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=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 EBE9AC28CC2 for ; Thu, 30 May 2019 01:05:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C56A7243D7 for ; Thu, 30 May 2019 01:05:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MsTTioVd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727427AbfE3BF0 (ORCPT ); Wed, 29 May 2019 21:05:26 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:46849 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727413AbfE3BF0 (ORCPT ); Wed, 29 May 2019 21:05:26 -0400 Received: by mail-pf1-f195.google.com with SMTP id y11so2761181pfm.13; Wed, 29 May 2019 18:05:25 -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=2Z5Idi/CPSKFvBQKuXpbeCGvfVzaiO/7Q4QPnwgN73w=; b=MsTTioVd0Q4UgE8TapYzvgKyK0YFqeLTqVZMeGpF0faA4drW/imNuPVPl88UU70BDd Vp0DiHzYxbVftjqJ9I3URqWMEI6pNtXLUFMJxUj+f5e/0Vkc+K+9650LzpkmAo7ZRNvG anoAwr9zoV6KEvhL1KCvcz3swsRUSK7EYmVV9VgH/kvbxZQBvDo5xF6HSK5nFL0ZYJwz 56sGJxWFGw83vCS1iC5hn0KlZP4VT6+/YW3w973NjQO4poAJoZ2/ngMb9lJgcuh0brPq CZpXEz4DyxOvfJ7X8FjSB8K1nw5FLAbvoKOXa4h0klV7kTo8zDcO/oyuwVUwp6889QJh SHlw== 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=2Z5Idi/CPSKFvBQKuXpbeCGvfVzaiO/7Q4QPnwgN73w=; b=ffuvhQKqkMmp6NzgFAxTZyv3nwcpxBAbYMqmUWg66gOnHc3XWr7om2xpSR/pluqnqe MP1u2ov8APf/gc1vvVSiDIN5OpF0ZMQRMUiDKj77I2Zbf0azyllxEwwF4KCZO7FRBBv5 95sCOrQRPlg+yrzYWQVW0cvdWaLFAwOBIRnvpxPR1cLlR1D1vN+PpBSnMtWuXWNu3Hxk wRhWfiZdt7Fd8za1qwhSXWhR9klRjrlF6iCM2VbzIVABFF7hjzy23iL65mWggo6GhIA4 E9U2H7TkfZYVkxOrrDIGUpk8yLwW0Qdxm22jnDvKqPWIwTuWa+UltcQDphH3OuXMRkUk OOBg== X-Gm-Message-State: APjAAAXsZisypqHeFZICy3qC11WWdQq0IJwBN+RLs5Es/2veS75/jOle lOgm+KNz50G5zMeAquRmuKA9Rhy2 X-Google-Smtp-Source: APXvYqwk6+JJYGYvr0hdpknvKOIwvBZmtpTrd/Ht+n3ygGFXlv4pYsSVn6lxop4vpnreCEsv7C9VRA== X-Received: by 2002:a63:fa16:: with SMTP id y22mr1000163pgh.15.1559178325168; Wed, 29 May 2019 18:05:25 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id c76sm861965pfc.43.2019.05.29.18.05.23 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 29 May 2019 18:05:24 -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 v3 3/3] KVM: X86: Expose PV_SCHED_YIELD CPUID feature bit to guest Date: Thu, 30 May 2019 09:05:07 +0800 Message-Id: <1559178307-6835-4-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559178307-6835-1-git-send-email-wanpengli@tencent.com> References: <1559178307-6835-1-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 Cc: Liran Alon 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