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=-8.6 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 972D5C31E46 for ; Wed, 12 Jun 2019 09:36:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 651F6208C4 for ; Wed, 12 Jun 2019 09:36:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RX83D3kf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437525AbfFLJgW (ORCPT ); Wed, 12 Jun 2019 05:36:22 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:39955 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437503AbfFLJgT (ORCPT ); Wed, 12 Jun 2019 05:36:19 -0400 Received: by mail-pl1-f193.google.com with SMTP id a93so6408628pla.7; Wed, 12 Jun 2019 02:36:19 -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 :mime-version:content-transfer-encoding; bh=XpEnBE6bGmJdt1K4+jFodyaadPKkbgqY+88bNzccZ0Y=; b=RX83D3kfSfz2ttjlAg5kltFuEKTsQhd1Hp5CMH+sKKNjyV2R/nRdt03FHbCoCHbeH2 c2CHMzShfy4JUsNBWNlCPOSWs/Kboo5aA6J21/TWY0k183hs4PJDvkj71drzOwBsUxXg OSWvXPtlEArFMeKzYgEyCR30N1fpfArZRO1Mb/bRXdx2MPW3dyzJ5NfWJMJsxvQYuJSM IeUCIOKgRt0+h9yLAVRgVJ0Lo51GQXxz2+9hGm4Ddb01aTWRsARZTsslcf+MmFiQ82BR LgKWuQ03cB7t4PlT+hIZUWgwKMbobcO1Eyf25d2uDAm+l5eH4IPuRICTCtbDJQlyhzbi 2sHQ== 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:mime-version:content-transfer-encoding; bh=XpEnBE6bGmJdt1K4+jFodyaadPKkbgqY+88bNzccZ0Y=; b=mZEAB4UoJC9mJWTBYCu03wlVRc7yZltnLDSSrMG4i2wRmbkLY9uK7BcUT3jbnEZ4ZY Xvla1Rc3rKABz/W1aolj3LWl+G0tcCtPkv2tNPTqa8Sn5vwXhkCU66hPf4NtAk7aYsUG iCi26qrsWnauQELw8mxF8/ZEP8fs/gr1Ev8+qrN8JOAKuVzsQcmjSOHFDOM/DBWXaRly uKSC40HzJtRxockCnPz/ssG5yYD2zs6tzwLuQoN+QZ08jMTj+DYOl3U4iyF4QdkaRRrW LugHhSt9x+jgaM4dpTZ1yI7V7vIFffuNlAF+Of0tF20otuUSN4jOP+/1StIiAUHw125X XTng== X-Gm-Message-State: APjAAAUO1WARUpZ5+r5HQVszdNX9SBG2aQWjR+yD5+8pDxoDDOE2ATKC yudb7RyZ8nZNJHMFPJHWJa+jZ9fL X-Google-Smtp-Source: APXvYqxW/4jY4bnjpg3tE9zUuZVmrDGHHptuTCc/LGAfkeBoJ6/NCjAgSZNHsfZYNVckFCL4nO+U5Q== X-Received: by 2002:a17:902:ba82:: with SMTP id k2mr73161407pls.323.1560332178485; Wed, 12 Jun 2019 02:36:18 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id 27sm6148936pgl.82.2019.06.12.02.36.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 12 Jun 2019 02:36:18 -0700 (PDT) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Sean Christopherson , Liran Alon Subject: [PATCH v3 4/5] KVM: LAPIC: Delay trace advance expire delta Date: Wed, 12 Jun 2019 17:35:59 +0800 Message-Id: <1560332160-17050-5-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560332160-17050-1-git-send-email-wanpengli@tencent.com> References: <1560332160-17050-1-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wanpeng Li wait_lapic_expire() call was moved above guest_enter_irqoff() because of its tracepoint, which violated the RCU extended quiescent state invoked by guest_enter_irqoff()[1][2]. This patch simply moves the tracepoint below guest_exit_irqoff() in vcpu_enter_guest(). Snapshot the delta before VM-Enter, but trace it after VM-Exit. This can help us to move wait_lapic_expire() just before vmentry in the later patch. [1] Commit 8b89fe1f6c43 ("kvm: x86: move tracepoints outside extended quiescent state") [2] https://patchwork.kernel.org/patch/7821111/ Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Sean Christopherson Cc: Liran Alon Signed-off-by: Wanpeng Li --- arch/x86/kvm/lapic.c | 16 ++++++++-------- arch/x86/kvm/lapic.h | 1 + arch/x86/kvm/x86.c | 2 ++ 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2f364fe..af38ece 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1502,27 +1502,27 @@ static inline void __wait_lapic_expire(struct kvm_vcpu *vcpu, u64 guest_cycles) } static inline void adaptive_tune_timer_advancement(struct kvm_vcpu *vcpu, - u64 guest_tsc, u64 tsc_deadline) + s64 advance_expire_delta) { struct kvm_lapic *apic = vcpu->arch.apic; u32 timer_advance_ns = apic->lapic_timer.timer_advance_ns; u64 ns; /* too early */ - if (guest_tsc < tsc_deadline) { - ns = (tsc_deadline - guest_tsc) * 1000000ULL; + if (advance_expire_delta < 0) { + ns = -advance_expire_delta * 1000000ULL; do_div(ns, vcpu->arch.virtual_tsc_khz); timer_advance_ns -= min((u32)ns, timer_advance_ns / LAPIC_TIMER_ADVANCE_ADJUST_STEP); } else { /* too late */ - ns = (guest_tsc - tsc_deadline) * 1000000ULL; + ns = advance_expire_delta * 1000000ULL; do_div(ns, vcpu->arch.virtual_tsc_khz); timer_advance_ns += min((u32)ns, timer_advance_ns / LAPIC_TIMER_ADVANCE_ADJUST_STEP); } - if (abs(guest_tsc - tsc_deadline) < LAPIC_TIMER_ADVANCE_ADJUST_DONE) + if (abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_DONE) apic->lapic_timer.timer_advance_adjust_done = true; if (unlikely(timer_advance_ns > 5000)) { timer_advance_ns = 0; @@ -1545,13 +1545,13 @@ void wait_lapic_expire(struct kvm_vcpu *vcpu) tsc_deadline = apic->lapic_timer.expired_tscdeadline; apic->lapic_timer.expired_tscdeadline = 0; guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc()); - trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline); + apic->lapic_timer.advance_expire_delta = guest_tsc - tsc_deadline; - if (guest_tsc < tsc_deadline) + if (apic->lapic_timer.advance_expire_delta < 0) __wait_lapic_expire(vcpu, tsc_deadline - guest_tsc); if (unlikely(!apic->lapic_timer.timer_advance_adjust_done)) - adaptive_tune_timer_advancement(vcpu, guest_tsc, tsc_deadline); + adaptive_tune_timer_advancement(vcpu, apic->lapic_timer.advance_expire_delta); } static void start_sw_tscdeadline(struct kvm_lapic *apic) diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index d6d049b..3e72a25 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -32,6 +32,7 @@ struct kvm_timer { u64 tscdeadline; u64 expired_tscdeadline; u32 timer_advance_ns; + s64 advance_expire_delta; atomic_t pending; /* accumulated triggered timers */ bool hv_timer_in_use; bool timer_advance_adjust_done; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f2e3847..4a7b00c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7961,6 +7961,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) ++vcpu->stat.exits; guest_exit_irqoff(); + trace_kvm_wait_lapic_expire(vcpu->vcpu_id, + vcpu->arch.apic->lapic_timer.advance_expire_delta); local_irq_enable(); preempt_enable(); -- 2.7.4