KVM: PPC: Book3S HV: XIVE: Compute the VP id in a common helper

Reduce code duplication by consolidating the checking of vCPU ids and VP
ids to a common helper used by both legacy and native XIVE KVM devices.
And explain the magic with a comment.

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 0b7859e..d84da9f 100644 (file)
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -1211,6 +1211,37 @@ void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu)
        vcpu->arch.xive_vcpu = NULL;
 }
 
+static bool kvmppc_xive_vcpu_id_valid(struct kvmppc_xive *xive, u32 cpu)
+{
+       /* We have a block of KVM_MAX_VCPUS VPs. We just need to check
+        * raw vCPU ids are below the expected limit for this guest's
+        * core stride ; kvmppc_pack_vcpu_id() will pack them down to an
+        * index that can be safely used to compute a VP id that belongs
+        * to the VP block.
+        */
+       return cpu < KVM_MAX_VCPUS * xive->kvm->arch.emul_smt_mode;
+}
+
+int kvmppc_xive_compute_vp_id(struct kvmppc_xive *xive, u32 cpu, u32 *vp)
+{
+       u32 vp_id;
+
+       if (!kvmppc_xive_vcpu_id_valid(xive, cpu)) {
+               pr_devel("Out of bounds !\n");
+               return -EINVAL;
+       }
+
+       vp_id = kvmppc_xive_vp(xive, cpu);
+       if (kvmppc_xive_vp_in_use(xive->kvm, vp_id)) {
+               pr_devel("Duplicate !\n");
+               return -EEXIST;
+       }
+
+       *vp = vp_id;
+
+       return 0;
+}
+
 int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
                             struct kvm_vcpu *vcpu, u32 cpu)
 {
@@ -1229,20 +1260,13 @@ int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
                return -EPERM;
        if (vcpu->arch.irq_type != KVMPPC_IRQ_DEFAULT)
                return -EBUSY;
-       if (cpu >= (KVM_MAX_VCPUS * vcpu->kvm->arch.emul_smt_mode)) {
-               pr_devel("Out of bounds !\n");
-               return -EINVAL;
-       }
 
        /* We need to synchronize with queue provisioning */
        mutex_lock(&xive->lock);
 
-       vp_id = kvmppc_xive_vp(xive, cpu);
-       if (kvmppc_xive_vp_in_use(xive->kvm, vp_id)) {
-               pr_devel("Duplicate !\n");
-               r = -EEXIST;
+       r = kvmppc_xive_compute_vp_id(xive, cpu, &vp_id);
+       if (r)
                goto bail;
-       }
 
        xc = kzalloc(sizeof(*xc), GFP_KERNEL);
        if (!xc) {

diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h
index fe3ed50..90cf6ec 100644 (file)
--- a/arch/powerpc/kvm/book3s_xive.h
+++ b/arch/powerpc/kvm/book3s_xive.h
@@ -296,6 +296,7 @@ int kvmppc_xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio,
 struct kvmppc_xive *kvmppc_xive_get_device(struct kvm *kvm, u32 type);
 void xive_cleanup_single_escalation(struct kvm_vcpu *vcpu,
                                    struct kvmppc_xive_vcpu *xc, int irq);
+int kvmppc_xive_compute_vp_id(struct kvmppc_xive *xive, u32 cpu, u32 *vp);
 
 #endif /* CONFIG_KVM_XICS */
 #endif /* _KVM_PPC_BOOK3S_XICS_H */

diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
index 43a8685..5bb480b 100644 (file)
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -118,19 +118,12 @@ int kvmppc_xive_native_connect_vcpu(struct kvm_device *dev,
                return -EPERM;
        if (vcpu->arch.irq_type != KVMPPC_IRQ_DEFAULT)
                return -EBUSY;
-       if (server_num >= (KVM_MAX_VCPUS * vcpu->kvm->arch.emul_smt_mode)) {
-               pr_devel("Out of bounds !\n");
-               return -EINVAL;
-       }
 
        mutex_lock(&xive->lock);
 
-       vp_id = kvmppc_xive_vp(xive, server_num);
-       if (kvmppc_xive_vp_in_use(xive->kvm, vp_id)) {
-               pr_devel("Duplicate !\n");
-               rc = -EEXIST;
+       rc = kvmppc_xive_compute_vp_id(xive, server_num, &vp_id);
+       if (rc)
                goto bail;
-       }
 
        xc = kzalloc(sizeof(*xc), GFP_KERNEL);
        if (!xc) {