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=-9.1 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 E4238C04AAF for ; Mon, 20 May 2019 08:18:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA0142081C for ; Mon, 20 May 2019 08:18:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gOskyFqv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731260AbfETISf (ORCPT ); Mon, 20 May 2019 04:18:35 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:35745 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731227AbfETISd (ORCPT ); Mon, 20 May 2019 04:18:33 -0400 Received: by mail-pg1-f193.google.com with SMTP id t1so5005363pgc.2; Mon, 20 May 2019 01:18:33 -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=pgbMJUS0t5EEMQVa4x2z1mBqXaayN9eDcVUF1ZHkpGo=; b=gOskyFqv4TYixDqOL3mWr4ZC8ZZtb79p7fL7c/1IBW0fSralC96MYcHJgyWH4jAal3 bnBr/jh0vRlGAXji9LVLh90zSPAFXv8SEoxgHi6xx9dkmbtu0/XcoXX5biOqaCCqqxXO sWromyHdk2tw4yfYti1DPOwoMJKIvGV1b8jsWKfglEugepEdBjPdqwwKqgBK1ISr3zC9 ugw9sWe9APCT2wiGTDK4Kol5l97HyQRDlM0AhLTsn/YSKun/5nnXrin6tTUE0llWhOar uDA2YRZSKPoY35rxCNYO8hvyTtoLIqEIUtU1G2lNWV2D9yaxXthEDXPoYxS8iUnzVyRs Q+8w== 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=pgbMJUS0t5EEMQVa4x2z1mBqXaayN9eDcVUF1ZHkpGo=; b=KSMELdH0UHj4b4wXE3U1k6/x00FTUOKh0JhJlRFcBEX39zfvRkG+vag/0oTIPk2mbH 1rOZuVTuB5xMFxEf2wbQex7Jg1ZDMiuCoDq9fL1J3nFT/EwBVECliPLkA1B+dfZnE92J fKEXmh0kIguxQragp7PxKjxkTMiqCepUyuuuxjlpbQaDKvZChDBedBODbTwZZ1lp5UrJ RO3pUtEwcPUQxXd+Xs8RNSYehFzE3Jnov88p8+wgdgNgDWnT2+yeta3YhXXFI0nS7O9z ooSSLBpPB/Cg8jYJcx4phCsIQOvaOVMQBzMnIwHwiB5gc176qOUCMbAMr0RlVRVTv/o2 kcgg== X-Gm-Message-State: APjAAAX0DbUBKUZt0F2b6Xs6BzkaANhqo1+EwkA6+BLgoxW6TLoMxm7V 3Sy0CFECCFLsGHgCK16xEYu9ycqg X-Google-Smtp-Source: APXvYqzUZMJcNkf5rEYtW9VtjGz/GwR/ogbXpYTmexsCYg+iIbwg7uUa4IwJyHKTlVXMlRziflDLKA== X-Received: by 2002:a65:5cca:: with SMTP id b10mr74406405pgt.444.1558340312802; Mon, 20 May 2019 01:18:32 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id z9sm18522110pgc.82.2019.05.20.01.18.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 20 May 2019 01:18:32 -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 v4 4/5] KVM: LAPIC: Delay trace advance expire delta Date: Mon, 20 May 2019 16:18:08 +0800 Message-Id: <1558340289-6857-5-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1558340289-6857-1-git-send-email-wanpengli@tencent.com> References: <1558340289-6857-1-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 | 14 +++++++------- arch/x86/kvm/lapic.h | 1 + arch/x86/kvm/x86.c | 4 ++++ 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 89ac82d..6652928 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) __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 3eb77e7..ac7353f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8017,6 +8017,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) ++vcpu->stat.exits; guest_exit_irqoff(); + if (lapic_in_kernel(vcpu) && + vcpu->arch.apic->lapic_timer.timer_advance_ns) + trace_kvm_wait_lapic_expire(vcpu->vcpu_id, + vcpu->arch.apic->lapic_timer.advance_expire_delta); local_irq_enable(); preempt_enable(); -- 2.7.4