KVM: s390: Allow NULL parameter for kvm_s390_get_regs_rre

We're not always interested in both registers that are specified
for an RRE instruction. So allow NULL as parameter, too, to indicate
that we do not need the corresponding value.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index a307a854a8d490c1b6a1d1b2b1fea3d62d75668f..b44912a3294941b8df9e9ca27d140ce52149408d 100644 (file)
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -90,8 +90,10 @@ static inline void kvm_s390_get_base_disp_sse(struct kvm_vcpu *vcpu,
 
 static inline void kvm_s390_get_regs_rre(struct kvm_vcpu *vcpu, int *r1, int *r2)
 {
-       *r1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 20;
-       *r2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16;
+       if (r1)
+               *r1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 20;
+       if (r2)
+               *r2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16;
 }
 
 static inline u64 kvm_s390_get_base_disp_rsy(struct kvm_vcpu *vcpu)