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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 3B734C4363D for ; Wed, 23 Sep 2020 14:47:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F27BA206FB for ; Wed, 23 Sep 2020 14:47:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726332AbgIWOrQ (ORCPT ); Wed, 23 Sep 2020 10:47:16 -0400 Received: from mga02.intel.com ([134.134.136.20]:59208 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726156AbgIWOrQ (ORCPT ); Wed, 23 Sep 2020 10:47:16 -0400 IronPort-SDR: j6W3uEjE9Y+3k9zHsmzK4wHpMq25AsGUDSUcozhNIqmWB+BrOiRodR14Wv1aI/Vo+IvUykgixA r/twI1UvUjjA== X-IronPort-AV: E=McAfee;i="6000,8403,9753"; a="148555259" X-IronPort-AV: E=Sophos;i="5.77,293,1596524400"; d="scan'208";a="148555259" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2020 07:47:16 -0700 IronPort-SDR: +Xbj246mPwIR7pSKj2Xz72hEM1umcXBC9/gNFta2Bio+n7wIj4HD2vUlCu2+KMNRXyxnLYDd3w 25GHJHBj+QqQ== X-IronPort-AV: E=Sophos;i="5.77,293,1596524400"; d="scan'208";a="486464881" Received: from linortne-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.49.223]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2020 07:47:09 -0700 Date: Wed, 23 Sep 2020 17:47:07 +0300 From: Jarkko Sakkinen To: Borislav Petkov Cc: Jethro Beekman , Sean Christopherson , x86@kernel.org, linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org, Haitao Huang , Chunyang Hui , Jordan Hand , Nathaniel McCallum , Seth Moore , Darren Kenny , Suresh Siddha , akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com, asapek@google.com, cedric.xing@intel.com, chenalexchen@google.com, conradparker@google.com, cyhanish@google.com, dave.hansen@intel.com, haitao.huang@intel.com, josh@joshtriplett.org, kai.huang@intel.com, kai.svahn@intel.com, kmoy@google.com, ludloff@google.com, luto@kernel.org, nhorman@redhat.com, puiterwijk@redhat.com, rientjes@google.com, tglx@linutronix.de, yaozhangx@google.com Subject: Re: [PATCH v38 14/24] x86/sgx: Add SGX_IOC_ENCLAVE_INIT Message-ID: <20200923144707.GF5160@linux.intel.com> References: <20200915112842.897265-1-jarkko.sakkinen@linux.intel.com> <20200915112842.897265-15-jarkko.sakkinen@linux.intel.com> <20200921173514.GI5901@zn.tnic> <20200921181021.GA24481@linux.intel.com> <20200921182753.GK5901@zn.tnic> <20200921191658.GA24823@linux.intel.com> <20200922082918.GC22660@zn.tnic> <20200922142909.GI22660@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200922142909.GI22660@zn.tnic> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Tue, Sep 22, 2020 at 04:29:09PM +0200, Borislav Petkov wrote: > On Tue, Sep 22, 2020 at 02:56:19PM +0200, Jethro Beekman wrote: > > I don't see why you'd need to retry indefinitely. Yes the MSRs may not > > match the cached value for “reasons”, but if after you've written > > them once it still doesn't work, clearly either 1) an “unhelpful” > > VMM is actively messing with the MSRs which I'd say is at best a VMM > > bug or 2) there was an EPC reset and your enclave is now invalid > > anyway, so no need to EINIT. > > /me likes that even more. OK, so I did not follow this particular discussion in high detail, so as a sanity check I'll preview my changes. I'd refine sgx_update_lepubkeyhash_msrs() to: static void sgx_update_lepubkeyhash_msrs(u64 *lepubkeyhash) { u64 *cache; int i; preempt_disable(); cache = per_cpu(sgx_lepubkeyhash_cache, smp_processor_id()); for (i = 0; i < 4; i++) { if (lepubkeyhash[i] != cache[i]) { wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]); cache[i] = lepubkeyhash[i]; } } preempt_enable(); } I'd drop sgx_einit() completely. Finally, in sgx_encl_init() I would call sgx_update_lepubkeyhash_msrs() directly: /* ... */ sgx_update_lepubkeyhash_msrs(mrsigner); ret = __einit(sigstruct, token, sgx_get_epc_addr(secs)); /* ... */ These staments would replace the call to sgx_einit(). Do I have the correct understanding? /Jarkko