We only want zero length mmio eventfd to be registered on KVM_FAST_MMIO_BUS. So check this explicitly when arg->len is zero to make sure this. Cc: stable@xxxxxxxxxxxxxxx Cc: Gleb Natapov <gleb@xxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> --- virt/kvm/eventfd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 9ff4193..e404806 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -846,7 +846,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) /* When length is ignored, MMIO is also put on a separate bus, for * faster lookups. */ - if (!args->len && !(args->flags & KVM_IOEVENTFD_FLAG_PIO)) { + if (!args->len && bus_idx == KVM_MMIO_BUS) { ret = kvm_io_bus_register_dev(kvm, KVM_FAST_MMIO_BUS, p->addr, 0, &p->dev); if (ret < 0) @@ -901,7 +901,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) continue; kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev); - if (!p->length) { + if (!p->length && p->bus_idx == KVM_MMIO_BUS) { kvm_io_bus_unregister_dev(kvm, KVM_FAST_MMIO_BUS, &p->dev); } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html