RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip

We expose APLIC registers as KVM device attributes of the in-kernel
AIA irqchip device. This will allow KVM user-space to save/restore
APLIC state using KVM device ioctls().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

2 files changed, 68 insertions, 0 deletions

diff --git a/arch/riscv/kvm/aia_aplic.c b/arch/riscv/kvm/aia_aplic.c
index eecd8f4abe21..39e72aa016a4 100644
--- a/arch/riscv/kvm/aia_aplic.c
+++ b/arch/riscv/kvm/aia_aplic.c
@@ -501,6 +501,49 @@ static struct kvm_io_device_ops aplic_iodoev_ops = {
 	.write = aplic_mmio_write,
 };
 
+int kvm_riscv_aia_aplic_set_attr(struct kvm *kvm, unsigned long type, u32 v)
+{
+	int rc;
+
+	if (!kvm->arch.aia.aplic_state)
+		return -ENODEV;
+
+	rc = aplic_mmio_write_offset(kvm, type, v);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+int kvm_riscv_aia_aplic_get_attr(struct kvm *kvm, unsigned long type, u32 *v)
+{
+	int rc;
+
+	if (!kvm->arch.aia.aplic_state)
+		return -ENODEV;
+
+	rc = aplic_mmio_read_offset(kvm, type, v);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+int kvm_riscv_aia_aplic_has_attr(struct kvm *kvm, unsigned long type)
+{
+	int rc;
+	u32 val;
+
+	if (!kvm->arch.aia.aplic_state)
+		return -ENODEV;
+
+	rc = aplic_mmio_read_offset(kvm, type, &val);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
 int kvm_riscv_aia_aplic_init(struct kvm *kvm)
 {
 	int i, ret = 0;
diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c
index 7ab555121872..c649ad6e8e0a 100644
--- a/arch/riscv/kvm/aia_device.c
+++ b/arch/riscv/kvm/aia_device.c
@@ -366,6 +366,15 @@ static int aia_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 		}
 
 		break;
+	case KVM_DEV_RISCV_AIA_GRP_APLIC:
+		if (copy_from_user(&nr, uaddr, sizeof(nr)))
+			return -EFAULT;
+
+		mutex_lock(&dev->kvm->lock);
+		r = kvm_riscv_aia_aplic_set_attr(dev->kvm, type, nr);
+		mutex_unlock(&dev->kvm->lock);
+
+		break;
 	}
 
 	return r;
@@ -413,6 +422,20 @@ static int aia_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 			return -EFAULT;
 
 		break;
+	case KVM_DEV_RISCV_AIA_GRP_APLIC:
+		if (copy_from_user(&nr, uaddr, sizeof(nr)))
+			return -EFAULT;
+
+		mutex_lock(&dev->kvm->lock);
+		r = kvm_riscv_aia_aplic_get_attr(dev->kvm, type, &nr);
+		mutex_unlock(&dev->kvm->lock);
+		if (r)
+			return r;
+
+		if (copy_to_user(uaddr, &nr, sizeof(nr)))
+			return -EFAULT;
+
+		break;
 	}
 
 	return r;
@@ -448,6 +471,8 @@ static int aia_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 			return 0;
 		}
 		break;
+	case KVM_DEV_RISCV_AIA_GRP_APLIC:
+		return kvm_riscv_aia_aplic_has_attr(dev->kvm, attr->attr);
 	}
 
 	return -ENXIO;