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=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 D983AC04AB3 for ; Tue, 28 May 2019 02:16:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A96FE2081C for ; Tue, 28 May 2019 02:16:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UhuemyhG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727958AbfE1CQB (ORCPT ); Mon, 27 May 2019 22:16:01 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:35317 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727271AbfE1CQA (ORCPT ); Mon, 27 May 2019 22:16:00 -0400 Received: by mail-pg1-f194.google.com with SMTP id t1so9979654pgc.2; Mon, 27 May 2019 19:16:00 -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=/ZDBl1BXJV4gRCiUXkGA71uLQKwoJlajjwqJkajUw+4=; b=UhuemyhGRRjpvjo5qVobP06kmI59kx+xyITzbazqCStpqZ97FJYVn8OTECed0kbTDB Kdwn02w1ZFAgYBYqhaJed3Bbdb79C1flxTAvxTnpLfQvnY4qChYZYEukAZYTl/WFu0XN MdiHX14Omw5l1lOKKJGr54Q+t2oLZlJuVm+pv76MeVgjT9OyBdwGBBkArl8dvr/rFg+S ztYiwoSaZm+WGfMhznmTRNdS3Z5lTr5dAuHhygrMqPpNY/iVLMNASMRkTMaEADuG5GsC mNII9V/PlJW1XlcQBREfPOw6Hkm7NQFc5M98s/jspk8zldav+ELzQEJzbCN2Wg9FbeA9 /9wA== 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=/ZDBl1BXJV4gRCiUXkGA71uLQKwoJlajjwqJkajUw+4=; b=rOzg3mR8HMWTpA/bgsFQUsowfBO0E3RgfWwQiOGOzZgs7s19VVIR1YkxnrTqFFL5vy aEzMF71m1gPJAzhpZxEH8r8FFoUws+o+GV3JdTld1p+a4y+eJwU+eoAb6rxOECs+fEIa LgKO/kOD4zu7SyZ/Nr/Aiok31kV4Ei58/9uIQGn9Sl/GvWH039hip1s68aybdkqXJ6Jd XNSN6szKvNyLR9GPqGVLPpWWslggCJ5SoI0nkx8NEp64/m+ZTENpFr7emRCVZiLYqtKM dAkQaTFdPJ89Mtk1v2V5FxWQ+BFPKF1I8f1vZARjiPi2F9SFemdlzzJqScpImXHYZ4eR QoDA== X-Gm-Message-State: APjAAAVAEShS5/2UMxyL4Jm6ZMdxbRXwCzE+OVurX4ddhU6SHmABXay0 04719IXTvrcBehEe92Px/vcjZYzN X-Google-Smtp-Source: APXvYqyZGwJxos1Cv1mf9pb4RExFP7Gu1enbMh3+ke3oKkyto5myX+hvjI6a7SDcbuslxz3SfhVkUg== X-Received: by 2002:a17:90a:1ac5:: with SMTP id p63mr2316194pjp.8.1559009759712; Mon, 27 May 2019 19:15:59 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id z11sm16816991pfg.187.2019.05.27.19.15.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 27 May 2019 19:15:58 -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] KVM: X86: Implement PV sched yield hypercall Date: Tue, 28 May 2019 10:15:52 +0800 Message-Id: <1559009752-8536-1-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559004795-19927-3-git-send-email-wanpengli@tencent.com> References: <1559004795-19927-3-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..2f9ec08 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); } +void kvm_sched_yield(struct kvm *kvm, u64 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