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=ham 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 6F76CC4338F for ; Wed, 18 Aug 2021 13:41:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 594766103A for ; Wed, 18 Aug 2021 13:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236970AbhHRNlg (ORCPT ); Wed, 18 Aug 2021 09:41:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:41394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238611AbhHRNlD (ORCPT ); Wed, 18 Aug 2021 09:41:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CF83D60238; Wed, 18 Aug 2021 13:40:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629294029; bh=80IaIFDHGWp7QnPlslmoBONoY+Zu3mlFuG4CYvGNkRI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j9bfDo033NsQwUiEzHOU9Px4wj9HNOad/7sRDzXkX1HcRJQtiBwM/PZ47Bxwihbtu J/l6NvO92buF2SRsR/itWFowe3/geUXGTHkPwAJLmff4e2l6XcgrTj0ZKS3rJuSXv5 6uDKVLvqvIrkvIqoIb3vvHH2V2VR/zddJ1QlyIJx+0+OaHf6SuW2hdLJFYsH3HuS+f z+71YvHeJSWJq5p686UecVrug5ZP+X1CHFkrW0Lm3rcCMKlxJvzKG13w+w0TyR2cHI 2NwRHkyWiDmB6UQ7ESrkxvuCY9DuVzIhrJW9U3DYzGVw9M7x3P2Op8mBDTdjhYrt9V kUfW4hbmhMHNQ== Date: Wed, 18 Aug 2021 16:40:26 +0300 From: Jarkko Sakkinen To: 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 Subject: Re: [PATCH] x86/sgx: Add SGX_MemTotal to /proc/meminfo Message-ID: <20210818134026.GA7967@iki.fi> References: <20210818132509.545997-1-jarkko@kernel.org> 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-doc@vger.kernel.org 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. > > > > 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: > > > > SGX_MemTotal: 22528 kB > > > > 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. > > > > 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(-) > > > > 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 > > +===================================== > > + > > +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! > > */ > > > > +#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 > > > > -int sgx_set_attribute(unsigned long *allowed_attributes, > > - unsigned int attribute_fd); > > - > > This change seems unrelated? 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. Since this is included to set_memory.c, based on this conclusion, I added the check. /Jarkko