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: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
include/linux/kvm_host.h | 2 +-
virt/kvm/eventfd.c | 8 +++++---
virt/kvm/kvm_main.c | 17 ++++++++++-------
3 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7c32905..220f251 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -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;
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index a8d5403..3e08b43 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -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++;
+ rcu_dereference_protected(kvm->buses[bus_idx], 1)->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 = rcu_dereference_protected(kvm->buses[bus_idx], 1);
+ if (bus)
+ bus->ioeventfd_count--;
ioeventfd_release(p);
ret = 0;
break;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index e3e6fec..e5ae3eb 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -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,
rcu_dereference_protected(kvm->memslots[i], 1));
@@ -741,8 +741,11 @@ 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);
@@ -3572,7 +3575,7 @@ 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 = rcu_dereference_protected(kvm->buses[bus_idx], 1);
if (!bus)
return -ENOMEM;
@@ -3601,7 +3604,7 @@ 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 = rcu_dereference_protected(kvm->buses[bus_idx], 1);
if (!bus)
return;
--
2.7.4
