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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1A448C433B4 for ; Thu, 1 Apr 2021 20:13:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3ADD60FED for ; Thu, 1 Apr 2021 20:13:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235185AbhDAUNT (ORCPT ); Thu, 1 Apr 2021 16:13:19 -0400 Received: from mga04.intel.com ([192.55.52.120]:64010 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234287AbhDAUNR (ORCPT ); Thu, 1 Apr 2021 16:13:17 -0400 IronPort-SDR: K5LR739EGlcZ4ePDyOOjl9gN+shmlqUBTzjIu9pV7Gi+CyPz5l4PHY/KZiZNHu69vqIo5dxZDE 6syS+xy1k63Q== X-IronPort-AV: E=McAfee;i="6000,8403,9941"; a="190092966" X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="190092966" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2021 13:13:17 -0700 IronPort-SDR: RpueqCdCkYF0xyV4nQ7CclK+I8bG6CuJ6aCpOmU6ifnqhXnhZg2ZaRuyzDymJGzX6LyrjP4aEm 3YqxPRORfotw== X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="611048545" Received: from pzlai-mobl.amr.corp.intel.com (HELO [10.213.169.242]) ([10.213.169.242]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2021 13:13:16 -0700 Subject: Re: [RFC v1 22/26] x86/tdx: Exclude Shared bit from __PHYSICAL_MASK To: Kuppuswamy Sathyanarayanan , Peter Zijlstra , Andy Lutomirski Cc: Andi Kleen , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Dan Williams , Raj Ashok , Sean Christopherson , linux-kernel@vger.kernel.org References: <76d1bc03ab6f12d1943f5bb83fcf0ff8eac55bc1.1612563142.git.sathyanarayanan.kuppuswamy@linux.intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <76d1bc03ab6f12d1943f5bb83fcf0ff8eac55bc1.1612563142.git.sathyanarayanan.kuppuswamy@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/5/21 3:38 PM, Kuppuswamy Sathyanarayanan wrote: > From: "Kirill A. Shutemov" > > tdx_shared_mask() returns the mask that has to be set in page table > entry to make page shared with VMM. Needs to be either: has to be set in a page table entry or has to be set in page table entries Pick one, please. But, the grammar is wrong as-is. > index 8fa654d61ac2..f10a00c4ad7f 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -875,6 +875,7 @@ config INTEL_TDX_GUEST > select PARAVIRT_XL > select X86_X2APIC > select SECURITY_LOCKDOWN_LSM > + select X86_MEM_ENCRYPT_COMMON > help > Provide support for running in a trusted domain on Intel processors > equipped with Trusted Domain eXtenstions. TDX is an new Intel > diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h > index b46ae140e39b..9bbfe6520ea4 100644 > --- a/arch/x86/include/asm/tdx.h > +++ b/arch/x86/include/asm/tdx.h > @@ -104,5 +104,6 @@ long tdx_kvm_hypercall3(unsigned int nr, unsigned long p1, unsigned long p2, > long tdx_kvm_hypercall4(unsigned int nr, unsigned long p1, unsigned long p2, > unsigned long p3, unsigned long p4); > > +phys_addr_t tdx_shared_mask(void); I know it's redundant, but extern this, please. Ditto for all the other declarations in that header. > #endif > #endif /* _ASM_X86_TDX_H */ > diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c > index ae37498df981..9681f4a0b4e0 100644 > --- a/arch/x86/kernel/tdx.c > +++ b/arch/x86/kernel/tdx.c > @@ -41,6 +41,11 @@ bool is_tdx_guest(void) > } > EXPORT_SYMBOL_GPL(is_tdx_guest); > > +phys_addr_t tdx_shared_mask(void) > +{ > + return 1ULL << (td_info.gpa_width - 1); > +} A comment would be helpful: /* The highest bit of a guest physical address is the "sharing" bit */ > static void tdx_get_info(void) > { > register long rcx asm("rcx"); > @@ -56,6 +61,9 @@ static void tdx_get_info(void) > > td_info.gpa_width = rcx & GENMASK(5, 0); > td_info.attributes = rdx; > + > + /* Exclude Shared bit from the __PHYSICAL_MASK */ > + physical_mask &= ~tdx_shared_mask(); > } I wish we had all of these 'physical_mask' manipulations in a single spot. Can we consolidate these instead of having TDX and SME poke at them individually?