kvm-s390: Dont exit SIE on SIGP sense running

[Christian Borntraeger <borntraeger@de.ibm.com>]

Avi, Marcello,

Newer (guest) kernels use sigp sense running in their spinlock
implementation to check if the other cpu is running before yielding
the processor. This revealed some wrong guest settings, causing
unnecessary exits for every sigp sense running.
 
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

---
 arch/s390/include/asm/kvm_host.h |    2 +-
 arch/s390/kvm/kvm-s390.c         |    4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

Index: kvm/arch/s390/include/asm/kvm_host.h
===================================================================
--- kvm.orig/arch/s390/include/asm/kvm_host.h
+++ kvm/arch/s390/include/asm/kvm_host.h
@@ -26,7 +26,7 @@
 
 struct sca_entry {
 	atomic_t scn;
-	__u64	reserved;
+	__u32	reserved;
 	__u64	sda;
 	__u64	reserved2[2];
 } __attribute__((packed));
Index: kvm/arch/s390/kvm/kvm-s390.c
===================================================================
--- kvm.orig/arch/s390/kvm/kvm-s390.c
+++ kvm/arch/s390/kvm/kvm-s390.c
@@ -207,6 +207,7 @@ out_nokvm:
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
 	VCPU_EVENT(vcpu, 3, "%s", "free cpu");
+	clear_bit(63 - vcpu->vcpu_id, (unsigned long *) &vcpu->kvm->arch.sca->mcn);
 	if (vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sda ==
 		(__u64) vcpu->arch.sie_block)
 		vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sda = 0;
@@ -296,7 +297,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu 
 {
 	atomic_set(&vcpu->arch.sie_block->cpuflags, CPUSTAT_ZARCH);
 	set_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests);
-	vcpu->arch.sie_block->ecb   = 2;
+	vcpu->arch.sie_block->ecb   = 6;
 	vcpu->arch.sie_block->eca   = 0xC1002001U;
 	vcpu->arch.sie_block->fac   = (int) (long) facilities;
 	hrtimer_init(&vcpu->arch.ckc_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
@@ -329,6 +330,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(st
 		kvm->arch.sca->cpu[id].sda = (__u64) vcpu->arch.sie_block;
 	vcpu->arch.sie_block->scaoh = (__u32)(((__u64)kvm->arch.sca) >> 32);
 	vcpu->arch.sie_block->scaol = (__u32)(__u64)kvm->arch.sca;
+	set_bit(63 - id, (unsigned long *) &kvm->arch.sca->mcn);
 
 	spin_lock_init(&vcpu->arch.local_int.lock);
 	INIT_LIST_HEAD(&vcpu->arch.local_int.list);