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authorPaolo Bonzini <pbonzini@redhat.com>2019-12-22 13:18:15 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2019-12-22 13:18:15 +0100
commitd68321dec1b2234fb32f423e32c3af5915eae36c (patch)
tree7c62b2c76d62ab607238bc2cccc24eed0b32687a /virt
parent19a049f1a44d18e38a311e723c19c33c81020a30 (diff)
parentd89c69f42bf0fe42d1f52ea9b3dca15b1ade7601 (diff)
Merge tag 'kvm-ppc-fixes-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master
PPC KVM fix for 5.5 - Fix a bug where we try to do an ultracall on a system without an ultravisor.
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/coalesced_mmio.c8
-rw-r--r--virt/kvm/kvm_main.c28
2 files changed, 22 insertions, 14 deletions
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 8ffd07e2a160..00c747dbc82e 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -110,14 +110,11 @@ static const struct kvm_io_device_ops coalesced_mmio_ops = {
int kvm_coalesced_mmio_init(struct kvm *kvm)
{
struct page *page;
- int ret;
- ret = -ENOMEM;
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!page)
- goto out_err;
+ return -ENOMEM;
- ret = 0;
kvm->coalesced_mmio_ring = page_address(page);
/*
@@ -128,8 +125,7 @@ int kvm_coalesced_mmio_init(struct kvm *kvm)
spin_lock_init(&kvm->ring_lock);
INIT_LIST_HEAD(&kvm->coalesced_zones);
-out_err:
- return ret;
+ return 0;
}
void kvm_coalesced_mmio_free(struct kvm *kvm)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fef50464d56a..00268290dcbd 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -838,6 +838,18 @@ void kvm_put_kvm(struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(kvm_put_kvm);
+/*
+ * Used to put a reference that was taken on behalf of an object associated
+ * with a user-visible file descriptor, e.g. a vcpu or device, if installation
+ * of the new file descriptor fails and the reference cannot be transferred to
+ * its final owner. In such cases, the caller is still actively using @kvm and
+ * will fail miserably if the refcount unexpectedly hits zero.
+ */
+void kvm_put_kvm_no_destroy(struct kvm *kvm)
+{
+ WARN_ON(refcount_dec_and_test(&kvm->users_count));
+}
+EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy);
static int kvm_vm_release(struct inode *inode, struct file *filp)
{
@@ -2739,17 +2751,18 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
goto unlock_vcpu_destroy;
}
- BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
+ vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus);
+ BUG_ON(kvm->vcpus[vcpu->vcpu_idx]);
/* Now it's all set up, let userspace reach it */
kvm_get_kvm(kvm);
r = create_vcpu_fd(vcpu);
if (r < 0) {
- kvm_put_kvm(kvm);
+ kvm_put_kvm_no_destroy(kvm);
goto unlock_vcpu_destroy;
}
- kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
+ kvm->vcpus[vcpu->vcpu_idx] = vcpu;
/*
* Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus
@@ -3183,7 +3196,7 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
kvm_get_kvm(kvm);
ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
if (ret < 0) {
- kvm_put_kvm(kvm);
+ kvm_put_kvm_no_destroy(kvm);
mutex_lock(&kvm->lock);
list_del(&dev->vm_node);
mutex_unlock(&kvm->lock);
@@ -4341,12 +4354,12 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
r = kvm_arch_hardware_setup();
if (r < 0)
- goto out_free_0a;
+ goto out_free_1;
for_each_online_cpu(cpu) {
smp_call_function_single(cpu, check_processor_compat, &r, 1);
if (r < 0)
- goto out_free_1;
+ goto out_free_2;
}
r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
@@ -4403,9 +4416,8 @@ out_free_3:
unregister_reboot_notifier(&kvm_reboot_notifier);
cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
out_free_2:
-out_free_1:
kvm_arch_hardware_unsetup();
-out_free_0a:
+out_free_1:
free_cpumask_var(cpus_hardware_enabled);
out_free_0:
kvm_irqfd_exit();