From patchwork Wed Jun 17 22:08:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11610839 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A1A8C913 for ; Wed, 17 Jun 2020 22:11:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9381021556 for ; Wed, 17 Jun 2020 22:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726899AbgFQWLL (ORCPT ); Wed, 17 Jun 2020 18:11:11 -0400 Received: from mga01.intel.com ([192.55.52.88]:27912 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726835AbgFQWLL (ORCPT ); Wed, 17 Jun 2020 18:11:11 -0400 IronPort-SDR: jUg1vkmhzKfOmvnM3pm/F0rwpKi6MZpEkOf+lctbwwk5avmMbzRctm9CGuDRpSsAKhGquSGtU3 3ZIQdd7Y8u2g== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jun 2020 15:11:10 -0700 IronPort-SDR: fi2u7e0Dw8uOzfPUuSQk8m9ErdAK6XywFjjhu6feuuNQt8CnxV6ajY4c6l6I4DMyaazGjO4u17 wRven0xGQRRQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,523,1583222400"; d="scan'208";a="421288257" Received: from ysharon1-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.49.131]) by orsmga004.jf.intel.com with ESMTP; 17 Jun 2020 15:10:57 -0700 From: Jarkko Sakkinen To: x86@kernel.org, linux-sgx@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Jarkko Sakkinen , Jethro Beekman , Sean Christopherson , akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com, asapek@google.com, bp@alien8.de, 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, npmccallum@redhat.com, puiterwijk@redhat.com, rientjes@google.com, tglx@linutronix.de, yaozhangx@google.com Subject: [PATCH v33 09/21] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Date: Thu, 18 Jun 2020 01:08:31 +0300 Message-Id: <20200617220844.57423-10-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200617220844.57423-1-jarkko.sakkinen@linux.intel.com> References: <20200617220844.57423-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Add __sgx_alloc_epc_page(), which iterates through EPC sections and borrows a page structure that is not used by anyone else. When a page is no longer needed it must be released with sgx_free_epc_page(). This function implicitly calls ENCLS[EREMOVE], which will return the page to the uninitialized state (i.e. not required from caller part). Acked-by: Jethro Beekman Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/main.c | 61 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 3 ++ 2 files changed, 64 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index c5831e3db14a..b776d249289f 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -83,6 +83,67 @@ static bool __init sgx_page_reclaimer_init(void) return true; } +static struct sgx_epc_page *__sgx_alloc_epc_page_from_section(struct sgx_epc_section *section) +{ + struct sgx_epc_page *page; + + if (list_empty(§ion->page_list)) + return NULL; + + page = list_first_entry(§ion->page_list, struct sgx_epc_page, list); + list_del_init(&page->list); + return page; +} + +/** + * __sgx_alloc_epc_page() - Allocate an EPC page + * + * Iterate through EPC sections and borrow a free EPC page to the caller. When a + * page is no longer needed it must be released with sgx_free_epc_page(). + * + * Return: + * an EPC page, + * -errno on error + */ +struct sgx_epc_page *__sgx_alloc_epc_page(void) +{ + struct sgx_epc_section *section; + struct sgx_epc_page *page; + int i; + + for (i = 0; i < sgx_nr_epc_sections; i++) { + section = &sgx_epc_sections[i]; + spin_lock(§ion->lock); + page = __sgx_alloc_epc_page_from_section(section); + spin_unlock(§ion->lock); + + if (page) + return page; + } + + return ERR_PTR(-ENOMEM); +} + +/** + * sgx_free_epc_page() - Free an EPC page + * @page: an EPC page + * + * Call EREMOVE for an EPC page and insert it back to the list of free pages. + */ +void sgx_free_epc_page(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_get_epc_section(page); + int ret; + + ret = __eremove(sgx_get_epc_addr(page)); + if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret)) + return; + + spin_lock(§ion->lock); + list_add_tail(&page->list, §ion->page_list); + spin_unlock(§ion->lock); +} + static void __init sgx_free_epc_section(struct sgx_epc_section *section) { struct sgx_epc_page *page; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 6508bfefd6d9..aae6bfb3bc8a 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -50,4 +50,7 @@ static inline void *sgx_get_epc_addr(struct sgx_epc_page *page) return section->va + (page->desc & PAGE_MASK) - section->pa; } +struct sgx_epc_page *__sgx_alloc_epc_page(void); +void sgx_free_epc_page(struct sgx_epc_page *page); + #endif /* _X86_SGX_H */