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,USER_AGENT_GIT autolearn=ham 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 471F4C54FD0 for ; Tue, 21 Apr 2020 11:20:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21E292078C for ; Tue, 21 Apr 2020 11:20:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ECVEWbex" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728765AbgDULUs (ORCPT ); Tue, 21 Apr 2020 07:20:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728662AbgDULUm (ORCPT ); Tue, 21 Apr 2020 07:20:42 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72F4CC061A0F; Tue, 21 Apr 2020 04:20:42 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id f20so387851pgl.12; Tue, 21 Apr 2020 04:20:42 -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=IJ6JZkiPYFKr9qoqt6fhwkwymZZp1I817zsI085cYIo=; b=ECVEWbexBcseymDuaNtzAX8DRgj4x6F5lrLy31bXwdmQ9Brgohq3AWboZMbe5FLtq0 21Z/i34UeIffbCfSEGwJ/pbCe8Id9ptcVngWM1patsbr5cFKh2HLHpf5Yx9oy0BeA82b NbW3Tkk3IIfcZaD/0nrEANyb7s2R+fgaduJDnfkWunplVVfVWHe34VXp2Cr942yKMOqT OV0N7gqXKj3I6ROqa1xRf7tlZITQ6tWRPRczo8ncKRlMlDMMZepSsNB+WhbXIs1/5fKe lZ/R7/4yESf+59jDTH/XK8AU3yp0lr5K6rv89zKJnJPD/gZG8hB0UssblhJ/XVmZLLp0 Q0+Q== 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=IJ6JZkiPYFKr9qoqt6fhwkwymZZp1I817zsI085cYIo=; b=E5UypdE0t3WnySIsQEIlak9H8y1f4QNIYdM/47VdiKGhHD3AR0PTjhuR6eBfo4FzXf 6h1CQgfJoDcGos3SGt43XdCW1Va7EUcyFBiPWrFH11KU/hu7pKzFRKKvu/Ii6i+0tqNP mpv8HQBHSpdXAUvInL8n6OOwoFaAFDd0F7P+h1Ui3nL6X+9Fw0wL9+wU+IWNfz3Bbz0/ I4oUxfxzRlcjZyOBa/7orXqitEXxk5YI1pV/vqGgHSEGQ68vLpBEpSEMBnXSPorjwh86 KWD8J4UxxouHK0/95NLCkL7cytvnFRJ7yI86YW4NuUHo2Avbmbr6x39SLl0ZrKCBMCWF e2Pg== X-Gm-Message-State: AGi0PuZoiZnHq9guh0W/5yeJ741sz+7tyu1IYkI5r0YR8OxXTQRUocBK q28bsT4BI7SwHgexCex5bR5pu/w7 X-Google-Smtp-Source: APiQypJY/VtK1rmXpeHsVWCjecFmk7L3oIOZ00v+D8RA2f62M4iRTOqukizWko3q6VDuP6l782PPOQ== X-Received: by 2002:a65:49cf:: with SMTP id t15mr21026486pgs.39.1587468041852; Tue, 21 Apr 2020 04:20:41 -0700 (PDT) Received: from localhost.localdomain ([103.7.29.6]) by smtp.googlemail.com with ESMTPSA id f74sm8643176pje.3.2020.04.21.04.20.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Apr 2020 04:20:41 -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 2/2] KVM: VMX: Handle preemption timer fastpath Date: Tue, 21 Apr 2020 19:20:26 +0800 Message-Id: <1587468026-15753-3-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1587468026-15753-1-git-send-email-wanpengli@tencent.com> References: <1587468026-15753-1-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): 5632.75ns -> 4559.25ns, 19% kvm-unit-test/vmexit.flat: w/o APICv, w/o advance timer: tscdeadline_immed: 4780.75 -> 3851 19.4% tscdeadline: 7474 -> 6528.5 12.7% w/o APICv, w/ adaptive advance timer default -1: tscdeadline_immed: 4845.75 -> 3930.5 18.9% tscdeadline: 6048 -> 5871.75 3% w/ APICv, w/o avanced timer: tscdeadline_immed: 2919 -> 2467.75 15.5% tscdeadline: 5661.75 -> 5188.25 8.4% w/ APICv, w/ adaptive advance timer default -1: tscdeadline_immed: 3018.5 -> 2561 15.2% tscdeadline: 4663.75 -> 4626.5 1% Tested-by: Haiwei Li Cc: Haiwei Li Signed-off-by: Wanpeng Li --- arch/x86/kvm/vmx/vmx.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 7688e40..623c4a0 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6593,12 +6593,53 @@ static void vmx_fast_deliver_interrupt(struct kvm_vcpu *vcpu) } } +static void vmx_cancel_hv_timer(struct kvm_vcpu *vcpu); + +static enum exit_fastpath_completion handle_fastpath_preemption_timer(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + struct kvm_lapic *apic = vcpu->arch.apic; + struct kvm_timer *ktimer = &apic->lapic_timer; + + if (vmx_event_needs_reinjection(vcpu)) + return EXIT_FASTPATH_NONE; + + if (!vmx->req_immediate_exit && + !unlikely(vmx->loaded_vmcs->hv_timer_soft_disabled)) { + if (!vmx_interrupt_allowed(vcpu) || + !apic_lvtt_tscdeadline(apic) || + vmx->rmode.vm86_active || + is_smm(vcpu) || + !kvm_apic_hw_enabled(apic)) + return EXIT_FASTPATH_NONE; + + if (!apic->lapic_timer.hv_timer_in_use) + return EXIT_FASTPATH_CONT_RUN; + + WARN_ON(swait_active(&vcpu->wq)); + vmx_cancel_hv_timer(vcpu); + apic->lapic_timer.hv_timer_in_use = false; + + if (atomic_read(&apic->lapic_timer.pending)) + return EXIT_FASTPATH_CONT_RUN; + + ktimer->expired_tscdeadline = ktimer->tscdeadline; + vmx_fast_deliver_interrupt(vcpu); + ktimer->tscdeadline = 0; + 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)) { 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