[PATCH v2 03/13] KVM: arm64: Add vm fd device attribute accessors

Oliver Upton
2023-03-30T15:50:20Z

A subsequent change will allow userspace to convey a filter for
hypercalls through a vm device attribute. Add the requisite boilerplate
for vm attribute accessors.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/arm.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 3bd732eaf087..b6e26c0e65e5 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1439,11 +1439,28 @@ static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
}
}

+static int kvm_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ default:
+ return -ENXIO;
+ }
+}
+
+static int kvm_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ default:
+ return -ENXIO;
+ }
+}
+
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm *kvm = filp->private_data;
void __user *argp = (void __user *)arg;
+ struct kvm_device_attr attr;

switch (ioctl) {
case KVM_CREATE_IRQCHIP: {
@@ -1479,6 +1496,18 @@ long kvm_arch_vm_ioctl(struct file *filp,
return -EFAULT;
return kvm_vm_ioctl_mte_copy_tags(kvm, &copy_tags);
}
+ case KVM_HAS_DEVICE_ATTR: {
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ return -EFAULT;
+
+ return kvm_vm_has_attr(kvm, &attr);
+ }
+ case KVM_SET_DEVICE_ATTR: {
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ return -EFAULT;
+
+ return kvm_vm_set_attr(kvm, &attr);
+ }
default:
return -EINVAL;
}
--
2.40.0.348.gf938b09366-goog