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=-8.9 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 F02F4C28CC2 for ; Thu, 30 May 2019 01:05:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9DA4243DA for ; Thu, 30 May 2019 01:05:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Lf/QLago" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727408AbfE3BFY (ORCPT ); Wed, 29 May 2019 21:05:24 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:38687 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727402AbfE3BFX (ORCPT ); Wed, 29 May 2019 21:05:23 -0400 Received: by mail-pf1-f194.google.com with SMTP id a186so2091627pfa.5; Wed, 29 May 2019 18:05:23 -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=Nl87Zzt2g/Jhk18hZDpMWkRfM4v7xHWaSrq5qLezpJc=; b=Lf/QLagolBqTstdBtF0EHeqzeM+OeTuLhSpkv/iHTh0H0681R/OJPR3dS9Lu92ch0C gC2Hyub52q69czChb5oYC5DDr+BQDqRClJJOf0UUNMJcPWzmC7EKsbLSi4heAHpJ1LX0 zT27udAuTMtT20uuAWhmHZS9ivfLb4V111AeyLNwC/K3p75Q313wSqUsbuiLk+BN+xys O1r1MjMWpOpEg+GSUz8d8P6smE1ZXxLuGlpHVl9kBO+daVsPmH6jnnTZ8e1ygQA8Eelg ikCkQQnkF/tWqFEyF2Jjs00VOOcs5AvJnz0dl61zcn5GkbIfGoZdEd8WPK+MriVfxQEK ER4w== 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=Nl87Zzt2g/Jhk18hZDpMWkRfM4v7xHWaSrq5qLezpJc=; b=IuWrRq9RIkF67TWcBpPTbivB4r5AmhZ46tHVANn5O3U0I7AdYzyEr3x5h0XPfmzIWr p5qWnjn8JbGk154N5Xz5KZAB0uU/pwZhGyAxKt+Hch33Y/xqv7He7VDXKUh4ei3WeYM8 oJRhaAHJ6atFIXibir6vA051joWOEemLudOiidnczj9Jnb+Iuy7TXBleY0eWY2Botw0W Anvb13NazSb+Zp+kEO3Zbrf3kXM5cfLwymYEBfAEsDapWzXmEkFNTxj3Ea/J/ALD9D8C URxS+y6LRnl0Q8+BNe5RAC1OaT74mv683oo/Uasw40l8WitA3GdOGL5sTMJnyJt7n+c9 t8Tw== X-Gm-Message-State: APjAAAVVvWDX4cxRudrQjyFbPHoiGwsibMtYAHm2P3x9cRwd337FCmQb p2dnGrcDTOgHZ9ZYzcaHFr77ulqx X-Google-Smtp-Source: APXvYqzn35UrHLbk3sYI0EeUtfr/XAbRlrVdSiTj/y3EKOPC/FZ7tWNsFsfV47WqqsEh3cl9SxPkZg== X-Received: by 2002:a62:ed0a:: with SMTP id u10mr621128pfh.243.1559178323036; Wed, 29 May 2019 18:05:23 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id c76sm861965pfc.43.2019.05.29.18.05.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 29 May 2019 18:05:22 -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?= , Liran Alon Subject: [PATCH v3 2/3] KVM: X86: Implement PV sched yield hypercall Date: Thu, 30 May 2019 09:05:06 +0800 Message-Id: <1559178307-6835-3-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559178307-6835-1-git-send-email-wanpengli@tencent.com> References: <1559178307-6835-1-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Wanpeng Li The target vCPUs are in runnable state after vcpu_kick and suitable as a yield target. This patch implements the sched yield hypercall. 17% performance increasement of ebizzy benchmark can be observed in an over-subscribe environment. (w/ kvm-pv-tlb disabled, testing TLB flush call-function IPI-many since call-function is not easy to be trigged by userspace workload). Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Liran Alon Signed-off-by: Wanpeng Li --- arch/x86/kvm/x86.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e7e57de..8575b36 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7172,6 +7172,28 @@ void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu) kvm_x86_ops->refresh_apicv_exec_ctrl(vcpu); } +static void kvm_sched_yield(struct kvm *kvm, unsigned long dest_id) +{ + struct kvm_vcpu *target = NULL; + struct kvm_apic_map *map = NULL; + + rcu_read_lock(); + map = rcu_dereference(kvm->arch.apic_map); + + if (unlikely(!map) || dest_id > map->max_apic_id) + goto out; + + if (map->phys_map[dest_id]->vcpu) { + target = map->phys_map[dest_id]->vcpu; + rcu_read_unlock(); + kvm_vcpu_yield_to(target); + } + +out: + if (!target) + rcu_read_unlock(); +} + int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) { unsigned long nr, a0, a1, a2, a3, ret; @@ -7218,6 +7240,10 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) case KVM_HC_SEND_IPI: ret = kvm_pv_send_ipi(vcpu->kvm, a0, a1, a2, a3, op_64_bit); break; + case KVM_HC_SCHED_YIELD: + kvm_sched_yield(vcpu->kvm, a0); + ret = 0; + break; default: ret = -KVM_ENOSYS; break; -- 2.7.4