From patchwork Tue Feb 2 18:57:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Gardon X-Patchwork-Id: 12062669 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 9EA1FC433DB for ; Tue, 2 Feb 2021 19:01:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59AF264F66 for ; Tue, 2 Feb 2021 19:01:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239133AbhBBTBJ (ORCPT ); Tue, 2 Feb 2021 14:01:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239221AbhBBS60 (ORCPT ); Tue, 2 Feb 2021 13:58:26 -0500 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B178C061573 for ; Tue, 2 Feb 2021 10:57:46 -0800 (PST) Received: by mail-qt1-x84a.google.com with SMTP id m21so15016007qtp.6 for ; Tue, 02 Feb 2021 10:57:46 -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=KTYEyXIgb4wI42K1yBcuqU69rlausMxtU1GwO2JJSfc=; b=A3SMO1A6jAqBUExSNWmRam6ysZiwsIlC52mBxT2bopExdqHIBugBrv/ileXZbdnRGF i8cVgOJh+zPcodoOUyleOTeF3fMbp4DaOIUDSujm6e6/7JmPxeQlrgtKDMigIhPBFzjW Xqiqa9WEoZ2UW+mP6GwHpblG/H2H8weZzseRVsKfn/YV7BCWl2E+gvJ1+3P7KBd7jGGp LnzaAVttOqPI9eBilD+UWW9acrjfAvbtPMLs/AaAe8Zff4CCewn7UMSyDnlipvlgHexG MDSPtzb/nEzSvA+2X8UUqlK54rdhJ9boWVXOg2MqNj8zbD0QK9BteYRh3RwsBw0UWm5Z 60Jw== 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=KTYEyXIgb4wI42K1yBcuqU69rlausMxtU1GwO2JJSfc=; b=bFROvdEAR+TnmHL1ZEmkWtfFqysucnsd0tm+rtikJchEbLfZfNTXsYjIAKCAcdOFVE roIBTAoxI7DiwWAov3hP39VB/2TMmVPknCsnvTz/jJQQlLQmSU9jKHw0gt+XCqpxHsPC F59zLijo2hUwwzKupmmEKvXiPWtxJDV35r3ZAStbsfLWHDJqw4/zeLYTDPDLWroaYivB NXNLX3Yr0fK6SbUzqOvv9hEkSTn35pka0vcOOAyd+YIyMW78xBR8n6iLnSeNszZv3S/7 PhHsY6peYjnqFf4xSlZ1wzLTmtk38FG5pCxrTXYUYZOMADBQBjCn8XIJACKq33ShPcfg C38A== X-Gm-Message-State: AOAM5326nzIEfatGeOkM5XyZq3fSIr5WbuUubWqm0qOMVJWFKUe5oo5y O+blmiJl3MlIylgdIjRc7IRgANzwSQV0 X-Google-Smtp-Source: ABdhPJw35iQ1myHf6nwzdvwrNMRryl3/GMsxE12DKFd8FH4ic90uHjpGrPkdi51usxmn3uQAKzCJ0aULv8k0 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:ad4:4f41:: with SMTP id eu1mr21827353qvb.34.1612292265673; Tue, 02 Feb 2021 10:57:45 -0800 (PST) Date: Tue, 2 Feb 2021 10:57:10 -0800 In-Reply-To: <20210202185734.1680553-1-bgardon@google.com> Message-Id: <20210202185734.1680553-5-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 04/28] 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 Reviewed-by: Sean Christopherson Acked-by: Paolo Bonzini Signed-off-by: Ben Gardon --- 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 b83a6a3ad29c..3828c0e83466 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -655,7 +655,6 @@ 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);