From patchwork Wed Apr 13 21:10:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 12812678 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 51B77C433EF for ; Wed, 13 Apr 2022 21:11:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239080AbiDMVN2 (ORCPT ); Wed, 13 Apr 2022 17:13:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238998AbiDMVNF (ORCPT ); Wed, 13 Apr 2022 17:13:05 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 433FA3AA77; Wed, 13 Apr 2022 14:10:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649884243; x=1681420243; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=bp3cIysKGbvkmL/gcaIqhOUdMRw7qGIRpQbHGfemHLI=; b=H93S0kahsQ4j4UyWFwXdSw3J2pDYDqXbb+lIVGTC07us2sR9gMZgaV0S Fjcz/PpzCPIBr1nnjXVojJraF3bGYkLMUgd8M3k0P2CrHfBOXM37S5lNt XII6+uaRG7Krjb6OJeieg5pll5CLgHOmB3/+j0vHQZmbHIVAhUUMmCNsm YLhWMHtBwwU8rbDcx+9HJsHSpa9KmmAxTYcfBU+Pg+HvzKA8xXhF4gKNB QS7q6C0/kvE3lVSfP6rjD8QpEdciez8Sb/S1wk7QKD3K9YVOydVOzf9Pg nEqGpZ2peMiOJJEYD0OsPQl+w1mhx/v85RHW4W6MtIV4U+OO+7nXtdRL4 A==; X-IronPort-AV: E=McAfee;i="6400,9594,10316"; a="323219000" X-IronPort-AV: E=Sophos;i="5.90,257,1643702400"; d="scan'208";a="323219000" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2022 14:10:41 -0700 X-IronPort-AV: E=Sophos;i="5.90,257,1643702400"; d="scan'208";a="725054243" Received: from rchatre-ws.ostc.intel.com ([10.54.69.144]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2022 14:10:40 -0700 From: Reinette Chatre To: dave.hansen@linux.intel.com, jarkko@kernel.org, tglx@linutronix.de, bp@alien8.de, luto@kernel.org, mingo@redhat.com, linux-sgx@vger.kernel.org, x86@kernel.org, shuah@kernel.org, linux-kselftest@vger.kernel.org Cc: seanjc@google.com, kai.huang@intel.com, cathy.zhang@intel.com, cedric.xing@intel.com, haitao.huang@intel.com, mark.shanahan@intel.com, vijay.dhanraj@intel.com, hpa@zytor.com, linux-kernel@vger.kernel.org Subject: [PATCH V4 03/31] x86/sgx: Add wrapper for SGX2 EMODT function Date: Wed, 13 Apr 2022 14:10:03 -0700 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Add a wrapper for the EMODT ENCLS leaf function used to change the type of an enclave page as maintained in the SGX hardware's Enclave Page Cache Map (EPCM). EMODT: 1) Updates the EPCM page type of the enclave page. 2) Sets the MODIFIED bit in the EPCM entry of the enclave page. This bit is reset by the enclave by invoking ENCLU leaf function EACCEPT or EACCEPTCOPY. Access from within the enclave to the enclave page is not possible while the MODIFIED bit is set. After changing the enclave page type by issuing EMODT the kernel needs to collaborate with the hardware to ensure that no logical processor continues to hold a reference to the changed page. This is required to ensure no required security checks are circumvented and is required for the enclave's EACCEPT/EACCEPTCOPY to succeed. Ensuring that no references to the changed page remain is accomplished with the ETRACK flow. Reviewed-by: Jarkko Sakkinen Signed-off-by: Reinette Chatre --- Changes since V3: - Add Jarkko's Reviewed-by tag. Changes since V1: - Split original patch ("x86/sgx: Add wrappers for SGX2 functions") in three to introduce the SGX2 functions separately (Jarkko). - Rewrite commit message to include how the EPCM within the hardware is changed by the SGX2 function as well as the calling conditions (Jarkko). arch/x86/kernel/cpu/sgx/encls.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h index 2b091912f038..7a1ecf704ec1 100644 --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -221,4 +221,10 @@ static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr) return __encls_ret_2(EMODPR, secinfo, addr); } +/* Change the type of an EPC page. */ +static inline int __emodt(struct sgx_secinfo *secinfo, void *addr) +{ + return __encls_ret_2(EMODT, secinfo, addr); +} + #endif /* _X86_ENCLS_H */