From patchwork Thu Jul 11 14:25:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Chartre X-Patchwork-Id: 11040121 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 1AE4F1395 for ; Thu, 11 Jul 2019 14:27:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0B8D728A5A for ; Thu, 11 Jul 2019 14:27:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F3CFB28AC8; Thu, 11 Jul 2019 14:27:43 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7C16C28A5A for ; Thu, 11 Jul 2019 14:27:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728760AbfGKO1h (ORCPT ); Thu, 11 Jul 2019 10:27:37 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:39270 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728440AbfGKO1g (ORCPT ); Thu, 11 Jul 2019 10:27:36 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x6BEOabr100891; Thu, 11 Jul 2019 14:26:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=Ccv45kVv21CrVP2UQjHtQ159yrdddBRkfeerFm1lQZs=; b=HGyms/pISRX5hcPdr6Z5qUYPoK8BQ52EIauuQPyhPhRre44rLyUHzvnoqOTRvXzrwhCv OTY05ptHcmicwwbGGPPXQN6m4TPthhy/xClxEZa4yF8uHSsKm7ZSH9u/tLfCQHG6hg1K +gEPReBvdFOuXQjB3QhAq8WvFQ4EtwdfdpRMWXWmCpj3REbSSnlT8iB9x+evcMVyxruc OTPrrYVoOXTGYADVN58b8Xu0sMhIRq/VtBIXKZS/5/ya9K9aD3oXpTX8QexDk1Ib94j1 ij8M3PZb4/wsMYxdM8hN/VwLMvqwLeYU8gvZc6wjF0NGEF6IBAOdWQJA2MvUwBG0KojU 6Q== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by aserp2120.oracle.com with ESMTP id 2tjkkq0c8m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Jul 2019 14:26:21 +0000 Received: from achartre-desktop.fr.oracle.com (dhcp-10-166-106-34.fr.oracle.com [10.166.106.34]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x6BEPcu4021444; Thu, 11 Jul 2019 14:26:18 GMT From: Alexandre Chartre To: pbonzini@redhat.com, rkrcmar@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, kvm@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: konrad.wilk@oracle.com, jan.setjeeilers@oracle.com, liran.alon@oracle.com, jwadams@google.com, graf@amazon.de, rppt@linux.vnet.ibm.com, alexandre.chartre@oracle.com Subject: [RFC v2 11/26] mm/asi: Functions to clear ASI page-table entries for a VA range Date: Thu, 11 Jul 2019 16:25:23 +0200 Message-Id: <1562855138-19507-12-git-send-email-alexandre.chartre@oracle.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1562855138-19507-1-git-send-email-alexandre.chartre@oracle.com> References: <1562855138-19507-1-git-send-email-alexandre.chartre@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9314 signatures=668688 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=905 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907110162 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Provide functions to clear page-table entries in the ASI page-table for a specified VA range. Functions also check that the clearing effectively happens in the ASI page-table and there is no crossing of the ASI page-table boundary (through references to the kernel page table), so that the kernel page table is not modified by mistake. As information (address, size, page-table level) about VA ranges mapped to the ASI page-table is tracked, clearing is done with just specifying the start address of the range. Signed-off-by: Alexandre Chartre --- arch/x86/include/asm/asi.h | 1 + arch/x86/mm/asi_pagetable.c | 134 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 135 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/asi.h b/arch/x86/include/asm/asi.h index be1c190..919129f 100644 --- a/arch/x86/include/asm/asi.h +++ b/arch/x86/include/asm/asi.h @@ -83,6 +83,7 @@ extern bool asi_fault(struct pt_regs *regs, unsigned long error_code, extern int asi_map_range(struct asi *asi, void *ptr, size_t size, enum page_table_level level); extern int asi_map(struct asi *asi, void *ptr, unsigned long size); +extern void asi_unmap(struct asi *asi, void *ptr); /* * Copy the memory mapping for the current module. This is defined as a diff --git a/arch/x86/mm/asi_pagetable.c b/arch/x86/mm/asi_pagetable.c index a09a22d..7aee236 100644 --- a/arch/x86/mm/asi_pagetable.c +++ b/arch/x86/mm/asi_pagetable.c @@ -670,3 +670,137 @@ int asi_map(struct asi *asi, void *ptr, unsigned long size) return asi_map_range(asi, ptr, size, PGT_LEVEL_PTE); } EXPORT_SYMBOL(asi_map); + +static void asi_clear_pte_range(struct asi *asi, pmd_t *pmd, + unsigned long addr, unsigned long end) +{ + pte_t *pte; + + pte = asi_pte_offset(asi, pmd, addr); + if (IS_ERR(pte)) + return; + + do { + pte_clear(NULL, addr, pte); + } while (pte++, addr += PAGE_SIZE, addr < end); +} + +static void asi_clear_pmd_range(struct asi *asi, pud_t *pud, + unsigned long addr, unsigned long end, + enum page_table_level level) +{ + unsigned long next; + pmd_t *pmd; + + pmd = asi_pmd_offset(asi, pud, addr); + if (IS_ERR(pmd)) + return; + + do { + next = pmd_addr_end(addr, end); + if (pmd_none(*pmd) || pmd_present(*pmd)) + continue; + if (level == PGT_LEVEL_PMD || pmd_trans_huge(*pmd) || + pmd_devmap(*pmd)) { + pmd_clear(pmd); + continue; + } + asi_clear_pte_range(asi, pmd, addr, next); + } while (pmd++, addr = next, addr < end); +} + +static void asi_clear_pud_range(struct asi *asi, p4d_t *p4d, + unsigned long addr, unsigned long end, + enum page_table_level level) +{ + unsigned long next; + pud_t *pud; + + pud = asi_pud_offset(asi, p4d, addr); + if (IS_ERR(pud)) + return; + + do { + next = pud_addr_end(addr, end); + if (pud_none(*pud)) + continue; + if (level == PGT_LEVEL_PUD || pud_trans_huge(*pud) || + pud_devmap(*pud)) { + pud_clear(pud); + continue; + } + asi_clear_pmd_range(asi, pud, addr, next, level); + } while (pud++, addr = next, addr < end); +} + +static void asi_clear_p4d_range(struct asi *asi, pgd_t *pgd, + unsigned long addr, unsigned long end, + enum page_table_level level) +{ + unsigned long next; + p4d_t *p4d; + + p4d = asi_p4d_offset(asi, pgd, addr); + if (IS_ERR(p4d)) + return; + + do { + next = p4d_addr_end(addr, end); + if (p4d_none(*p4d)) + continue; + if (level == PGT_LEVEL_P4D) { + p4d_clear(p4d); + continue; + } + asi_clear_pud_range(asi, p4d, addr, next, level); + } while (p4d++, addr = next, addr < end); +} + +static void asi_clear_pgd_range(struct asi *asi, pgd_t *pagetable, + unsigned long addr, unsigned long end, + enum page_table_level level) +{ + unsigned long next; + pgd_t *pgd; + + pgd = pgd_offset_pgd(pagetable, addr); + do { + next = pgd_addr_end(addr, end); + if (pgd_none(*pgd)) + continue; + if (level == PGT_LEVEL_PGD) { + pgd_clear(pgd); + continue; + } + asi_clear_p4d_range(asi, pgd, addr, next, level); + } while (pgd++, addr = next, addr < end); +} + +/* + * Clear page table entries in the specified ASI page-table. + */ +void asi_unmap(struct asi *asi, void *ptr) +{ + struct asi_range_mapping *range_mapping; + unsigned long addr, end; + unsigned long flags; + + spin_lock_irqsave(&asi->lock, flags); + + range_mapping = asi_get_range_mapping(asi, ptr); + if (!range_mapping) { + pr_debug("ASI %p: UNMAP %px - not mapped\n", asi, ptr); + goto done; + } + + addr = (unsigned long)range_mapping->ptr; + end = addr + range_mapping->size; + pr_debug("ASI %p: UNMAP %px/%lx/%d\n", asi, ptr, + range_mapping->size, range_mapping->level); + asi_clear_pgd_range(asi, asi->pgd, addr, end, range_mapping->level); + list_del(&range_mapping->list); + kfree(range_mapping); +done: + spin_unlock_irqrestore(&asi->lock, flags); +} +EXPORT_SYMBOL(asi_unmap);