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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=no 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 7D56FC433EF for ; Thu, 23 Sep 2021 20:55:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 672CB60F6F for ; Thu, 23 Sep 2021 20:55:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243136AbhIWU4w (ORCPT ); Thu, 23 Sep 2021 16:56:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242950AbhIWU4o (ORCPT ); Thu, 23 Sep 2021 16:56:44 -0400 Received: from mail-oo1-xc29.google.com (mail-oo1-xc29.google.com [IPv6:2607:f8b0:4864:20::c29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7F19C061757 for ; Thu, 23 Sep 2021 13:55:12 -0700 (PDT) Received: by mail-oo1-xc29.google.com with SMTP id g4-20020a4ab044000000b002900bf3b03fso2604296oon.1 for ; Thu, 23 Sep 2021 13:55:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=tuAuDbYoqWTX1qLGSlEdN/vEAB2ogbMYztyFItd+EBc=; b=kffc8Bs2M9fmas9cVTmc2dxOYcmX43mfJnInRmBRfKL4ci0Ra/Ed4N8E9aIVQqSA24 y6quxScpBT1ZO+7locgf2IBsBtTWSV1MKNtI2oVT4do2OZeKdRz10YZCGL/52KyupAbV 8aWkm3j9u3p+CMwFtEy2BYAl++cwlQPKQPEbredKllWpQDcZG0YCswdFmrI0IV65882C QrAs7PCAcggjX4Ld0w7WKDz9iYcyrX72CHPj2bDCzmi5ujt9pcaMq+9eQgQMIWSurH2G Eys/T351rHFPil0fxp9pW01KjxiNyz8ucX3AGU0NrklTz5k2qrrM1pH/hsaX+WoH5gj0 HvuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=tuAuDbYoqWTX1qLGSlEdN/vEAB2ogbMYztyFItd+EBc=; b=I75MV/ZcsRyqH6SGuebdaE3ka0DhLaXCZ2ulRAnALkOJLN1mTPS6pnvzEmFWSFGM+P Xzw/bnJcAlYK4CNXNiRTplaxUixkcVRDqr5oZ+XQyyRcUfuH5dBVNw38AEchcCrj2p+r unSGrGByp5GLJGXlSdiV6papUNZUtEIDys1Z5Hbqf99J8XPfWdodESyBYVXxn7Pf68bo RHxD1dKAdY5kCmvWcAEOXOeItk9CHxB9SPJCK4fpM5B5En+jIv9MGs6p+yGbN9YU8x+r 5vx/J3IFS9ohSwvF0OK/KXffml9GqJBvu3ilgW4lNv63ztPncl2V4ozSZ5FnbEYDqMKX OyDA== X-Gm-Message-State: AOAM531lwnpb1cMYcC9cVG8P44g0ipXzPVHtGwJQLBvdJL7DCzZ5inGA 04tiIzjw/bcPI2FdnKdZq1ptk0CgqfD+Zqkzxwvd/g== X-Google-Smtp-Source: ABdhPJyrQCd4do4odQK5DYKgmv7IsQ+AMJhA+BxnQq44T7hGl3RRh3tzoKAYCmy4S2uMMD9KFjWXH8MfmAL80dEIdbw= X-Received: by 2002:a4a:7452:: with SMTP id t18mr5499065ooe.20.1632430511717; Thu, 23 Sep 2021 13:55:11 -0700 (PDT) MIME-Version: 1.0 References: <20210820155918.7518-1-brijesh.singh@amd.com> <20210820155918.7518-22-brijesh.singh@amd.com> <9f89fce8-421a-2219-91d0-73147aca4689@amd.com> In-Reply-To: <9f89fce8-421a-2219-91d0-73147aca4689@amd.com> From: Marc Orr Date: Thu, 23 Sep 2021 13:55:00 -0700 Message-ID: Subject: Re: [PATCH Part2 v5 21/45] KVM: SVM: Make AVIC backing, VMSA and VMCB memory allocation SNP safe To: Brijesh Singh Cc: "Dr. David Alan Gilbert" , x86 , LKML , kvm list , linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Borislav Petkov , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , tony.luck@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 23, 2021 at 1:44 PM Brijesh Singh wrote: > > > On 9/23/21 2:17 PM, Marc Orr wrote: > > >>>> + > >>>> +struct page *snp_safe_alloc_page(struct kvm_vcpu *vcpu) > >>>> +{ > >>>> + unsigned long pfn; > >>>> + struct page *p; > >>>> + > >>>> + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) > >>>> + return alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); > > Continuing my other comment, above: if we introduce a > > `snp_globally_enabled` var, we could use that here, rather than > > `cpu_feature_enabled(X86_FEATURE_SEV_SNP)`. > > > Maybe I am missing something, what is wrong with > cpu_feature_enabled(...) check ? It's same as creating a global > variable. The feature enabled bit is not set if the said is not > enabled. See the patch #3 [1] in this series. > > [1] > https://lore.kernel.org/linux-mm/YUN+L0dlFMbC3bd4@zn.tnic/T/#m2ac1242b33abfcd0d9fb22a89f4c103eacf67ea7 > > thanks You are right. Patch #3 does exactly what I was asking for in `snp_rmptable_init()`. Thanks!