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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04D95C433F5 for ; Sun, 6 Mar 2022 00:16:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230076AbiCFARD (ORCPT ); Sat, 5 Mar 2022 19:17:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229752AbiCFARC (ORCPT ); Sat, 5 Mar 2022 19:17:02 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F8EE36B6B; Sat, 5 Mar 2022 16:16:12 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DE95960EC8; Sun, 6 Mar 2022 00:16:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF420C004E1; Sun, 6 Mar 2022 00:16:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646525771; bh=fRzblLoTU0IIepSzyJUSFHl7AXMCwFYni+g4JkSYhbg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QXV9fKVCKfPzG9vF33d7AEPx1yP3YesqHNp08TJJc2sL8HfLEXA/XzmXHNh+A+sLB gwuoW6jbm1JS+gms6qn2NrNlXfKZl0MAS1fEtV2fZW6Wlrhe0nf6itzIud25uuxnKJ CCA1n/BCF4a+e7+JoFap54ZyxIrCxCCg1DXcSYjaLKLKvRTG7RqF/wYQ5N2xZrbkaG jAyhus3BL7L7QynDTZ2uxFs7Y5/8sLjMtOX3GTUr/4v2VaWUhl1phIpM/Yg7B9+a+Z axIMqCx6vpEIOK3PcFQmIk3LQUPPbl30kzigbwpc+VnhEdl1LTl6+IVvQpm+rBbzwZ pobOlAh8xYGrQ== Date: Sun, 6 Mar 2022 02:15:29 +0200 From: Jarkko Sakkinen To: Dave Hansen Cc: Reinette Chatre , Haitao Huang , "Dhanraj, Vijay" , "dave.hansen@linux.intel.com" , "tglx@linutronix.de" , "bp@alien8.de" , "Lutomirski, Andy" , "mingo@redhat.com" , "linux-sgx@vger.kernel.org" , "x86@kernel.org" , "Christopherson,, Sean" , "Huang, Kai" , "Zhang, Cathy" , "Xing, Cedric" , "Huang, Haitao" , "Shanahan, Mark" , "hpa@zytor.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH V2 16/32] x86/sgx: Support restricting of enclave page permissions Message-ID: References: <2d2d3471-78ce-9faa-daf6-138078f5ffaa@intel.com> <6f65287a-f69c-971e-be2c-929e327e7ff9@intel.com> <19155cab-ecff-a8a6-f724-98c4535642ef@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Sat, Mar 05, 2022 at 05:19:24AM +0200, Jarkko Sakkinen wrote: > Sorry, I missed this. > > On Thu, Mar 03, 2022 at 01:44:14PM -0800, Dave Hansen wrote: > > On 3/3/22 13:23, Reinette Chatre wrote: > > > Unfortunately MAP_POPULATE is not supported by SGX VMAs because of their > > > VM_IO and VM_PFNMAP flags. When VMAs with such flags obtain this capability > > > then I believe that SGX would benefit. > > > > Some Intel folks asked for this quite a while ago. I think it's > > entirely doable: add a new vm_ops->populate() function that will allow > > ignoring VM_IO|VM_PFNMAP if present. > > I'm sorry what I don't understand what you mean by ignoring here, > i.e. cannot fully comprehend the last sentece. > > And would the vm_ops->populate() be called right after the existing ones > involved with the VMA creation process? > > > Or, if nobody wants to waste all of the vm_ops space, just add an > > arch_vma_populate() or something which can call over into SGX. > > > > I'll happily review the patches if anyone can put such a beast together. > > I'll start with vm_ops->populate() and check the feedback first for > that. I would instead extend populate() in file_operations into: int (*populate)(struct file *, struct vm_area_struct *, bool populate); This does not add to memory consumption. BR, Jarkko