From patchwork Tue Jan 12 18:10:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Gardon X-Patchwork-Id: 12014301 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 68675C4332B for ; Tue, 12 Jan 2021 18:12:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 240E92311D for ; Tue, 12 Jan 2021 18:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405554AbhALSMM (ORCPT ); Tue, 12 Jan 2021 13:12:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404494AbhALSMM (ORCPT ); Tue, 12 Jan 2021 13:12:12 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 968EEC061575 for ; Tue, 12 Jan 2021 10:11:01 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id 98so1970582pla.12 for ; Tue, 12 Jan 2021 10:11:01 -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=W0JHfjmfnxHKf2KI8mDZYKQfzNwrieJpg4TDviTJuJA=; b=OZR2XS2wu1SIfSOY7z9UqFZW6+1Ao4td++fjUL/YO0IpVbUC8TW7X8LfQv20YCjHZc jTNW5MV5uqC1dSRZUkTaO7IXSG8sBQAGIcrabx16Nw2I18yXHS2/J9Q6J83ay93xEott 3fTyxv6mLtQvMzdx5e+s8wYklZKZ49NhTOP/Tt47BLJCdnxDOsmGNDFDFc+fVL7wPp+J 5dsiPi5J7zTNwkhBDVlvqJZXBdQOyM2N8jp0b3LVSgBLdSxwhJjhgoNWGrpqeFiG2Bmg JVLq01gBFKyooNNabQ28AP6AxcB0LQoQoxqVQ0JwsHR7F65da4Y/J9xgTQeCInCyh63R fnUg== 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=W0JHfjmfnxHKf2KI8mDZYKQfzNwrieJpg4TDviTJuJA=; b=StxCE9TVPTc9caqikSBIhF2PBRlF+gvVLg+4kXujq3KLhwC9xK1YmUq9LuTS41ZlSF APChGRqQ/XAVjcpGWgqCdYU2LzvxgdxCujwmPxxPL92FGCbpR8S6rYYHXXv3oJYy/ESC wvLp2CM+hS0g8CP5pwTAUo2txA5xzta4mSSc/KwXpGSR8rC6GQWI2C/XZsNZ6S8dNUOr drlbP7Ge1hixbcf3FHATP9xXe30nAdttLZ0diJCoCtpstlAZBAK2DZJnw/clP14b/tJQ fTmFZK0/lhldUBA3g0zmbhx67elssmzG85seqEn4s9+X0KVjCHS3ZgAC5QyEkV8yceBR mPhw== X-Gm-Message-State: AOAM533jCDs47/3wF4eZ57Z81K2qoiacpO6MzJU5t8nxF4LMOEYUGizU XoloVkMBVANQMY9F+z8HTkp88YMVDZGx X-Google-Smtp-Source: ABdhPJwW40lcFfs/Thl05pWnSw40XLyYUcm72yWABZV24LMePwMOXTV9j9umbwRl2OuKGbF6tDxbT6+LVNR9 Sender: "bgardon via sendgmr" X-Received: from bgardon.sea.corp.google.com ([2620:15c:100:202:f693:9fff:fef4:a293]) (user=bgardon job=sendgmr) by 2002:a17:902:724b:b029:de:229a:47f1 with SMTP id c11-20020a170902724bb02900de229a47f1mr427024pll.10.1610475061143; Tue, 12 Jan 2021 10:11:01 -0800 (PST) Date: Tue, 12 Jan 2021 10:10:26 -0800 In-Reply-To: <20210112181041.356734-1-bgardon@google.com> Message-Id: <20210112181041.356734-10-bgardon@google.com> Mime-Version: 1.0 References: <20210112181041.356734-1-bgardon@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH 09/24] kvm: x86/mmu: Don't redundantly clear TDP MMU pt memory 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 The KVM MMU caches already guarantee that shadow page table memory will be zeroed, so there is no reason to re-zero the page in the TDP MMU page fault handler. No functional change intended. Reviewed-by: Peter Feiner Signed-off-by: Ben Gardon Reviewed-by: Sean Christopherson --- arch/x86/kvm/mmu/tdp_mmu.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 411938e97a00..55df596696c7 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -665,7 +665,6 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level); list_add(&sp->link, &vcpu->kvm->arch.tdp_mmu_pages); child_pt = sp->spt; - clear_page(child_pt); new_spte = make_nonleaf_spte(child_pt, !shadow_accessed_mask);