1 files changed, 22 insertions, 21 deletions

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 4cf35a0a79e7..c1c7c683fa26 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -142,12 +142,16 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_ONE_REG:
         case KVM_CAP_ENABLE_CAP:
         case KVM_CAP_S390_CSS_SUPPORT:
+        case KVM_CAP_IOEVENTFD:
                 r = 1;
                 break;
         case KVM_CAP_NR_VCPUS:
         case KVM_CAP_MAX_VCPUS:
                 r = KVM_MAX_VCPUS;
                 break;
+        case KVM_CAP_NR_MEMSLOTS:
+                r = KVM_USER_MEM_SLOTS;
+                break;
         case KVM_CAP_S390_COW:
                 r = MACHINE_HAS_ESOP;
                 break;
@@ -632,8 +636,7 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
                 } else {
                         VCPU_EVENT(vcpu, 3, "%s", "fault in sie instruction");
                         trace_kvm_s390_sie_fault(vcpu);
-                        kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
-                        rc = 0;
+                        rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
                 }
         }
         VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
@@ -974,22 +977,13 @@ int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
 /* Section: memory related */
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                    struct kvm_memory_slot *memslot,
-                                   struct kvm_memory_slot old,
                                    struct kvm_userspace_memory_region *mem,
-                                   bool user_alloc)
+                                   enum kvm_mr_change change)
 {
-        /* A few sanity checks. We can have exactly one memory slot which has
-           to start at guest virtual zero and which has to be located at a
-           page boundary in userland and which has to end at a page boundary.
-           The memory in userland is ok to be fragmented into various different
-           vmas. It is okay to mmap() and munmap() stuff in this slot after
-           doing this call at any time */
-
-        if (mem->slot)
-                return -EINVAL;
-
-        if (mem->guest_phys_addr)
-                return -EINVAL;
+        /* A few sanity checks. We can have memory slots which have to be
+           located/ended at a segment boundary (1MB). The memory in userland is
+           ok to be fragmented into various different vmas. It is okay to mmap()
+           and munmap() stuff in this slot after doing this call at any time */
 
         if (mem->userspace_addr & 0xffffful)
                 return -EINVAL;
@@ -997,19 +991,26 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
         if (mem->memory_size & 0xffffful)
                 return -EINVAL;
 
-        if (!user_alloc)
-                return -EINVAL;
-
         return 0;
 }
 
 void kvm_arch_commit_memory_region(struct kvm *kvm,
                                 struct kvm_userspace_memory_region *mem,
-                                struct kvm_memory_slot old,
-                                bool user_alloc)
+                                const struct kvm_memory_slot *old,
+                                enum kvm_mr_change change)
 {
         int rc;
 
+        /* If the basics of the memslot do not change, we do not want
+         * to update the gmap. Every update causes several unnecessary
+         * segment translation exceptions. This is usually handled just
+         * fine by the normal fault handler + gmap, but it will also
+         * cause faults on the prefix page of running guest CPUs.
+         */
+        if (old->userspace_addr == mem->userspace_addr &&
+            old->base_gfn * PAGE_SIZE == mem->guest_phys_addr &&
+            old->npages * PAGE_SIZE == mem->memory_size)
+                return;
 
         rc = gmap_map_segment(kvm->arch.gmap, mem->userspace_addr,
                 mem->guest_phys_addr, mem->memory_size);