KVM: ARM: Introduce KVM_ARM_SET_DEVICE_ADDR ioctl
On ARM some bits are specific to the model being emulated for the guest and
user space needs a way to tell the kernel about those bits. An example is mmio
device base addresses, where KVM must know the base address for a given device
to properly emulate mmio accesses within a certain address range or directly
map a device with virtualiation extensions into the guest address space.
We make this API ARM-specific as we haven't yet reached a consensus for a
generic API for all KVM architectures that will allow us to do something like
this.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 2d30e3a..523f77a 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -167,6 +167,8 @@
case KVM_CAP_COALESCED_MMIO:
r = KVM_COALESCED_MMIO_PAGE_OFFSET;
break;
+ case KVM_CAP_ARM_SET_DEVICE_ADDR:
+ r = 1;
case KVM_CAP_NR_VCPUS:
r = num_online_cpus();
break;
@@ -827,10 +829,29 @@
return -EINVAL;
}
+static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
+ struct kvm_arm_device_addr *dev_addr)
+{
+ return -ENODEV;
+}
+
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
- return -EINVAL;
+ struct kvm *kvm = filp->private_data;
+ void __user *argp = (void __user *)arg;
+
+ switch (ioctl) {
+ case KVM_ARM_SET_DEVICE_ADDR: {
+ struct kvm_arm_device_addr dev_addr;
+
+ if (copy_from_user(&dev_addr, argp, sizeof(dev_addr)))
+ return -EFAULT;
+ return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
+ }
+ default:
+ return -EINVAL;
+ }
}
static void cpu_init_hyp_mode(void *vector)