From mboxrd@z Thu Jan 1 00:00:00 1970 From: Janosch Frank Subject: [RFC/PATCH v2 14/22] s390/mm: Make protect_rmap EDAT1 compatible Date: Wed, 13 Dec 2017 13:53:25 +0100 Message-ID: <1513169613-13509-15-git-send-email-frankja@linux.vnet.ibm.com> References: <1513169613-13509-1-git-send-email-frankja@linux.vnet.ibm.com> Cc: schwidefsky@de.ibm.com, borntraeger@de.ibm.com, david@redhat.com, dominik.dingel@gmail.com, linux-s390@vger.kernel.org To: kvm@vger.kernel.org Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48552 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753166AbdLMMyk (ORCPT ); Wed, 13 Dec 2017 07:54:40 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vBDCs14b102438 for ; Wed, 13 Dec 2017 07:54:40 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0b-001b2d01.pphosted.com with ESMTP id 2eu439hm2a-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 13 Dec 2017 07:54:39 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 13 Dec 2017 12:54:38 -0000 In-Reply-To: <1513169613-13509-1-git-send-email-frankja@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: When shadowing, we must make sure, that any changes to the GMAP inside guest N will also be directly reflected in our shadow GMAP. This is done by write-protecting guest N memory at the places where it stores DAT tables for guest N + 1. This still lacks EDAT1 support, so let's add it. Signed-off-by: Janosch Frank --- arch/s390/mm/gmap.c | 80 +++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 66 insertions(+), 14 deletions(-) diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 828eadf..d45ac26da 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -1275,6 +1275,51 @@ static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr, } } +static int gmap_protect_rmap_pmd(struct gmap *sg, struct gmap_rmap *rmap, + unsigned long paddr, unsigned long vmaddr, + pmd_t *pmdp, int prot) +{ + int rc = 0; + + /* We have no upper segment, let's go back and fix this up. */ + if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) + return -EAGAIN; + + spin_lock(&sg->guest_table_lock); + rc = gmap_protect_large(sg->parent, paddr, pmdp, + prot, GMAP_NOTIFY_SHADOW); + if (!rc) + gmap_insert_rmap(sg, vmaddr & HPAGE_MASK, rmap); + + spin_unlock(&sg->guest_table_lock); + return rc; +} + +static int gmap_protect_rmap_pte(struct gmap *sg, struct gmap_rmap *rmap, + unsigned long paddr, unsigned long vmaddr, + pmd_t *pmdp, int prot) +{ + int rc = 0; + pte_t *ptep = NULL; + spinlock_t *ptl = NULL; + + /* We have no upper segment, let's go back and fix this up. */ + if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) + return -EAGAIN; + + ptep = pte_alloc_map_lock(sg->parent->mm, pmdp, paddr, &ptl); + if (ptep) { + spin_lock(&sg->guest_table_lock); + rc = ptep_force_prot(sg->parent->mm, paddr, ptep, prot, + PGSTE_VSIE_BIT); + if (!rc) + gmap_insert_rmap(sg, vmaddr, rmap); + spin_unlock(&sg->guest_table_lock); + gmap_pte_op_end(ptl); + } + return rc; +} + /** * gmap_protect_rmap - modify access rights to memory and create an rmap * @sg: pointer to the shadow guest address space structure @@ -1291,9 +1336,8 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, { struct gmap *parent; struct gmap_rmap *rmap; - unsigned long vmaddr; - spinlock_t *ptl; - pte_t *ptep; + unsigned long vmaddr, dist; + pmd_t *pmdp; int rc; BUG_ON(!gmap_is_shadow(sg)); @@ -1312,15 +1356,25 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, return rc; } rc = -EAGAIN; - ptep = gmap_pte_op_walk(parent, paddr, &ptl); - if (ptep) { - spin_lock(&sg->guest_table_lock); - rc = ptep_force_prot(parent->mm, paddr, ptep, prot, - GMAP_NOTIFY_SHADOW); - if (!rc) - gmap_insert_rmap(sg, vmaddr, rmap); - spin_unlock(&sg->guest_table_lock); - gmap_pte_op_end(ptl); + pmdp = gmap_pmd_op_walk(parent, paddr); + if (pmdp) { + if (!pmd_large(*pmdp)) { + rc = gmap_protect_rmap_pte(sg, rmap, paddr, + vmaddr, pmdp, prot); + if (!rc) { + paddr += PAGE_SIZE; + len -= PAGE_SIZE; + } + } else { + rc = gmap_protect_rmap_pmd(sg, rmap, paddr, + vmaddr, pmdp, prot); + if (!rc) { + dist = HPAGE_SIZE - (paddr & ~HPAGE_MASK); + len = len < dist ? 0 : len - dist; + paddr = (paddr & HPAGE_MASK) + HPAGE_SIZE; + } + } + gmap_pmd_op_end(parent, pmdp); } radix_tree_preload_end(); if (rc) { @@ -1330,8 +1384,6 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, return rc; continue; } - paddr += PAGE_SIZE; - len -= PAGE_SIZE; } return 0; } -- 2.7.4