqVlYbY1LzTp65H3gu Lx22ne9MPa5b0aF/VtD2oudMwEPrREJTuxiW1WqnMFHu+4jYWmS4DLseSdKEJt/0FmWx ddZdgZ68yLSTDpBVmX5AjgZVjtrPIj5d680P8N5v6UZ/CZAjbY07BfFxvb5DK8wqlMMa jCVQ== X-Gm-Message-State: AGi0PuaqHTssG9V/tsf/jO57rcLbkEKcF7gySZaSAx8QG1a7RyvJWphw XBCZ71E6UYoQPyIG4NsEOOC9VzKo X-Google-Smtp-Source: APiQypLCAowU4naaUsrYWj3L8M20ZXDYtGd/6A8oMccsd8PP/tZvLc1tOnBHQsjPeJzsALADPaxi5w== X-Received: by 2002:a62:7c51:: with SMTP id x78mr7651501pfc.227.1587709375986; Thu, 23 Apr 2020 23:22:55 -0700 (PDT) Received: from localhost.localdomain ([103.7.29.6]) by smtp.googlemail.com with ESMTPSA id l30sm3920674pgu.29.2020.04.23.23.22.52 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 23 Apr 2020 23:22:54 -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 v3 0/5] KVM: VMX: Tscdeadline timer emulation fastpath Date: Fri, 24 Apr 2020 14:22:39 +0800 Message-Id: <1587709364-19090-1-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: 2885 -> 2431.25 15.7% tscdeadline: 5668.75 -> 5188.5 8.4% w/ adaptive advance timer default -1: tscdeadline_immed: 2965.25 -> 2520 15.0% tscdeadline: 4663.75 -> 4537 2.7% Tested-by: Haiwei Li Cc: Haiwei Li 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 (5): KVM: VMX: Introduce generic fastpath handler KVM: X86: Introduce need_cancel_enter_guest 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 | 1 + arch/x86/kvm/lapic.c | 18 +++++++++----- arch/x86/kvm/vmx/vmx.c | 52 ++++++++++++++++++++++++++++++++++------- arch/x86/kvm/x86.c | 40 ++++++++++++++++++++++++------- arch/x86/kvm/x86.h | 1 + virt/kvm/kvm_main.c | 1 + 6 files changed, 91 insertions(+), 22 deletions(-)