[PATCH v3 08/10] RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip

Anup Patel
2023-06-15T07:35:52Z

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>
---
arch/riscv/include/asm/kvm_aia.h | 3 +++
arch/riscv/include/uapi/asm/kvm.h | 6 +++++
arch/riscv/kvm/aia_aplic.c | 43 +++++++++++++++++++++++++++++++
arch/riscv/kvm/aia_device.c | 25 ++++++++++++++++++
4 files changed, 77 insertions(+)

diff --git a/arch/riscv/include/asm/kvm_aia.h b/arch/riscv/include/asm/kvm_aia.h
index f6bd8523395f..ba939c0054aa 100644
--- a/arch/riscv/include/asm/kvm_aia.h
+++ b/arch/riscv/include/asm/kvm_aia.h
@@ -129,6 +129,9 @@ static inline void kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu *vcpu)
{
}

+int kvm_riscv_aia_aplic_set_attr(struct kvm *kvm, unsigned long type, u32 v);
+int kvm_riscv_aia_aplic_get_attr(struct kvm *kvm, unsigned long type, u32 *v);
+int kvm_riscv_aia_aplic_has_attr(struct kvm *kvm, unsigned long type);
int kvm_riscv_aia_aplic_inject(struct kvm *kvm, u32 source, bool level);
int kvm_riscv_aia_aplic_init(struct kvm *kvm);
void kvm_riscv_aia_aplic_cleanup(struct kvm *kvm);
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index 047c8fc5bd71..9ed822fc5589 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -249,6 +249,12 @@ enum KVM_RISCV_SBI_EXT_ID {
#define KVM_DEV_RISCV_AIA_GRP_CTRL 2
#define KVM_DEV_RISCV_AIA_CTRL_INIT 0

+/*
+ * The device attribute type contains the memory mapped offset of the
+ * APLIC register (range 0x0000-0x3FFF) and it must be 4-byte aligned.
+ */
+#define KVM_DEV_RISCV_AIA_GRP_APLIC 3
+
/* One single KVM irqchip, ie. the AIA */
#define KVM_NR_IRQCHIPS 1

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
@@ -365,6 +365,15 @@ static int aia_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
break;
}

+ 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;
}

@@ -412,6 +421,20 @@ static int aia_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
if (copy_to_user(uaddr, &addr, sizeof(addr)))
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;
}

@@ -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;
--
2.34.1