diff options
| author | Janosch Frank <frankja@linux.ibm.com> | 2019-07-16 13:08:37 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2020-02-27 19:47:11 +0100 |
| commit | fa0c5eabbdd33012b369cf75d6a39389cc9ae707 (patch) | |
| tree | 7456128145b210018c8acc80d98c8125d5a7cef7 /arch/s390/mm | |
| parent | 29b40f105ec8d555984c1f72dc9133b122e51903 (diff) | |
KVM: s390: protvirt: Secure memory is not mergeable
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>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/gmap.c | 30 |
1 files changed, 20 insertions, 10 deletions
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: |