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 4B81AC04E84 for ; Tue, 28 May 2019 07:51:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D81A2075B for ; Tue, 28 May 2019 07:51:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fhmqGhRR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727815AbfE1HvX (ORCPT ); Tue, 28 May 2019 03:51:23 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:37092 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727039AbfE1HvQ (ORCPT ); Tue, 28 May 2019 03:51:16 -0400 Received: by mail-pf1-f194.google.com with SMTP id a23so10974951pff.4; Tue, 28 May 2019 00:51:15 -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=i/suq6wlpwcJ3ogbpvRkyctj8x187X3vDma99VWceU4=; b=fhmqGhRRa8i8a6S8GSmhVDciQYdTzBHI8j7g3gBIlXSDPxDSOedp/VUnDbrv9X+u+7 p8hzNpoXUdMR6+uHxAoox+5EESk1C9OQYZ/A74lZKKG+o7TjFV48PkMx4Wyz2BP7V9i3 oRACxdQUZNk4U1DoJN3Lh71P7S1BBzjMxz4BG4IlQu/yAytuwN0lrT8bmOwZKsc8NMHP QRNgJA4XF7lJmv9OFDQR/wzM6lnGZYuUAxLz2PONuQet6+MhrCYES7ZhRW0YGKfaur6X wWTwm2tk9Pb/vVrLPXrgHv7ZQqrWBEnus3rGKFPPEfG0A6CquNM+kWAyZzPK0MFXEg+h 2fRA== 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=i/suq6wlpwcJ3ogbpvRkyctj8x187X3vDma99VWceU4=; b=XNF8T4vMZyL5u5ZOANV1dpHeOpM6o1xPOlM5QBrHU5ThKE68Z1eyPG4ThNnb7eOAs7 ldjaKjOUgRIqQy2UF3lTTuQpzN8JACC/ZA8w0kzcyWIM1WHiiLxZKsa1ncHeo04SPjFF VN7H+tQ7XRMH9Ifr3hvVbpCesO7ecbacbXZHyKmw9YdquadV3up3lIGKF+l53JSl4Wj6 D+juY/JppDaW4LYpjYLnCEkUpHxg1W5eTeB/1RD+uHyaEYNfLttG6hKus5uvWwHKHp8x aPfUJ+e5gteX8jVD/lZHwWaTlc1sWGS/oZizSvzXm+aMzxs1qjKOMp/yxFjM6cQH2YXp VYyQ== X-Gm-Message-State: APjAAAWF85Eh2gNq+WBz+wLw1B3aPUrbgvySsUlnnVkqiuRh/jjYd9zL 5GH7S7QqbJe5epIcakwr8cUdAsp/ X-Google-Smtp-Source: APXvYqx2orV7SyXM3bS035NmgSHft4vsSFCAjVZ8qQQO+Ml3q/pKYbpNhUBpHu6rRnhhYK8smX5obQ== X-Received: by 2002:a63:dc09:: with SMTP id s9mr90719142pgg.425.1559029875282; Tue, 28 May 2019 00:51:15 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id q20sm18201400pgq.66.2019.05.28.00.51.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 28 May 2019 00:51:14 -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 3/3] KVM: X86: Expose PV_SCHED_YIELD CPUID feature bit to guest Date: Tue, 28 May 2019 15:50:57 +0800 Message-Id: <1559029857-2750-4-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 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 Expose PV_SCHED_YIELD feature bit to guest, the guest can check this feature bit before using paravirtualized sched yield. Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li --- Documentation/virtual/kvm/cpuid.txt | 4 ++++ arch/x86/kvm/cpuid.c | 3 ++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt index 97ca194..1c39683 100644 --- a/Documentation/virtual/kvm/cpuid.txt +++ b/Documentation/virtual/kvm/cpuid.txt @@ -66,6 +66,10 @@ KVM_FEATURE_PV_SEND_IPI || 11 || guest checks this feature bit || || before using paravirtualized || || send IPIs. ------------------------------------------------------------------------------ +KVM_FEATURE_PV_SHED_YIELD || 12 || guest checks this feature bit + || || before using paravirtualized + || || sched yield. +------------------------------------------------------------------------------ KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side || || per-cpu warps are expected in || || kvmclock. diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index e18a9f9..c018fc8 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -643,7 +643,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, (1 << KVM_FEATURE_PV_UNHALT) | (1 << KVM_FEATURE_PV_TLB_FLUSH) | (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | - (1 << KVM_FEATURE_PV_SEND_IPI); + (1 << KVM_FEATURE_PV_SEND_IPI) | + (1 << KVM_FEATURE_PV_SCHED_YIELD); if (sched_info_on()) entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); -- 2.7.4