[dpdk-dev] [PATCH v3 5/5] vhost: message handling implemented as a callback array
Nikolay Nikolaev
nicknickolaev at gmail.com
Thu Sep 20 08:34:03 CEST 2018
On Wed, Sep 19, 2018 at 10:37 AM Maxime Coquelin
<maxime.coquelin at redhat.com> wrote:
>
>
>
> On 09/15/2018 07:20 AM, Nikolay Nikolaev wrote:
> > Introduce vhost_message_handlers, which maps the message request
> > type to the message handler. Then replace the switch construct
> > with a map and call.
> >
> > Failing vhost_user_set_features is fatal and all processing should
> > stop immediately and propagate the error to the upper layers. Change
> > the code accordingly to reflect that.
> >
> > Signed-off-by: Nikolay Nikolaev <nicknickolaev at gmail.com>
> > ---
> > lib/librte_vhost/vhost_user.c | 161 +++++++++++++++++------------------------
> > 1 file changed, 66 insertions(+), 95 deletions(-)
> >
> > diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> > index 81c0396de..9004e1ac8 100644
> > --- a/lib/librte_vhost/vhost_user.c
> > +++ b/lib/librte_vhost/vhost_user.c
> > @@ -73,6 +73,8 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
> >
> > /* The possible results of a message handling function */
> > enum vh_result {
> > + /* Message handling failed with an unrecoverable error */
> > + VH_RESULT_FATAL = -2,
> > /* Message handling failed */
> > VH_RESULT_ERR = -1,
> > /* Message handling successful */
> > @@ -206,7 +208,7 @@ vhost_user_set_features(struct virtio_net **pdev, VhostUserMsg *msg)
> > RTE_LOG(ERR, VHOST_CONFIG,
> > "(%d) received invalid negotiated features.\n",
> > dev->vid);
> > - return VH_RESULT_ERR;
> > + return VH_RESULT_FATAL;
> > }
> >
> > if (dev->flags & VIRTIO_DEV_RUNNING) {
> > @@ -222,7 +224,7 @@ vhost_user_set_features(struct virtio_net **pdev, VhostUserMsg *msg)
> > RTE_LOG(ERR, VHOST_CONFIG,
> > "(%d) features changed while device is running.\n",
> > dev->vid);
> > - return VH_RESULT_ERR;
> > + return VH_RESULT_FATAL;
> > }
> >
> > if (dev->notify_ops->features_changed)
> > @@ -1477,6 +1479,34 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, VhostUserMsg *msg)
> > return VH_RESULT_OK;
> > }
> >
> > +typedef int (*vhost_message_handler_t)(struct virtio_net **pdev, VhostUserMsg * msg);
> > +static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
> > + [VHOST_USER_NONE] = NULL,
> > + [VHOST_USER_GET_FEATURES] = vhost_user_get_features,
> > + [VHOST_USER_SET_FEATURES] = vhost_user_set_features,
> > + [VHOST_USER_SET_OWNER] = vhost_user_set_owner,
> > + [VHOST_USER_RESET_OWNER] = vhost_user_reset_owner,
> > + [VHOST_USER_SET_MEM_TABLE] = vhost_user_set_mem_table,
> > + [VHOST_USER_SET_LOG_BASE] = vhost_user_set_log_base,
> > + [VHOST_USER_SET_LOG_FD] = vhost_user_set_log_fd,
> > + [VHOST_USER_SET_VRING_NUM] = vhost_user_set_vring_num,
> > + [VHOST_USER_SET_VRING_ADDR] = vhost_user_set_vring_addr,
> > + [VHOST_USER_SET_VRING_BASE] = vhost_user_set_vring_base,
> > + [VHOST_USER_GET_VRING_BASE] = vhost_user_get_vring_base,
> > + [VHOST_USER_SET_VRING_KICK] = vhost_user_set_vring_kick,
> > + [VHOST_USER_SET_VRING_CALL] = vhost_user_set_vring_call,
> > + [VHOST_USER_SET_VRING_ERR] = vhost_user_set_vring_err,
> > + [VHOST_USER_GET_PROTOCOL_FEATURES] = vhost_user_get_protocol_features,
> > + [VHOST_USER_SET_PROTOCOL_FEATURES] = vhost_user_set_protocol_features,
> > + [VHOST_USER_GET_QUEUE_NUM] = vhost_user_get_queue_num,
> > + [VHOST_USER_SET_VRING_ENABLE] = vhost_user_set_vring_enable,
> > + [VHOST_USER_SEND_RARP] = vhost_user_send_rarp,
> > + [VHOST_USER_NET_SET_MTU] = vhost_user_net_set_mtu,
> > + [VHOST_USER_SET_SLAVE_REQ_FD] = vhost_user_set_req_fd,
> > + [VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
> > +};
> > +
> > +
> > /* return bytes# of read on success or negative val on failure. */
> > static int
> > read_vhost_message(int sockfd, VhostUserMsg *msg)
> > @@ -1629,6 +1659,7 @@ vhost_user_msg_handler(int vid, int fd)
> > int ret;
> > int unlock_required = 0;
> > uint32_t skip_master = 0;
> > + int request;
> >
> > dev = get_device(vid);
> > if (dev == NULL)
> > @@ -1721,100 +1752,40 @@ vhost_user_msg_handler(int vid, int fd)
> > goto skip_to_post_handle;
> > }
> >
> > - switch (msg.request.master) {
> > - case VHOST_USER_GET_FEATURES:
> > - ret = vhost_user_get_features(&dev, &msg);
> > - send_vhost_reply(fd, &msg);
> > - break;
> > - case VHOST_USER_SET_FEATURES:
> > - ret = vhost_user_set_features(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_GET_PROTOCOL_FEATURES:
> > - ret = vhost_user_get_protocol_features(&dev, &msg);
> > - send_vhost_reply(fd, &msg);
> > - break;
> > - case VHOST_USER_SET_PROTOCOL_FEATURES:
> > - ret = vhost_user_set_protocol_features(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_OWNER:
> > - ret = vhost_user_set_owner(&dev, &msg);
> > - break;
> > - case VHOST_USER_RESET_OWNER:
> > - ret = vhost_user_reset_owner(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_MEM_TABLE:
> > - ret = vhost_user_set_mem_table(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_LOG_BASE:
> > - ret = vhost_user_set_log_base(&dev, &msg);
> > - if (ret)
> > - goto skip_to_reply;
> > - /* it needs a reply */
> > - send_vhost_reply(fd, &msg);
> > - break;
> > - case VHOST_USER_SET_LOG_FD:
> > - ret = vhost_user_set_log_fd(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_VRING_NUM:
> > - ret = vhost_user_set_vring_num(&dev, &msg);
> > - break;
> > - case VHOST_USER_SET_VRING_ADDR:
> > - ret = vhost_user_set_vring_addr(&dev, &msg);
> > - break;
> > - case VHOST_USER_SET_VRING_BASE:
> > - ret = vhost_user_set_vring_base(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_GET_VRING_BASE:
> > - ret = vhost_user_get_vring_base(&dev, &msg);
> > - if (ret)
> > - goto skip_to_reply;
> > - send_vhost_reply(fd, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_VRING_KICK:
> > - ret = vhost_user_set_vring_kick(&dev, &msg);
> > - break;
> > - case VHOST_USER_SET_VRING_CALL:
> > - ret = vhost_user_set_vring_call(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_VRING_ERR:
> > - ret = vhost_user_set_vring_err(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_GET_QUEUE_NUM:
> > - ret = vhost_user_get_queue_num(&dev, &msg);
> > - send_vhost_reply(fd, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_VRING_ENABLE:
> > - ret = vhost_user_set_vring_enable(&dev, &msg);
> > - break;
> > - case VHOST_USER_SEND_RARP:
> > - ret = vhost_user_send_rarp(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_NET_SET_MTU:
> > - ret = vhost_user_net_set_mtu(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_SET_SLAVE_REQ_FD:
> > - ret = vhost_user_set_req_fd(&dev, &msg);
> > - break;
> > -
> > - case VHOST_USER_IOTLB_MSG:
> > - ret = vhost_user_iotlb_msg(&dev, &msg);
> > - break;
> > + request = msg.request.master;
> > + if (request > VHOST_USER_NONE && request < VHOST_USER_MAX) {
> > + if (!vhost_message_handlers[request])
> > + goto skip_to_post_handle;
> > + ret = vhost_message_handlers[request](&dev, &msg);
> >
> > - default:
> > - ret = -1;
> > - break;
> > + switch (ret) {
> > + case VH_RESULT_FATAL:
> > + RTE_LOG(ERR, VHOST_CONFIG,
> > + "Processing %s failed with an unrecoverable error.\n",
> > + vhost_message_str[request]);
> > + /* Propagate the error to the upper layer */
> > + return -1;
> If I'm not mistaken, you are missing to release the lock if it was
> taken, which could stuck the PMD threads:
>
> if (unlock_required)
> vhost_user_unlock_all_queue_pairs(dev);
>
> Also the behavior is changed, as if the message for which handling
> failed has the VHOST_USER_NEED_REPLY flag set, error is reported to the
> master, and function returns 0:
>
> skip_to_reply:
> if (unlock_required)
> vhost_user_unlock_all_queue_pairs(dev);
>
> if (msg.flags & VHOST_USER_NEED_REPLY) {
> msg.payload.u64 = !!ret;
> msg.size = sizeof(msg.payload.u64);
> send_vhost_reply(fd, &msg);
> } else if (ret) {
> RTE_LOG(ERR, VHOST_CONFIG,
> "vhost message handling failed.\n");
> return -1;
> }
>
Thanks Maxime. I'll revisit this patch and post new version in the
next couple of day.
Nikolay NIkolaev
>
> > + case VH_RESULT_ERR:
> > + RTE_LOG(ERR, VHOST_CONFIG,
> > + "Processing %s failed.\n",
> > + vhost_message_str[request]);
> > + break;
> > + case VH_RESULT_OK:
> > + RTE_LOG(DEBUG, VHOST_CONFIG,
> > + "Processing %s succeeded.\n",
> > + vhost_message_str[request]);
> > + break;
> > + case VH_RESULT_REPLY:
> > + RTE_LOG(INFO, VHOST_CONFIG,
> > + "Processing %s succeeded and needs reply.\n",
> > + vhost_message_str[request]);
> > + send_vhost_reply(fd, &msg);
> > + break;
> > + }
> > + } else {
> > + RTE_LOG(ERR, VHOST_CONFIG,
> > + "Requested invalid message type %d.\n", request);
> > + ret = VH_RESULT_ERR;
> > }
> >
> > skip_to_post_handle:
> >
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