KVM: s390: rework code that sets the prefix

There are several places in the kvm module, which set the prefix register.
Since we need to flush the cpu, lets combine this operation into a helper
function. This helper will also explicitely mask out the unused bits.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 62aa5f19bb98..ff28f9d1c9eb 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -58,6 +58,13 @@ static inline int kvm_is_ucontrol(struct kvm *kvm)
         return 0;
 #endif
 }
+
+static inline void kvm_s390_set_prefix(struct kvm_vcpu *vcpu, u32 prefix)
+{
+        vcpu->arch.sie_block->prefix = prefix & 0x7fffe000u;
+        vcpu->arch.sie_block->ihcpu  = 0xffff;
+}
+
 int kvm_s390_handle_wait(struct kvm_vcpu *vcpu);
 enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer);
 void kvm_s390_tasklet(unsigned long parm);