diff options
Diffstat (limited to 'arch/s390/kvm/gaccess.c')
| -rw-r--r-- | arch/s390/kvm/gaccess.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index b2783dd71854..e70f916c1079 100644 --- a/arch/s390/kvm/gaccess.c +++ b/arch/s390/kvm/gaccess.c @@ -1073,6 +1073,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, /** * kvm_s390_shadow_fault - handle fault on a shadow page table + * @vcpu: virtual cpu * @sg: pointer to the shadow guest address space structure * @saddr: faulting address in the shadow gmap * @@ -1082,7 +1083,8 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, * - -EFAULT when accessing invalid guest addresses * - -ENOMEM if out of memory */ -int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr) +int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg, + unsigned long saddr) { union vaddress vaddr; union page_table_entry pte; @@ -1091,6 +1093,12 @@ int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr) int rc; down_read(&sg->mm->mmap_sem); + /* + * We don't want any guest-2 tables to change - so the parent + * tables/pointers we read stay valid - unshadowing is however + * always possible - only guest_table_lock protects us. + */ + ipte_lock(vcpu); rc = gmap_shadow_pgt_lookup(sg, saddr, &pgt, &dat_protection); if (rc) @@ -1105,6 +1113,7 @@ int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr) rc = PGM_TRANSLATION_SPEC; if (!rc) rc = gmap_shadow_page(sg, saddr, __pte(pte.val)); + ipte_unlock(vcpu); up_read(&sg->mm->mmap_sem); return rc; } |