On 2016/03/10 15:39, Tan, Jianfeng wrote:
>
> On 3/10/2016 2:34 PM, Tetsuya Mukawa wrote:
>> On 2016/03/10 15:25, Tan, Jianfeng wrote:
>>>
>>> On 3/10/2016 2:14 PM, Tetsuya Mukawa wrote:
>>>> Currently, default value of kickfd and callfd is -1.
>>>> If the value is -1, current code guess kickfd and callfd hasn't been
>>>> initialized yet. And vhost library will guess the virtqueue isn't
>>>> ready
>>>> for processing.
>>>> But callfd and kickfd will be set as -1 when "--enable-kvm"
>>>> isn't specified in QEMU command line. It means we cannot treat -1 as
>>>> uninitialized state. The patch changes default value to -2. And the
>>>> patch defines -2 as VIRTIO_UNINITIALIZED_EVENTFD.
>>>>
>>>> Signed-off-by: Tetsuya Mukawa <mukawa at igel.co.jp>
>>>> ---
>>>> lib/librte_vhost/rte_virtio_net.h | 1 +
>>>> lib/librte_vhost/vhost_user/virtio-net-user.c | 7 ++++---
>>>> lib/librte_vhost/virtio-net.c | 4 ++--
>>>> 3 files changed, 7 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/lib/librte_vhost/rte_virtio_net.h
>>>> b/lib/librte_vhost/rte_virtio_net.h
>>>> index 7d1fde2..d745707 100644
>>>> --- a/lib/librte_vhost/rte_virtio_net.h
>>>> +++ b/lib/librte_vhost/rte_virtio_net.h
>>>> @@ -89,6 +89,7 @@ struct vhost_virtqueue {
>>>> uint16_t vhost_hlen; /**< Vhost header length
>>>> (varies depending on RX merge buffers. */
>>>> volatile uint16_t last_used_idx; /**< Last index used
>>>> on the available ring */
>>>> volatile uint16_t last_used_idx_res; /**< Used for
>>>> multiple devices reserving buffers. */
>>>> +#define VIRTIO_UNINITIALIZED_EVENTFD (-2)
>>>> int callfd; /**< Used to notify the guest
>>>> (trigger interrupt). */
>>>> int kickfd; /**< Currently unused as
>>>> polling mode is enabled. */
>>>> int enabled;
>>>> diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c
>>>> b/lib/librte_vhost/vhost_user/virtio-net-user.c
>>>> index 65b5652..591f9bf 100644
>>>> --- a/lib/librte_vhost/vhost_user/virtio-net-user.c
>>>> +++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
>>>> @@ -225,8 +225,8 @@ static int
>>>> vq_is_ready(struct vhost_virtqueue *vq)
>>>> {
>>>> return vq && vq->desc &&
>>>> - vq->kickfd != -1 &&
>>>> - vq->callfd != -1;
>>>> + vq->kickfd != VIRTIO_UNINITIALIZED_EVENTFD &&
>>>> + vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD;
>>>> }
>>>> static int
>>>> @@ -318,7 +318,8 @@ user_get_vring_base(struct vhost_device_ctx ctx,
>>>> */
>>>> if (dev->virtqueue[state->index]->kickfd >= 0) {
>>>> close(dev->virtqueue[state->index]->kickfd);
>>> Then -1 will be a valid value, need to check if it's not -1 to
>>> close()? Nevertheless, close(-1) brings no big problem.
>>>
>> We did it in above 'if' condition checking, then close(-1) will not be
>> called.
>
> Sorry, missed that. So when kickfd == -1, need to be set to
> VIRTIO_UNINITIALIZED_EVENTFD?
>
Aha, I've got it. Will change it.
Thanks,
Tetsuya
> Thanks,
> Jianfeng
>
>>
>> Thanks,
>> Tetsuya
>>
>>> Thanks,
>>> Jianfeng
>>>
>>>> - dev->virtqueue[state->index]->kickfd = -1;
>>>> + dev->virtqueue[state->index]->kickfd =
>>>> + VIRTIO_UNINITIALIZED_EVENTFD;
>>>> }
>>>> return 0;
>>>> diff --git a/lib/librte_vhost/virtio-net.c
>>>> b/lib/librte_vhost/virtio-net.c
>>>> index fe1a77e..3498e9d 100644
>>>> --- a/lib/librte_vhost/virtio-net.c
>>>> +++ b/lib/librte_vhost/virtio-net.c
>>>> @@ -263,8 +263,8 @@ init_vring_queue(struct vhost_virtqueue *vq, int
>>>> qp_idx)
>>>> {
>>>> memset(vq, 0, sizeof(struct vhost_virtqueue));
>>>> - vq->kickfd = -1;
>>>> - vq->callfd = -1;
>>>> + vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
>>>> + vq->callfd = VIRTIO_UNINITIALIZED_EVENTFD;
>>>> /* Backends are set to -1 indicating an inactive device. */
>>>> vq->backend = -1;
>
