diff options
author | Christian Borntraeger <borntraeger@de.ibm.com> | 2019-12-16 10:48:11 -0500 |
---|---|---|
committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2020-02-27 19:47:11 +0100 |
commit | 1274800792dced8e5b6d54c71ec049c4d1e34189 (patch) | |
tree | 7d969ddc78286f9cc4e7e623f3115b25967766ce | |
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>
-rw-r--r-- | arch/s390/include/asm/gmap.h | 1 | ||||
-rw-r--r-- | arch/s390/kvm/pv.c | 3 | ||||
-rw-r--r-- | arch/s390/mm/gmap.c | 35 |
3 files changed, 39 insertions, 0 deletions
diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h index 6f9ff7a69fa2..a816fb4734b8 100644 --- a/arch/s390/include/asm/gmap.h +++ b/arch/s390/include/asm/gmap.h @@ -149,4 +149,5 @@ 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); +void s390_reset_acc(struct mm_struct *mm); #endif /* _ASM_S390_GMAP_H */ diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index e9e020475f4a..9840ee49e572 100644 --- a/arch/s390/kvm/pv.c +++ b/arch/s390/kvm/pv.c @@ -140,6 +140,9 @@ int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc) { int cc; + /* make all pages accessible before destroying the guest */ + s390_reset_acc(kvm->mm); + cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm), UVC_CMD_DESTROY_SEC_CONF, rc, rrc); WRITE_ONCE(kvm->arch.gmap->guest_handle, 0); 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); |