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, 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 B32E4C4CEC9 for ; Tue, 17 Sep 2019 23:13:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B540216C8 for ; Tue, 17 Sep 2019 23:13:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728577AbfIQXN2 (ORCPT ); Tue, 17 Sep 2019 19:13:28 -0400 Received: from mga09.intel.com ([134.134.136.24]:53119 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725801AbfIQXN2 (ORCPT ); Tue, 17 Sep 2019 19:13:28 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Sep 2019 16:13:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,518,1559545200"; d="scan'208";a="193891776" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by FMSMGA003.fm.intel.com with ESMTP; 17 Sep 2019 16:13:26 -0700 Date: Tue, 17 Sep 2019 16:13:26 -0700 From: Sean Christopherson To: Jarkko Sakkinen 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: <20190917231326.GF10319@linux.intel.com> References: <20190916101803.30726-1-jarkko.sakkinen@linux.intel.com> <20190916101803.30726-10-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190916101803.30726-10-jarkko.sakkinen@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org 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); SGX_ENCL_PAGE_RECLAIMED is left dangling on encl_page in the SGX_ENCL_DEAD case. It doesn't affect functionality, but it could complicate debug if anything goes awry. > + } else { > + sgx_encl_ewb(epc_page, SGX_ENCL_PAGE_INDEX(encl_page)); > } > > encl_page->epc_page = NULL; > -- > 2.20.1 >