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Commit 07f0a7bd authored by Scott Wood's avatar Scott Wood Committed by Alexander Graf
Browse files

kvm: destroy emulated devices on VM exit 



The hassle of getting refcounting right was greater than the hassle
of keeping a list of devices to destroy on VM exit.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent 22e64024

arch/powerpc/kvm/mpic.c

+0 −2
Original line number Diff line number Diff line
@@ -1781,7 +1781,6 @@ int kvmppc_mpic_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu, 
	if (opp->mpic_mode_mask == GCR_MODE_PROXY)

		vcpu->arch.epr_flags |= KVMPPC_EPR_KERNEL;



	kvm_device_get(dev);

out:

	spin_unlock_irq(&opp->lock);

	return ret;
@@ -1797,7 +1796,6 @@ void kvmppc_mpic_disconnect_vcpu(struct openpic *opp, struct kvm_vcpu *vcpu) 
	BUG_ON(!opp->dst[vcpu->arch.irq_cpu_id].vcpu);



	opp->dst[vcpu->arch.irq_cpu_id].vcpu = NULL;

	kvm_device_put(opp->dev);

}



/*

include/linux/kvm_host.h

+2 −1
Original line number Diff line number Diff line
@@ -393,6 +393,7 @@ struct kvm { 
	long mmu_notifier_count;

#endif

	long tlbs_dirty;

	struct list_head devices;

};



#define kvm_err(fmt, ...) \
@@ -1069,8 +1070,8 @@ struct kvm_device_ops; 
struct kvm_device {

	struct kvm_device_ops *ops;

	struct kvm *kvm;

	atomic_t users;

	void *private;

	struct list_head vm_node;

};



/* create, destroy, and name are mandatory */

virt/kvm/kvm_main.c

+16 −13
Original line number Diff line number Diff line
@@ -504,6 +504,7 @@ static struct kvm *kvm_create_vm(unsigned long type) 
	mutex_init(&kvm->irq_lock);

	mutex_init(&kvm->slots_lock);

	atomic_set(&kvm->users_count, 1);

	INIT_LIST_HEAD(&kvm->devices);



	r = kvm_init_mmu_notifier(kvm);

	if (r)
@@ -581,6 +582,19 @@ void kvm_free_physmem(struct kvm *kvm) 
	kfree(kvm->memslots);

}



static void kvm_destroy_devices(struct kvm *kvm)

{

	struct list_head *node, *tmp;



	list_for_each_safe(node, tmp, &kvm->devices) {

		struct kvm_device *dev =

			list_entry(node, struct kvm_device, vm_node);



		list_del(node);

		dev->ops->destroy(dev);

	}

}



static void kvm_destroy_vm(struct kvm *kvm)

{

	int i;
@@ -600,6 +614,7 @@ static void kvm_destroy_vm(struct kvm *kvm) 
	kvm_arch_flush_shadow_all(kvm);

#endif

	kvm_arch_destroy_vm(kvm);

	kvm_destroy_devices(kvm);

	kvm_free_physmem(kvm);

	cleanup_srcu_struct(&kvm->srcu);

	kvm_arch_free_vm(kvm);
@@ -2195,23 +2210,11 @@ static long kvm_device_ioctl(struct file *filp, unsigned int ioctl, 
	}

}



void kvm_device_get(struct kvm_device *dev)

{

	atomic_inc(&dev->users);

}



void kvm_device_put(struct kvm_device *dev)

{

	if (atomic_dec_and_test(&dev->users))

		dev->ops->destroy(dev);

}



static int kvm_device_release(struct inode *inode, struct file *filp)

{

	struct kvm_device *dev = filp->private_data;

	struct kvm *kvm = dev->kvm;



	kvm_device_put(dev);

	kvm_put_kvm(kvm);

	return 0;

}
@@ -2257,7 +2260,6 @@ static int kvm_ioctl_create_device(struct kvm *kvm, 


	dev->ops = ops;

	dev->kvm = kvm;

	atomic_set(&dev->users, 1);



	ret = ops->create(dev, cd->type);

	if (ret < 0) {
@@ -2271,6 +2273,7 @@ static int kvm_ioctl_create_device(struct kvm *kvm, 
		return ret;

	}



	list_add(&dev->vm_node, &kvm->devices);

	kvm_get_kvm(kvm);

	cd->fd = ret;

	return 0;