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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0ED29C433F5 for ; Fri, 31 Dec 2021 02:35:58 +0000 (UTC) Received: from localhost ([::1]:41466 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n37lt-0006aP-QK for qemu-devel@archiver.kernel.org; Thu, 30 Dec 2021 21:35:57 -0500 Received: from eggs.gnu.org ([209.51.188.92]:56198) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n37kO-0005uS-GU for qemu-devel@nongnu.org; Thu, 30 Dec 2021 21:34:24 -0500 Received: from mga05.intel.com ([192.55.52.43]:30651) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n37kM-00035b-8P for qemu-devel@nongnu.org; Thu, 30 Dec 2021 21:34:24 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1640918062; x=1672454062; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=3xgj6YPF/dL11Z/52845rvYXUsZ6jR0j7Y9+NOsvBzY=; b=K95VyQj5wuV86bskUaDdSUixrL8sxio6Z3gyrV98cTQP5FwcieIL0QHQ RdqCN28GNPi8gM8wmN2cG/c4C14YP1womD+SP/xFgGFc1DimWc+b4zOF7 LIcT+GZJmkKauxBCP8fdUh96zOzwPEaswHRt1Xl8fuoxIn7nQ/poNy4Ks EaHdH1MafxaCQchMeg1iWQP++LQw5SNrJ4j02yoHXX0lr6sPgI2tRSHkV H/IyeYpt+B8Q3OxEUxbR7297ZlyGRK8ORo7jbjehikKiPnG4AMMicAouw LarhhJGIfRav+FsHMlfqHQq9D6sSB/53j5O8H9tVXRpo73+SbeM/lw9LP g==; X-IronPort-AV: E=McAfee;i="6200,9189,10213"; a="328096166" X-IronPort-AV: E=Sophos;i="5.88,250,1635231600"; d="scan'208";a="328096166" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Dec 2021 18:34:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,250,1635231600"; d="scan'208";a="666706992" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.192.101]) by fmsmga001.fm.intel.com with ESMTP; 30 Dec 2021 18:34:10 -0800 Date: Fri, 31 Dec 2021 10:33:34 +0800 From: Chao Peng To: Sean Christopherson Subject: Re: [PATCH v3 kvm/queue 11/16] KVM: Add kvm_map_gfn_range Message-ID: <20211231023334.GA7255@chaop.bj.intel.com> References: <20211223123011.41044-1-chao.p.peng@linux.intel.com> <20211223123011.41044-12-chao.p.peng@linux.intel.com> <20211224041351.GB44042@chaop.bj.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211224041351.GB44042@chaop.bj.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Received-SPF: none client-ip=192.55.52.43; envelope-from=chao.p.peng@linux.intel.com; helo=mga05.intel.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) DKIMWL_WL_HIGH=-0.573, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Chao Peng Cc: Wanpeng Li , jun.nakajima@intel.com, kvm@vger.kernel.org, david@redhat.com, qemu-devel@nongnu.org, "J . Bruce Fields" , linux-mm@kvack.org, "H . Peter Anvin" , ak@linux.intel.com, Jonathan Corbet , Joerg Roedel , x86@kernel.org, Hugh Dickins , Ingo Molnar , Borislav Petkov , luto@kernel.org, Thomas Gleixner , Vitaly Kuznetsov , Jim Mattson , dave.hansen@intel.com, susie.li@intel.com, Jeff Layton , linux-kernel@vger.kernel.org, john.ji@intel.com, Yu Zhang , linux-fsdevel@vger.kernel.org, Paolo Bonzini , Andrew Morton , "Kirill A . Shutemov" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Dec 24, 2021 at 12:13:51PM +0800, Chao Peng wrote: > On Thu, Dec 23, 2021 at 06:06:19PM +0000, Sean Christopherson wrote: > > On Thu, Dec 23, 2021, Chao Peng wrote: > > > This new function establishes the mapping in KVM page tables for a > > > given gfn range. It can be used in the memory fallocate callback for > > > memfd based memory to establish the mapping for KVM secondary MMU when > > > the pages are allocated in the memory backend. > > > > NAK, under no circumstance should KVM install SPTEs in response to allocating > > memory in a file. The correct thing to do is to invalidate the gfn range > > associated with the newly mapped range, i.e. wipe out any shared SPTEs associated > > with the memslot. > > Right, thanks. BTW, I think the current fallocate() callback is just useless as long as we don't want to install KVM SPTEs in response to allocating memory in a file. The invalidation of the shared SPTEs should be notified through mmu_notifier of the shared memory backend, not memfd_notifier of the private memory backend. Thanks, Chao