[PATCH 1/7] KVM: arm-vgic: Support KVM_CREATE_DEVICE for VGIC

[Christoffer Dall]

Support creating the ARM VGIC device through the KVM_CREATE_DEVICE
ioctl, which can then later be leveraged to use the
KVM_{GET/SET}_DEVICE_ATTR, which is useful both for setting addresses in
a more generic API than the ARM-specific one and is useful for
save/restore of VGIC state.

Adds KVM_CAP_DEVICE_CTRL to ARM capabilities.

Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
 Documentation/virtual/kvm/devices/arm-vgic.txt |   10 +++++++
 arch/arm/include/uapi/asm/kvm.h                |    8 ++++++
 arch/arm/kvm/arm.c                             |    1 +
 include/linux/kvm_host.h                       |    1 +
 include/uapi/linux/kvm.h                       |    1 +
 virt/kvm/arm/vgic.c                            |   34 ++++++++++++++++++++++++
 virt/kvm/kvm_main.c                            |    4 +++
 7 files changed, 59 insertions(+)
 create mode 100644 Documentation/virtual/kvm/devices/arm-vgic.txt

diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
new file mode 100644
index 0000000..25fd2d9
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
@@ -0,0 +1,10 @@
+MPIC interrupt controller
+=========================
+
+Device types supported:
+  KVM_DEV_TYPE_ARM_VGIC        ARM Generic Interrupt Controller v2.0
+
+Only one VGIC instance may be instantiated through either this API or the
+legacy KVM_CREATE_IRQCHIP api.  The created VGIC will act as the VM interrupt
+controller, requiring emulated user-space devices to inject interrupts to the
+VGIC instead of directly to CPUs.
diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index c1ee007..587f1ae 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -142,6 +142,14 @@ struct kvm_arch_memory_slot {
 #define KVM_REG_ARM_VFP_FPINST		0x1009
 #define KVM_REG_ARM_VFP_FPINST2		0x100A
 
+/* Device Control API: ARM VGIC */
+#define KVM_DEV_ARM_VGIC_GRP_ADDR	0
+#define KVM_DEV_ARM_VGIC_GRP_DIST_REGS	1
+#define KVM_DEV_ARM_VGIC_GRP_CPU_REGS	2
+#define   KVM_DEV_ARM_VGIC_CPUID_SHIFT	32
+#define   KVM_DEV_ARM_VGIC_CPUID_MASK	(0xffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT)
+#define   KVM_DEV_ARM_VGIC_OFFSET_SHIFT	0
+#define   KVM_DEV_ARM_VGIC_OFFSET_MASK	(0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT)
 
 /* KVM_IRQ_LINE irq field index values */
 #define KVM_ARM_IRQ_TYPE_SHIFT		24
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 741f66a..b8e3b6e 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -187,6 +187,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_IRQCHIP:
 		r = vgic_present;
 		break;
+	case KVM_CAP_DEVICE_CTRL:
 	case KVM_CAP_USER_MEMORY:
 	case KVM_CAP_SYNC_MMU:
 	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d9a3c30..e2d6556 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1086,6 +1086,7 @@ struct kvm_device *kvm_device_from_filp(struct file *filp);
 
 extern struct kvm_device_ops kvm_mpic_ops;
 extern struct kvm_device_ops kvm_xics_ops;
+extern struct kvm_device_ops kvm_arm_vgic_ops;
 
 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a5c86fc..4f2a4ab 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -839,6 +839,7 @@ struct kvm_device_attr {
 #define KVM_DEV_TYPE_FSL_MPIC_20	1
 #define KVM_DEV_TYPE_FSL_MPIC_42	2
 #define KVM_DEV_TYPE_XICS		3
+#define KVM_DEV_TYPE_ARM_VGIC		4
 
 /*
  * ioctls for VM fds
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 17c5ac7..b3dcd66 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1497,3 +1497,37 @@ int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
 	mutex_unlock(&kvm->lock);
 	return r;
 }
+
+static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+	return -ENXIO;
+}
+
+static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+	return -ENXIO;
+}
+
+static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+	return -ENXIO;
+}
+
+static void vgic_destroy(struct kvm_device *dev)
+{
+	kfree(dev);
+}
+
+static int vgic_create(struct kvm_device *dev, u32 type)
+{
+	return kvm_vgic_create(dev->kvm);
+}
+
+struct kvm_device_ops kvm_arm_vgic_ops = {
+	.name = "kvm-arm-vgic",
+	.create = vgic_create,
+	.destroy = vgic_destroy,
+	.set_attr = vgic_set_attr,
+	.get_attr = vgic_get_attr,
+	.has_attr = vgic_has_attr,
+};
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b547a1c..774e77c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2282,6 +2282,10 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
 		ops = &kvm_xics_ops;
 		break;
 #endif
+#ifdef CONFIG_KVM_ARM_VGIC
+	case KVM_DEV_TYPE_ARM_VGIC:
+		ops = &kvm_arm_vgic_ops;
+#endif
 	default:
 		return -ENODEV;
 	}
-- 
1.7.9.5