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| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-10-26 13:35:56 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-10-26 14:06:51 +0200 |
| commit | 36343f6ea721e003ed11b48a6a05d77a255b3a62 (patch) | |
| tree | c32e2452c7269e97ef001eb8f8428a106e9434cf /virt/kvm/eventfd.c | |
| parent | e1e575f6b026734be3b1f075e780e91ab08ca541 (diff) | |
| download | linux-36343f6ea721e003ed11b48a6a05d77a255b3a62.tar.bz2 | |
KVM: fix OOPS on flush_work
The conversion done by commit 3706feacd007 ("KVM: Remove deprecated
create_singlethread_workqueue") is broken. It flushes a single work
item &irqfd->shutdown instead of all of them, and even worse if there
is no irqfd on the list then you get a NULL pointer dereference.
Revert the virt/kvm/eventfd.c part of that patch; to avoid the
deprecated function, just allocate our own workqueue---it does
not even have to be unbound---with alloc_workqueue.
Fixes: 3706feacd007
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt/kvm/eventfd.c')
| -rw-r--r-- | virt/kvm/eventfd.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index f397e9b20370..a29786dd9522 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -42,6 +42,7 @@ #ifdef CONFIG_HAVE_KVM_IRQFD +static struct workqueue_struct *irqfd_cleanup_wq; static void irqfd_inject(struct work_struct *work) @@ -167,7 +168,7 @@ irqfd_deactivate(struct kvm_kernel_irqfd *irqfd) list_del_init(&irqfd->list); - schedule_work(&irqfd->shutdown); + queue_work(irqfd_cleanup_wq, &irqfd->shutdown); } int __attribute__((weak)) kvm_arch_set_irq_inatomic( @@ -554,7 +555,7 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args) * so that we guarantee there will not be any more interrupts on this * gsi once this deassign function returns. */ - flush_work(&irqfd->shutdown); + flush_workqueue(irqfd_cleanup_wq); return 0; } @@ -591,7 +592,7 @@ kvm_irqfd_release(struct kvm *kvm) * Block until we know all outstanding shutdown jobs have completed * since we do not take a kvm* reference. */ - flush_work(&irqfd->shutdown); + flush_workqueue(irqfd_cleanup_wq); } @@ -621,8 +622,23 @@ void kvm_irq_routing_update(struct kvm *kvm) spin_unlock_irq(&kvm->irqfds.lock); } +/* + * create a host-wide workqueue for issuing deferred shutdown requests + * aggregated from all vm* instances. We need our own isolated + * queue to ease flushing work items when a VM exits. + */ +int kvm_irqfd_init(void) +{ + irqfd_cleanup_wq = alloc_workqueue("kvm-irqfd-cleanup", 0, 0); + if (!irqfd_cleanup_wq) + return -ENOMEM; + + return 0; +} + void kvm_irqfd_exit(void) { + destroy_workqueue(irqfd_cleanup_wq); } #endif |