[PATCH v2 1/8] KVM: s390: vsie: Fix dat_split_ste()

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

If the guest misbehaves and puts the page tables for its nested guest
inside the memory of the nested guest itself, the shadow mapping will
lose synchronization with the actual mapping.

Propagate the vsie_notif bit from shadowed large pages to smaller pages
when splitting a large page.

Fixes: 2db149a0a6c5 ("KVM: s390: KVM page table management functions: walks")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 arch/s390/kvm/dat.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/s390/kvm/dat.c b/arch/s390/kvm/dat.c
index 670404d4fa44..48b5f2bcf172 100644
--- a/arch/s390/kvm/dat.c
+++ b/arch/s390/kvm/dat.c
@@ -292,6 +292,7 @@ static int dat_split_ste(struct kvm_s390_mmu_cache *mc, union pmd *pmdp, gfn_t g
 				pt->ptes[i].val = init.val | i * PAGE_SIZE;
 			/* No need to take locks as the page table is not installed yet. */
 			pgste_init.prefix_notif = old.s.fc1.prefix_notif;
+			pgste_init.vsie_notif = old.s.fc1.vsie_notif;
 			pgste_init.pcl = uses_skeys && init.h.i;
 			dat_init_pgstes(pt, pgste_init.val);
 		} else {
-- 
2.53.0