KVM: s390: Provide SCA-aware helpers for VCPU add/del

This patch provides SCA-aware helpers to create/delete a VCPU.
This is to prepare for upcoming introduction of Extended SCA support.

Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 5c36c8e7e937a73ec7349b63435fb0cf1966644e..8ddd48848a8301411adcdb8e8d9c33b8c7d24c60 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -283,6 +283,8 @@ static void kvm_s390_sync_dirty_log(struct kvm *kvm,
 }
 
 /* Section: vm related */
+static void sca_del_vcpu(struct kvm_vcpu *vcpu);
+
 /*
  * Get (and clear) the dirty memory log for a memory slot.
  */
@@ -1189,11 +1191,7 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
        kvm_s390_clear_local_irqs(vcpu);
        kvm_clear_async_pf_completion_queue(vcpu);
        if (!kvm_is_ucontrol(vcpu->kvm)) {
-               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;
+               sca_del_vcpu(vcpu);
        }
        smp_mb();
 
@@ -1249,6 +1247,32 @@ static int __kvm_ucontrol_vcpu_init(struct kvm_vcpu *vcpu)
        return 0;
 }
 
+static void sca_del_vcpu(struct kvm_vcpu *vcpu)
+{
+       struct sca_block *sca = vcpu->kvm->arch.sca;
+
+       clear_bit_inv(vcpu->vcpu_id, (unsigned long *) &sca->mcn);
+       if (sca->cpu[vcpu->vcpu_id].sda == (__u64) vcpu->arch.sie_block)
+               sca->cpu[vcpu->vcpu_id].sda = 0;
+}
+
+static void sca_add_vcpu(struct kvm_vcpu *vcpu, struct kvm *kvm,
+                       unsigned int id)
+{
+       struct sca_block *sca = kvm->arch.sca;
+
+       if (!sca->cpu[id].sda)
+               sca->cpu[id].sda = (__u64) vcpu->arch.sie_block;
+       vcpu->arch.sie_block->scaoh = (__u32)(((__u64)sca) >> 32);
+       vcpu->arch.sie_block->scaol = (__u32)(__u64)sca;
+       set_bit_inv(id, (unsigned long *) &sca->mcn);
+}
+
+static int sca_can_add_vcpu(struct kvm *kvm, unsigned int id)
+{
+       return id < KVM_MAX_VCPUS;
+}
+
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 {
        vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
@@ -1465,7 +1489,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
        struct sie_page *sie_page;
        int rc = -EINVAL;
 
-       if (id >= KVM_MAX_VCPUS)
+       if (!sca_can_add_vcpu(kvm, id))
                goto out;
 
        rc = -ENOMEM;
@@ -1487,13 +1511,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
                        WARN_ON_ONCE(1);
                        goto out_free_cpu;
                }
-               if (!kvm->arch.sca->cpu[id].sda)
-                       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);
+               sca_add_vcpu(vcpu, kvm, id);
        }
 
        spin_lock_init(&vcpu->arch.local_int.lock);