From patchwork Tue May 28 07:50:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 10964043 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id ABD17933 for ; Tue, 28 May 2019 07:51:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 96EAF2625B for ; Tue, 28 May 2019 07:51:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8B890286BF; Tue, 28 May 2019 07:51:21 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI 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 26B7F2625B for ; Tue, 28 May 2019 07:51:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727710AbfE1HvQ (ORCPT ); Tue, 28 May 2019 03:51:16 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:36033 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727538AbfE1HvO (ORCPT ); Tue, 28 May 2019 03:51:14 -0400 Received: by mail-pf1-f196.google.com with SMTP id u22so3659954pfm.3; Tue, 28 May 2019 00:51:13 -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=XY0HxMyg3d3xjt/T3hbdmJ9e+Yd85ljT2M6BbObRgNwhuAzKyh+J4/xZwPZoG8BAEA AeJLhF6tBBkEHEm1FZWWBJ4tRSg0uQRtYoqLltgWcDjuInf4N5y8jtJ4SUlmYCnG3Nlc CuU5OpcFM/EzYvK9Aq6XZT0WlsS9pis0QSFgC7ga4jVqOJ3fkqJyq/mFh1+vuW+BDscB xxJzjolO0pIxzh10FEI2XmUfTHBklzwI0xAyZTfN4cqiohIYIyXg94isQzZfoT9mY9Yg 0Wzc4uSZlL2PWPzg9Yu9maMniEIFgUwcqcxyddJKeuZgEFMRjKH1h9AhBNaaUaBLGBmN 8khA== 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=txYcO4aQK0bRAHFS7di6TugHnpYaKRkb52mOBGWua8l3cAukVOQz+1FynvXQJDQuww NNE3m6RHnL+D1tyFr8yqcs7Yod3SK6qjRd+3elvO6FyccClH6zqZYijddatKs9zZIWRZ gjGHxRZa1a2WKVGSyIxnQETk1C7/+Laz1udgawkhq2ZtSr9B1Ur99RN7m4MNqOObmvEq v/dZ/ziuQFBJB6ju4/Y1AA6cs/WysnFfSCoSurLcKw+ZUgulcw2tusVOqbz6lC4Axv7U IxpHpoeuhw81j0Z+yd+3jUzKC8WrkukaUlSTkVsx5GwRIa1ur2bVh/dNdwMPVIkrBsfY fc3w== X-Gm-Message-State: APjAAAWCJLfjSuMe0/1pQ6pCBYSQlW34egzxrIbSmtMrLYoDUlb42lQB 9h/+DpvSzS/fQKDhkkvqijj8MeQi X-Google-Smtp-Source: APXvYqzCI5UwtJPB62OKAfQrkw4+Gy5neK//ERcEeBfdhJn4r0dlhxT9mven2MVqpojMBhFxlpTVbA== X-Received: by 2002:a63:e50c:: with SMTP id r12mr116030865pgh.284.1559029873373; Tue, 28 May 2019 00:51:13 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id q20sm18201400pgq.66.2019.05.28.00.51.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 28 May 2019 00:51:12 -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?b?UmFkaW0gS3LEjW3DocWZ?= Subject: [PATCH RESEND v2 2/3] KVM: X86: Implement PV sched yield hypercall Date: Tue, 28 May 2019 15:50:56 +0800 Message-Id: <1559029857-2750-3-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559029857-2750-1-git-send-email-wanpengli@tencent.com> References: <1559004795-19927-3-git-send-email-wanpengli@tencent.com> <1559029857-2750-1-git-send-email-wanpengli@tencent.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 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;