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 88AA8C04AB6 for ; Tue, 28 May 2019 07:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 614E72075B for ; Tue, 28 May 2019 07:56:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="r9JapoW1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727980AbfE1H4u (ORCPT ); Tue, 28 May 2019 03:56:50 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:47062 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727707AbfE1H4o (ORCPT ); Tue, 28 May 2019 03:56:44 -0400 Received: by mail-pg1-f196.google.com with SMTP id v9so4081118pgr.13; Tue, 28 May 2019 00:56:44 -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=IcCjT6H+ppzU8yxObmCoxmme1+yJ2Skn/UpNWVNXol4=; b=r9JapoW1TH03Z/msb2tYdBDcW+hg2JYfMfbi9w7RxLk2HRF018D93yT2si+fcWvWJY awPPWDkG3esohpIPq+sPC+d9BmmDseTIzY+MY7hgLZSfnX+bemH8hy6ftlhBI74VHnLR 6jj6HKcdtouJ68EbmdMAVXrC02sUsTtkwgwMs/GZe/jnlKaQVcBlJ5cm7o5VVAQZQK6n +Gk8ec9f7wATmcKF9Jo7vZ+l1XKsXscjs7KpjDVstDmhNXQx6Otj9c1lLGsaSA4Lc+hV zOHe4ve5j7rYdLat+R7sraBfQT65GZm91JLYLJ22YlrHWfL4i0Vy70zYCZFUFMHHCkeQ jw8A== 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=IcCjT6H+ppzU8yxObmCoxmme1+yJ2Skn/UpNWVNXol4=; b=GR8S+RuS7Xi16znXoR6jqJUxXqED3Vs4Z2c/WSDRc3Lq8n1xKAY5QNo9A9zwCg0xNA JVIFfqXpYRI+vUVHi3SBch8O3TepWfRRAb+yK2rikfSXqqaySmHCsOjkGWpQd9kf40AY f43fzFoyWxw5h6IcdZeuA5xLUbNfPUdiRLphiYNyUV+rmWe1Ubk7fC2xy9e+TQBE7C7a WWkrTAY32auGdWUbNZcKGe3vj23skZHZrfI7d/VVoyfn/58+NIcMDcNDHbbRDR6KURjr XpaIsAg9+EyizLNzsFUZUzxuWMCQ7GCps0OfSk6tgwx9mplBglLHqPMj9iIthyW3C7uA VW+g== X-Gm-Message-State: APjAAAXu0XQXFo4gErt1UIfqsvpeSDaUS4r8ZzEaSYioNh7wSGptGCVV bqv7ktxxljzO5Kpek7VTKYZqylV9 X-Google-Smtp-Source: APXvYqykojq1rbvP+sqE1AFM44WkyozcRq8ufVLdy925zEx8t//KLsj8Hj/DGg7G8sgPNaOqUhEzrQ== X-Received: by 2002:a63:246:: with SMTP id 67mr132546747pgc.145.1559030203643; Tue, 28 May 2019 00:56:43 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id t64sm2906920pjb.0.2019.05.28.00.56.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 28 May 2019 00:56:43 -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?= Subject: [PATCH RESEND v2 2/3] KVM: X86: Implement PV sched yield hypercall Date: Tue, 28 May 2019 15:56:34 +0800 Message-Id: <1559030195-2872-3-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559030195-2872-1-git-send-email-wanpengli@tencent.com> References: <1559030195-2872-1-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 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 increase 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 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..f73af3b 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; + struct kvm_apic_map *map; + + rcu_read_lock(); + map = rcu_dereference(kvm->arch.apic_map); + + if (unlikely(!map)) + 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