KVM: s390: reinject io interrupt on tpi failure

The tpi instruction should be suppressed on addressing and protection
exceptions, so we need to re-inject the dequeued io interrupt in that
case.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

3 files changed, 17 insertions, 1 deletions

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index a1403ba75bfc..1c74bb92329b 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -846,6 +846,12 @@ int kvm_s390_inject_vm(struct kvm *kvm,
         return __inject_vm(kvm, inti);
 }
 
+void kvm_s390_reinject_io_int(struct kvm *kvm,
+                              struct kvm_s390_interrupt_info *inti)
+{
+        __inject_vm(kvm, inti);
+}
+
 int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
                          struct kvm_s390_interrupt *s390int)
 {
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 11ed0a596b5a..dc506f3782ea 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -137,6 +137,8 @@ int __must_check kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
 int __must_check kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code);
 struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm,
                                                     u64 cr6, u64 schid);
+void kvm_s390_reinject_io_int(struct kvm *kvm,
+                              struct kvm_s390_interrupt_info *inti);
 int kvm_s390_mask_adapter(struct kvm *kvm, unsigned int id, bool masked);
 
 /* implemented in priv.c */
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 4f6bc165d79b..f4451f09b9ed 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -259,7 +259,15 @@ static int handle_tpi(struct kvm_vcpu *vcpu)
                 if (write_guest_lc(vcpu, __LC_SUBCHANNEL_ID, &tpi_data, len))
                         rc = -EFAULT;
         }
-        kfree(inti);
+        /*
+         * If we encounter a problem storing the interruption code, the
+         * instruction is suppressed from the guest's view: reinject the
+         * interrupt.
+         */
+        if (!rc)
+                kfree(inti);
+        else
+                kvm_s390_reinject_io_int(vcpu->kvm, inti);
 no_interrupt:
         /* Set condition code and we're done. */
         if (!rc)