KVM: x86: Pass reference pvclock as a param to kvm_setup_guest_pvclock()

Pass the reference pvclock structure that's used to setup each individual
pvclock as a parameter to kvm_setup_guest_pvclock() as a preparatory step
toward removing kvm_vcpu_arch.hv_clock.

No functional change intended.

Reviewed-by: Paul Durrant <paul@xen.org>
Link: https://lore.kernel.org/r/20250201013827.680235-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

arch/x86/kvm/x86.c

@@ -3116,17 +3116,17 @@ u64 get_kvmclock_ns(struct kvm *kvm)
 	return data.clock;
 }
 
-static void kvm_setup_guest_pvclock(struct kvm_vcpu *v,
+static void kvm_setup_guest_pvclock(struct pvclock_vcpu_time_info *ref_hv_clock,
+				    struct kvm_vcpu *vcpu,
 				    struct gfn_to_pfn_cache *gpc,
 				    unsigned int offset,
 				    bool force_tsc_unstable)
 {
-	struct kvm_vcpu_arch *vcpu = &v->arch;
 	struct pvclock_vcpu_time_info *guest_hv_clock;
 	struct pvclock_vcpu_time_info hv_clock;
 	unsigned long flags;
 
-	memcpy(&hv_clock, &vcpu->hv_clock, sizeof(hv_clock));
+	memcpy(&hv_clock, ref_hv_clock, sizeof(hv_clock));
 
 	read_lock_irqsave(&gpc->lock, flags);
 	while (!kvm_gpc_check(gpc, offset + sizeof(*guest_hv_clock))) {
@@ -3165,7 +3165,7 @@ static void kvm_setup_guest_pvclock(struct kvm_vcpu *v,
 	kvm_gpc_mark_dirty_in_slot(gpc);
 	read_unlock_irqrestore(&gpc->lock, flags);
 
-	trace_kvm_pvclock_update(v->vcpu_id, &hv_clock);
+	trace_kvm_pvclock_update(vcpu->vcpu_id, &hv_clock);
 }
 
 static int kvm_guest_time_update(struct kvm_vcpu *v)
@@ -3272,18 +3272,18 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 			vcpu->hv_clock.flags |= PVCLOCK_GUEST_STOPPED;
 			vcpu->pvclock_set_guest_stopped_request = false;
 		}
-		kvm_setup_guest_pvclock(v, &vcpu->pv_time, 0, false);
+		kvm_setup_guest_pvclock(&vcpu->hv_clock, v, &vcpu->pv_time, 0, false);
 
 		vcpu->hv_clock.flags &= ~PVCLOCK_GUEST_STOPPED;
 	}
 
 #ifdef CONFIG_KVM_XEN
 	if (vcpu->xen.vcpu_info_cache.active)
-		kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_info_cache,
+		kvm_setup_guest_pvclock(&vcpu->hv_clock, v, &vcpu->xen.vcpu_info_cache,
 					offsetof(struct compat_vcpu_info, time),
 					xen_pvclock_tsc_unstable);
 	if (vcpu->xen.vcpu_time_info_cache.active)
-		kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_time_info_cache, 0,
+		kvm_setup_guest_pvclock(&vcpu->hv_clock, v, &vcpu->xen.vcpu_time_info_cache, 0,
 					xen_pvclock_tsc_unstable);
 #endif
 	kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);