KVM: arm64: Share the parts of get/set events useful to 32bit

The get/set events helpers to do some work to check reserved
and padding fields are zero. This is useful on 32bit too.

Move this code into virt/kvm/arm/arm.c, and give the arch
code some underscores.

This is temporarily hidden behind __KVM_HAVE_VCPU_EVENTS until
32bit is wired up.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm64/include/asm/kvm_host.h

@@ -350,10 +350,10 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
-int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
+int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
 			      struct kvm_vcpu_events *events);
 
-int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
+int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
 			      struct kvm_vcpu_events *events);
 
 #define KVM_ARCH_WANT_MMU_NOTIFIER

arch/arm64/kvm/guest.c

@@ -289,11 +289,9 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	return -EINVAL;
 }
 
-int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
+int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
 			      struct kvm_vcpu_events *events)
 {
-	memset(events, 0, sizeof(*events));
-
 	events->exception.serror_pending = !!(vcpu->arch.hcr_el2 & HCR_VSE);
 	events->exception.serror_has_esr = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
 
@@ -303,23 +301,12 @@ int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
-int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
+int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
 			      struct kvm_vcpu_events *events)
 {
-	int i;
 	bool serror_pending = events->exception.serror_pending;
 	bool has_esr = events->exception.serror_has_esr;
 
-	/* check whether the reserved field is zero */
-	for (i = 0; i < ARRAY_SIZE(events->reserved); i++)
-		if (events->reserved[i])
-			return -EINVAL;
-
-	/* check whether the pad field is zero */
-	for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++)
-		if (events->exception.pad[i])
-			return -EINVAL;
-
 	if (serror_pending && has_esr) {
 		if (!cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
 			return -EINVAL;

virt/kvm/arm/arm.c

@@ -1050,6 +1050,34 @@ static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
+#ifdef __KVM_HAVE_VCPU_EVENTS	/* temporary: until 32bit is wired up */
+static int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
+				   struct kvm_vcpu_events *events)
+{
+	memset(events, 0, sizeof(*events));
+
+	return __kvm_arm_vcpu_get_events(vcpu, events);
+}
+
+static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
+				   struct kvm_vcpu_events *events)
+{
+	int i;
+
+	/* check whether the reserved field is zero */
+	for (i = 0; i < ARRAY_SIZE(events->reserved); i++)
+		if (events->reserved[i])
+			return -EINVAL;
+
+	/* check whether the pad field is zero */
+	for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++)
+		if (events->exception.pad[i])
+			return -EINVAL;
+
+	return __kvm_arm_vcpu_set_events(vcpu, events);
+}
+#endif /* __KVM_HAVE_VCPU_EVENTS */
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg)
 {