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 DF3FFC433F5 for ; Fri, 1 Apr 2022 08:11:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344214AbiDAINn (ORCPT ); Fri, 1 Apr 2022 04:13:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344281AbiDAIM7 (ORCPT ); Fri, 1 Apr 2022 04:12:59 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49391204C92; Fri, 1 Apr 2022 01:11:11 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id c2so1827945pga.10; Fri, 01 Apr 2022 01:11:11 -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=LuKtWHDzvGHRbTbHDfM3kJ4nrniR7w02cItd/4r8DqU=; b=YdX39apgvnvZ8QQVQdWr5LlQxY8QpbVH31PhVXTAMoy91XsIiSLDTvhI7PCXp10QRP F39A+XLdemPxw9t/hrX1kk62N4zBPjQkxNM1qA0kVNpK/fL4Lud/12YNHeL5vt1IdeZO n+GfYKa5uAQrmqq9ZI0C6Xlc7kMY/DbBj/j+ts/HBhQMt6VS7lyhaPrwPgcgUDbny/YD VZbIcMuzV9HULOEwrh0ZbNlmtcW3HMDd/taNaonlgvEbCJG1Re/Fs5SOPynqFPwYt2K1 ko270Zis3TJSJEEqQk1PbC3q23n0GATDTYVdX9wmM66K/3eRY6PG6DB0BykYq9VOZ4r9 XsTA== 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=LuKtWHDzvGHRbTbHDfM3kJ4nrniR7w02cItd/4r8DqU=; b=KRSTuYEqwwdy/4UFM4Lr/n1N5K/1guiKqI9BzC1+W05TrAlGWdvpkv/bAcZH5sLq/s LBIvaHNZXXU14UEJKShC/Ofxvt2HXv4g5dsx4Q3kW7uEjjK5thUFdHKyaeSsIzyWp+IU PGsw+Q+JPn+dCSRiCkOa3iINR7iNBNFXnNGfLiegyLpNY25llWGoYl2Eb9/+IWHLkytI DhkdiugQlBmELccyEQp4qrwex2RA4q0XQ9zVHn0YI5zXUOOVFM0E1an8/E9RowKvdOoK AT9sU1OoWj4MiAFG81diNefQGnzEoCGgBw+2sadiCyVTc4OAJ936TnxolYSf7s5Cw6rg Abww== X-Gm-Message-State: AOAM531cUiXIzmEVrFAmmbSKogN60lkE/7nfevt2hVDqtFM5vP/e2fae hFgg5ADD7qxxkrNkTCPMsH7Ah81ubvw= X-Google-Smtp-Source: ABdhPJwvsw4GLwJVMFco4Y6dng/C9MrWFoCGIYj0lk98wlFSIAaeN8N8I+LQnuoKvVQb9K/faEfR1A== X-Received: by 2002:a63:1c14:0:b0:36b:28ef:f8ce with SMTP id c20-20020a631c14000000b0036b28eff8cemr14111944pgc.96.1648800670613; Fri, 01 Apr 2022 01:11:10 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.113]) by smtp.googlemail.com with ESMTPSA id hg5-20020a17090b300500b001c795eedcffsm11634790pjb.13.2022.04.01.01.11.08 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Apr 2022 01:11:10 -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 v2 4/5] x86/kvm: Add MSR_KVM_PREEMPT_COUNT guest support Date: Fri, 1 Apr 2022 01:10:04 -0700 Message-Id: <1648800605-18074-5-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1648800605-18074-1-git-send-email-wanpengli@tencent.com> References: <1648800605-18074-1-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 79e0b8d63ffa..5b900334de6e 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