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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 61A9FC48BE5 for ; Tue, 15 Jun 2021 16:29:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45F8F6157F for ; Tue, 15 Jun 2021 16:29:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230318AbhFOQbS (ORCPT ); Tue, 15 Jun 2021 12:31:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230299AbhFOQbP (ORCPT ); Tue, 15 Jun 2021 12:31:15 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 385B6C061574 for ; Tue, 15 Jun 2021 09:29:09 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id q63-20020a25d9420000b0290532e824f77cso20717569ybg.10 for ; Tue, 15 Jun 2021 09:29:09 -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=BqMhVGwGdPs1vVNGZdNQGbFGvAB3o8/QDK+Em5NGJQ4=; b=DlpB6KGTch0dP7bG9NbH4d7cdmOYPKFaKI1i2bNyCzusIKUAMd4hzuwMEypEj9jruJ 2IAXeZFGanjcG6VNc5yIYf/nBI2xaAvWC9ljxPFReS5iLQIFvZ4ojLMusw2H9hnrYeRB h0+cLoIH8NkrZbSthgxZg+X4F+iqidefR2+8op1B0i2jKmREo2LWSSb0U9Zt8Ohmrvr5 qKw3NXilTXmpPu/qau9qt+PiWPgJHTu13vRQrOtd/sCozh8PwHAvY3NgvJn8fSE5pli/ qocQQZIcwjdclzRcmSpZZ93d5R9C8NlXFwMLAAJ/bjkudHJ6q/WmQ9M53VDyyxq0nvbw Gqqg== 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=BqMhVGwGdPs1vVNGZdNQGbFGvAB3o8/QDK+Em5NGJQ4=; b=KmTn8c02UFlxB08+2DoP32zXWAx0j+C7M+/Tf6m2ossoQISC+7Zt/p4f80ppcXVYZ+ gWWAoIe1EmEUZJc3GgXL63HoKk1OLDsw/dnBT2VDACF1ERgO6ck0DzTlr42bO3ci2pIF 09TRj60BF8Y/A3DCQry6kZkmZvn/bM3qGrcTkqrKCParCH7xaEmIjtcKv17bPc6ZTIwx y4EqMREMzqpH8Z8nIWgaPSL36tkP5pcX+r1LB0rH65LkdG1ZG9dBQUm8qXnVddkNzsDF YSGlZwt0iX2O9BZaCz0FL6vdI25zLKCxs2+nGKerKxMBmug5g9tj+wmcpC9+93Xwct0Z V9rA== X-Gm-Message-State: AOAM531L1AeKLnXGuFcxiB6c1cedQiPOssV1VU9iwuqETciv/sY2675d e1qCS9QZJHVB5wMgDoZt8GWkaslAG6o= X-Google-Smtp-Source: ABdhPJz9C0vQXeCctY8YoylreZqfG4txJ9hThQc+122bpb1TKJoLDJ7pe6agDPoozs94JZTqpfOXZz027r8= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:13fc:a8bd:9d6b:e5]) (user=seanjc job=sendgmr) by 2002:a25:bec6:: with SMTP id k6mr35017110ybm.187.1623774548423; Tue, 15 Jun 2021 09:29:08 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 15 Jun 2021 09:29:05 -0700 Message-Id: <20210615162905.2132937-1-seanjc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.32.0.272.g935e593368-goog Subject: [PATCH] KVM: x86/mmu: Grab nx_lpage_splits as an unsigned long before division 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Snapshot kvm->stats.nx_lpage_splits into a local unsigned long to avoid 64-bit division on 32-bit kernels. Casting to an unsigned long is safe because the maximum number of shadow pages, n_max_mmu_pages, is also an unsigned long, i.e. KVM will start recycling shadow pages before the number of splits can exceed a 32-bit value. ERROR: modpost: "__udivdi3" [arch/x86/kvm/kvm.ko] undefined! Fixes: 7ee093d4f3f5 ("KVM: switch per-VM stats to u64") Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 720ceb0a1f5c..7d3e57678d34 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -6043,6 +6043,7 @@ static int set_nx_huge_pages_recovery_ratio(const char *val, const struct kernel static void kvm_recover_nx_lpages(struct kvm *kvm) { + unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; int rcu_idx; struct kvm_mmu_page *sp; unsigned int ratio; @@ -6054,7 +6055,7 @@ static void kvm_recover_nx_lpages(struct kvm *kvm) write_lock(&kvm->mmu_lock); ratio = READ_ONCE(nx_huge_pages_recovery_ratio); - to_zap = ratio ? DIV_ROUND_UP(kvm->stat.nx_lpage_splits, ratio) : 0; + to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; for ( ; to_zap; --to_zap) { if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) break; -- 2.32.0.272.g935e593368-goog