On 12/20/2022 11:04 AM, Wang, Wei W wrote:
On Tuesday, December 20, 2022 1:19 AM, Sean Christopherson wrote:
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c index
0be80c213f7f..5ef88f5a0864 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -187,15 +187,17 @@ int
kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
r = kvm_io_bus_unregister_dev(kvm,
zone->pio ? KVM_PIO_BUS : KVM_MMIO_BUS, &dev->dev);
+ kvm_iodevice_destructor(&dev->dev);
+
/*
* On failure, unregister destroys all devices on the
* bus _except_ the target device, i.e. coalesced_zones
- * has been modified. No need to restart the walk as
- * there aren't any zones left.
+ * has been modified. Bail after destroying the target
+ * device, there's no need to restart the walk as there
+ * aren't any zones left.
*/
if (r)
break;
- kvm_iodevice_destructor(&dev->dev);
}
}
Another option is to let kvm_io_bus_unregister_dev handle this, and no need for callers
to make the extra kvm_iodevice_destructor() call. This simplifies the usage for callers
(e.g. reducing LOCs and no leakages like this):
One vote for this option : )
diff --git a/include/kvm/iodev.h b/include/kvm/iodev.h
index d75fc4365746..56619e33251e 100644
--- a/include/kvm/iodev.h
+++ b/include/kvm/iodev.h
@@ -55,10 +55,4 @@ static inline int kvm_iodevice_write(struct kvm_vcpu *vcpu,
: -EOPNOTSUPP;
}
-static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
-{
- if (dev->ops->destructor)
- dev->ops->destructor(dev);
-}
-
#endif /* __KVM_IODEV_H__ */
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 0be80c213f7f..d7135a5e76f8 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -195,7 +195,6 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
*/
if (r)
break;
- kvm_iodevice_destructor(&dev->dev);
}
}
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 2a3ed401ce46..1b277afb545b 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -898,7 +898,6 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
bus = kvm_get_bus(kvm, bus_idx);
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 13e88297f999..582757ebdce6 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5200,6 +5200,12 @@ static struct notifier_block kvm_reboot_notifier = {
.priority = 0,
};
+static void kvm_iodevice_destructor(struct kvm_io_device *dev)
+{
+ if (dev->ops->destructor)
+ dev->ops->destructor(dev);
+}
+
static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
{
int i;
@@ -5423,7 +5429,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
struct kvm_io_device *dev)
{
- int i, j;
+ int i;
struct kvm_io_bus *new_bus, *bus;
lockdep_assert_held(&kvm->slots_lock);
@@ -5453,18 +5459,18 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
synchronize_srcu_expedited(&kvm->srcu);
- /* Destroy the old bus _after_ installing the (null) bus. */
+ /*
+ * If (null) bus is installed, destroy the old bus, including all the
+ * attached devices. Otherwise, destroy the caller's device only.
+ */
if (!new_bus) {
pr_err("kvm: failed to shrink bus, removing it completely\n");
- for (j = 0; j < bus->dev_count; j++) {
- if (j == i)
- continue;
- kvm_iodevice_destructor(bus->range[j].dev);
- }
+ kvm_io_bus_destroy(bus);
+ return -ENOMEM;
}
- kfree(bus);
- return new_bus ? 0 : -ENOMEM;
+ kvm_iodevice_destructor(dev);
+ return 0;
}
struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
