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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 81CFEC4338F for ; Thu, 19 Aug 2021 11:32:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6924860F5E for ; Thu, 19 Aug 2021 11:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238745AbhHSLdZ (ORCPT ); Thu, 19 Aug 2021 07:33:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:58026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231210AbhHSLdX (ORCPT ); Thu, 19 Aug 2021 07:33:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3F1EF60F11; Thu, 19 Aug 2021 11:32:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629372767; bh=qqUv0afXLlZmgpuXp+0i7xIq823VG8q0+CKIHc5YFx0=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=X8pTqxxyptHJwxAfARUDxpKpRvfj7JlO9CM3caAQ4738Nk5gdAs6MNutinaEnf1us JEj1Ulcgq/lXtuGAl6KZg30vRfot3DVKfhNjizlXFXF62diZKes2ZFzmrjUqqkDZiB gvbsF3XtiW7bYNkQbAGN+NKCtkAmI6jl5Wtuz0GHqFuytdmtQfc346a6ror8bUqvhp pywcAtRV8h3xw0OJ1GM757bWFfMg4vtYF/ZKXh5RBOKQft/UufbaNPMk0dtqnFm3ig Is7J/fhdGuUuDtmj8OjNdlELOudPx+Onyqu8bMPIxSGEjThdS35svcIa+8I8WscRGy cXBOdd1bUkhgw== Message-ID: <565b8fdebe3ff6017bbf46e8928866ee49b44e97.camel@kernel.org> Subject: Re: [PATCH] x86/sgx: Add SGX_MemTotal to /proc/meminfo From: Jarkko Sakkinen To: Shuah Khan , Jethro Beekman Cc: linux-sgx@vger.kernel.org, Shuah Khan , Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Jonathan Corbet , Andy Lutomirski , Peter Zijlstra , Andrew Morton , Mike Rapoport , "Kirill A. Shutemov" , Saravanan D , "Aneesh Kumar K.V" , Krish Sadhukhan , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Date: Thu, 19 Aug 2021 14:32:45 +0300 In-Reply-To: References: <20210818132509.545997-1-jarkko@kernel.org> <20210818134026.GA7967@iki.fi> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.36.5-0ubuntu1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2021-08-18 at 12:34 -0600, Shuah Khan wrote: > On 8/18/21 7:40 AM, Jarkko Sakkinen wrote: > > On Wed, Aug 18, 2021 at 03:29:59PM +0200, Jethro Beekman wrote: > > > On 2021-08-18 15:25, Jarkko Sakkinen wrote: > > > > The amount of SGX memory on the system is determined by the > > > > BIOS and it > > > > varies wildly between systems. It can be from dozens of MB's > > > > on desktops > > > > or VM's, up to many GB's on servers. Just like for regular > > > > memory, it is > > > > sometimes useful to know the amount of usable SGX memory in the > > > > system. > > > >=20 > > > > Add SGX_MemTotal field to /proc/meminfo, which shows the total > > > > amount of > > > > usable SGX memory in the system. E.g. with 32 MB reserved for > > > > SGX from > > > > BIOS, the printout would be: > > > >=20 > > > > SGX_MemTotal: 22528 kB > > > >=20 > > > > It is less than 32 MB because some of the space is reserved for > > > > Enclave > > > > Page Cache Metadata (EPCM), which contains state variables for > > > > all the > > > > pages in the Enclave Page Cache (EPC). The latter contains the > > > > pages, > > > > which applications can use to create enclaves. > > > >=20 > > > > Signed-off-by: Jarkko Sakkinen > > > > --- > > > > Documentation/x86/sgx.rst | 6 ++++++ > > > > arch/x86/include/asm/sgx.h | 10 +++++++--- > > > > arch/x86/kernel/cpu/sgx/main.c | 7 ++++++- > > > > arch/x86/mm/pat/set_memory.c | 5 +++++ > > > > 4 files changed, 24 insertions(+), 4 deletions(-) > > > >=20 > > > > diff --git a/Documentation/x86/sgx.rst > > > > b/Documentation/x86/sgx.rst > > > > index dd0ac96ff9ef..68ee171e1d8f 100644 > > > > --- a/Documentation/x86/sgx.rst > > > > +++ b/Documentation/x86/sgx.rst > > > > @@ -250,3 +250,9 @@ user wants to deploy SGX applications both > > > > on the host and in guests > > > > on the same machine, the user should reserve enough EPC (by > > > > taking out > > > > total virtual EPC size of all SGX VMs from the physical EPC > > > > size) for > > > > host SGX applications so they can run with acceptable > > > > performance. > > > > + > > > > +Supplemental fields for /proc/meminfo > > > > +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > > > + > > > > +SGX_MemTotal > > > > + The total usable SGX protected memory in kilobytes. > > > > diff --git a/arch/x86/include/asm/sgx.h > > > > b/arch/x86/include/asm/sgx.h > > > > index 05f3e21f01a7..2ae9dc8c9411 100644 > > > > --- a/arch/x86/include/asm/sgx.h > > > > +++ b/arch/x86/include/asm/sgx.h > > > > @@ -365,6 +365,13 @@ struct sgx_sigstruct { > > > > * comment! > > > > */ > > > > =20 > > > > +#if defined(CONFIG_X86_SGX) || defined(CONFIG_X86_SGX_KVM) > > > > +extern unsigned long sgx_nr_all_pages; > > > > + > > > > +int sgx_set_attribute(unsigned long *allowed_attributes, > > > > + unsigned int attribute_fd); > > > > +#endif > > > > + > > > > #ifdef CONFIG_X86_SGX_KVM > > > > int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void > > > > __user *secs, > > > > int *trapnr); > > > > @@ -372,7 +379,4 @@ int sgx_virt_einit(void __user *sigstruct, > > > > void __user *token, > > > > void __user *secs, u64 *lepubkeyhash, int > > > > *trapnr); > > > > #endif > > > > =20 > > > > -int sgx_set_attribute(unsigned long *allowed_attributes, > > > > - unsigned int attribute_fd); > > > > - > > >=20 > > > This change seems unrelated? > >=20 > > It's just a good practice not to define symbols that do not exist, > > so that > > if the symbol is ever used, we get a compilation error, not linking > > error. > >=20 > > Since this is included to set_memory.c, based on this conclusion, I > > added > > the check. > >=20 >=20 > It would make sense to make this change in a separate patch since. >=20 > thanks, > -- Shuah NP, I can split it. /Jarkko