4 files changed, 44 insertions, 22 deletions

diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index f639a152869f..a0775e1f08df 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -20,7 +20,7 @@ static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
         VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
         vcpu->stat.diagnose_44++;
         vcpu_put(vcpu);
-        schedule();
+        yield();
         vcpu_load(vcpu);
         return 0;
 }
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index fcd1ed8015c1..84a7fed4cd4e 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -339,6 +339,11 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
         if (kvm_cpu_has_interrupt(vcpu))
                 return 0;
 
+        __set_cpu_idle(vcpu);
+        spin_lock_bh(&vcpu->arch.local_int.lock);
+        vcpu->arch.local_int.timer_due = 0;
+        spin_unlock_bh(&vcpu->arch.local_int.lock);
+
         if (psw_interrupts_disabled(vcpu)) {
                 VCPU_EVENT(vcpu, 3, "%s", "disabled wait");
                 __unset_cpu_idle(vcpu);
@@ -366,8 +371,6 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
 no_timer:
         spin_lock_bh(&vcpu->arch.local_int.float_int->lock);
         spin_lock_bh(&vcpu->arch.local_int.lock);
-        __set_cpu_idle(vcpu);
-        vcpu->arch.local_int.timer_due = 0;
         add_wait_queue(&vcpu->arch.local_int.wq, &wait);
         while (list_empty(&vcpu->arch.local_int.list) &&
                 list_empty(&vcpu->arch.local_int.float_int->list) &&
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 0ac36a649eba..6558b09ff579 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -423,6 +423,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
         return -EINVAL; /* not implemented yet */
 }
 
+extern void s390_handle_mcck(void);
+
 static void __vcpu_run(struct kvm_vcpu *vcpu)
 {
         memcpy(&vcpu->arch.sie_block->gg14, &vcpu->arch.guest_gprs[14], 16);
@@ -430,13 +432,21 @@ static void __vcpu_run(struct kvm_vcpu *vcpu)
         if (need_resched())
                 schedule();
 
+        if (test_thread_flag(TIF_MCCK_PENDING))
+                s390_handle_mcck();
+
+        kvm_s390_deliver_pending_interrupts(vcpu);
+
         vcpu->arch.sie_block->icptcode = 0;
         local_irq_disable();
         kvm_guest_enter();
         local_irq_enable();
         VCPU_EVENT(vcpu, 6, "entering sie flags %x",
                    atomic_read(&vcpu->arch.sie_block->cpuflags));
-        sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs);
+        if (sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs)) {
+                VCPU_EVENT(vcpu, 3, "%s", "fault in sie instruction");
+                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+        }
         VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
                    vcpu->arch.sie_block->icptcode);
         local_irq_disable();
@@ -475,7 +485,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         might_sleep();
 
         do {
-                kvm_s390_deliver_pending_interrupts(vcpu);
                 __vcpu_run(vcpu);
                 rc = kvm_handle_sie_intercept(vcpu);
         } while (!signal_pending(current) && !rc);
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 5c1aea97cd12..3d98ba82ea67 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -254,36 +254,46 @@ void disable_noexec(struct mm_struct *mm, struct task_struct *tsk)
 int s390_enable_sie(void)
 {
         struct task_struct *tsk = current;
-        struct mm_struct *mm;
-        int rc;
+        struct mm_struct *mm, *old_mm;
 
-        task_lock(tsk);
-
-        rc = 0;
+        /* Do we have pgstes? if yes, we are done */
         if (tsk->mm->context.pgstes)
-                goto unlock;
+                return 0;
 
-        rc = -EINVAL;
+        /* lets check if we are allowed to replace the mm */
+        task_lock(tsk);
         if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
-            tsk->mm != tsk->active_mm || tsk->mm->ioctx_list)
-                goto unlock;
+            tsk->mm != tsk->active_mm || tsk->mm->ioctx_list) {
+                task_unlock(tsk);
+                return -EINVAL;
+        }
+        task_unlock(tsk);
 
-        tsk->mm->context.pgstes = 1;    /* dirty little tricks .. */
+        /* we copy the mm with pgstes enabled */
+        tsk->mm->context.pgstes = 1;
         mm = dup_mm(tsk);
         tsk->mm->context.pgstes = 0;
-
-        rc = -ENOMEM;
         if (!mm)
-                goto unlock;
-        mmput(tsk->mm);
+                return -ENOMEM;
+
+        /* Now lets check again if somebody attached ptrace etc */
+        task_lock(tsk);
+        if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
+            tsk->mm != tsk->active_mm || tsk->mm->ioctx_list) {
+                mmput(mm);
+                task_unlock(tsk);
+                return -EINVAL;
+        }
+
+        /* ok, we are alone. No ptrace, no threads, etc. */
+        old_mm = tsk->mm;
         tsk->mm = tsk->active_mm = mm;
         preempt_disable();
         update_mm(mm, tsk);
         cpu_set(smp_processor_id(), mm->cpu_vm_mask);
         preempt_enable();
-        rc = 0;
-unlock:
         task_unlock(tsk);
-        return rc;
+        mmput(old_mm);
+        return 0;
 }
 EXPORT_SYMBOL_GPL(s390_enable_sie);