arm64: KVM: Introduce per-vcpu kvm device controls

In some cases it needs to get/set attributes specific to a vcpu and so
needs something else than ONE_REG.

Let's copy the KVM_DEVICE approach, and define the respective ioctls
for the vcpu file descriptor.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 9d133df2da53..166232356291 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -828,11 +828,51 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
         return 0;
 }
 
+static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu,
+                                 struct kvm_device_attr *attr)
+{
+        int ret = -ENXIO;
+
+        switch (attr->group) {
+        default:
+                break;
+        }
+
+        return ret;
+}
+
+static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu,
+                                 struct kvm_device_attr *attr)
+{
+        int ret = -ENXIO;
+
+        switch (attr->group) {
+        default:
+                break;
+        }
+
+        return ret;
+}
+
+static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
+                                 struct kvm_device_attr *attr)
+{
+        int ret = -ENXIO;
+
+        switch (attr->group) {
+        default:
+                break;
+        }
+
+        return ret;
+}
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
                          unsigned int ioctl, unsigned long arg)
 {
         struct kvm_vcpu *vcpu = filp->private_data;
         void __user *argp = (void __user *)arg;
+        struct kvm_device_attr attr;
 
         switch (ioctl) {
         case KVM_ARM_VCPU_INIT: {
@@ -875,6 +915,21 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
                         return -E2BIG;
                 return kvm_arm_copy_reg_indices(vcpu, user_list->reg);
         }
+        case KVM_SET_DEVICE_ATTR: {
+                if (copy_from_user(&attr, argp, sizeof(attr)))
+                        return -EFAULT;
+                return kvm_arm_vcpu_set_attr(vcpu, &attr);
+        }
+        case KVM_GET_DEVICE_ATTR: {
+                if (copy_from_user(&attr, argp, sizeof(attr)))
+                        return -EFAULT;
+                return kvm_arm_vcpu_get_attr(vcpu, &attr);
+        }
+        case KVM_HAS_DEVICE_ATTR: {
+                if (copy_from_user(&attr, argp, sizeof(attr)))
+                        return -EFAULT;
+                return kvm_arm_vcpu_has_attr(vcpu, &attr);
+        }
         default:
                 return -EINVAL;
         }