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 0BF2BC433F5 for ; Mon, 2 May 2022 22:07:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1387816AbiEBWKi (ORCPT ); Mon, 2 May 2022 18:10:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1387811AbiEBWIb (ORCPT ); Mon, 2 May 2022 18:08:31 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41FDEDEED for ; Mon, 2 May 2022 15:03:55 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-2f8d487f575so73910057b3.5 for ; Mon, 02 May 2022 15:03:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=2gUboy0WpFlCg1gFI2kR0+guXhO1kfu4J8SY0iPJjDQ=; b=GewRa3J35S+FRxNXKKNFgCgf7atU9k5i09pFjVniOagEm8rpyRY7mK3a3MyKONvGMZ gNesx2hOixBJwkSpuKBZr1Po+U8aUb/Qb1UO7c2JL7F4D8oofG4pzq2GuXujTlHJpNWt pG8PVZxHVVVztANqRqQO0xzma2sAQyz2xZGXKGEMCkWPMpuNzmPIyn44DoiKCbMN/gQW Nrm86pDSQkwH8uo5SJHT0q+enzstOYvIvtu5iWpKQdvVrzV01Wy3rTMY0T6G24zBII2+ 8YRJOGw6Ics802QVk8asorbOB7jvWxV15lAvXI6HHNBDcuUdLRq+JZ2a0RGoFc+GRqaJ NnaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=2gUboy0WpFlCg1gFI2kR0+guXhO1kfu4J8SY0iPJjDQ=; b=xiBGTfPUzEEGc7MHG+/I/Gn3YIDbUHuAKzJaoa0z43lppFj8Za8zoREO1CAMZgodnm W6pqOBBPwGxw/gLvlMxFtQtebgQXC5C/NuyVfZiZtDn0ckBSL7RssRFwxo1owTIN6fPM mlnmlMjkhgl0iOLl79WbjavlC0QKoUvx64/t+cmRtyIXSCZtViL8gbkiuaDO58F3aNr7 D2mLJHngFug3wH7KXF2jLJhnfPxtDGcJrvRjM04ORMfOicvJwfVyKlP9rD/75qYhtU6P 3aGvlSS9A2StlNLv4ySGAzKaxva5xCKi7ZrjBFjjCxkVtYOe+nRs0JKsEs5vwpful+MO AiuA== X-Gm-Message-State: AOAM530OG+DZGGPS4vtJ+naK9Z164t7QXKP/Dy3L6rTN83LZ+u0vBDja stFxfm9UdAB23NedIeLFoKWs9aqmJ90M X-Google-Smtp-Source: ABdhPJzMjKvSd35EBOdYVwnOBd4B9dGqLkUE0gmUdyvpyWamIAbFHfgnhXf5yZ6H5mWCliCMcfTaEIE80lu+ X-Received: from vipinsh.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:36b0]) (user=vipinsh job=sendgmr) by 2002:a5b:68a:0:b0:648:fcd2:3767 with SMTP id j10-20020a5b068a000000b00648fcd23767mr12309259ybq.358.1651529034451; Mon, 02 May 2022 15:03:54 -0700 (PDT) Date: Mon, 2 May 2022 22:03:47 +0000 Message-Id: <20220502220347.174664-1-vipinsh@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.0.464.gb9c8b46e94-goog Subject: [PATCH v2] KVM: x86/mmu: Speed up slot_rmap_walk_next for sparsely populated rmaps From: Vipin Sharma To: pbonzini@redhat.com Cc: seanjc@google.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, dmatlack@google.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vipin Sharma Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Avoid calling handlers on empty rmap entries and skip to the next non empty rmap entry. Empty rmap entries are noop in handlers. Signed-off-by: Vipin Sharma Suggested-by: Sean Christopherson --- v2: - Removed noinline from slot_rmap_walk_next signature v1: - https://lore.kernel.org/lkml/20220325233125.413634-1-vipinsh@google.com arch/x86/kvm/mmu/mmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 77785587332e..4e8d546431eb 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1501,9 +1501,11 @@ static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) { - if (++iterator->rmap <= iterator->end_rmap) { + while (++iterator->rmap <= iterator->end_rmap) { iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); - return; + + if (iterator->rmap->val) + return; } if (++iterator->level > iterator->end_level) { base-commit: 71d7c575a673d42ad7175ad5fc27c85c80330311 -- 2.36.0.464.gb9c8b46e94-goog