diff options
author | Christian Borntraeger <borntraeger@de.ibm.com> | 2019-12-16 18:48:11 +0300 |
---|---|---|
committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2020-02-27 21:47:11 +0300 |
commit | 1274800792dced8e5b6d54c71ec049c4d1e34189 (patch) | |
tree | 7d969ddc78286f9cc4e7e623f3115b25967766ce /arch/s390/mm/gmap.c | |
parent | fa0c5eabbdd33012b369cf75d6a39389cc9ae707 (diff) |
KVM: s390/mm: Make pages accessible before destroying the guest
Before we destroy the secure configuration, we better make all
pages accessible again. This also happens during reboot, where we reboot
into a non-secure guest that then can go again into secure mode. As
this "new" secure guest will have a new ID we cannot reuse the old page
state.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Diffstat (limited to 'arch/s390/mm/gmap.c')
-rw-r--r-- | arch/s390/mm/gmap.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 7291452fe5f0..27926a06df32 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -2650,3 +2650,38 @@ void s390_reset_cmma(struct mm_struct *mm) up_write(&mm->mmap_sem); } EXPORT_SYMBOL_GPL(s390_reset_cmma); + +/* + * make inaccessible pages accessible again + */ +static int __s390_reset_acc(pte_t *ptep, unsigned long addr, + unsigned long next, struct mm_walk *walk) +{ + pte_t pte = READ_ONCE(*ptep); + + if (pte_present(pte)) + WARN_ON_ONCE(uv_convert_from_secure(pte_val(pte) & PAGE_MASK)); + return 0; +} + +static const struct mm_walk_ops reset_acc_walk_ops = { + .pte_entry = __s390_reset_acc, +}; + +#include <linux/sched/mm.h> +void s390_reset_acc(struct mm_struct *mm) +{ + /* + * we might be called during + * reset: we walk the pages and clear + * close of all kvm file descriptors: we walk the pages and clear + * exit of process on fd closure: vma already gone, do nothing + */ + if (!mmget_not_zero(mm)) + return; + down_read(&mm->mmap_sem); + walk_page_range(mm, 0, TASK_SIZE, &reset_acc_walk_ops, NULL); + up_read(&mm->mmap_sem); + mmput(mm); +} +EXPORT_SYMBOL_GPL(s390_reset_acc); |