From patchwork Thu Jul 26 12:37:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janosch Frank X-Patchwork-Id: 10545791 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 88FAC112B for ; Thu, 26 Jul 2018 12:37:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 31B182AB4C for ; Thu, 26 Jul 2018 12:37:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 220052B13B; Thu, 26 Jul 2018 12:37:38 +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=ham 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 A39F22B135 for ; Thu, 26 Jul 2018 12:37:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730474AbeGZNyP (ORCPT ); Thu, 26 Jul 2018 09:54:15 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46820 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730178AbeGZNyP (ORCPT ); Thu, 26 Jul 2018 09:54:15 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6QCYTlk059012 for ; Thu, 26 Jul 2018 08:37:35 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2kfe7nrp0x-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 26 Jul 2018 08:37:35 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 26 Jul 2018 13:37:33 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp04.uk.ibm.com (192.168.101.134) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 26 Jul 2018 13:37:29 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w6QCbSrv40108220 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 26 Jul 2018 12:37:28 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1EF7311C058; Thu, 26 Jul 2018 15:37:42 +0100 (BST) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DDDA611C04C; Thu, 26 Jul 2018 15:37:41 +0100 (BST) Received: from s38lp20.boeblingen.de.ibm.com (unknown [9.152.224.110]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 26 Jul 2018 15:37:41 +0100 (BST) From: Janosch Frank To: kvm@vger.kernel.org Cc: david@redhat.com, borntraeger@de.ibm.com, schwidefsky@de.ibm.com Subject: [PATCH v9 04/13] s390/mm: Add gmap pmd notification bit setting Date: Thu, 26 Jul 2018 13:37:01 +0100 X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180726123710.13131-1-frankja@linux.ibm.com> References: <20180726123710.13131-1-frankja@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18072612-0016-0000-0000-000001EC4FD2 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18072612-0017-0000-0000-0000324153ED Message-Id: <20180726123710.13131-5-frankja@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-26_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=819 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807260132 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Like for ptes, we also need invalidation notification for pmds, to make sure the guest lowcore pages are always accessible and later addition of shadowed pmds. With PMDs we do not have PGSTEs or some other bits we could use in the host PMD. Instead we pick one of the free bits in the gmap PMD. Every time a host pmd will be invalidated, we will check if the respective gmap PMD has the bit set and in that case fire up the notifier. Signed-off-by: Janosch Frank --- arch/s390/include/asm/gmap.h | 3 +++ arch/s390/mm/gmap.c | 60 +++++++++++++++++++++++++++++++++++++++----- 2 files changed, 57 insertions(+), 6 deletions(-) diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h index c1bc5633fc6e..276268b48aff 100644 --- a/arch/s390/include/asm/gmap.h +++ b/arch/s390/include/asm/gmap.h @@ -13,6 +13,9 @@ #define GMAP_NOTIFY_SHADOW 0x2 #define GMAP_NOTIFY_MPROT 0x1 +/* Status bits only for huge segment entries */ +#define _SEGMENT_ENTRY_GMAP_IN 0x8000 /* invalidation notify bit */ + /** * struct gmap_struct - guest address space * @list: list head for the mm->context gmap list diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 870e81fcb0cf..96dd94d51ad4 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -911,6 +911,40 @@ static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp) spin_unlock(&gmap->guest_table_lock); } +/* + * gmap_protect_pmd - remove access rights to memory and set pmd notification bits + * @pmdp: pointer to the pmd to be protected + * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE + * @bits: notification bits to set + * + * Returns: + * 0 if successfully protected + * -EAGAIN if a fixup is needed + * -EINVAL if unsupported notifier bits have been specified + * + * Expected to be called with sg->mm->mmap_sem in read and + * guest_table_lock held. + */ +static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr, + pmd_t *pmdp, int prot, unsigned long bits) +{ + int pmd_i = pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID; + int pmd_p = pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT; + + /* Fixup needed */ + if ((pmd_i && (prot != PROT_NONE)) || (pmd_p && (prot == PROT_WRITE))) + return -EAGAIN; + + if (bits & GMAP_NOTIFY_MPROT) + pmd_val(*pmdp) |= _SEGMENT_ENTRY_GMAP_IN; + + /* Shadow GMAP protection needs split PMDs */ + if (bits & GMAP_NOTIFY_SHADOW) + return -EINVAL; + + return 0; +} + /* * gmap_protect_pte - remove access rights to memory and set pgste bits * @gmap: pointer to guest mapping meta data structure @@ -963,7 +997,7 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr, static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, unsigned long len, int prot, unsigned long bits) { - unsigned long vmaddr; + unsigned long vmaddr, dist; pmd_t *pmdp; int rc; @@ -972,15 +1006,29 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, rc = -EAGAIN; pmdp = gmap_pmd_op_walk(gmap, gaddr); if (pmdp) { - rc = gmap_protect_pte(gmap, gaddr, pmdp, prot, - bits); - if (!rc) { - len -= PAGE_SIZE; - gaddr += PAGE_SIZE; + if (!pmd_large(*pmdp)) { + rc = gmap_protect_pte(gmap, gaddr, pmdp, prot, + bits); + if (!rc) { + len -= PAGE_SIZE; + gaddr += PAGE_SIZE; + } + } else { + rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot, + bits); + if (!rc) { + dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK); + len = len < dist ? 0 : len - dist; + gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE; + } } gmap_pmd_op_end(gmap, pmdp); } if (rc) { + if (rc == -EINVAL) + return rc; + + /* -EAGAIN, fixup of userspace mm and gmap */ vmaddr = __gmap_translate(gmap, gaddr); if (IS_ERR_VALUE(vmaddr)) return vmaddr;