From patchwork Tue Sep 15 11:28:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11778623 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 A77126CA for ; Wed, 16 Sep 2020 00:55:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86D4C20936 for ; Wed, 16 Sep 2020 00:55:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kapsi.fi header.i=@kapsi.fi header.b="Jih0OG3z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726216AbgIPAzC (ORCPT ); Tue, 15 Sep 2020 20:55:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726297AbgIOLbo (ORCPT ); Tue, 15 Sep 2020 07:31:44 -0400 Received: from mail.kapsi.fi (mail.kapsi.fi [IPv6:2001:67c:1be8::25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12898C061355; Tue, 15 Sep 2020 04:28:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kapsi.fi; s=20161220; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=VQfxU9etoAX9NoRDjTZJvNO+0WR8I6R02xxEqCNX2jQ=; b=Jih0OG3zGRqxdCBiwpPSf+ji/v 25lRnKusbP6riEgza2rirVzSvutxdjFx21+YxvvrhlanmPAyubO8RRfc2lHEmMHbsvXP1nMONPd4Z EbgM4EgIndc/j3bH2CySH+nFhhFYFaTSoK9zoUQw3j+ABctwX5pYfwhRngu7H3lqxG9qcTskahyjd abCxdAiS+Z0gM0HeV+OnjkZNGH/Fl8KT3qfC8AGvxyiafCXVU8ayQiajUT8sz2ed1F0BS2rd8zFXE sOfF9jmHxkKODAIK4cvzZIY9efJ+7t4JlEYvhqJBanJCWFAltBY8G7gcWqJ1I9ppKqkY5WOL1nHhp U/ITxCJg==; Received: from 83-245-197-237.elisa-laajakaista.fi ([83.245.197.237] helo=localhost) by mail.kapsi.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1kI98j-0000iz-He; Tue, 15 Sep 2020 14:28:49 +0300 From: Jarkko Sakkinen To: x86@kernel.org, linux-sgx@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Jarkko Sakkinen , Jethro Beekman , Darren Kenny , 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 v38 09/24] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Date: Tue, 15 Sep 2020 14:28:27 +0300 Message-Id: <20200915112842.897265-10-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200915112842.897265-1-jarkko.sakkinen@linux.intel.com> References: <20200915112842.897265-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 83.245.197.237 X-SA-Exim-Mail-From: jjs@kapsi.fi X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false 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 Reviewed-by: Darren Kenny Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/main.c | 62 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 3 ++ 2 files changed, 65 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index c5831e3db14a..97c6895fb6c9 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -83,6 +83,68 @@ 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 dff4f5f16d09..fce756c3434b 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -49,4 +49,7 @@ 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 */