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 27605b62b980d1901067c40faa05b7c9f2102c78..b95710a1f5dd479044dda36e1aedf4070104728e 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 0079b8c2a9a6976e45b0d1526b1642fc4af90ef4..08a3b35d30be5bc185f95540fcfb548e079106e9 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);