From patchwork Wed Jun 12 11:54:52 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 2709751 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C0C89C1459 for ; Wed, 12 Jun 2013 11:55:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D298A2022F for ; Wed, 12 Jun 2013 11:55:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF1982022B for ; Wed, 12 Jun 2013 11:55:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750862Ab3FLLzF (ORCPT ); Wed, 12 Jun 2013 07:55:05 -0400 Received: from e06smtp14.uk.ibm.com ([195.75.94.110]:60600 "EHLO e06smtp14.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750747Ab3FLLzD (ORCPT ); Wed, 12 Jun 2013 07:55:03 -0400 Received: from /spool/local by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 12 Jun 2013 12:48:02 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id D45FB1B08061; Wed, 12 Jun 2013 12:54:59 +0100 (BST) Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213]) by b06cxnps4076.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5CBsmdk25034902; Wed, 12 Jun 2013 11:54:48 GMT Received: from d06av03.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r5CBswFh031742; Wed, 12 Jun 2013 05:54:59 -0600 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id r5CBsw3A031712; Wed, 12 Jun 2013 05:54:58 -0600 From: Cornelia Huck To: Gleb Natapov , Paolo Bonzini Cc: Christian Borntraeger , Heiko Carstens , Martin Schwidefsky , KVM , linux-s390 Subject: [PATCH 1/6] KVM: s390: Provide function for setting the guest storage key Date: Wed, 12 Jun 2013 13:54:52 +0200 Message-Id: <1371038097-28577-2-git-send-email-cornelia.huck@de.ibm.com> X-Mailer: git-send-email 1.8.1.6 In-Reply-To: <1371038097-28577-1-git-send-email-cornelia.huck@de.ibm.com> References: <1371038097-28577-1-git-send-email-cornelia.huck@de.ibm.com> X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13061211-1948-0000-0000-00000567A912 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Christian Borntraeger From time to time we need to set the guest storage key. Lets provide a helper function that handles the changes with all the right locking and checking. Signed-off-by: Christian Borntraeger Signed-off-by: Cornelia Huck --- arch/s390/include/asm/pgalloc.h | 3 +++ arch/s390/mm/pgtable.c | 48 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h index 590c321..e1408dd 100644 --- a/arch/s390/include/asm/pgalloc.h +++ b/arch/s390/include/asm/pgalloc.h @@ -22,6 +22,9 @@ unsigned long *page_table_alloc(struct mm_struct *, unsigned long); void page_table_free(struct mm_struct *, unsigned long *); void page_table_free_rcu(struct mmu_gather *, unsigned long *); +int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, + unsigned long key, bool nq); + static inline void clear_table(unsigned long *s, unsigned long val, size_t n) { typedef struct { char _[n]; } addrtype; diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 1e0c438..44b1450 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -771,6 +771,54 @@ static inline void page_table_free_pgste(unsigned long *table) __free_page(page); } +int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, + unsigned long key, bool nq) +{ + spinlock_t *ptl; + pgste_t old, new; + pte_t *ptep; + + down_read(&mm->mmap_sem); + ptep = get_locked_pte(current->mm, addr, &ptl); + if (unlikely(!ptep)) { + up_read(&mm->mmap_sem); + return -EFAULT; + } + + new = old = pgste_get_lock(ptep); + pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | + PGSTE_ACC_BITS | PGSTE_FP_BIT); + pgste_val(new) |= (key & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48; + pgste_val(new) |= (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + unsigned long address, bits; + unsigned char skey; + + address = pte_val(*ptep) & PAGE_MASK; + skey = page_get_storage_key(address); + bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); + /* Set storage key ACC and FP */ + page_set_storage_key(address, + (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)), + !nq); + + /* Merge host changed & referenced into pgste */ + pgste_val(new) |= bits << 52; + /* Transfer skey changed & referenced bit to kvm user bits */ + pgste_val(new) |= bits << 45; /* PGSTE_UR_BIT & PGSTE_UC_BIT */ + } + /* changing the guest storage key is considered a change of the page */ + if ((pgste_val(new) ^ pgste_val(old)) & + (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT)) + pgste_val(new) |= PGSTE_UC_BIT; + + pgste_set_unlock(ptep, new); + pte_unmap_unlock(*ptep, ptl); + up_read(&mm->mmap_sem); + return 0; +} +EXPORT_SYMBOL(set_guest_storage_key); + #else /* CONFIG_PGSTE */ static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,