On 15.03.2017 09:01, Peter Xu wrote:
> When releasing the bus, let's clear the bus pointers to mark it out. If
> any further device unregister happens on this bus, we know that we're
> done if we found the bus being released already.
>
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
> ---
> virt/kvm/kvm_main.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index a17d787..7445566 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -727,8 +727,10 @@ 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++)
> + for (i = 0; i < KVM_NR_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);
> @@ -3579,6 +3581,14 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
> struct kvm_io_bus *new_bus, *bus;
>
> bus = kvm->buses[bus_idx];
> +
> + /*
> + * It's possible the bus being released before hand. If so,
> + * we're done here.
> + */
/* the bus might have already been destroyed */ ?
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> + if (!bus)
> + return 0;
> +
> r = -ENOENT;
> for (i = 0; i < bus->dev_count; i++)
> if (bus->range[i].dev == dev) {
>
--
Thanks,
David
