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 23017C4332F for ; Fri, 11 Mar 2022 08:30:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237762AbiCKIb1 (ORCPT ); Fri, 11 Mar 2022 03:31:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236470AbiCKIbT (ORCPT ); Fri, 11 Mar 2022 03:31:19 -0500 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69FEA1B988B; Fri, 11 Mar 2022 00:30:15 -0800 (PST) Received: by mail-pf1-x42b.google.com with SMTP id z16so7309133pfh.3; Fri, 11 Mar 2022 00:30:15 -0800 (PST) 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=VqrLn451/V+9LmXpVS924CzvE55eM93ytE7ZgyeTObSH2OrmQXwl9qDfSaFJ/vazxR AODWzxxPe5qwA4AO7E6sUHWvtmCTUlQVPgu8wmZ8H05v3RPixnsKTEMtE5t9z7ehRSuI 18prbPVHZ8xhGX4LdwK5xRsK1GJU/gRpl29QQ+bdAUriUyuR3vHW+3vg9eSzeXOnj6vH pQ9xSN7CksgJkbOEcJmwR1cqFBpkZGodZJOMigZjJOpRiVwUWppFuoINEzsXIO+bPyTJ Q+6HbzGdD5gmEaiVq2zUrAvb3g9/lM/Kv9BYcRggrDqB6vb7DRLRhhzlUG7T6czvaUia qs0g== 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=M7ZIwkjLDhbNqt6yAeTKCs+kbBKNDf4eaFc53dZZ8c+EIKfgxAItFyYE+WeIzCcrDT QNy2C3XLUuM355lApIt88p36MgN4VgMkmWbKXNdvmBL0QBnyUwpLuyPutt/TtHQVmQls b4unoTuatD6onDqWQzjAe0Y8CzYM1z+uIwgdNiecX0isqUklmOFRTDSMqAPf9+zQpjjD 12YB1aTyNHiVtAST2H4uAlmTvnO8wmETTr88NEny/LHZA78cgtxmwPkD2R5IzbzXerUe 683YRLeHVskS4K6dkwi4gZn1amlwzZ99i275nixzc4D2lKhWZUawU/W3N1Wm7rIhbw7T Zwag== X-Gm-Message-State: AOAM530OHxHQbrp4IawIYVKmoYjyYrtk8u8uEyIMnMQKi2BOOc9vLtir YPvUhZED+bsdtA2nywBkJwNKBVxX1kM= X-Google-Smtp-Source: ABdhPJxkwC/ucfh7BHQHX2m5BBwxJbpRbTv0HYpts41pL4Iwh309L3G4S9C8putZrR2mYydEc+WHOQ== X-Received: by 2002:a05:6a00:885:b0:4f4:17d8:be31 with SMTP id q5-20020a056a00088500b004f417d8be31mr9128043pfj.57.1646987414815; Fri, 11 Mar 2022 00:30:14 -0800 (PST) Received: from localhost.localdomain ([203.205.141.111]) by smtp.googlemail.com with ESMTPSA id l1-20020a17090aec0100b001bfa1bafeadsm9090576pjy.53.2022.03.11.00.30.12 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 11 Mar 2022 00:30:14 -0800 (PST) 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 4/5] x86/kvm: Add MSR_KVM_PREEMPT_COUNT guest support Date: Fri, 11 Mar 2022 00:29:13 -0800 Message-Id: <1646987354-28644-5-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1646987354-28644-1-git-send-email-wanpengli@tencent.com> References: <1646987354-28644-1-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