From patchwork Thu Oct 13 11:34:18 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 9374847 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D62E860487 for ; Thu, 13 Oct 2016 11:36:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C750029FEA for ; Thu, 13 Oct 2016 11:36:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BBE2829FFB; Thu, 13 Oct 2016 11:36:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 752DD29E81 for ; Thu, 13 Oct 2016 11:36:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754727AbcJMLgD (ORCPT ); Thu, 13 Oct 2016 07:36:03 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:34644 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754120AbcJMLfa (ORCPT ); Thu, 13 Oct 2016 07:35:30 -0400 Received: by mail-pf0-f195.google.com with SMTP id 128so4924194pfz.1; Thu, 13 Oct 2016 04:34:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UIgLt1Sz72qgiN5EtjkSHSTCdKfzuiJ0gSvGZWoO8nk=; b=qjjsPSyxWmUWyHgkIXJNTocc1xqqB3ZkpqryxvpRJqWMNtA4wFBHde4IfHDw9FQL9q Z1BfPfDPU8JTnjBpFBGuMwVdMm92n/w9sKUzRiDmgduyGxroRk0hgWT8n4TZCrmIYrqy cioo6h1LhDiGNICct3FZ+QwHVNsMWxRcxKKI3jzpyPP2a8lLFqwVp6sXMbMFomT7f+I6 RYv5nLYTqk34ETuK0Y7udzxm8xq5d9eTludDR+LnovNYWGsCPnMcAzDEv4DqLal9RvDt FuuzJsK2FzpeBKAJY4gn38uorGIGEf43zzDPvm3T+3tCMlD2Pe8ngJYoru9U8jjK0MUg Q0mA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UIgLt1Sz72qgiN5EtjkSHSTCdKfzuiJ0gSvGZWoO8nk=; b=eEH3qolszMvqhgPtzOrrfxVNo874EFXFbiZbzGJjLU2CW4Gp7+CH/xCZploeOF46ep pksSLTLRRj4lMbYgYUSRRVWSlUpXDUtEmmF8Kv9iXrlH7sgEbhsbQOLJnaDHkrrYJmNG 5NZjiniFzQPpDju90Zju8KN/mH9YWBWZ0m5lkrQgn2RjOJMOIVImjp9hvjpfBpsYQrEf 0Eb/AyMYt/2p7sClVjvw+34LdgC/oRf8/cSrXM+28gjiKYqZCxNtYoqhgsET4eIYHSQY zeYIjSQUSUEJ+ARt+ZvJmUjZr30/lYy1cYku7b9/5Y8dAkdRWyjU78NWbZoR8PeNA3gL doug== X-Gm-Message-State: AA6/9Rl3eCfDE74v/sA3uIuiq5QSjivRJIIKDYpAS3h2D7zyF/YfLRSRVu5m9XDhu+NJzg== X-Received: by 10.99.218.69 with SMTP id l5mr7651876pgj.95.1476358484506; Thu, 13 Oct 2016 04:34:44 -0700 (PDT) Received: from kernel.kingsoft.cn ([114.255.44.132]) by smtp.gmail.com with ESMTPSA id af17sm19095088pac.14.2016.10.13.04.34.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 13 Oct 2016 04:34:43 -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?= , Yunhong Jiang , Wanpeng Li Subject: [PATCH RFC V3 6/6] KVM: LAPIC: Add APIC Timer periodic/oneshot mode VMX preemption timer support Date: Thu, 13 Oct 2016 19:34:18 +0800 Message-Id: <1476358458-3525-7-git-send-email-wanpeng.li@hotmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1476358458-3525-1-git-send-email-wanpeng.li@hotmail.com> References: <1476358458-3525-1-git-send-email-wanpeng.li@hotmail.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Wanpeng Li Most windows guests still utilize APIC Timer periodic/oneshot mode instead of tsc-deadline mode, and the APIC Timer periodic/oneshot mode are still emulated by high overhead hrtimer on host. This patch converts the expected expire time of the periodic/oneshot mode to guest deadline tsc in order to leverage VMX preemption timer logic for APIC Timer tsc-deadline mode. After each preemption timer vmexit preemption timer is restarted to emulate LVTT current-count register is automatically reloaded from the initial-count register when the count reaches 0. Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Yunhong Jiang Signed-off-by: Wanpeng Li --- arch/x86/kvm/lapic.c | 100 ++++++++++++++++++++------------------------------- 1 file changed, 39 insertions(+), 61 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index e93e549..7663246 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1090,7 +1090,7 @@ static void apic_send_ipi(struct kvm_lapic *apic) static u32 apic_get_tmcct(struct kvm_lapic *apic) { - ktime_t remaining; + ktime_t remaining, now; s64 ns; u32 tmcct; @@ -1101,7 +1101,8 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic) apic->lapic_timer.period == 0) return 0; - remaining = hrtimer_get_remaining(&apic->lapic_timer.timer); + now = apic->lapic_timer.timer.base->get_time(); + remaining = ktime_sub(apic->lapic_timer.target_expiration, now); if (ktime_to_ns(remaining) < 0) remaining = ktime_set(0, 0); @@ -1349,46 +1350,9 @@ static void start_sw_tscdeadline(struct kvm_lapic *apic) static void start_sw_period(struct kvm_lapic *apic) { - ktime_t now; - - /* lapic timer in oneshot or periodic mode */ - now = apic->lapic_timer.timer.base->get_time(); - apic->lapic_timer.period = (u64)kvm_lapic_get_reg(apic, APIC_TMICT) - * APIC_BUS_CYCLE_NS * apic->divide_count; - - if (!apic->lapic_timer.period) - return; - /* - * Do not allow the guest to program periodic timers with small - * interval, since the hrtimers are not throttled by the host - * scheduler. - */ - if (apic_lvtt_period(apic)) { - s64 min_period = min_timer_period_us * 1000LL; - - if (apic->lapic_timer.period < min_period) { - pr_info_ratelimited( - "kvm: vcpu %i: requested %lld ns " - "lapic timer period limited to %lld ns\n", - apic->vcpu->vcpu_id, - apic->lapic_timer.period, min_period); - apic->lapic_timer.period = min_period; - } - } - hrtimer_start(&apic->lapic_timer.timer, - ktime_add_ns(now, apic->lapic_timer.period), - HRTIMER_MODE_ABS_PINNED); - - apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016" - PRIx64 ", " - "timer initial count 0x%x, period %lldns, " - "expire @ 0x%016" PRIx64 ".\n", __func__, - APIC_BUS_CYCLE_NS, ktime_to_ns(now), - kvm_lapic_get_reg(apic, APIC_TMICT), - apic->lapic_timer.period, - ktime_to_ns(ktime_add_ns(now, - apic->lapic_timer.period))); + apic->lapic_timer.target_expiration, + HRTIMER_MODE_ABS_PINNED); } static bool set_target_expiration(struct kvm_lapic *apic) @@ -1453,22 +1417,12 @@ static void cancel_hv_timer(struct kvm_lapic *apic) apic->lapic_timer.hv_timer_in_use = false; } -void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu) -{ - struct kvm_lapic *apic = vcpu->arch.apic; - - WARN_ON(!apic->lapic_timer.hv_timer_in_use); - WARN_ON(swait_active(&vcpu->wq)); - cancel_hv_timer(apic); - apic_timer_expired(apic); -} -EXPORT_SYMBOL_GPL(kvm_lapic_expired_hv_timer); - static bool start_hv_timer(struct kvm_lapic *apic) { u64 tscdeadline = apic->lapic_timer.tscdeadline; - if (atomic_read(&apic->lapic_timer.pending) || + if ((atomic_read(&apic->lapic_timer.pending) && + !apic_lvtt_period(apic)) || kvm_x86_ops->set_hv_timer(apic->vcpu, tscdeadline)) { if (apic->lapic_timer.hv_timer_in_use) cancel_hv_timer(apic); @@ -1477,7 +1431,8 @@ static bool start_hv_timer(struct kvm_lapic *apic) hrtimer_cancel(&apic->lapic_timer.timer); /* In case the sw timer triggered in the window */ - if (atomic_read(&apic->lapic_timer.pending)) + if (atomic_read(&apic->lapic_timer.pending) && + !apic_lvtt_period(apic)) cancel_hv_timer(apic); } trace_kvm_hv_timer_state(apic->vcpu->vcpu_id, @@ -1485,14 +1440,29 @@ static bool start_hv_timer(struct kvm_lapic *apic) return apic->lapic_timer.hv_timer_in_use; } +void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu) +{ + struct kvm_lapic *apic = vcpu->arch.apic; + + WARN_ON(!apic->lapic_timer.hv_timer_in_use); + WARN_ON(swait_active(&vcpu->wq)); + cancel_hv_timer(apic); + apic_timer_expired(apic); + + if (apic_lvtt_period(apic) && + set_target_expiration(apic) && + !start_hv_timer(apic)) + start_sw_period(apic); +} +EXPORT_SYMBOL_GPL(kvm_lapic_expired_hv_timer); + void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; WARN_ON(apic->lapic_timer.hv_timer_in_use); - if (apic_lvtt_tscdeadline(apic)) - start_hv_timer(apic); + start_hv_timer(apic); } EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_hv_timer); @@ -1509,7 +1479,10 @@ void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu) if (atomic_read(&apic->lapic_timer.pending)) return; - start_sw_tscdeadline(apic); + if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) + start_sw_period(apic); + else if (apic_lvtt_tscdeadline(apic)) + start_sw_tscdeadline(apic); } EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_sw_timer); @@ -1517,9 +1490,11 @@ static void start_apic_timer(struct kvm_lapic *apic) { atomic_set(&apic->lapic_timer.pending, 0); - if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) - start_sw_period(apic); - else if (apic_lvtt_tscdeadline(apic)) { + if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) { + if (set_target_expiration(apic) && + !(kvm_x86_ops->set_hv_timer && start_hv_timer(apic))) + start_sw_period(apic); + } else if (apic_lvtt_tscdeadline(apic)) { if (!(kvm_x86_ops->set_hv_timer && start_hv_timer(apic))) start_sw_tscdeadline(apic); } @@ -2052,8 +2027,11 @@ void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu) if (atomic_read(&apic->lapic_timer.pending) > 0) { kvm_apic_local_deliver(apic, APIC_LVTT); - if (apic_lvtt_tscdeadline(apic)) + if (!(apic_lvtt_period(apic) && + kvm_lapic_hv_timer_in_use(vcpu))) { apic->lapic_timer.tscdeadline = 0; + apic->lapic_timer.target_expiration = ktime_set(0, 0); + } atomic_set(&apic->lapic_timer.pending, 0); } }