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Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/eventfd.c3
-rw-r--r--virt/kvm/kvm_main.c40
2 files changed, 30 insertions, 13 deletions
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 46dbc0a7dfc1..49001fa84ead 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -868,7 +868,8 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
continue;
kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
- kvm->buses[bus_idx]->ioeventfd_count--;
+ if (kvm->buses[bus_idx])
+ kvm->buses[bus_idx]->ioeventfd_count--;
ioeventfd_release(p);
ret = 0;
break;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 336ed267c407..cb092bd9965b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -654,8 +654,11 @@ static void kvm_destroy_vm(struct kvm *kvm)
list_del(&kvm->vm_list);
spin_unlock(&kvm_lock);
kvm_free_irq_routing(kvm);
- for (i = 0; i < KVM_NR_BUSES; i++)
- kvm_io_bus_destroy(kvm->buses[i]);
+ for (i = 0; i < KVM_NR_BUSES; i++) {
+ if (kvm->buses[i])
+ kvm_io_bus_destroy(kvm->buses[i]);
+ kvm->buses[i] = NULL;
+ }
kvm_coalesced_mmio_free(kvm);
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
@@ -3271,6 +3274,8 @@ int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
};
bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
+ if (!bus)
+ return -ENOMEM;
r = __kvm_io_bus_write(vcpu, bus, &range, val);
return r < 0 ? r : 0;
}
@@ -3288,6 +3293,8 @@ int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
};
bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
+ if (!bus)
+ return -ENOMEM;
/* First try the device referenced by cookie. */
if ((cookie >= 0) && (cookie < bus->dev_count) &&
@@ -3338,6 +3345,8 @@ int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
};
bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
+ if (!bus)
+ return -ENOMEM;
r = __kvm_io_bus_read(vcpu, bus, &range, val);
return r < 0 ? r : 0;
}
@@ -3350,6 +3359,9 @@ 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];
+ if (!bus)
+ return -ENOMEM;
+
/* exclude ioeventfd which is limited by maximum fd */
if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
return -ENOSPC;
@@ -3369,37 +3381,41 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
}
/* Caller must hold slots_lock. */
-int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
- struct kvm_io_device *dev)
+void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
+ struct kvm_io_device *dev)
{
- int i, r;
+ int i;
struct kvm_io_bus *new_bus, *bus;
bus = kvm->buses[bus_idx];
- r = -ENOENT;
+ if (!bus)
+ return;
+
for (i = 0; i < bus->dev_count; i++)
if (bus->range[i].dev == dev) {
- r = 0;
break;
}
- if (r)
- return r;
+ if (i == bus->dev_count)
+ return;
new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count - 1) *
sizeof(struct kvm_io_range)), GFP_KERNEL);
- if (!new_bus)
- return -ENOMEM;
+ if (!new_bus) {
+ pr_err("kvm: failed to shrink bus, removing it completely\n");
+ goto broken;
+ }
memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
new_bus->dev_count--;
memcpy(new_bus->range + i, bus->range + i + 1,
(new_bus->dev_count - i) * sizeof(struct kvm_io_range));
+broken:
rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
synchronize_srcu_expedited(&kvm->srcu);
kfree(bus);
- return r;
+ return;
}
static struct notifier_block kvm_cpu_notifier = {