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=-8.6 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=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 A87A5C4321B for ; Tue, 11 Jun 2019 12:24:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F4E42089E for ; Tue, 11 Jun 2019 12:24:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bF8RdgWy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389085AbfFKMYD (ORCPT ); Tue, 11 Jun 2019 08:24:03 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:46795 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388969AbfFKMYA (ORCPT ); Tue, 11 Jun 2019 08:24:00 -0400 Received: by mail-pf1-f193.google.com with SMTP id 81so7326713pfy.13; Tue, 11 Jun 2019 05:23:59 -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=cGX8ZE5HpPEM8W1A+XwV2MspPdA5BLlcqW7hwnjzPDE=; b=bF8RdgWyt+9d2epLHryzbj0tkgROcIvkGYmrBrdLRN79pcvcqY37JfpJ2yPxoAXF51 14GP4T4+hsfzmtZenxi9nRf5wGYW3AbdcQodHfOs4Fr/0A6CDYXsWDxenABFwwhqnNNl v9RDab5wX4VMQlZHJCTtpkdN4fg65xnDcD9QeUT/ZeVxccf+Gs70X0mG1KXCKGPKoqhi epkBZYEPX3AHnKFD3iPWfKMV37psb+PiV0mDDuV1eiaEBxnNqh1QTduJ44zi3RtW2oQp hUhE7a0GuX2hpjDB99OoPrkrjcvgyAbgok0zslDPluKScVDjgGdRgdIU7UsL5hIYWpi9 UAoQ== 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=cGX8ZE5HpPEM8W1A+XwV2MspPdA5BLlcqW7hwnjzPDE=; b=eBrhqfDIo3pfHSutvTfi2KbAujy6vpGrntq0qW2Dpk4omBNQQ1rbmEhzRHnmo6lZ9x D8Db4oVa0YgYct/vNth5zrFAmj27cMGhm9Ujuc0bkOmM7/E+kIPkMa/Rs5i8LZLdZv7M NgTDZkUXYGoOhRHC5kTqo3op4AB3gy7lM2SiNY1Wt7UorjkeRII3hhPO+l2TfHQSZIDD ewJsNOCRJYuCmJ8IEaD07J26BXs7ZzoO6IVzzHfHVyiKJrXJqT/bJaFbRRgIwoRm3r+i Z9dFS652YxGvAuE89Bn83DlnXc/eccfKuQrg4SeStVAeH1Udj/Yup0fU4R+YuOtbYGH3 CRdQ== X-Gm-Message-State: APjAAAWc+AX6EznOhsCpmbD1ssQv/8wHNsB6sTJiRhlwq/nsd6tLS9LA yHkLbL5ubXn6RwVcTGCntCe32aBS X-Google-Smtp-Source: APXvYqwTdZo6LzWhDaT78xZ1R7AU2rhrg0GhTSGylvLrBLcM8qPZeHoK6vpu2bdOS8lFNxcrONfxYg== X-Received: by 2002:a63:2c50:: with SMTP id s77mr19852056pgs.175.1560255838924; Tue, 11 Jun 2019 05:23:58 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id 127sm14832271pfc.159.2019.06.11.05.23.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 11 Jun 2019 05:23:58 -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?= , Liran Alon Subject: [PATCH v4 2/3] KVM: X86: Implement PV sched yield hypercall Date: Tue, 11 Jun 2019 20:23:49 +0800 Message-Id: <1560255830-8656-3-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560255830-8656-1-git-send-email-wanpengli@tencent.com> References: <1560255830-8656-1-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 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 | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 35c4884..6d49ea0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7160,6 +7160,23 @@ 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; + + rcu_read_lock(); + map = rcu_dereference(kvm->arch.apic_map); + + if (likely(map) && dest_id <= map->max_apic_id && map->phys_map[dest_id]) + target = map->phys_map[dest_id]->vcpu; + + rcu_read_unlock(); + + if (target) + kvm_vcpu_yield_to(target); +} + int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) { unsigned long nr, a0, a1, a2, a3, ret; @@ -7206,6 +7223,10 @@ 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