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 C6745C04AB3 for ; Mon, 27 May 2019 10:34:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A7F72146F for ; Mon, 27 May 2019 10:34:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="KM/wQeMt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727008AbfE0Keb (ORCPT ); Mon, 27 May 2019 06:34:31 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:43648 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726966AbfE0Ke0 (ORCPT ); Mon, 27 May 2019 06:34:26 -0400 Received: by mail-pf1-f194.google.com with SMTP id c6so9356532pfa.10; Mon, 27 May 2019 03:34:26 -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=KM/wQeMtXxU5Vx49+QokFlUXZuaHcWVOERnaL+ZNQQ7Iua5QA+FLVFtlfKTucwFSlh Yib1TEkh0PHPfc0xVNRM/nfHs/b6biN6VItfQ7uYq2GDrHTJQaFNTdcV4Vmk1Vc3vA96 JTGc5BDtmAbtYNOa8yNWaXLBroo8wMZYqWuExL+VdOqVdWYO6FCY7bFLvRYloKYpM2Sw yYHmPIa8voeA6mhRyJg3hg5FjMOGmv3m4UR4iC241+/SmnU2BYl/GcFglR9zv0RADYYa DpApbJDnXqHT4xBUn/YOeHTgMbOB7cjb6dzoZcswmGB3UN3EvZLz7vSZDVfx2EOs9vdS TI7w== 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=OXybjskZre2ODLIC080s7VH8Q0cx7va/KzS3p19jiD7qZbKuuW978MIhKzw6tkNPOd ggKCOn9D0vCmoMNYtSt664b+NoZkbnVozR+3yK2u1gXY0uiXUpv0rwjXj32J+T9g0dKu y8gHKis8MVsknEQbagFz3IfIxPak8nMYUM7tauI/L1N1xF1oOAExZAOeVr3mOT4B6560 HNzdpJIQn52Fqotyzc0Ph31dm/nQxnUxFAFqv3NjauXxvnTfyDuwheoEnG+ZCceLmHhW 79Ck7WPvAySMf0L2sGG16KoqjB7dBmz1CD8fTPaB2N9+5K38hN5i7IIDpxQ+tCZZcD+l rhgA== X-Gm-Message-State: APjAAAW+aLnjvLNN5ae6AuY5lanrSigcAvPTZUXMV2wp1XwhijaUeTk9 Xlj6RM1253qH0duBf9VplhBrt2WF X-Google-Smtp-Source: APXvYqzAT7QeHLGJyQ/o+5xUOpLK6bOYfK3aacI1sGN1vtBbJwsA7VWvShHuB+34piV9p8/IeVhlCw== X-Received: by 2002:a63:6647:: with SMTP id a68mr107738296pgc.292.1558953265907; Mon, 27 May 2019 03:34:25 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id y16sm19216452pfo.133.2019.05.27.03.34.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 27 May 2019 03:34:25 -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 3/3] KVM: X86: Expose PV_SCHED_YIELD CPUID feature bit to guest Date: Mon, 27 May 2019 18:34:15 +0800 Message-Id: <1558953255-9432-4-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1558953255-9432-1-git-send-email-wanpengli@tencent.com> References: <1558953255-9432-1-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