s390/kvm: fix psw rewinding in handle_skey

The PSW can wrap if the guest has been running in the 24 bit or 31 bit
addressing mode. Use __rewind_psw to find the correct address.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 6bbd7b5..ecc58a6 100644 (file)
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -105,7 +105,8 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
 static int handle_skey(struct kvm_vcpu *vcpu)
 {
        vcpu->stat.instruction_storage_key++;
-       vcpu->arch.sie_block->gpsw.addr -= 4;
+       vcpu->arch.sie_block->gpsw.addr =
+               __rewind_psw(vcpu->arch.sie_block->gpsw, 4);
        VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
        return 0;
 }