The slow path of the fault handler ultimately called gmap_link(), which assumed the fault was a major fault, and blindly called dat_link(). In case of minor faults, things were not always handled properly; in particular the prefix and vsie marker bits were ignored. Move dat_link() into gmap.c, renaming it accordingly. Once moved, the new _gmap_link() function will be able to correctly honour the prefix and vsie markers. Signed-off-by: Claudio Imbrenda Fixes: 94fd9b16cc67 ("KVM: s390: KVM page table management functions: lifecycle management") Fixes: a2c17f9270cc ("KVM: s390: New gmap code") --- arch/s390/kvm/dat.c | 48 -------------------------------------- arch/s390/kvm/dat.h | 2 -- arch/s390/kvm/gmap.c | 55 ++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 51 insertions(+), 54 deletions(-) diff --git a/arch/s390/kvm/dat.c b/arch/s390/kvm/dat.c index b673e86c8ae5..bfa84074f433 100644 --- a/arch/s390/kvm/dat.c +++ b/arch/s390/kvm/dat.c @@ -996,54 +996,6 @@ bool dat_test_age_gfn(union asce asce, gfn_t start, gfn_t end) return _dat_walk_gfn_range(start, end, asce, &test_age_ops, 0, NULL) > 0; } -int dat_link(struct kvm_s390_mmu_cache *mc, union asce asce, int level, - bool uses_skeys, struct guest_fault *f) -{ - union crste oldval, newval; - union pte newpte, oldpte; - union pgste pgste; - int rc = 0; - - rc = dat_entry_walk(mc, f->gfn, asce, DAT_WALK_ALLOC_CONTINUE, level, &f->crstep, &f->ptep); - if (rc == -EINVAL || rc == -ENOMEM) - return rc; - if (rc) - return -EAGAIN; - - if (WARN_ON_ONCE(unlikely(get_level(f->crstep, f->ptep) > level))) - return -EINVAL; - - if (f->ptep) { - pgste = pgste_get_lock(f->ptep); - oldpte = *f->ptep; - newpte = _pte(f->pfn, f->writable, f->write_attempt | oldpte.s.d, !f->page); - newpte.s.sd = oldpte.s.sd; - oldpte.s.sd = 0; - if (oldpte.val == _PTE_EMPTY.val || oldpte.h.pfra == f->pfn) { - pgste = __dat_ptep_xchg(f->ptep, pgste, newpte, f->gfn, asce, uses_skeys); - if (f->callback) - f->callback(f); - } else { - rc = -EAGAIN; - } - pgste_set_unlock(f->ptep, pgste); - } else { - oldval = READ_ONCE(*f->crstep); - newval = _crste_fc1(f->pfn, oldval.h.tt, f->writable, - f->write_attempt | oldval.s.fc1.d); - newval.s.fc1.sd = oldval.s.fc1.sd; - if (oldval.val != _CRSTE_EMPTY(oldval.h.tt).val && - crste_origin_large(oldval) != crste_origin_large(newval)) - return -EAGAIN; - if (!dat_crstep_xchg_atomic(f->crstep, oldval, newval, f->gfn, asce)) - return -EAGAIN; - if (f->callback) - f->callback(f); - } - - return rc; -} - static long dat_set_pn_crste(union crste *crstep, gfn_t gfn, gfn_t next, struct dat_walk *walk) { union crste newcrste, oldcrste; diff --git a/arch/s390/kvm/dat.h b/arch/s390/kvm/dat.h index 22dafc775335..efedcf96110c 100644 --- a/arch/s390/kvm/dat.h +++ b/arch/s390/kvm/dat.h @@ -540,8 +540,6 @@ int dat_set_slot(struct kvm_s390_mmu_cache *mc, union asce asce, gfn_t start, gf u16 type, u16 param); int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn); bool dat_test_age_gfn(union asce asce, gfn_t start, gfn_t end); -int dat_link(struct kvm_s390_mmu_cache *mc, union asce asce, int level, - bool uses_skeys, struct guest_fault *f); int dat_perform_essa(union asce asce, gfn_t gfn, int orc, union essa_state *state, bool *dirty); long dat_reset_cmma(union asce asce, gfn_t start_gfn); diff --git a/arch/s390/kvm/gmap.c b/arch/s390/kvm/gmap.c index 3ae746fada36..759a2ed17038 100644 --- a/arch/s390/kvm/gmap.c +++ b/arch/s390/kvm/gmap.c @@ -626,10 +626,59 @@ static inline bool gmap_1m_allowed(struct gmap *gmap, gfn_t gfn) return test_bit(GMAP_FLAG_ALLOW_HPAGE_1M, &gmap->flags); } +static int _gmap_link(struct kvm_s390_mmu_cache *mc, struct gmap *gmap, int level, + struct guest_fault *f) +{ + union crste oldval, newval; + union pte newpte, oldpte; + union pgste pgste; + int rc = 0; + + rc = dat_entry_walk(mc, f->gfn, gmap->asce, DAT_WALK_ALLOC_CONTINUE, level, + &f->crstep, &f->ptep); + if (rc == -ENOMEM) + return rc; + if (KVM_BUG_ON(rc == -EINVAL, gmap->kvm)) + return rc; + if (rc) + return -EAGAIN; + if (KVM_BUG_ON(get_level(f->crstep, f->ptep) > level, gmap->kvm)) + return -EINVAL; + + if (f->ptep) { + pgste = pgste_get_lock(f->ptep); + oldpte = *f->ptep; + newpte = _pte(f->pfn, f->writable, f->write_attempt | oldpte.s.d, !f->page); + newpte.s.sd = oldpte.s.sd; + oldpte.s.sd = 0; + if (oldpte.val == _PTE_EMPTY.val || oldpte.h.pfra == f->pfn) { + pgste = gmap_ptep_xchg(gmap, f->ptep, newpte, pgste, f->gfn); + if (f->callback) + f->callback(f); + } else { + rc = -EAGAIN; + } + pgste_set_unlock(f->ptep, pgste); + } else { + oldval = READ_ONCE(*f->crstep); + newval = _crste_fc1(f->pfn, oldval.h.tt, f->writable, + f->write_attempt | oldval.s.fc1.d); + newval.s.fc1.sd = oldval.s.fc1.sd; + if (oldval.val != _CRSTE_EMPTY(oldval.h.tt).val && + crste_origin_large(oldval) != crste_origin_large(newval)) + return -EAGAIN; + gmap_crstep_xchg(gmap, f->crstep, newval, f->gfn); + if (f->callback) + f->callback(f); + } + + return rc; +} + int gmap_link(struct kvm_s390_mmu_cache *mc, struct gmap *gmap, struct guest_fault *f) { unsigned int order; - int rc, level; + int level; lockdep_assert_held(&gmap->kvm->mmu_lock); @@ -641,9 +690,7 @@ int gmap_link(struct kvm_s390_mmu_cache *mc, struct gmap *gmap, struct guest_fau else if (order >= get_order(_SEGMENT_SIZE) && gmap_1m_allowed(gmap, f->gfn)) level = TABLE_TYPE_SEGMENT; } - rc = dat_link(mc, gmap->asce, level, uses_skeys(gmap), f); - KVM_BUG_ON(rc == -EINVAL, gmap->kvm); - return rc; + return _gmap_link(mc, gmap, level, f); } static int gmap_ucas_map_one(struct kvm_s390_mmu_cache *mc, struct gmap *gmap, -- 2.53.0