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=-21.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 E58BAC433B4 for ; Thu, 15 Apr 2021 22:21:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C188B610FB for ; Thu, 15 Apr 2021 22:21:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236376AbhDOWVi (ORCPT ); Thu, 15 Apr 2021 18:21:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234969AbhDOWVi (ORCPT ); Thu, 15 Apr 2021 18:21:38 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4FC5C061574 for ; Thu, 15 Apr 2021 15:21:14 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id g186so2474696qke.23 for ; Thu, 15 Apr 2021 15:21:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:message-id:mime-version:subject:from:to:cc; bh=idyJBHB3aj+yzlWK6cDPev1Rpg8zeSoDNtXngbtjsz4=; b=AZh7zKKHUCfrzkZWZ/vE2t7RwQ1yja5O9PUCkcECAY1mEd/FGtO7mtGxl7i/Trs0me mNt4tcvic4/HAMsK9m1FuKs88rViIm6MWc4VeQKZMLlsGDDlslg5ZIa0/wMgHOo4/Ozf WIDfgqoHY0+CdRlDEz+xAJfUR76aPM4qEbT0LVK/7/Q/UrvBPkQiA0dnTPXUbbxUCTTL T+/U28uiY5qkFjV6G3tLJ7P74lu8kTqnMC9Mpb/Gbdxf6ZzR0loNJQIqIL0d6CzkGi8Z YkL9Q5Md/3j1vELZNuE+2vV98dK3eVc8yMKVGbAFStESq99YYHoMxLKJxZTn5UKQMcGG l6mg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:message-id:mime-version:subject :from:to:cc; bh=idyJBHB3aj+yzlWK6cDPev1Rpg8zeSoDNtXngbtjsz4=; b=kCIvPDQe7x8MrGvFYJ1esyBeYpwrFlA3GZ6WzkMjkn3y9D7Pf2EkA5AoS4DTqSTp1r PI7XjNjtSNFftXcgdOFNiq14gv3lvTkIvKw2itAYKwbBIXvbZpCO6HMQbXmYeBQFSA4M /HA8s3utRsJQTRacmgeEigATlv19T3XYqtLH2z+K1Dd4qQvlAledzn8NVMMW9+yIT+Kj JWtPN6OEzTv4wunJulr5aE5KDzQshqpm6w8yLCSjpF44dtyVHswWHqiymBhHk2FIOXiA 6tfc6kZZ3Rb0udm5aXyNr5/X5vdzvfh4L1kzAwQ+JT0DTmcrkz1kKKFARu2DlLp1KkNS CC6A== X-Gm-Message-State: AOAM532eBz97iknq+GvtlDLIVU1QV5zKx6eMSj42H5MV2lv+ClRKuWjm UiAnxx4U0UOHs7meHmYG2Ebpsnaquio= X-Google-Smtp-Source: ABdhPJyzq2DFbJV2Asv7A8wZh4pNHIG7vnTBd4k7SUprsKaon5I87ZlHqAwJcVNXzpddgQHCsOALUImGaec= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:6c93:ada0:6bbf:e7db]) (user=seanjc job=sendgmr) by 2002:a0c:d605:: with SMTP id c5mr5279271qvj.25.1618525273925; Thu, 15 Apr 2021 15:21:13 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 15 Apr 2021 15:20:57 -0700 Message-Id: <20210415222106.1643837-1-seanjc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.31.1.368.gbe11c130af-goog Subject: [PATCH v3 0/9] KVM: Fix tick-based accounting for x86 guests From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Michael Tokarev , Christian Borntraeger Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This is a continuation of Wanpeng's series[1] to fix tick-based CPU time accounting on x86, with my cleanups[2] bolted on top. The core premise of Wanpeng's patches are preserved, but they are heavily stripped down. Specifically, only the "guest exit" paths are split, and no code is consolidated. The intent is to do as little as possible in the three patches that need to be backported. Keeping those changes as small as possible also meant that my cleanups did not need to unwind much refactoring. On x86, tested CONFIG_VIRT_CPU_ACCOUNTING_GEN =y and =n, and with CONFIG_DEBUG_ENTRY=y && CONFIG_VALIDATE_STACKS=y. Compile tested arm64, MIPS, PPC, and s390, the latter with CONFIG_DEBUG_ENTRY=y for giggles. One last note: I elected to use vtime_account_guest_exit() in the x86 code instead of open coding these equivalents: if (vtime_accounting_enabled_this_cpu()) vtime_guest_exit(current); ... if (!vtime_accounting_enabled_this_cpu()) current->flags &= ~PF_VCPU; With CONFIG_VIRT_CPU_ACCOUNTING_GEN=n, this is a complete non-issue, but for the =y case it means context_tracking_enabled_this_cpu() is being checked back-to-back. The redundant checks bug me, but open coding the gory details in x86 or providing funky variants in vtime.h felt worse. Delta from Wanpeng's v2: - s/context_guest/context_tracking_guest, purely to match the existing functions. I have no strong opinion either way. - Split only the "exit" functions. - Partially open code vcpu_account_guest_exit() and __vtime_account_guest_exit() in x86 to avoid churn when segueing into my cleanups (see above). [1] https://lkml.kernel.org/r/1618298169-3831-1-git-send-email-wanpengli@tencent.com [2] https://lkml.kernel.org/r/20210413182933.1046389-1-seanjc@google.com Sean Christopherson (6): sched/vtime: Move vtime accounting external declarations above inlines sched/vtime: Move guest enter/exit vtime accounting to vtime.h context_tracking: Consolidate guest enter/exit wrappers context_tracking: KVM: Move guest enter/exit wrappers to KVM's domain KVM: x86: Consolidate guest enter/exit logic to common helpers KVM: Move instrumentation-safe annotations for enter/exit to x86 code Wanpeng Li (3): context_tracking: Move guest exit context tracking to separate helpers context_tracking: Move guest exit vtime accounting to separate helpers KVM: x86: Defer tick-based accounting 'til after IRQ handling arch/x86/kvm/svm/svm.c | 39 +-------- arch/x86/kvm/vmx/vmx.c | 39 +-------- arch/x86/kvm/x86.c | 8 ++ arch/x86/kvm/x86.h | 52 ++++++++++++ include/linux/context_tracking.h | 92 ++++----------------- include/linux/kvm_host.h | 38 +++++++++ include/linux/vtime.h | 138 +++++++++++++++++++------------ 7 files changed, 204 insertions(+), 202 deletions(-) -- 2.31.1.368.gbe11c130af-goog