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authorChristoffer Dall <christoffer.dall@linaro.org>2013-10-25 17:29:18 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2013-12-21 10:01:16 -0800
commit7330672befe6269e575f79b924a7068b26c144b4 (patch)
tree1eb2d427d0be36103633b623182b65e8a3dfbf42
parente1ba0207a1b3714bb3f000e506285ae5123cdfa7 (diff)
downloadlinux-7330672befe6269e575f79b924a7068b26c144b4.tar.gz
KVM: arm-vgic: Support KVM_CREATE_DEVICE for VGIC
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 out if any VCPUs were ever run. This is an important distinction that shouldn't break anything, but allows creating the VGIC after the VCPUs have been created. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
-rw-r--r--Documentation/virtual/kvm/devices/arm-vgic.txt10
-rw-r--r--arch/arm/kvm/arm.c1
-rw-r--r--include/linux/kvm_host.h1
-rw-r--r--include/uapi/linux/kvm.h1
-rw-r--r--virt/kvm/arm/vgic.c63
-rw-r--r--virt/kvm/kvm_main.c5
6 files changed, 79 insertions, 2 deletions
diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
new file mode 100644
index 00000000000..38f27f709a9
--- /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/kvm/arm.c b/arch/arm/kvm/arm.c
index c9fe9d71be7..cc7c41af9c3 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -190,6 +190,7 @@ 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 4ecf10775c4..1f46f66f60a 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1075,6 +1075,7 @@ 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_vfio_ops;
+extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 902f1246187..b647c291739 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -853,6 +853,7 @@ struct kvm_device_attr {
#define KVM_DEV_VFIO_GROUP 1
#define KVM_DEV_VFIO_GROUP_ADD 1
#define KVM_DEV_VFIO_GROUP_DEL 2
+#define KVM_DEV_TYPE_ARM_VGIC_V2 5
/*
* ioctls for VM fds
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 5e9df47778f..b15d6c17a09 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1433,20 +1433,45 @@ out:
int kvm_vgic_create(struct kvm *kvm)
{
- int ret = 0;
+ int i, vcpu_lock_idx = -1, 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;
}
+ /*
+ * Any time a vcpu is run, vcpu_load is called which tries to grab the
+ * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
+ * that no other VCPUs are run while we create the vgic.
+ */
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!mutex_trylock(&vcpu->mutex))
+ goto out_unlock;
+ vcpu_lock_idx = i;
+ }
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (vcpu->arch.has_run_once) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ }
+
spin_lock_init(&kvm->arch.vgic.lock);
kvm->arch.vgic.vctrl_base = vgic_vctrl_base;
kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+out_unlock:
+ for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
+ vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
+ mutex_unlock(&vcpu->mutex);
+ }
+
out:
mutex_unlock(&kvm->lock);
return ret;
@@ -1510,3 +1535,37 @@ 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_v2_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 03c97e7ae4c..3efba97bdce 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2273,6 +2273,11 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
ops = &kvm_vfio_ops;
break;
#endif
+#ifdef CONFIG_KVM_ARM_VGIC
+ case KVM_DEV_TYPE_ARM_VGIC_V2:
+ ops = &kvm_arm_vgic_v2_ops;
+ break;
+#endif
default:
return -ENODEV;
}