[v2,2/8] KVM: arm-vgic: Support KVM_CREATE_DEVICE for VGIC

Commit Message

Christoffer Dall Sept. 26, 2013, 7:01 p.m. UTC

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.

Note that we change the check for creating a VGIC from bailing out if
any VCPUs were created to bailing if any VCPUs were ever run.  This is
an important distinction that doesn't break anything, but allows
creating the VGIC after the VCPUs have been created.

Signed-off-by: Christoffer Dall <[e-mail]>
Reviewed-by: Alexander Graf <[e-mail]>
---
 Documentation/virtual/kvm/devices/arm-vgic.txt |   10 ++++++
 arch/arm/include/uapi/asm/kvm.h                |    1 -
 arch/arm/kvm/arm.c                             |    1 +
 include/linux/kvm_host.h                       |    1 +
 include/uapi/linux/kvm.h                       |    1 +
 virt/kvm/arm/vgic.c                            |   46 ++++++++++++++++++++++--
 virt/kvm/kvm_main.c                            |    5 +++
 7 files changed, 62 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/virtual/kvm/devices/arm-vgic.txt

Patch

diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
new file mode 100644
index 0000000..38f27f7
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
@@ -0,0 +1,10 @@ 
+ARM Virtual Generic Interrupt Controller (VGIC)
+===============================================
+
+Device types supported:
+  KVM_DEV_TYPE_ARM_VGIC_V2     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..1c85102 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -142,7 +142,6 @@  struct kvm_arch_memory_slot {
 #define KVM_REG_ARM_VFP_FPINST		0x1009
 #define KVM_REG_ARM_VFP_FPINST2		0x100A
 
-
 /* KVM_IRQ_LINE irq field index values */
 #define KVM_ARM_IRQ_TYPE_SHIFT		24
 #define KVM_ARM_IRQ_TYPE_MASK		0xff
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 2b1091a..ab96af2 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 ca645a0..2906b79 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1065,6 +1065,7 @@  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 99c2533..2d50233 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -843,6 +843,7 @@  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_V2	4
 
 /*
  * ioctls for VM fds
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 5ce100f..79a8bae 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1434,15 +1434,23 @@  out:
 
 int kvm_vgic_create(struct kvm *kvm)
 {
-	int ret = 0;
+	int i, ret = 0;
+	struct kvm_vcpu *vcpu;
 
 	mutex_lock(&kvm->lock);
 
-	if (atomic_read(&kvm->online_vcpus) || kvm->arch.vgic.vctrl_base) {
+	if (kvm->arch.vgic.vctrl_base) {
 		ret = -EEXIST;
 		goto out;
 	}
 
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		if (vcpu->arch.has_run_once) {
+			ret = -EBUSY;
+			goto out;
+		}
+	}
+
 	spin_lock_init(&kvm->arch.vgic.lock);
 	kvm->arch.vgic.vctrl_base = vgic_vctrl_base;
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
@@ -1511,3 +1519,37 @@  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 bf040c4..534fd3a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2265,6 +2265,11 @@  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_V2:
+		ops = &kvm_arm_vgic_ops;
+		break;
+#endif
 	default:
 		return -ENODEV;
 	}