From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f173.google.com (mail-pf1-f173.google.com [209.85.210.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D39C72 for ; Thu, 15 Jul 2021 18:39:17 +0000 (UTC) Received: by mail-pf1-f173.google.com with SMTP id q10so6291006pfj.12 for ; Thu, 15 Jul 2021 11:39:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=f3Y0+ogDVT6wqAQ9ZQs2NyHc5pJHUCbPNwTdIK9PvNA=; b=Qv3S59LCo5Nmv9xeE85vyXWs0GZOA6KpAsz49t1UEOxMwgH2P9Y4ljAK74msMmTt2O UNWvggYks0hDjPx8QyMfkCWn1CjZq5S9eiunJ77QL6TXq8rwRbAtkjCrdhgbFBYUHgxn L09H6z5RM3mwM5tX1LZl0rsd/lRhtL/FHHzGNIW6VhH3AJY+KQQ3s+h2yPt5segk0grk 8v5UWFkaC2eF83kmN+zNi9f9KERgDwDm+RB+yjbQirrVge0ZjGQhKibLQ48L41+LPY+j 7ZDohtKMPav2yX+ZJlS4XbJ63NiCsEP02INCQtD+ISzPHyO6hXsIkY+T4rbRtxzv5vb1 fVSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=f3Y0+ogDVT6wqAQ9ZQs2NyHc5pJHUCbPNwTdIK9PvNA=; b=dbF3pf1dxusWBVYtS8Tc/dFmBl764Hl45r9C4qC5wxABO/iejkywz8KsUrL7ha/CQI MN3lJG6Vjb7HimBrmOMjenPG+1WR0JphwhnlBGM7WCcWfpKj12xnSmTcXJmeFKLGxKo9 rpSr0WtaWGcLdKHuzl34shoIQ9ZIkycSGCTqLuYjn8MOsY1ux+uyIII4Hpff/Vq25wzC NI/YoUJw03etfM5mcFezgcBBD4AXpmcafLNg4F18+I/eCciJdVa4RVq5uKhdwcTFt1D3 iiaJmosAE2CfYSk8HXhmyGiOwnOzE23C8peHD5vChE39RbWpXDzirMPvuT6JeKgjC/kt kcoA== X-Gm-Message-State: AOAM533oJch9TrDBzNFCZuP2LJ7Un02AmXqNr4Yxtq1W8nraUGFiHB6r FZ4uEfUdAekKidV1wHldsbIDpQ== X-Google-Smtp-Source: ABdhPJz+1iaVBL+ABO/O1tBChzrqhVRnDYERNo2Clv19fhDRGqCjbjbdtc1OIE70QPX9w7Agiv3K8Q== X-Received: by 2002:a62:19c9:0:b029:32a:129f:542d with SMTP id 192-20020a6219c90000b029032a129f542dmr5859523pfz.8.1626374356838; Thu, 15 Jul 2021 11:39:16 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id 73sm6267842pjz.24.2021.07.15.11.39.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Jul 2021 11:39:16 -0700 (PDT) Date: Thu, 15 Jul 2021 18:39:12 +0000 From: Sean Christopherson To: Brijesh Singh Cc: x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, 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 , 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 , tony.luck@intel.com, npmccallum@redhat.com, brijesh.ksingh@gmail.com Subject: Re: [PATCH Part2 RFC v4 07/40] x86/sev: Split the physmap when adding the page in RMP table Message-ID: References: <20210707183616.5620-1-brijesh.singh@amd.com> <20210707183616.5620-8-brijesh.singh@amd.com> <41f83ddf-a8a5-daf3-dc77-15fc164f77c6@amd.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41f83ddf-a8a5-daf3-dc77-15fc164f77c6@amd.com> On Thu, Jul 15, 2021, Brijesh Singh wrote: > The memfd_secrets uses the set_direct_map_{invalid,default}_noflush() and it > is designed to remove/add the present bit in the direct map. We can't use > them, because in our case the page may get accessed by the KVM (e.g > kvm_guest_write, kvm_guest_map etc). But KVM should never access a guest private page, i.e. the direct map should always be restored to PRESENT before KVM attempts to access the page.