KVM: Store immutable gfn_to_pfn_cache properties

Move the assignment of immutable properties @kvm, @vcpu, and @usage to
the initializer.  Make _activate() and _deactivate() use stored values.

Note, @len is also effectively immutable for most cases, but not in the
case of the Xen runstate cache, which may be split across two pages and
the length of the first segment will depend on its address.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
[sean: handle @len in a separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>
[dwmw2: acknowledge that @len can actually change for some use cases]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

1 files changed, 30 insertions, 35 deletions

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 3e434dc339fb..55257c2a1610 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -42,13 +42,12 @@ static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
 	int idx = srcu_read_lock(&kvm->srcu);
 
 	if (gfn == GPA_INVALID) {
-		kvm_gpc_deactivate(kvm, gpc);
+		kvm_gpc_deactivate(gpc);
 		goto out;
 	}
 
 	do {
-		ret = kvm_gpc_activate(kvm, gpc, NULL, KVM_HOST_USES_PFN, gpa,
-				       PAGE_SIZE);
+		ret = kvm_gpc_activate(gpc, gpa, PAGE_SIZE);
 		if (ret)
 			goto out;
 
@@ -323,8 +322,8 @@ static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic)
 			 * to the second page now because the guest changed to
 			 * 64-bit mode, the second GPC won't have been set up.
 			 */
-			if (kvm_gpc_activate(v->kvm, gpc2, NULL, KVM_HOST_USES_PFN,
-					     gpc1->gpa + user_len1, user_len2))
+			if (kvm_gpc_activate(gpc2, gpc1->gpa + user_len1,
+					     user_len2))
 				return;
 
 			/*
@@ -711,15 +710,13 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 			     offsetof(struct compat_vcpu_info, time));
 
 		if (data->u.gpa == GPA_INVALID) {
-			kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.vcpu_info_cache);
+			kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_info_cache);
 			r = 0;
 			break;
 		}
 
-		r = kvm_gpc_activate(vcpu->kvm,
-				     &vcpu->arch.xen.vcpu_info_cache, NULL,
-				     KVM_HOST_USES_PFN, data->u.gpa,
-				     sizeof(struct vcpu_info));
+		r = kvm_gpc_activate(&vcpu->arch.xen.vcpu_info_cache,
+				     data->u.gpa, sizeof(struct vcpu_info));
 		if (!r)
 			kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
 
@@ -727,15 +724,13 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 
 	case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
 		if (data->u.gpa == GPA_INVALID) {
-			kvm_gpc_deactivate(vcpu->kvm,
-					   &vcpu->arch.xen.vcpu_time_info_cache);
+			kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_time_info_cache);
 			r = 0;
 			break;
 		}
 
-		r = kvm_gpc_activate(vcpu->kvm,
-				     &vcpu->arch.xen.vcpu_time_info_cache,
-				     NULL, KVM_HOST_USES_PFN, data->u.gpa,
+		r = kvm_gpc_activate(&vcpu->arch.xen.vcpu_time_info_cache,
+				     data->u.gpa,
 				     sizeof(struct pvclock_vcpu_time_info));
 		if (!r)
 			kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -751,10 +746,8 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 		if (data->u.gpa == GPA_INVALID) {
 			r = 0;
 		deactivate_out:
-			kvm_gpc_deactivate(vcpu->kvm,
-					   &vcpu->arch.xen.runstate_cache);
-			kvm_gpc_deactivate(vcpu->kvm,
-					   &vcpu->arch.xen.runstate2_cache);
+			kvm_gpc_deactivate(&vcpu->arch.xen.runstate_cache);
+			kvm_gpc_deactivate(&vcpu->arch.xen.runstate2_cache);
 			break;
 		}
 
@@ -770,20 +763,18 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 
 		/* How much fits in the (first) page? */
 		sz1 = PAGE_SIZE - (data->u.gpa & ~PAGE_MASK);
-		r = kvm_gpc_activate(vcpu->kvm, &vcpu->arch.xen.runstate_cache,
-				     NULL, KVM_HOST_USES_PFN, data->u.gpa, sz1);
+		r = kvm_gpc_activate(&vcpu->arch.xen.runstate_cache,
+				     data->u.gpa, sz1);
 		if (r)
 			goto deactivate_out;
 
 		/* Either map the second page, or deactivate the second GPC */
 		if (sz1 >= sz) {
-			kvm_gpc_deactivate(vcpu->kvm,
-					   &vcpu->arch.xen.runstate2_cache);
+			kvm_gpc_deactivate(&vcpu->arch.xen.runstate2_cache);
 		} else {
 			sz2 = sz - sz1;
 			BUG_ON((data->u.gpa + sz1) & ~PAGE_MASK);
-			r = kvm_gpc_activate(vcpu->kvm, &vcpu->arch.xen.runstate2_cache,
-					     NULL, KVM_HOST_USES_PFN,
+			r = kvm_gpc_activate(&vcpu->arch.xen.runstate2_cache,
 					     data->u.gpa + sz1, sz2);
 			if (r)
 				goto deactivate_out;
@@ -2051,10 +2042,14 @@ void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu)
 
 	timer_setup(&vcpu->arch.xen.poll_timer, cancel_evtchn_poll, 0);
 
-	kvm_gpc_init(&vcpu->arch.xen.runstate_cache);
-	kvm_gpc_init(&vcpu->arch.xen.runstate2_cache);
-	kvm_gpc_init(&vcpu->arch.xen.vcpu_info_cache);
-	kvm_gpc_init(&vcpu->arch.xen.vcpu_time_info_cache);
+	kvm_gpc_init(&vcpu->arch.xen.runstate_cache, vcpu->kvm, NULL,
+		     KVM_HOST_USES_PFN);
+	kvm_gpc_init(&vcpu->arch.xen.runstate2_cache, vcpu->kvm, NULL,
+		     KVM_HOST_USES_PFN);
+	kvm_gpc_init(&vcpu->arch.xen.vcpu_info_cache, vcpu->kvm, NULL,
+		     KVM_HOST_USES_PFN);
+	kvm_gpc_init(&vcpu->arch.xen.vcpu_time_info_cache, vcpu->kvm, NULL,
+		     KVM_HOST_USES_PFN);
 }
 
 void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
@@ -2062,10 +2057,10 @@ void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
 	if (kvm_xen_timer_enabled(vcpu))
 		kvm_xen_stop_timer(vcpu);
 
-	kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.runstate_cache);
-	kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.runstate2_cache);
-	kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.vcpu_info_cache);
-	kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.vcpu_time_info_cache);
+	kvm_gpc_deactivate(&vcpu->arch.xen.runstate_cache);
+	kvm_gpc_deactivate(&vcpu->arch.xen.runstate2_cache);
+	kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_info_cache);
+	kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_time_info_cache);
 
 	del_timer_sync(&vcpu->arch.xen.poll_timer);
 }
@@ -2073,7 +2068,7 @@ void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
 void kvm_xen_init_vm(struct kvm *kvm)
 {
 	idr_init(&kvm->arch.xen.evtchn_ports);
-	kvm_gpc_init(&kvm->arch.xen.shinfo_cache);
+	kvm_gpc_init(&kvm->arch.xen.shinfo_cache, kvm, NULL, KVM_HOST_USES_PFN);
 }
 
 void kvm_xen_destroy_vm(struct kvm *kvm)
@@ -2081,7 +2076,7 @@ void kvm_xen_destroy_vm(struct kvm *kvm)
 	struct evtchnfd *evtchnfd;
 	int i;
 
-	kvm_gpc_deactivate(kvm, &kvm->arch.xen.shinfo_cache);
+	kvm_gpc_deactivate(&kvm->arch.xen.shinfo_cache);
 
 	idr_for_each_entry(&kvm->arch.xen.evtchn_ports, evtchnfd, i) {
 		if (!evtchnfd->deliver.port.port)