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-rw-r--r--arch/arm/kvm/arm.c6
-rw-r--r--arch/powerpc/kvm/book3s_xics.c2
-rw-r--r--include/linux/kvm_host.h6
-rw-r--r--virt/kvm/arm/vgic/vgic-init.c17
-rw-r--r--virt/kvm/kvm_main.c13
5 files changed, 27 insertions, 17 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index d94bb9093ead..75f130ef6504 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -1009,9 +1009,13 @@ long kvm_arch_vm_ioctl(struct file *filp,
switch (ioctl) {
case KVM_CREATE_IRQCHIP: {
+ int ret;
if (!vgic_present)
return -ENXIO;
- return kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
+ mutex_lock(&kvm->lock);
+ ret = kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
+ mutex_unlock(&kvm->lock);
+ return ret;
}
case KVM_ARM_SET_DEVICE_ADDR: {
struct kvm_arm_device_addr dev_addr;
diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
index f2def8e45fef..05aa11399a78 100644
--- a/arch/powerpc/kvm/book3s_xics.c
+++ b/arch/powerpc/kvm/book3s_xics.c
@@ -1329,12 +1329,10 @@ static int kvmppc_xics_create(struct kvm_device *dev, u32 type)
xics->kvm = kvm;
/* Already there ? */
- mutex_lock(&kvm->lock);
if (kvm->arch.xics)
ret = -EEXIST;
else
kvm->arch.xics = xics;
- mutex_unlock(&kvm->lock);
if (ret) {
kfree(xics);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d3c9b82812c3..9c28b4d4c90b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1113,6 +1113,12 @@ struct kvm_device {
/* create, destroy, and name are mandatory */
struct kvm_device_ops {
const char *name;
+
+ /*
+ * create is called holding kvm->lock and any operations not suitable
+ * to do while holding the lock should be deferred to init (see
+ * below).
+ */
int (*create)(struct kvm_device *dev, u32 type);
/*
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index fb4b0a79a950..83777c1cbae0 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -73,12 +73,8 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
int i, vcpu_lock_idx = -1, ret;
struct kvm_vcpu *vcpu;
- mutex_lock(&kvm->lock);
-
- if (irqchip_in_kernel(kvm)) {
- ret = -EEXIST;
- goto out;
- }
+ if (irqchip_in_kernel(kvm))
+ return -EEXIST;
/*
* This function is also called by the KVM_CREATE_IRQCHIP handler,
@@ -87,10 +83,8 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
* the proper checks already.
*/
if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
- !kvm_vgic_global_state.can_emulate_gicv2) {
- ret = -ENODEV;
- goto out;
- }
+ !kvm_vgic_global_state.can_emulate_gicv2)
+ return -ENODEV;
/*
* Any time a vcpu is run, vcpu_load is called which tries to grab the
@@ -138,9 +132,6 @@ out_unlock:
vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
mutex_unlock(&vcpu->mutex);
}
-
-out:
- mutex_unlock(&kvm->lock);
return ret;
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ae642452e91a..195078225aa5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -696,6 +696,11 @@ static void kvm_destroy_devices(struct kvm *kvm)
{
struct kvm_device *dev, *tmp;
+ /*
+ * We do not need to take the kvm->lock here, because nobody else
+ * has a reference to the struct kvm at this point and therefore
+ * cannot access the devices list anyhow.
+ */
list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) {
list_del(&dev->vm_node);
dev->ops->destroy(dev);
@@ -2832,11 +2837,15 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
dev->ops = ops;
dev->kvm = kvm;
+ mutex_lock(&kvm->lock);
ret = ops->create(dev, cd->type);
if (ret < 0) {
+ mutex_unlock(&kvm->lock);
kfree(dev);
return ret;
}
+ list_add(&dev->vm_node, &kvm->devices);
+ mutex_unlock(&kvm->lock);
if (ops->init)
ops->init(dev);
@@ -2844,10 +2853,12 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
if (ret < 0) {
ops->destroy(dev);
+ mutex_lock(&kvm->lock);
+ list_del(&dev->vm_node);
+ mutex_unlock(&kvm->lock);
return ret;
}
- list_add(&dev->vm_node, &kvm->devices);
kvm_get_kvm(kvm);
cd->fd = ret;
return 0;