On Thu, Dec 19, 2019 at 04:54:06PM +0800, Li Feng wrote:
> This msg is used to notify qemu that should get the config of backend.
>
> For example, vhost-user-blk uses this msg to notify guest os the
> capacity of backend has changed.
>
> The need_reply flag is not mandatory because it will block the sender
> thread and master process will send get_config message to fetch the
> configuration, this need an extra thread to process the vhost message.
>
> Signed-off-by: Li Feng <fen...@smartx.com>
> ---
> v4:
> * Fix type and code style.
> * Add need_reply support.
>
> v3:
> * Move the declare to rte_vhost.h
> * Add the symbol in rte_vhost_version.map
>
> v2:
> * Fix a little log typo.
>
> lib/librte_vhost/rte_vhost.h | 15 +++++++++++++++
> lib/librte_vhost/rte_vhost_version.map | 1 +
> lib/librte_vhost/vhost_user.c | 35
> ++++++++++++++++++++++++++++++++++
> lib/librte_vhost/vhost_user.h | 1 +
> 4 files changed, 52 insertions(+)
>
> diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
> index 7b5dc87c2..c7b619ae0 100644
> --- a/lib/librte_vhost/rte_vhost.h
> +++ b/lib/librte_vhost/rte_vhost.h
> @@ -10,6 +10,7 @@
> * Interface to vhost-user
> */
>
> +#include <stdbool.h>
> #include <stdint.h>
> #include <sys/eventfd.h>
>
> @@ -977,6 +978,20 @@ __rte_experimental
> int
> rte_vhost_get_vdpa_device_id(int vid);
>
> +/**
> + * Notify the guest that should get virtio configuration space from backend.
> + *
> + * @param vid
> + * vhost device ID
> + * @param need_reply
> + * wait for the master response the status of this operation
> + * @return
> + * 0 on success, < 0 on failure
> + */
> +__rte_experimental
> +int
> +rte_vhost_slave_config_change(int vid, bool need_reply);
> +
> #ifdef __cplusplus
> }
> #endif
> diff --git a/lib/librte_vhost/rte_vhost_version.map
> b/lib/librte_vhost/rte_vhost_version.map
> index c512377fe..051d08c12 100644
> --- a/lib/librte_vhost/rte_vhost_version.map
> +++ b/lib/librte_vhost/rte_vhost_version.map
> @@ -65,4 +65,5 @@ EXPERIMENTAL {
> rte_vhost_clr_inflight_desc_packed;
> rte_vhost_get_vhost_ring_inflight;
> rte_vhost_get_vring_base_from_inflight;
> + rte_vhost_slave_config_change;
> };
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 0cfb8b792..aed1210b1 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -2840,6 +2840,41 @@ vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t
> iova, uint8_t perm)
> return 0;
> }
>
> +static int
> +vhost_user_slave_config_change(struct virtio_net *dev, bool need_reply)
> +{
> + int ret;
> + uint32_t flags = VHOST_USER_VERSION;
> + if (need_reply)
> + flags |= VHOST_USER_NEED_REPLY;
> + struct VhostUserMsg msg = {
> + .request.slave = VHOST_USER_SLAVE_CONFIG_CHANGE_MSG,
> + .flags = flags,
> + .size = 0,
> + };
Normally, we don't mix the declarations and code.
Something like this looks better to me:
struct VhostUserMsg msg = {
.request.slave = VHOST_USER_SLAVE_CONFIG_CHANGE_MSG,
.flags = VHOST_USER_VERSION,
};
if (need_reply)
msg.flags |= VHOST_USER_NEED_REPLY;
> +
> + ret = send_vhost_slave_message(dev, &msg);
> + if (ret < 0) {
> + RTE_LOG(ERR, VHOST_CONFIG,
> + "Failed to send config change (%d)\n",
> + ret);
> + return ret;
> + }
> + if (need_reply)
> + return process_slave_message_reply(dev, &msg);
We can call process_slave_message_reply() unconditionally.
https://github.com/DPDK/dpdk/blob/f26c2b39b271/lib/librte_vhost/vhost_user.c#L2794-L2795
> + return 0;
> +}
> +
> +int
> +rte_vhost_slave_config_change(int vid, bool need_reply)
> +{
> + struct virtio_net *dev;
Looks better to add an empty line here.
> + dev = get_device(vid);
> + if (!dev)
> + return -ENODEV;
> + return vhost_user_slave_config_change(dev, need_reply);
> +}
> +
> static int vhost_user_slave_set_vring_host_notifier(struct virtio_net *dev,
> int index, int fd,
> uint64_t offset,
> diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
> index 6563f7315..86c364a93 100644
> --- a/lib/librte_vhost/vhost_user.h
> +++ b/lib/librte_vhost/vhost_user.h
> @@ -62,6 +62,7 @@ typedef enum VhostUserRequest {
> typedef enum VhostUserSlaveRequest {
> VHOST_USER_SLAVE_NONE = 0,
> VHOST_USER_SLAVE_IOTLB_MSG = 1,
> + VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
> VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
> VHOST_USER_SLAVE_MAX
> } VhostUserSlaveRequest;
> --
> 2.11.0
>
>
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