From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A108C2BA1A for ; Fri, 24 Apr 2020 06:23:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6B4920700 for ; Fri, 24 Apr 2020 06:23:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ALTyvKyQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726700AbgDXGXQ (ORCPT ); Fri, 24 Apr 2020 02:23:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726699AbgDXGXN (ORCPT ); Fri, 24 Apr 2020 02:23:13 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A078C09B045; Thu, 23 Apr 2020 23:23:12 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id fu13so2966738pjb.5; Thu, 23 Apr 2020 23:23:12 -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:in-reply-to:references; bh=MxB/5+Kd2C0pw05dDYhqC6sr311SJsuN/Ux6MEaNAeM=; b=ALTyvKyQUjtlg1598kuRSm4WumDxkjhA8gT+IOrw0J1iqMj9KYEY90As0WJHEcHVWz SamkGK23L+Z9bffWYiSZeLeAxbnhyNhJR+dLizlJvZK68g3vmHopsd4o+qQQXcHlTSdh YsrptaoTIB1yjQd/1JFsnNOWXYiyu/FXkikO7RG0v6ecwBhF7dzayOUPzRT03K5cYgxr zIoFFlYjjq+GnIZ1PUWjzQBOjTcTDVniEbb9vEMqgWyvEYc4lx25ZjNpzthl3tIHQ3K6 uxXvG0nn+9CxfZnNS8HNZSVipbvLF4gi/HiYMMQNyNpDQ4bVFC9/bZOauoHktiqZD7jB lfMQ== 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:in-reply-to :references; bh=MxB/5+Kd2C0pw05dDYhqC6sr311SJsuN/Ux6MEaNAeM=; b=KyEYEkCur6d+JCH/th/ozfnkwCfWLhmQx42wsAyF2cUTI1tnqZj50gxzAzGFqaCl0d zO6kg7F2wiDU+evjjswTXATb6dsVanzsaE/5Z9S2juwrXFra9rC5KwQsDm03pP9beF1i sw8+qN9nvcRsrobMRJQ+v7pC5lq68O8UB7S6AngfvUQ5bbWnZTmWfWCOjxEXaMMRKhYl 5TbkUcFpZ0qbekOXwNvMbClqsTx83ANgeOVNeTkep2O68kZk8njroBwPpP9xIaE2vPkG dnI5O0Ub9trtIhynUKiqTMc708p6hu/qk8q5K8YvuKxDdfGavQp0un4iGEnd0L6DN1Bb KPmg== X-Gm-Message-State: AGi0PuZvh8N8SjnmAYP10PZbuTLOf8MhBxzsBFfBzOMMmpOyLX4eE9A4 7rLfebTZwERVTCZdCXjw2Gg0Kqab X-Google-Smtp-Source: APiQypK/mIzK+C1SxJQBVgxJKD0z5j932b08/NaZVr/QTI123ZiXW+iATgxaMwlHykGir3aFTd+rPA== X-Received: by 2002:a17:90a:db53:: with SMTP id u19mr4771195pjx.41.1587709391365; Thu, 23 Apr 2020 23:23:11 -0700 (PDT) Received: from localhost.localdomain ([103.7.29.6]) by smtp.googlemail.com with ESMTPSA id l30sm3920674pgu.29.2020.04.23.23.23.08 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 23 Apr 2020 23:23:10 -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 5/5] KVM: VMX: Handle preemption timer fastpath Date: Fri, 24 Apr 2020 14:22:44 +0800 Message-Id: <1587709364-19090-6-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1587709364-19090-1-git-send-email-wanpengli@tencent.com> References: <1587709364-19090-1-git-send-email-wanpengli@tencent.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wanpeng Li This patch implements handle preemption timer fastpath, after timer fire due to VMX-preemption timer counts down to zero, handle it as soon as possible 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 Signed-off-by: Wanpeng Li --- arch/x86/kvm/vmx/vmx.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d21b66b..028967a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6560,12 +6560,28 @@ void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp) } } +static enum exit_fastpath_completion handle_fastpath_preemption_timer(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + + if (!vmx->req_immediate_exit && + !unlikely(vmx->loaded_vmcs->hv_timer_soft_disabled)) { + kvm_lapic_expired_hv_timer(vcpu); + trace_kvm_exit(EXIT_REASON_PREEMPTION_TIMER, vcpu, KVM_ISA_VMX); + return EXIT_FASTPATH_CONT_RUN; + } + + return EXIT_FASTPATH_NONE; +} + static enum exit_fastpath_completion vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu) { if (!is_guest_mode(vcpu) && vcpu->arch.apicv_active) { switch (to_vmx(vcpu)->exit_reason) { case EXIT_REASON_MSR_WRITE: return handle_fastpath_set_msr_irqoff(vcpu); + case EXIT_REASON_PREEMPTION_TIMER: + return handle_fastpath_preemption_timer(vcpu); default: return EXIT_FASTPATH_NONE; } -- 2.7.4