From patchwork Wed Jul 31 15:07:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 11068185 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 DFFD2746 for ; Wed, 31 Jul 2019 15:14:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CA61B20134 for ; Wed, 31 Jul 2019 15:14:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BE487203B9; Wed, 31 Jul 2019 15:14:23 +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=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 58B13205FB for ; Wed, 31 Jul 2019 15:14:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DE8DE8E0029; Wed, 31 Jul 2019 11:13:56 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id B14D48E002C; Wed, 31 Jul 2019 11:13:56 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7B13E8E0029; Wed, 31 Jul 2019 11:13:56 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id E8C318E0022 for ; Wed, 31 Jul 2019 11:13:55 -0400 (EDT) Received: by mail-ed1-f70.google.com with SMTP id i9so42591655edr.13 for ; Wed, 31 Jul 2019 08:13:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:from:to:cc:subject:date :message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=6dcOutisXa7w0OA/k2AObJgMHjT+CIuNqnczE3/DBrQ=; b=qVVdOWqB8PvXf5R7ai/IlfpdOr8HL4rWmy21Rw6QQb0pUTbuZVK2DYGhakMNH6GdV5 OQPLqTCbjRuEDud1bdmOMevIJproozBSEgjUgJXbbl4UBhrJ9gphA0GSVSqqmeX0VWAy b7QzFCV132A/9+7xF7F9Q9q2Ho6VXQQP8QwKuZaXZG/bWNnObRCuuTJn4y94iuORawc0 KDUDTLKQHvA6/GlBvkYbEwCRqUWUoMhON/RDfI+eUvEn+a18sbvjUmRn2hYa15DtrNle 0dmbnBamj4aPxYV7XH78QPj9BOMUxc+phFs3Tn/h9c13Tg5KzhA7AMi1LxFqe/2Ui5N0 8Ihw== X-Gm-Message-State: APjAAAX1wlh/TkIjpSl92/jfwB4iETHAcsRBOv77RFkX48ZpslBDgMov UwyXoob1GeL50Dag/9xlsGwcYRCwYH51kEw9spgC8NuLyU52Xov5aLpla0fcezIRDq6YZNXt1T6 PdrbvexIvcBZe/qlvp4SeQ1Jl0+yHOubHyQUXi75eubEGpBH14FPpwFbn8FL1NuM= X-Received: by 2002:a17:906:418:: with SMTP id d24mr96713192eja.258.1564586035434; Wed, 31 Jul 2019 08:13:55 -0700 (PDT) X-Received: by 2002:a17:906:418:: with SMTP id d24mr96713032eja.258.1564586033415; Wed, 31 Jul 2019 08:13:53 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1564586033; cv=none; d=google.com; s=arc-20160816; b=GJTMWYj3ElLZfmxx9syfqn7PDxc35isX4a2X7bfYp89DSAC8+TS3axNAQT0gG/0MpO O/O8m7QEOUGCCid2crGz8C7LgtSicDo6Dfj2F0YOHhG1EnTTEG9VFN7T6w7u+CwKKLAv HaFkbMO+ZH3a3LsZfnjAaT77j4ExkNCLV66ZDSg9VQN/nTuckQohQLi4Y2TT0GNwynXq 1V8eIl99vto3mo+wPlVQQ96n85XSjxPYScmCxkQgtGgBE8SUxoCm64oRG3vHXUrlOS7u Wn1zD9+o2zY1bg6mIA+YjurSzDzUXhxBoVW8WkrZYhcLed6kuG7YmH6JcjaOH6husnBr oNvA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:dkim-signature; bh=6dcOutisXa7w0OA/k2AObJgMHjT+CIuNqnczE3/DBrQ=; b=xNiiToZISoHYm1HwWPoRCWNpEVlZhU+fVi6gkMSm1rU3xnLHXS3aAfyhh58Ec7TR4d LD85/bQKfcbACYPYrrcNJr5LUh69+XYXQZiLwFy20FGVU5GYSjeq/wl6HbneeEli8FwK p1OVjjdkvxl1SaswfQftcApkc9coJUxtfjqORY8zE1+QAg4nEzIk51wXVRKinepCPXbl Q1S2CghnSiDZ7l61kLioe27P9K335BZXZeGG2Gcvmx81GTOt/S/x5KalZjQeogWEkRnk gCKveV7yw2l7l882sqUsGR8GWv5Oc1EV7yOJ/Pcd/HgukEMA0wXZDwOzuHqQZ2bi4jkw tKWA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@shutemov-name.20150623.gappssmtp.com header.s=20150623 header.b=uMkV7dlR; spf=neutral (google.com: 209.85.220.65 is neither permitted nor denied by best guess record for domain of kirill@shutemov.name) smtp.mailfrom=kirill@shutemov.name Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. 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Shutemov" X-Google-Original-From: "Kirill A. Shutemov" Received: by box.localdomain (Postfix, from userid 1000) id 733161030BA; Wed, 31 Jul 2019 18:08:16 +0300 (+03) 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: [PATCHv2 19/59] x86/mm: Implement syncing per-KeyID direct mappings Date: Wed, 31 Jul 2019 18:07:33 +0300 Message-Id: <20190731150813.26289-20-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190731150813.26289-1-kirill.shutemov@linux.intel.com> References: <20190731150813.26289-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: X-Virus-Scanned: ClamAV using ClamSMTP For MKTME we use per-KeyID direct mappings. This allows kernel to have access to encrypted memory. sync_direct_mapping() sync per-KeyID direct mappings with a canonical one -- KeyID-0. The function tracks changes in the canonical mapping: - creating or removing chunks of the translation tree; - changes in mapping flags (i.e. protection bits); - splitting huge page mapping into a page table; - replacing page table with a huge page mapping; The function need to be called on every change to the direct mapping: hotplug, hotremove, changes in permissions bits, etc. The function is nop until MKTME is enabled. Signed-off-by: Kirill A. Shutemov --- arch/x86/include/asm/mktme.h | 6 + arch/x86/mm/init_64.c | 7 + arch/x86/mm/mktme.c | 439 +++++++++++++++++++++++++++++++++++ arch/x86/mm/pageattr.c | 27 +++ 4 files changed, 479 insertions(+) diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h index 3fc246acc279..d26ada6b65f7 100644 --- a/arch/x86/include/asm/mktme.h +++ b/arch/x86/include/asm/mktme.h @@ -62,6 +62,8 @@ static inline void arch_free_page(struct page *page, int order) free_encrypted_page(page, order); } +int sync_direct_mapping(unsigned long start, unsigned long end); + #else #define mktme_keyid_mask() ((phys_addr_t)0) #define mktme_nr_keyids() 0 @@ -76,6 +78,10 @@ static inline bool mktme_enabled(void) static inline void mktme_disable(void) {} +static inline int sync_direct_mapping(unsigned long start, unsigned long end) +{ + return 0; +} #endif #endif diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 4c1f93df47a5..6769650ad18d 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -726,6 +726,7 @@ __kernel_physical_mapping_init(unsigned long paddr_start, { bool pgd_changed = false; unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last; + int ret; paddr_last = paddr_end; vaddr = (unsigned long)__va(paddr_start); @@ -762,6 +763,9 @@ __kernel_physical_mapping_init(unsigned long paddr_start, pgd_changed = true; } + ret = sync_direct_mapping(vaddr_start, vaddr_end); + WARN_ON(ret); + if (pgd_changed) sync_global_pgds(vaddr_start, vaddr_end - 1); @@ -1201,10 +1205,13 @@ void __ref vmemmap_free(unsigned long start, unsigned long end, static void __meminit kernel_physical_mapping_remove(unsigned long start, unsigned long end) { + int ret; start = (unsigned long)__va(start); end = (unsigned long)__va(end); remove_pagetable(start, end, true, NULL); + ret = sync_direct_mapping(start, end); + WARN_ON(ret); } void __ref arch_remove_memory(int nid, u64 start, u64 size, diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c index 1e8d662e5bff..ed13967bb543 100644 --- a/arch/x86/mm/mktme.c +++ b/arch/x86/mm/mktme.c @@ -1,6 +1,8 @@ #include #include #include +#include +#include /* Mask to extract KeyID from physical address. */ phys_addr_t __mktme_keyid_mask; @@ -54,6 +56,8 @@ static bool need_page_mktme(void) static void init_page_mktme(void) { static_branch_enable(&mktme_enabled_key); + + sync_direct_mapping(PAGE_OFFSET, PAGE_OFFSET + direct_mapping_size); } struct page_ext_operations page_mktme_ops = { @@ -148,3 +152,438 @@ void free_encrypted_page(struct page *page, int order) page++; } } + +static int sync_direct_mapping_pte(unsigned long keyid, + pmd_t *dst_pmd, pmd_t *src_pmd, + unsigned long addr, unsigned long end) +{ + pte_t *src_pte, *dst_pte; + pte_t *new_pte = NULL; + bool remove_pte; + + /* + * We want to unmap and free the page table if the source is empty and + * the range covers whole page table. + */ + remove_pte = !src_pmd && PAGE_ALIGNED(addr) && PAGE_ALIGNED(end); + + /* + * PMD page got split into page table. + * Clear PMD mapping. Page table will be established instead. + */ + if (pmd_large(*dst_pmd)) { + spin_lock(&init_mm.page_table_lock); + pmd_clear(dst_pmd); + spin_unlock(&init_mm.page_table_lock); + } + + /* Allocate a new page table if needed. */ + if (pmd_none(*dst_pmd)) { + new_pte = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!new_pte) + return -ENOMEM; + dst_pte = new_pte + pte_index(addr + keyid * direct_mapping_size); + } else { + dst_pte = pte_offset_map(dst_pmd, addr + keyid * direct_mapping_size); + } + src_pte = src_pmd ? pte_offset_map(src_pmd, addr) : NULL; + + spin_lock(&init_mm.page_table_lock); + + do { + pteval_t val; + + if (!src_pte || pte_none(*src_pte)) { + set_pte(dst_pte, __pte(0)); + goto next; + } + + if (!pte_none(*dst_pte)) { + /* + * Sanity check: PFNs must match between source + * and destination even if the rest doesn't. + */ + BUG_ON(pte_pfn(*dst_pte) != pte_pfn(*src_pte)); + } + + /* Copy entry, but set KeyID. */ + val = pte_val(*src_pte) | keyid << mktme_keyid_shift(); + val &= __supported_pte_mask; + set_pte(dst_pte, __pte(val)); +next: + addr += PAGE_SIZE; + dst_pte++; + if (src_pte) + src_pte++; + } while (addr != end); + + if (new_pte) + pmd_populate_kernel(&init_mm, dst_pmd, new_pte); + + if (remove_pte) { + __free_page(pmd_page(*dst_pmd)); + pmd_clear(dst_pmd); + } + + spin_unlock(&init_mm.page_table_lock); + + return 0; +} + +static int sync_direct_mapping_pmd(unsigned long keyid, + pud_t *dst_pud, pud_t *src_pud, + unsigned long addr, unsigned long end) +{ + pmd_t *src_pmd, *dst_pmd; + pmd_t *new_pmd = NULL; + bool remove_pmd = false; + unsigned long next; + int ret = 0; + + /* + * We want to unmap and free the page table if the source is empty and + * the range covers whole page table. + */ + remove_pmd = !src_pud && IS_ALIGNED(addr, PUD_SIZE) && IS_ALIGNED(end, PUD_SIZE); + + /* + * PUD page got split into page table. + * Clear PUD mapping. Page table will be established instead. + */ + if (pud_large(*dst_pud)) { + spin_lock(&init_mm.page_table_lock); + pud_clear(dst_pud); + spin_unlock(&init_mm.page_table_lock); + } + + /* Allocate a new page table if needed. */ + if (pud_none(*dst_pud)) { + new_pmd = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!new_pmd) + return -ENOMEM; + dst_pmd = new_pmd + pmd_index(addr + keyid * direct_mapping_size); + } else { + dst_pmd = pmd_offset(dst_pud, addr + keyid * direct_mapping_size); + } + src_pmd = src_pud ? pmd_offset(src_pud, addr) : NULL; + + do { + pmd_t *__src_pmd = src_pmd; + + next = pmd_addr_end(addr, end); + if (!__src_pmd || pmd_none(*__src_pmd)) { + if (pmd_none(*dst_pmd)) + goto next; + if (pmd_large(*dst_pmd)) { + spin_lock(&init_mm.page_table_lock); + set_pmd(dst_pmd, __pmd(0)); + spin_unlock(&init_mm.page_table_lock); + goto next; + } + __src_pmd = NULL; + } + + if (__src_pmd && pmd_large(*__src_pmd)) { + pmdval_t val; + + if (pmd_large(*dst_pmd)) { + /* + * Sanity check: PFNs must match between source + * and destination even if the rest doesn't. + */ + BUG_ON(pmd_pfn(*dst_pmd) != pmd_pfn(*__src_pmd)); + } else if (!pmd_none(*dst_pmd)) { + /* + * Page table is replaced with a PMD page. + * Free and unmap the page table. + */ + __free_page(pmd_page(*dst_pmd)); + spin_lock(&init_mm.page_table_lock); + pmd_clear(dst_pmd); + spin_unlock(&init_mm.page_table_lock); + } + + /* Copy entry, but set KeyID. */ + val = pmd_val(*__src_pmd) | keyid << mktme_keyid_shift(); + val &= __supported_pte_mask; + spin_lock(&init_mm.page_table_lock); + set_pmd(dst_pmd, __pmd(val)); + spin_unlock(&init_mm.page_table_lock); + goto next; + } + + ret = sync_direct_mapping_pte(keyid, dst_pmd, __src_pmd, + addr, next); +next: + addr = next; + dst_pmd++; + if (src_pmd) + src_pmd++; + } while (addr != end && !ret); + + if (new_pmd) { + spin_lock(&init_mm.page_table_lock); + pud_populate(&init_mm, dst_pud, new_pmd); + spin_unlock(&init_mm.page_table_lock); + } + + if (remove_pmd) { + spin_lock(&init_mm.page_table_lock); + __free_page(pud_page(*dst_pud)); + pud_clear(dst_pud); + spin_unlock(&init_mm.page_table_lock); + } + + return ret; +} + +static int sync_direct_mapping_pud(unsigned long keyid, + p4d_t *dst_p4d, p4d_t *src_p4d, + unsigned long addr, unsigned long end) +{ + pud_t *src_pud, *dst_pud; + pud_t *new_pud = NULL; + bool remove_pud = false; + unsigned long next; + int ret = 0; + + /* + * We want to unmap and free the page table if the source is empty and + * the range covers whole page table. + */ + remove_pud = !src_p4d && IS_ALIGNED(addr, P4D_SIZE) && IS_ALIGNED(end, P4D_SIZE); + + /* + * P4D page got split into page table. + * Clear P4D mapping. Page table will be established instead. + */ + if (p4d_large(*dst_p4d)) { + spin_lock(&init_mm.page_table_lock); + p4d_clear(dst_p4d); + spin_unlock(&init_mm.page_table_lock); + } + + /* Allocate a new page table if needed. */ + if (p4d_none(*dst_p4d)) { + new_pud = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!new_pud) + return -ENOMEM; + dst_pud = new_pud + pud_index(addr + keyid * direct_mapping_size); + } else { + dst_pud = pud_offset(dst_p4d, addr + keyid * direct_mapping_size); + } + src_pud = src_p4d ? pud_offset(src_p4d, addr) : NULL; + + do { + pud_t *__src_pud = src_pud; + + next = pud_addr_end(addr, end); + if (!__src_pud || pud_none(*__src_pud)) { + if (pud_none(*dst_pud)) + goto next; + if (pud_large(*dst_pud)) { + spin_lock(&init_mm.page_table_lock); + set_pud(dst_pud, __pud(0)); + spin_unlock(&init_mm.page_table_lock); + goto next; + } + __src_pud = NULL; + } + + if (__src_pud && pud_large(*__src_pud)) { + pudval_t val; + + if (pud_large(*dst_pud)) { + /* + * Sanity check: PFNs must match between source + * and destination even if the rest doesn't. + */ + BUG_ON(pud_pfn(*dst_pud) != pud_pfn(*__src_pud)); + } else if (!pud_none(*dst_pud)) { + /* + * Page table is replaced with a pud page. + * Free and unmap the page table. + */ + __free_page(pud_page(*dst_pud)); + spin_lock(&init_mm.page_table_lock); + pud_clear(dst_pud); + spin_unlock(&init_mm.page_table_lock); + } + + /* Copy entry, but set KeyID. */ + val = pud_val(*__src_pud) | keyid << mktme_keyid_shift(); + val &= __supported_pte_mask; + spin_lock(&init_mm.page_table_lock); + set_pud(dst_pud, __pud(val)); + spin_unlock(&init_mm.page_table_lock); + goto next; + } + + ret = sync_direct_mapping_pmd(keyid, dst_pud, __src_pud, + addr, next); +next: + addr = next; + dst_pud++; + if (src_pud) + src_pud++; + } while (addr != end && !ret); + + if (new_pud) { + spin_lock(&init_mm.page_table_lock); + p4d_populate(&init_mm, dst_p4d, new_pud); + spin_unlock(&init_mm.page_table_lock); + } + + if (remove_pud) { + spin_lock(&init_mm.page_table_lock); + __free_page(p4d_page(*dst_p4d)); + p4d_clear(dst_p4d); + spin_unlock(&init_mm.page_table_lock); + } + + return ret; +} + +static int sync_direct_mapping_p4d(unsigned long keyid, + pgd_t *dst_pgd, pgd_t *src_pgd, + unsigned long addr, unsigned long end) +{ + p4d_t *src_p4d, *dst_p4d; + p4d_t *new_p4d_1 = NULL, *new_p4d_2 = NULL; + bool remove_p4d = false; + unsigned long next; + int ret = 0; + + /* + * We want to unmap and free the page table if the source is empty and + * the range covers whole page table. + */ + remove_p4d = !src_pgd && IS_ALIGNED(addr, PGDIR_SIZE) && IS_ALIGNED(end, PGDIR_SIZE); + + /* Allocate a new page table if needed. */ + if (pgd_none(*dst_pgd)) { + new_p4d_1 = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!new_p4d_1) + return -ENOMEM; + dst_p4d = new_p4d_1 + p4d_index(addr + keyid * direct_mapping_size); + } else { + dst_p4d = p4d_offset(dst_pgd, addr + keyid * direct_mapping_size); + } + src_p4d = src_pgd ? p4d_offset(src_pgd, addr) : NULL; + + do { + p4d_t *__src_p4d = src_p4d; + + next = p4d_addr_end(addr, end); + if (!__src_p4d || p4d_none(*__src_p4d)) { + if (p4d_none(*dst_p4d)) + goto next; + __src_p4d = NULL; + } + + ret = sync_direct_mapping_pud(keyid, dst_p4d, __src_p4d, + addr, next); +next: + addr = next; + dst_p4d++; + + /* + * Direct mappings are 1TiB-aligned. With 5-level paging it + * means that on PGD level there can be misalignment between + * source and distiantion. + * + * Allocate the new page table if dst_p4d crosses page table + * boundary. + */ + if (!((unsigned long)dst_p4d & ~PAGE_MASK) && addr != end) { + if (pgd_none(dst_pgd[1])) { + new_p4d_2 = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!new_p4d_2) + ret = -ENOMEM; + dst_p4d = new_p4d_2; + } else { + dst_p4d = p4d_offset(dst_pgd + 1, 0); + } + } + if (src_p4d) + src_p4d++; + } while (addr != end && !ret); + + if (new_p4d_1 || new_p4d_2) { + spin_lock(&init_mm.page_table_lock); + if (new_p4d_1) + pgd_populate(&init_mm, dst_pgd, new_p4d_1); + if (new_p4d_2) + pgd_populate(&init_mm, dst_pgd + 1, new_p4d_2); + spin_unlock(&init_mm.page_table_lock); + } + + if (remove_p4d) { + spin_lock(&init_mm.page_table_lock); + __free_page(pgd_page(*dst_pgd)); + pgd_clear(dst_pgd); + spin_unlock(&init_mm.page_table_lock); + } + + return ret; +} + +static int sync_direct_mapping_keyid(unsigned long keyid, + unsigned long addr, unsigned long end) +{ + pgd_t *src_pgd, *dst_pgd; + unsigned long next; + int ret = 0; + + dst_pgd = pgd_offset_k(addr + keyid * direct_mapping_size); + src_pgd = pgd_offset_k(addr); + + do { + pgd_t *__src_pgd = src_pgd; + + next = pgd_addr_end(addr, end); + if (pgd_none(*__src_pgd)) { + if (pgd_none(*dst_pgd)) + continue; + __src_pgd = NULL; + } + + ret = sync_direct_mapping_p4d(keyid, dst_pgd, __src_pgd, + addr, next); + } while (dst_pgd++, src_pgd++, addr = next, addr != end && !ret); + + return ret; +} + +/* + * For MKTME we maintain per-KeyID direct mappings. This allows kernel to have + * access to encrypted memory. + * + * sync_direct_mapping() sync per-KeyID direct mappings with a canonical + * one -- KeyID-0. + * + * The function tracks changes in the canonical mapping: + * - creating or removing chunks of the translation tree; + * - changes in mapping flags (i.e. protection bits); + * - splitting huge page mapping into a page table; + * - replacing page table with a huge page mapping; + * + * The function need to be called on every change to the direct mapping: + * hotplug, hotremove, changes in permissions bits, etc. + * + * The function is nop until MKTME is enabled. + */ +int sync_direct_mapping(unsigned long start, unsigned long end) +{ + int i, ret = 0; + + if (!mktme_enabled()) + return 0; + + for (i = 1; !ret && i <= mktme_nr_keyids(); i++) + ret = sync_direct_mapping_keyid(i, start, end); + + flush_tlb_all(); + + return ret; +} diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 6a9a77a403c9..f4e3205d2cdd 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -347,6 +347,33 @@ static void cpa_flush(struct cpa_data *data, int cache) BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); + if (mktme_enabled()) { + unsigned long start, end; + + start = PAGE_OFFSET + (cpa->pfn << PAGE_SHIFT); + end = start + cpa->numpages * PAGE_SIZE; + + /* Round to cover huge page possibly split by the change */ + start = round_down(start, direct_gbpages ? PUD_SIZE : PMD_SIZE); + end = round_up(end, direct_gbpages ? PUD_SIZE : PMD_SIZE); + + /* Sync all direct mapping for an array */ + if (cpa->flags & CPA_ARRAY) { + start = PAGE_OFFSET; + end = PAGE_OFFSET + direct_mapping_size; + } + + /* + * Sync per-KeyID direct mappings with the canonical one + * (KeyID-0). + * + * sync_direct_mapping() does full TLB flush. + */ + sync_direct_mapping(start, end); + if (!cache) + return; + } + if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) { cpa_flush_all(cache); return;