Fix _do_shadow_pte() to use the correct pointer (guest pte instead of nested guest) to set up the new pte. Add a check to return -EOPNOTSUPP if the mapping for the nested guest is writeable but the same page in the guest is only read-only. Signed-off-by: Claudio Imbrenda Fixes: e38c884df921 ("KVM: s390: Switch to new gmap") --- arch/s390/kvm/gaccess.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index 8fd690255e1b..6bc30f678921 100644 --- a/arch/s390/kvm/gaccess.c +++ b/arch/s390/kvm/gaccess.c @@ -1436,13 +1436,19 @@ static int _do_shadow_pte(struct gmap *sg, gpa_t raddr, union pte *ptep_h, union if (!pgste_get_trylock(ptep_h, &pgste)) return -EAGAIN; - newpte = _pte(f->pfn, f->writable, !p, 0); - newpte.s.d |= ptep->s.d; - newpte.s.sd |= ptep->s.sd; - newpte.h.p &= ptep->h.p; - pgste = _gmap_ptep_xchg(sg->parent, ptep_h, newpte, pgste, f->gfn, false); - pgste.vsie_notif = 1; + newpte = _pte(f->pfn, f->writable, !p, ptep_h->s.s); + newpte.s.d |= ptep_h->s.d; + newpte.s.sd |= ptep_h->s.sd; + newpte.h.p &= ptep_h->h.p; + if (!newpte.h.p && !f->writable) { + rc = -EOPNOTSUPP; + } else { + pgste = _gmap_ptep_xchg(sg->parent, ptep_h, newpte, pgste, f->gfn, false); + pgste.vsie_notif = 1; + } pgste_set_unlock(ptep_h, pgste); + if (rc) + return rc; newpte = _pte(f->pfn, 0, !p, 0); if (!pgste_get_trylock(ptep, &pgste)) @@ -1477,6 +1483,9 @@ static int _do_shadow_crste(struct gmap *sg, gpa_t raddr, union crste *host, uni newcrste.h.p &= oldcrste.h.p; newcrste.s.fc1.vsie_notif = 1; newcrste.s.fc1.prefix_notif = oldcrste.s.fc1.prefix_notif; + newcrste.s.fc1.s = oldcrste.s.fc1.s; + if (!newcrste.h.p && !f->writable) + return -EOPNOTSUPP; } while (!_gmap_crstep_xchg_atomic(sg->parent, host, oldcrste, newcrste, f->gfn, false)); newcrste = _crste_fc1(f->pfn, oldcrste.h.tt, 0, !p); -- 2.53.0