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Commit 4a12f951 authored by Christian Borntraeger's avatar Christian Borntraeger
Browse files

KVM: mark kvm->busses as rcu protected 



mark kvm->busses as rcu protected and use the correct access
function everywhere.

found by sparse
virt/kvm/kvm_main.c:3490:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3509:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3561:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3644:15: error: incompatible types in comparison expression (different address spaces)

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 5535f800

include/linux/kvm_host.h

+7 −1
Original line number Diff line number Diff line
@@ -404,7 +404,7 @@ struct kvm { 
	int last_boosted_vcpu;

	struct list_head vm_list;

	struct mutex lock;

	struct kvm_io_bus *buses[KVM_NR_BUSES];

	struct kvm_io_bus __rcu *buses[KVM_NR_BUSES];

#ifdef CONFIG_HAVE_KVM_EVENTFD

	struct {

		spinlock_t        lock;
@@ -473,6 +473,12 @@ struct kvm { 
#define vcpu_err(vcpu, fmt, ...)					\

	kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)



static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)

{

	return srcu_dereference_check(kvm->buses[idx], &kvm->srcu,

				      lockdep_is_held(&kvm->slots_lock));

}



static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)

{

	/* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, in case

virt/kvm/eventfd.c

+5 −3
Original line number Diff line number Diff line
@@ -825,7 +825,7 @@ static int kvm_assign_ioeventfd_idx(struct kvm *kvm, 
	if (ret < 0)

		goto unlock_fail;



	kvm->buses[bus_idx]->ioeventfd_count++;

	kvm_get_bus(kvm, bus_idx)->ioeventfd_count++;

	list_add_tail(&p->list, &kvm->ioeventfds);



	mutex_unlock(&kvm->slots_lock);
@@ -848,6 +848,7 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx, 
{

	struct _ioeventfd        *p, *tmp;

	struct eventfd_ctx       *eventfd;

	struct kvm_io_bus	 *bus;

	int                       ret = -ENOENT;



	eventfd = eventfd_ctx_fdget(args->fd);
@@ -870,8 +871,9 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx, 
			continue;



		kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);

		if (kvm->buses[bus_idx])

			kvm->buses[bus_idx]->ioeventfd_count--;

		bus = kvm_get_bus(kvm, bus_idx);

		if (bus)

			bus->ioeventfd_count--;

		ioeventfd_release(p);

		ret = 0;

		break;

virt/kvm/kvm_main.c

+10 −7
Original line number Diff line number Diff line
@@ -679,8 +679,8 @@ static struct kvm *kvm_create_vm(unsigned long type) 
	if (init_srcu_struct(&kvm->irq_srcu))

		goto out_err_no_irq_srcu;

	for (i = 0; i < KVM_NR_BUSES; i++) {

		kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),

					GFP_KERNEL);

		rcu_assign_pointer(kvm->buses[i],

			kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL));

		if (!kvm->buses[i])

			goto out_err;

	}
@@ -705,7 +705,7 @@ static struct kvm *kvm_create_vm(unsigned long type) 
	hardware_disable_all();

out_err_no_disable:

	for (i = 0; i < KVM_NR_BUSES; i++)

		kfree(kvm->buses[i]);

		kfree(rcu_access_pointer(kvm->buses[i]));

	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)

		kvm_free_memslots(kvm, kvm->memslots[i]);

	kvm_arch_free_vm(kvm);
@@ -740,8 +740,11 @@ static void kvm_destroy_vm(struct kvm *kvm) 
	spin_unlock(&kvm_lock);

	kvm_free_irq_routing(kvm);

	for (i = 0; i < KVM_NR_BUSES; i++) {

		if (kvm->buses[i])

			kvm_io_bus_destroy(kvm->buses[i]);

		struct kvm_io_bus *bus;



		bus = rcu_dereference_protected(kvm->buses[i], 1);

		if (bus)

			kvm_io_bus_destroy(bus);

		kvm->buses[i] = NULL;

	}

	kvm_coalesced_mmio_free(kvm);
@@ -3570,7 +3573,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, 
{

	struct kvm_io_bus *new_bus, *bus;



	bus = kvm->buses[bus_idx];

	bus = kvm_get_bus(kvm, bus_idx);

	if (!bus)

		return -ENOMEM;
@@ -3599,7 +3602,7 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, 
	int i;

	struct kvm_io_bus *new_bus, *bus;



	bus = kvm->buses[bus_idx];

	bus = kvm_get_bus(kvm, bus_idx);

	if (!bus)

		return;