KVM: s390: Don't exit SIE on SIGP sense running

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>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 4 insertions, 2 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 27605b62b980..b95710a1f5dd 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/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));
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 0079b8c2a9a6..08a3b35d30be 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/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 *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(struct kvm *kvm,
                 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);