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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 682E7C4CED4 for ; Wed, 18 Sep 2019 04:16:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E631214AF for ; Wed, 18 Sep 2019 04:16:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725903AbfIREQ4 (ORCPT ); Wed, 18 Sep 2019 00:16:56 -0400 Received: from mga02.intel.com ([134.134.136.20]:48837 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725902AbfIREQz (ORCPT ); Wed, 18 Sep 2019 00:16:55 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Sep 2019 21:16:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,519,1559545200"; d="scan'208";a="186352914" Received: from mordehay-mobl.ger.corp.intel.com (HELO localhost) ([10.252.37.53]) by fmsmga008.fm.intel.com with ESMTP; 17 Sep 2019 21:16:51 -0700 Date: Wed, 18 Sep 2019 07:16:51 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-sgx@vger.kernel.org, Shay Katz-zamir , Serge Ayoun Subject: Re: [PATCH v3 09/17] x86/sgx: Move SGX_ENCL_DEAD check to sgx_reclaimer_write() Message-ID: <20190918041651.GF22434@linux.intel.com> References: <20190916101803.30726-1-jarkko.sakkinen@linux.intel.com> <20190916101803.30726-10-jarkko.sakkinen@linux.intel.com> <20190917232119.GG10319@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190917232119.GG10319@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Tue, Sep 17, 2019 at 04:21:19PM -0700, Sean Christopherson wrote: > On Mon, Sep 16, 2019 at 01:17:55PM +0300, Jarkko Sakkinen wrote: > > Do enclave state checks only in sgx_reclaimer_write(). Checking the > > enclave state is not part of the sgx_encl_ewb() flow. The check is done > > differently for SECS and for addressable pages. > > > > Cc: Sean Christopherson > > Cc: Shay Katz-zamir > > Cc: Serge Ayoun > > Signed-off-by: Jarkko Sakkinen > > --- > > arch/x86/kernel/cpu/sgx/reclaim.c | 69 +++++++++++++++---------------- > > 1 file changed, 34 insertions(+), 35 deletions(-) > > > > diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c > > index e758a06919e4..a3e36f959c74 100644 > > --- a/arch/x86/kernel/cpu/sgx/reclaim.c > > +++ b/arch/x86/kernel/cpu/sgx/reclaim.c > > @@ -308,47 +308,45 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page, > > > > encl_page->desc &= ~SGX_ENCL_PAGE_RECLAIMED; > > > > - if (!(atomic_read(&encl->flags) & SGX_ENCL_DEAD)) { > > - va_page = list_first_entry(&encl->va_pages, struct sgx_va_page, > > - list); > > - va_offset = sgx_alloc_va_slot(va_page); > > - if (sgx_va_page_full(va_page)) > > - list_move_tail(&va_page->list, &encl->va_pages); > > + va_page = list_first_entry(&encl->va_pages, struct sgx_va_page, > > + list); > > + va_offset = sgx_alloc_va_slot(va_page); > > + if (sgx_va_page_full(va_page)) > > + list_move_tail(&va_page->list, &encl->va_pages); > > + > > + ret = __sgx_encl_ewb(encl, epc_page, va_page, va_offset, > > + page_index); > > + if (ret == SGX_NOT_TRACKED) { > > + ret = __etrack(sgx_epc_addr(encl->secs.epc_page)); > > + if (ret) { > > + if (encls_failed(ret) || > > + encls_returned_code(ret)) > > + ENCLS_WARN(ret, "ETRACK"); > > + } > > > > ret = __sgx_encl_ewb(encl, epc_page, va_page, va_offset, > > page_index); > > if (ret == SGX_NOT_TRACKED) { > > - ret = __etrack(sgx_epc_addr(encl->secs.epc_page)); > > - if (ret) { > > - if (encls_failed(ret) || > > - encls_returned_code(ret)) > > - ENCLS_WARN(ret, "ETRACK"); > > - } > > - > > - ret = __sgx_encl_ewb(encl, epc_page, va_page, va_offset, > > - page_index); > > - if (ret == SGX_NOT_TRACKED) { > > - /* > > - * Slow path, send IPIs to kick cpus out of the > > - * enclave. Note, it's imperative that the cpu > > - * mask is generated *after* ETRACK, else we'll > > - * miss cpus that entered the enclave between > > - * generating the mask and incrementing epoch. > > - */ > > - on_each_cpu_mask(sgx_encl_ewb_cpumask(encl), > > - sgx_ipi_cb, NULL, 1); > > - ret = __sgx_encl_ewb(encl, epc_page, va_page, > > - va_offset, page_index); > > - } > > + /* > > + * Slow path, send IPIs to kick cpus out of the > > + * enclave. Note, it's imperative that the cpu > > + * mask is generated *after* ETRACK, else we'll > > + * miss cpus that entered the enclave between > > + * generating the mask and incrementing epoch. > > + */ > > + on_each_cpu_mask(sgx_encl_ewb_cpumask(encl), > > + sgx_ipi_cb, NULL, 1); > > + ret = __sgx_encl_ewb(encl, epc_page, va_page, > > + va_offset, page_index); > > } > > + } > > > > - if (ret) > > - if (encls_failed(ret) || encls_returned_code(ret)) > > - ENCLS_WARN(ret, "EWB"); > > + if (ret) > > + if (encls_failed(ret) || encls_returned_code(ret)) > > + ENCLS_WARN(ret, "EWB"); > > > > - encl_page->desc |= va_offset; > > - encl_page->va_page = va_page; > > - } > > + encl_page->desc |= va_offset; > > + encl_page->va_page = va_page; > > } > > > > static void sgx_reclaimer_write(struct sgx_epc_page *epc_page) > > @@ -359,10 +357,11 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page) > > > > mutex_lock(&encl->lock); > > > > - sgx_encl_ewb(epc_page, SGX_ENCL_PAGE_INDEX(encl_page)); > > if (atomic_read(&encl->flags) & SGX_ENCL_DEAD) { > > ret = __eremove(sgx_epc_addr(epc_page)); > > WARN(ret, "EREMOVE returned %d\n", ret); > > + } else { > > + sgx_encl_ewb(epc_page, SGX_ENCL_PAGE_INDEX(encl_page)); > > The sgx_encl_ewb() for SECS also needs to be skipped, otherwise we'll > attempt EWB on a dead enclave. If the enclave is dead we can simply > free the SECS. Thanks! I'll refine. /Jarkko