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>

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 27605b6..b95710a 100644 (file)
--- 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 0079b8c..08a3b35 100644 (file)
--- 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);