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 643FAC072B1 for ; Tue, 28 May 2019 07:56:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C4F72075B for ; Tue, 28 May 2019 07:56:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ECYqfw7g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727951AbfE1H4s (ORCPT ); Tue, 28 May 2019 03:56:48 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:45685 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbfE1H4q (ORCPT ); Tue, 28 May 2019 03:56:46 -0400 Received: by mail-pg1-f196.google.com with SMTP id w34so5804347pga.12; Tue, 28 May 2019 00:56:45 -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=ECYqfw7gsUzl3sA/NMdyK82zPejq0iU0eFkiPFVAoME0Qa3iZzAwZNgvBuXJkmdANB c1xG8te3/3BcbDvLIdQwEuw3vO/W8Cb7R1MwBfUs2fLqFvKl3/ubr3/aS4/PcjQahdQg g6ZIide7yY0c4/NlSxHoYnryflJTZuCqc9I7vgLuNsb5gGsnvvJcugKVzwZPTbPap7ll 2sXVDzGcaaVaGvzfsczAL9f7/UEoy4qWfn7Z3LvgNKzDXWtBxEOT/qdamNv5l9X5SY9X 2+LbJ7KKndXocJxlSlwkd0YUcf/vtsC3f+pGQTxX7AHHk7Xgz8V45Hgc9SApTu98iqDS FemQ== 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=kvA83/YRWTyQGGdJd/6/2DeAKLaoCNXmVokPzqitFyPrPQ1wL6fP/DkyyucImeZ7QO eg3BV/qIKpZ5gIigbQfKXFV9fLFXDxXj00AkEbLWydw950NbMgfSeA/sfshyL2ZWc0bp obmNaUkWiPDzhF48/afPBHQgCBVKZXkk852QB0CcUr7qU/9zpjSn6iwPz6Y4mpar1mUH tjPhfSMl60yJ3MbOwRNvzOBk7q12mtYAOEF+othPoZEjZO4C6mMw6JytSpnF6TyMsLMm gc+iEDPO4HFnvNq1A0AebFF3vezp+Q4K9Ez4IxYHEHZGQZV7OgYe4AHsEJouAf0ijV1o Qizw== X-Gm-Message-State: APjAAAVyqNaPrtIaIwB3vI2rbrWQhzXNr8IKzJe4qSooY4pXlwmkON5n 6Mo233sUOqkWDPuuXEUsQ5HqUy7M X-Google-Smtp-Source: APXvYqzLwS6S67O6iGxhlvp+de+SklbtDAPQhSBt8APPY0ylnxElE1Ll524sT2mFjHjyUjXlhQH+Aw== X-Received: by 2002:a65:4b88:: with SMTP id t8mr131708342pgq.374.1559030205498; Tue, 28 May 2019 00:56:45 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id t64sm2906920pjb.0.2019.05.28.00.56.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 28 May 2019 00:56:45 -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 15:56:35 +0800 Message-Id: <1559030195-2872-4-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559030195-2872-1-git-send-email-wanpengli@tencent.com> References: <1559030195-2872-1-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