From patchwork Wed May 8 14:43:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "kirill.shutemov@linux.intel.com" X-Patchwork-Id: 10936023 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0E06B933 for ; Wed, 8 May 2019 14:51:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 00264286CD for ; Wed, 8 May 2019 14:51:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F233028A56; Wed, 8 May 2019 14:51:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 799F328A17 for ; Wed, 8 May 2019 14:51:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728184AbfEHOom (ORCPT ); Wed, 8 May 2019 10:44:42 -0400 Received: from mga04.intel.com ([192.55.52.120]:61868 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728136AbfEHOol (ORCPT ); Wed, 8 May 2019 10:44:41 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 May 2019 07:44:40 -0700 X-ExtLoop1: 1 Received: from black.fi.intel.com ([10.237.72.28]) by orsmga005.jf.intel.com with ESMTP; 08 May 2019 07:44:35 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 323C8739; Wed, 8 May 2019 17:44:29 +0300 (EEST) From: "Kirill A. Shutemov" To: Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , David Howells Cc: Kees Cook , Dave Hansen , Kai Huang , Jacob Pan , Alison Schofield , linux-mm@kvack.org, kvm@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH, RFC 11/62] x86/mm: Add a helper to retrieve KeyID for a page Date: Wed, 8 May 2019 17:43:31 +0300 Message-Id: <20190508144422.13171-12-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> References: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP page_ext allows to store additional per-page information without growing main struct page. The additional space can be requested at boot time. Store KeyID in bits 31:16 of extended page flags. These bits are unused. page_keyid() returns zero until page_ext is ready. page_ext initializer enables a static branch to indicate that page_keyid() can use page_ext. The same static branch will gate MKTME readiness in general. We don't yet set KeyID for the page. It will come in the following patch that implements prep_encrypted_page(). All pages have KeyID-0 for now. page_keyid() will be used by KVM which can be built as a module. We need to export mktme_enabled_key to be able to inline page_keyid(). Signed-off-by: Kirill A. Shutemov --- arch/x86/include/asm/mktme.h | 28 ++++++++++++++++++++++++++++ arch/x86/include/asm/page.h | 1 + arch/x86/mm/mktme.c | 21 +++++++++++++++++++++ include/linux/mm.h | 2 +- include/linux/page_ext.h | 11 ++++++++++- mm/page_ext.c | 3 +++ 6 files changed, 64 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h index df31876ec48c..51f831b94179 100644 --- a/arch/x86/include/asm/mktme.h +++ b/arch/x86/include/asm/mktme.h @@ -2,15 +2,43 @@ #define _ASM_X86_MKTME_H #include +#include +#include #ifdef CONFIG_X86_INTEL_MKTME extern phys_addr_t mktme_keyid_mask; extern int mktme_nr_keyids; extern int mktme_keyid_shift; + +DECLARE_STATIC_KEY_FALSE(mktme_enabled_key); +static inline bool mktme_enabled(void) +{ + return static_branch_unlikely(&mktme_enabled_key); +} + +extern struct page_ext_operations page_mktme_ops; + +#define page_keyid page_keyid +static inline int page_keyid(const struct page *page) +{ + if (!mktme_enabled()) + return 0; + + return lookup_page_ext(page)->keyid; +} + + #else #define mktme_keyid_mask ((phys_addr_t)0) #define mktme_nr_keyids 0 #define mktme_keyid_shift 0 + +#define page_keyid(page) 0 + +static inline bool mktme_enabled(void) +{ + return false; +} #endif #endif diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index 7555b48803a8..39af59487d5f 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -19,6 +19,7 @@ struct page; #include +#include extern struct range pfn_mapped[]; extern int nr_pfn_mapped; diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c index 91a415612519..9dc256e3654b 100644 --- a/arch/x86/mm/mktme.c +++ b/arch/x86/mm/mktme.c @@ -9,3 +9,24 @@ phys_addr_t mktme_keyid_mask; int mktme_nr_keyids; /* Shift of KeyID within physical address. */ int mktme_keyid_shift; + +DEFINE_STATIC_KEY_FALSE(mktme_enabled_key); +EXPORT_SYMBOL_GPL(mktme_enabled_key); + +static bool need_page_mktme(void) +{ + /* Make sure keyid doesn't collide with extended page flags */ + BUILD_BUG_ON(__NR_PAGE_EXT_FLAGS > 16); + + return !!mktme_nr_keyids; +} + +static void init_page_mktme(void) +{ + static_branch_enable(&mktme_enabled_key); +} + +struct page_ext_operations page_mktme_ops = { + .need = need_page_mktme, + .init = init_page_mktme, +}; diff --git a/include/linux/mm.h b/include/linux/mm.h index 07c36f4673f6..2684245f8503 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1607,7 +1607,7 @@ static inline int vma_keyid(struct vm_area_struct *vma) #endif #ifndef page_keyid -static inline int page_keyid(struct page *page) +static inline int page_keyid(const struct page *page) { return 0; } diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h index f84f167ec04c..d9c5aae9523f 100644 --- a/include/linux/page_ext.h +++ b/include/linux/page_ext.h @@ -23,6 +23,7 @@ enum page_ext_flags { PAGE_EXT_YOUNG, PAGE_EXT_IDLE, #endif + __NR_PAGE_EXT_FLAGS }; /* @@ -33,7 +34,15 @@ enum page_ext_flags { * then the page_ext for pfn always exists. */ struct page_ext { - unsigned long flags; + union { + unsigned long flags; +#ifdef CONFIG_X86_INTEL_MKTME + struct { + unsigned short __pad; + unsigned short keyid; + }; +#endif + }; }; extern void pgdat_page_ext_init(struct pglist_data *pgdat); diff --git a/mm/page_ext.c b/mm/page_ext.c index d8f1aca4ad43..1af8b82087f2 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -68,6 +68,9 @@ static struct page_ext_operations *page_ext_ops[] = { #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT) &page_idle_ops, #endif +#ifdef CONFIG_X86_INTEL_MKTME + &page_mktme_ops, +#endif }; static unsigned long total_usage;