From patchwork Tue Feb 2 18:57:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Gardon X-Patchwork-Id: 12062677 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=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 957A4C433E0 for ; Tue, 2 Feb 2021 19:02:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5750564F6A for ; Tue, 2 Feb 2021 19:02:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239311AbhBBTCn (ORCPT ); Tue, 2 Feb 2021 14:02:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239309AbhBBTA3 (ORCPT ); Tue, 2 Feb 2021 14:00:29 -0500 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FDA0C061224 for ; Tue, 2 Feb 2021 10:58:05 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id o11so11986461pgn.1 for ; Tue, 02 Feb 2021 10:58:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=TvzNxZEmeauTq2Q8+NC26kwWaevzAKsfhvaBGBmdGZw=; b=T+DimJrwM2NuQebN6GQIVbIHXPhvE6MCkly0TwLwZfbQAzn865KoEtBuZzk4JO3R1v pkgXztB7dyVKmSGuyYfBNMzHE6JbhBjNKjHfFnkxuO/LBRg8BQ4pmpxd0RjE6ZR+jOUw OTxW/3s9L2DcmM6t60b5OZZm26CfiQ97p0RLtZIOLom5oz7QW+MKJh3UDiV5P66CfoBH end2v+qmW3oic7P1yvm0YYujO6S29t9glJYKRRYHX11iNNEHXG8m8Ij6l5k9EPVd1bj+ rUA9Yaq3tfSpD2e0a6z1SWatxGFl53QN1fL/D3uATKsvN62XdSxngWdyGsvO2cAeERZs UOVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=TvzNxZEmeauTq2Q8+NC26kwWaevzAKsfhvaBGBmdGZw=; b=XcSrQ0QD5YPa+Krje4kdiqWaNVkRq43twS5EJHC3L9d7GRBJN1DpNWdxtEst1yCTRs 84I1xnm5nzzR+CLtmhL0m+CuPUUOJrusJYRnW/5qs/LjGoEScFmQa3tDw6AmbLNrJYUd ZiCs2VAUZwRwsbd2RwcpyTy2MBIRgCUrZ8cUl5PYgmZJTwqwAuh73lx9jolZ56E7m4IN wNvfIpadOpwKCHAzWnPfb6HB2ammLbzf94Dobv5vSwU64AWiyocbSrgy3YieyI0Qwo0S sI/B1NoxiGOuKfP/OfY91xwkoncQJgcNuupzgLrjjbYTWPiTfwz5d82sjCva0D4pev2y J5jg== X-Gm-Message-State: AOAM532erHSeSXScVxiO0YZ8p4Q06hOY9PsydhZIrf7oqUuPTEMS77mC jTlZFGyNI685pvqtuGRW6VP75NSop25l X-Google-Smtp-Source: ABdhPJxAoifktld/mM+14GeUwIjNAf6XLVqMicqaxaKI0BFtXVEKCZdf91ZkAToJ7z7NNV1jwuaH7UXFTYdR Sender: "bgardon via sendgmr" X-Received: from bgardon.sea.corp.google.com ([2620:15c:100:202:9090:561:5a98:6d47]) (user=bgardon job=sendgmr) by 2002:a63:703:: with SMTP id 3mr23018613pgh.272.1612292285011; Tue, 02 Feb 2021 10:58:05 -0800 (PST) Date: Tue, 2 Feb 2021 10:57:21 -0800 In-Reply-To: <20210202185734.1680553-1-bgardon@google.com> Message-Id: <20210202185734.1680553-16-bgardon@google.com> Mime-Version: 1.0 References: <20210202185734.1680553-1-bgardon@google.com> X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH v2 15/28] KVM: x86/mmu: Skip no-op changes in TDP MMU functions From: Ben Gardon To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Peter Xu , Sean Christopherson , Peter Shier , Peter Feiner , Junaid Shahid , Jim Mattson , Yulei Zhang , Wanpeng Li , Vitaly Kuznetsov , Xiao Guangrong , Ben Gardon Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Skip setting SPTEs if no change is expected. Reviewed-by: Peter Feiner Signed-off-by: Ben Gardon --- v1 -> v2 - Merged no-op checks into exiting old_spte check arch/x86/kvm/mmu/tdp_mmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index c8a1149cb229..aeb05f626b55 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -888,7 +888,8 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, continue; if (!is_shadow_present_pte(iter.old_spte) || - !is_last_spte(iter.old_spte, iter.level)) + !is_last_spte(iter.old_spte, iter.level) || + !(iter.old_spte & PT_WRITABLE_MASK)) continue; new_spte = iter.old_spte & ~PT_WRITABLE_MASK; @@ -1065,7 +1066,8 @@ static bool set_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, if (tdp_mmu_iter_cond_resched(kvm, &iter, false)) continue; - if (!is_shadow_present_pte(iter.old_spte)) + if (!is_shadow_present_pte(iter.old_spte) || + iter.old_spte & shadow_dirty_mask) continue; new_spte = iter.old_spte | shadow_dirty_mask;