From patchwork Tue Jun 11 12:23:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 10986753 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 CF4E514E5 for ; Tue, 11 Jun 2019 12:24:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C0D1A287D3 for ; Tue, 11 Jun 2019 12:24:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B49B428852; Tue, 11 Jun 2019 12:24:26 +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 A603F28831 for ; Tue, 11 Jun 2019 12:24:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389125AbfFKMYH (ORCPT ); Tue, 11 Jun 2019 08:24:07 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:46803 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389014AbfFKMYC (ORCPT ); Tue, 11 Jun 2019 08:24:02 -0400 Received: by mail-pf1-f196.google.com with SMTP id 81so7326786pfy.13; Tue, 11 Jun 2019 05:24:01 -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=jpK78n7EuwzwuUYa9uLDGGpmavtbv1Fbssm0HIpkmiA=; b=V4KwM3GLF7HCRFJQBiPn0U0u3Yoq3BpbibnG1fmmwO4ZjhuKm5myUMGG1TFMWlClpo P8JMYHtkcGHvWtDoTgrA8Kyze2rcwUkcgE3vzogbTcBG9+oHJqZFcaQmEJ7mW4FgQLqU UpQkPWnK75g4Wx7sM9bBlItGeVBxl9U8IdYU53ZGmkl9eONwB88AwrvJ+/DegmNS+vnB z/zRVEO89+JJ4m1g4zo6hk779nyb1gWqbQ5OFGFoOR7NWRSSOAte30ANIc3H8yKJRKUu LrlqSgV6ngJ1MA/VMMQob1JnseU5xbbz0gpHBksces9aOZ95CWmmk/tcJ/faHr5Jx1Be ifeg== 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=jpK78n7EuwzwuUYa9uLDGGpmavtbv1Fbssm0HIpkmiA=; b=Z2qePusxNFkeu+gTgoq9Eb61TpE94riAzM2OuKYgnAFSIU0MvtOtShFBUv+nk6hQQ3 x9kyZ9N3ORf2AFj3Lb5gLZHaA5WPl8VCAH/knYRcFBBy9Q3hOqm4U1Li9mjrezBwcwxa XVZvz9SRYOQ8vysDPIqIgkqq3ImPpJdpEs+0NL0jmQBAnUM88Th6HNLw0IEbHg7DcWbb eIOIlhujvwoNqwfCcrKJuD+sVh13jzaY5JU1m8RJeOqdIH1zhnrATuQ16sekmTYNf/F1 6gx1ClfsQmpQymtSbZtpZqtKsnjPSjipdh9p6lHkH/1AOtDOKCTGvP40rD49Dd22LtDe gfuQ== X-Gm-Message-State: APjAAAWi/jNICoS/2S0i9jRfoYHoM06F4SD1SKT6m0t1GNuGRzcII/8x iHEfPi6b2wOsw1be10KD2+X018/Q X-Google-Smtp-Source: APXvYqwUCQThZamEpHtqoJvNjZFPGs7bzsmpbp1MOs9ez3BVKjK/e0lKZvGo0G0RX7J3ChoivEUPkA== X-Received: by 2002:a65:4b88:: with SMTP id t8mr20722333pgq.374.1560255841015; Tue, 11 Jun 2019 05:24:01 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id 127sm14832271pfc.159.2019.06.11.05.23.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 11 Jun 2019 05:24:00 -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?= , Liran Alon Subject: [PATCH v4 3/3] KVM: X86: Expose PV_SCHED_YIELD CPUID feature bit to guest Date: Tue, 11 Jun 2019 20:23:50 +0800 Message-Id: <1560255830-8656-4-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1560255830-8656-1-git-send-email-wanpengli@tencent.com> References: <1560255830-8656-1-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 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 60f87ba..38fc653 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -653,7 +653,8 @@ 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);