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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63BD8C433EF for ; Fri, 25 Mar 2022 13:59:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359252AbiCYOB1 (ORCPT ); Fri, 25 Mar 2022 10:01:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358938AbiCYOBN (ORCPT ); Fri, 25 Mar 2022 10:01:13 -0400 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06A9360A92; Fri, 25 Mar 2022 06:59:35 -0700 (PDT) Received: by mail-pl1-x62c.google.com with SMTP id m18so3214506plx.3; Fri, 25 Mar 2022 06:59:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=4jbCwzr0mct8OKs/Lgqse4ZkWggPrV/4VXWHupxqHk0=; b=nT728+6kR20X1SoIl0V5jnB6v7lr0+IpMj+2Vafc9rc9beExEQmjLTm2p2TOZLz2rN VfynJ8uduC92IgQRDDXKz/VEJvV4l2XdlT1yKY7wOAjqJQcsXG7iuyruqR/wOpQGAsWo pjPvTowRroLFlAwJab3PdPh3/3TplhmVsRinWI3HXC2hBRNC0SVDAc47xfj17McKbNPW bXB3QzVuCLiyXA92OtOv2/lh7VxfeEDuVGshLX8LhatAr+lEyXIByScvhSnMFYduKAr1 LvsMoIO5xvdO8X0BTnDrDXMrmaS76+bW51+kwbvFDCCQkvEDbKng68ovq4G5ueo8VW4c wZLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=4jbCwzr0mct8OKs/Lgqse4ZkWggPrV/4VXWHupxqHk0=; b=jj1j6yKEs+dk5k8FXd9ddVXbz9DfaWWqGV+5ggJOXig+2KIRnohCxRHgxn5Y4pdqc6 dJZYjKo28dqJZkTpImpyGl0m8u0mSAy/S14CNSocvFj2O+iOPdVbth/MUKJFQke2G4IT WpogTS0HeJbwIpNXRPFUjKY0DIQDPtr5xnFmQSLiv1OSWeiRsMWjlgeKSYzx84Qq/gbQ +s0FxDBa/4cpqZQqll0TOx9XM7iLq27U0zIcM9a3aaCg76+PjF9fr1YbbuR3HnKib/nZ k3jOEkaaBa10ZvZF5sEkiXQ+EZAp+0z+nJy/oyKnsy65H8GQsIte74/fpUyZqBZvNEC7 R9/w== X-Gm-Message-State: AOAM533hMVg9f024QL3ppAJWcydy4pleHivKxZvMFxs6z1HLXxxM6jqK P4N3wJrqpMgdKW8eLS0IpR2rwA7Uml8= X-Google-Smtp-Source: ABdhPJxjmkgO4hGCqv5qcydxjfqbeQere/uio1LGQxcMv22iZukZrTDZQvjrF16csQcLHjItIV2f8w== X-Received: by 2002:a17:90b:1d08:b0:1c7:5523:6a1f with SMTP id on8-20020a17090b1d0800b001c755236a1fmr25263357pjb.225.1648216775134; Fri, 25 Mar 2022 06:59:35 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.113]) by smtp.googlemail.com with ESMTPSA id lw4-20020a17090b180400b001c7327d09c3sm14470875pjb.53.2022.03.25.06.59.32 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 25 Mar 2022 06:59:34 -0700 (PDT) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: [PATCH RESEND 4/5] x86/kvm: Add MSR_KVM_PREEMPT_COUNT guest support Date: Fri, 25 Mar 2022 06:58:28 -0700 Message-Id: <1648216709-44755-5-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1648216709-44755-1-git-send-email-wanpengli@tencent.com> References: <1648216709-44755-1-git-send-email-wanpengli@tencent.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wanpeng Li The x86 guest passes the per-cpu preempt_count value to the hypervisor, so the hypervisor knows whether the guest is running in the critical section. Signed-off-by: Wanpeng Li --- arch/x86/kernel/kvm.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 21933095a10e..e389fa4393ae 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -366,6 +366,14 @@ static void kvm_guest_cpu_init(void) if (has_steal_clock) kvm_register_steal_time(); + + if (kvm_para_has_feature(KVM_FEATURE_PREEMPT_COUNT)) { + u64 pa = slow_virt_to_phys(this_cpu_ptr(&__preempt_count)) + | KVM_MSR_ENABLED; + wrmsrl(MSR_KVM_PREEMPT_COUNT, pa); + + pr_debug("setup pv preempt_count: cpu %d\n", smp_processor_id()); + } } static void kvm_pv_disable_apf(void) @@ -442,6 +450,8 @@ static void kvm_guest_cpu_offline(bool shutdown) if (!shutdown) apf_task_wake_all(); kvmclock_disable(); + if (kvm_para_has_feature(KVM_FEATURE_PREEMPT_COUNT)) + wrmsrl(MSR_KVM_PREEMPT_COUNT, 0); } static int kvm_cpu_online(unsigned int cpu) -- 2.25.1