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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 14CB0C43334 for ; Tue, 4 Sep 2018 15:30:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC5DC206BA for ; Tue, 4 Sep 2018 15:30:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC5DC206BA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727680AbeIDT4G (ORCPT ); Tue, 4 Sep 2018 15:56:06 -0400 Received: from mga01.intel.com ([192.55.52.88]:16423 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727223AbeIDT4F (ORCPT ); Tue, 4 Sep 2018 15:56:05 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Sep 2018 08:30:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,329,1531810800"; d="scan'208";a="230117360" Received: from schoebin-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.35.203]) by orsmga004.jf.intel.com with ESMTP; 04 Sep 2018 08:30:23 -0700 Date: Tue, 4 Sep 2018 18:30:21 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: "Huang, Kai" , "platform-driver-x86@vger.kernel.org" , "x86@kernel.org" , "nhorman@redhat.com" , "linux-kernel@vger.kernel.org" , "tglx@linutronix.de" , "suresh.b.siddha@intel.com" , "Ayoun, Serge" , "hpa@zytor.com" , "npmccallum@redhat.com" , "mingo@redhat.com" , "linux-sgx@vger.kernel.org" , "Hansen, Dave" Subject: Re: [PATCH v13 10/13] x86/sgx: Add sgx_einit() for initializing enclaves Message-ID: <20180904153021.GB8344@linux.intel.com> References: <20180827185507.17087-1-jarkko.sakkinen@linux.intel.com> <20180827185507.17087-11-jarkko.sakkinen@linux.intel.com> <1535406078.3416.9.camel@intel.com> <20180828070129.GA5301@linux.intel.com> <105F7BF4D0229846AF094488D65A09893541037C@PGSMSX112.gar.corp.intel.com> <20180831121645.GA18075@linux.intel.com> <20180831181509.GB21555@linux.intel.com> <20180903191926.GC13497@linux.intel.com> <105F7BF4D0229846AF094488D65A09893541970F@PGSMSX112.gar.corp.intel.com> <20180904145451.GA5233@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180904145451.GA5233@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 04, 2018 at 07:54:51AM -0700, Sean Christopherson wrote: > I don't see any value in trying to rule out specific causes of > INVALID_TOKEN, but we should only retry EINIT if ret==INVALID_TOKEN > and RDMSR(HASH0) != sgx_lepubkeyhash[0]. Only the first MSR needs to > be checked for validity as they're a package deal, i.e. they'll all be > valid or all be reset. There shouldn't be a limit on retry attempts, > e.g. the MSRs could theoretically be reset between WRMSR and EINIT. Why is doing rdmsrs necessary? With the INVALID_TOKEN error we know we are out-of-sync i.e. have been sleeping and then one just needs to do wrmsrs. I think one retry should be enough given that VMM traps EINIT. One retry is needed to take care of the guest itself (or host if we are running on bare metal) having been in a sleep state. /Jarkko From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga01.intel.com ([192.55.52.88]:16423 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727223AbeIDT4F (ORCPT ); Tue, 4 Sep 2018 15:56:05 -0400 Date: Tue, 4 Sep 2018 18:30:21 +0300 From: Jarkko Sakkinen To: Sean Christopherson CC: "Huang, Kai" , "platform-driver-x86@vger.kernel.org" , "x86@kernel.org" , "nhorman@redhat.com" , "linux-kernel@vger.kernel.org" , "tglx@linutronix.de" , "suresh.b.siddha@intel.com" , "Ayoun, Serge" , "hpa@zytor.com" , "npmccallum@redhat.com" , "mingo@redhat.com" , "linux-sgx@vger.kernel.org" , "Hansen, Dave" Subject: Re: [PATCH v13 10/13] x86/sgx: Add sgx_einit() for initializing enclaves Message-ID: <20180904153021.GB8344@linux.intel.com> References: <20180827185507.17087-1-jarkko.sakkinen@linux.intel.com> <20180827185507.17087-11-jarkko.sakkinen@linux.intel.com> <1535406078.3416.9.camel@intel.com> <20180828070129.GA5301@linux.intel.com> <105F7BF4D0229846AF094488D65A09893541037C@PGSMSX112.gar.corp.intel.com> <20180831121645.GA18075@linux.intel.com> <20180831181509.GB21555@linux.intel.com> <20180903191926.GC13497@linux.intel.com> <105F7BF4D0229846AF094488D65A09893541970F@PGSMSX112.gar.corp.intel.com> <20180904145451.GA5233@linux.intel.com> Content-Type: text/plain; charset="us-ascii" In-Reply-To: <20180904145451.GA5233@linux.intel.com> Sender: List-ID: Return-Path: linux-sgx-owner@vger.kernel.org MIME-Version: 1.0 On Tue, Sep 04, 2018 at 07:54:51AM -0700, Sean Christopherson wrote: > I don't see any value in trying to rule out specific causes of > INVALID_TOKEN, but we should only retry EINIT if ret==INVALID_TOKEN > and RDMSR(HASH0) != sgx_lepubkeyhash[0]. Only the first MSR needs to > be checked for validity as they're a package deal, i.e. they'll all be > valid or all be reset. There shouldn't be a limit on retry attempts, > e.g. the MSRs could theoretically be reset between WRMSR and EINIT. Why is doing rdmsrs necessary? With the INVALID_TOKEN error we know we are out-of-sync i.e. have been sleeping and then one just needs to do wrmsrs. I think one retry should be enough given that VMM traps EINIT. One retry is needed to take care of the guest itself (or host if we are running on bare metal) having been in a sleep state. /Jarkko