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 <[email protected]> Signed-off-by: Avi Kivity <[email protected]>
iegor · Aug 1, 2010 · fc34531 · fc34531
1 parent 971eb77
commit fc34531
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git 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
@@ -207,6 +207,7 @@ struct kvm *kvm_arch_create_vm(void)
 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);