From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
Janosch Frank <frankja@linux.vnet.ibm.com>
Cc: KVM <kvm@vger.kernel.org>, Cornelia Huck <cohuck@redhat.com>,
David Hildenbrand <david@redhat.com>,
Thomas Huth <thuth@redhat.com>,
Ulrich Weigand <Ulrich.Weigand@de.ibm.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Andrea Arcangeli <aarcange@redhat.com>,
linux-s390 <linux-s390@vger.kernel.org>,
Michael Mueller <mimu@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 10/35] KVM: s390: protvirt: Secure memory is not mergeable
Date: Fri, 7 Feb 2020 06:39:33 -0500 [thread overview]
Message-ID: <20200207113958.7320-11-borntraeger@de.ibm.com> (raw)
In-Reply-To: <20200207113958.7320-1-borntraeger@de.ibm.com>
From: Janosch Frank <frankja@linux.ibm.com>
KSM will not work on secure pages, because when the kernel reads a
secure page, it will be encrypted and hence no two pages will look the
same.
Let's mark the guest pages as unmergeable when we transition to secure
mode.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
arch/s390/include/asm/gmap.h | 1 +
arch/s390/kvm/kvm-s390.c | 8 ++++++++
arch/s390/mm/gmap.c | 30 ++++++++++++++++++++----------
3 files changed, 29 insertions(+), 10 deletions(-)
diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index e2d2f48c5c7c..e1f2cc0b2b00 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -146,4 +146,5 @@ int gmap_mprotect_notify(struct gmap *, unsigned long start,
void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
unsigned long gaddr, unsigned long vmaddr);
+int gmap_mark_unmergeable(void);
#endif /* _ASM_S390_GMAP_H */
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e1bccbb41fdd..ad86e74e27ec 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2182,6 +2182,14 @@ static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
if (r)
break;
+ down_write(¤t->mm->mmap_sem);
+ r = gmap_mark_unmergeable();
+ up_write(¤t->mm->mmap_sem);
+ if (r) {
+ kvm_s390_pv_dealloc_vm(kvm);
+ break;
+ }
+
mutex_lock(&kvm->lock);
kvm_s390_vcpu_block_all(kvm);
/* FMT 4 SIE needs esca */
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index edcdca97e85e..7291452fe5f0 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2548,6 +2548,22 @@ int s390_enable_sie(void)
}
EXPORT_SYMBOL_GPL(s390_enable_sie);
+int gmap_mark_unmergeable(void)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
+ MADV_UNMERGEABLE, &vma->vm_flags)) {
+ return -ENOMEM;
+ }
+ }
+ mm->def_flags &= ~VM_MERGEABLE;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gmap_mark_unmergeable);
+
/*
* Enable storage key handling from now on and initialize the storage
* keys with the default key.
@@ -2593,7 +2609,6 @@ static const struct mm_walk_ops enable_skey_walk_ops = {
int s390_enable_skey(void)
{
struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
int rc = 0;
down_write(&mm->mmap_sem);
@@ -2601,16 +2616,11 @@ int s390_enable_skey(void)
goto out_up;
mm->context.uses_skeys = 1;
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
- if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
- MADV_UNMERGEABLE, &vma->vm_flags)) {
- mm->context.uses_skeys = 0;
- rc = -ENOMEM;
- goto out_up;
- }
+ rc = gmap_mark_unmergeable();
+ if (rc) {
+ mm->context.uses_skeys = 0;
+ goto out_up;
}
- mm->def_flags &= ~VM_MERGEABLE;
-
walk_page_range(mm, 0, TASK_SIZE, &enable_skey_walk_ops, NULL);
out_up:
--
2.24.0
next prev parent reply other threads:[~2020-02-07 11:40 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-07 11:39 [PATCH 00/35] KVM: s390: Add support for protected VMs Christian Borntraeger
2020-02-07 11:39 ` [PATCH 01/35] mm:gup/writeback: add callbacks for inaccessible pages Christian Borntraeger
2020-02-10 17:27 ` Christian Borntraeger
2020-02-11 11:26 ` Will Deacon
2020-02-11 11:43 ` Christian Borntraeger
2020-02-13 14:48 ` Christian Borntraeger
2020-02-18 16:02 ` Will Deacon
2020-02-13 19:56 ` Sean Christopherson
2020-02-13 20:13 ` Christian Borntraeger
2020-02-13 20:46 ` Sean Christopherson
2020-02-17 20:55 ` Tom Lendacky
2020-02-17 21:14 ` Christian Borntraeger
2020-02-10 18:17 ` David Hildenbrand
2020-02-10 18:28 ` Christian Borntraeger
2020-02-10 18:43 ` David Hildenbrand
2020-02-10 18:51 ` Christian Borntraeger
2020-02-18 3:36 ` Tian, Kevin
2020-02-18 6:44 ` Christian Borntraeger
2020-02-07 11:39 ` [PATCH 02/35] KVM: s390/interrupt: do not pin adapter interrupt pages Christian Borntraeger
2020-02-10 12:26 ` David Hildenbrand
2020-02-10 18:38 ` Christian Borntraeger
2020-02-10 19:33 ` David Hildenbrand
2020-02-11 9:23 ` [PATCH v2 RFC] " Christian Borntraeger
2020-02-12 11:52 ` Christian Borntraeger
2020-02-12 12:16 ` David Hildenbrand
2020-02-12 12:22 ` Christian Borntraeger
2020-02-12 12:47 ` David Hildenbrand
2020-02-12 12:39 ` Cornelia Huck
2020-02-12 12:44 ` Christian Borntraeger
2020-02-12 13:07 ` Cornelia Huck
2020-02-10 18:56 ` [PATCH 02/35] KVM: s390/interrupt: do not pin adapter interrupt Ulrich Weigand
2020-02-10 12:40 ` [PATCH 02/35] KVM: s390/interrupt: do not pin adapter interrupt pages David Hildenbrand
2020-02-07 11:39 ` [PATCH 05/35] s390/mm: provide memory management functions for protected KVM guests Christian Borntraeger
2020-02-12 13:42 ` Cornelia Huck
2020-02-13 7:43 ` Christian Borntraeger
2020-02-13 8:44 ` Cornelia Huck
2020-02-14 17:59 ` David Hildenbrand
2020-02-14 21:17 ` Christian Borntraeger
2020-02-07 11:39 ` [PATCH 06/35] s390/mm: add (non)secure page access exceptions handlers Christian Borntraeger
2020-02-14 18:05 ` David Hildenbrand
2020-02-14 19:59 ` Christian Borntraeger
2020-02-07 11:39 ` Christian Borntraeger [this message]
2020-02-07 11:39 ` [PATCH 11/35] KVM: s390/mm: Make pages accessible before destroying the guest Christian Borntraeger
2020-02-14 18:40 ` David Hildenbrand
2020-02-07 11:39 ` [PATCH 21/35] KVM: s390/mm: handle guest unpin events Christian Borntraeger
2020-02-10 14:58 ` Thomas Huth
2020-02-11 13:21 ` Cornelia Huck
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