From patchwork Fri Jul 6 13:55:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janosch Frank X-Patchwork-Id: 10511807 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6B4ED600CA for ; Fri, 6 Jul 2018 13:55:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5C46F28738 for ; Fri, 6 Jul 2018 13:55:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 508E52873C; Fri, 6 Jul 2018 13:55:52 +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 CDE6A28738 for ; Fri, 6 Jul 2018 13:55:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933125AbeGFNzt (ORCPT ); Fri, 6 Jul 2018 09:55:49 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:49202 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932995AbeGFNzs (ORCPT ); Fri, 6 Jul 2018 09:55:48 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w66DnD8d052595 for ; Fri, 6 Jul 2018 09:55:47 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 2k28hfucd1-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 06 Jul 2018 09:55:46 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 6 Jul 2018 14:55:43 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w66DtgMf41484414 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 6 Jul 2018 13:55:42 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 80FCAA4059; Fri, 6 Jul 2018 16:56:06 +0100 (BST) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D8749A4040; Fri, 6 Jul 2018 16:56:05 +0100 (BST) Received: from s38lp20.boeblingen.de.ibm.com (unknown [9.145.48.3]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 6 Jul 2018 16:56:05 +0100 (BST) From: Janosch Frank To: kvm@vger.kernel.org Cc: david@redhat.com, borntraeger@de.ibm.com, schwidefsky@de.ibm.com Subject: [PATCH v5 01/11] s390/mm: make gmap_protect_range more modular Date: Fri, 6 Jul 2018 14:55:19 +0100 X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180706135529.88966-1-frankja@linux.ibm.com> References: <20180706135529.88966-1-frankja@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18070613-0008-0000-0000-000002506A8D X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18070613-0009-0000-0000-000021B689E8 Message-Id: <20180706135529.88966-2-frankja@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-07-06_04:, , 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=642 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807060153 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Janosch Frank This patch reworks the gmap_protect_range logic and extracts the pte handling into an own function. Also we do now walk to the pmd and make it accessible in the function for later use. This way we can add huge page handling logic more easily. Signed-off-by: Janosch Frank Reviewed-by: Christian Borntraeger Reviewed-by: Martin Schwidefsky --- arch/s390/mm/gmap.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 83 insertions(+), 10 deletions(-) diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index bc56ec8abcf7..71b0e9ca0137 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -864,7 +864,79 @@ static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr, */ static void gmap_pte_op_end(spinlock_t *ptl) { - spin_unlock(ptl); + if (ptl) + spin_unlock(ptl); +} + +/** + * gmap_pmd_op_walk - walk the gmap tables, get the guest table lock + * and return the pmd pointer + * @gmap: pointer to guest mapping meta data structure + * @gaddr: virtual address in the guest address space + * + * Returns a pointer to the pmd for a guest address, or NULL + */ +static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr) +{ + pmd_t *pmdp; + + BUG_ON(gmap_is_shadow(gmap)); + spin_lock(&gmap->guest_table_lock); + pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1); + + if (!pmdp || pmd_none(*pmdp)) { + spin_unlock(&gmap->guest_table_lock); + return NULL; + } + + /* 4k page table entries are locked via the pte (pte_alloc_map_lock). */ + if (!pmd_large(*pmdp)) + spin_unlock(&gmap->guest_table_lock); + return pmdp; +} + +/** + * gmap_pmd_op_end - release the guest_table_lock if needed + * @gmap: pointer to the guest mapping meta data structure + * @pmdp: pointer to the pmd + */ +static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp) +{ + if (pmd_large(*pmdp)) + spin_unlock(&gmap->guest_table_lock); +} + +/* + * gmap_protect_pte - remove access rights to memory and set pgste bits + * @gmap: pointer to guest mapping meta data structure + * @gaddr: virtual address in the guest address space + * @pmdp: pointer to the pmd associated with the pte + * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE + * @bits: pgste notification bits to set + * + * Returns 0 if successfully protected, -ENOMEM if out of memory and + * -EAGAIN if a fixup is needed. + * + * Expected to be called with sg->mm->mmap_sem in read + */ +static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr, + pmd_t *pmdp, int prot, unsigned long bits) +{ + int rc; + pte_t *ptep; + spinlock_t *ptl = NULL; + + if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) + return -EAGAIN; + + ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, &ptl); + if (!ptep) + return -ENOMEM; + + /* Protect and unlock. */ + rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits); + gmap_pte_op_end(ptl); + return rc; } /* @@ -884,17 +956,21 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, unsigned long len, int prot, unsigned long bits) { unsigned long vmaddr; - spinlock_t *ptl; - pte_t *ptep; + pmd_t *pmdp; int rc; BUG_ON(gmap_is_shadow(gmap)); while (len) { rc = -EAGAIN; - ptep = gmap_pte_op_walk(gmap, gaddr, &ptl); - if (ptep) { - rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits); - gmap_pte_op_end(ptl); + 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; + } + gmap_pmd_op_end(gmap, pmdp); } if (rc) { vmaddr = __gmap_translate(gmap, gaddr); @@ -903,10 +979,7 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot); if (rc) return rc; - continue; } - gaddr += PAGE_SIZE; - len -= PAGE_SIZE; } return 0; }