Hi Adrian,
> -----Original Message-----
> From: dev <dev-boun...@dpdk.org> On Behalf Of Adrian Moreno
> Sent: Thursday, July 2, 2020 4:33 PM
> To: dev@dpdk.org; Ye, Xiaolong <xiaolong...@intel.com>;
> shah...@mellanox.com; ma...@mellanox.com; maxime.coque...@redhat.com;
> Wang, Xiao W <xiao.w.w...@intel.com>; viachesl...@mellanox.com
> Cc: jasow...@redhat.com; l...@redhat.com; Adrian Moreno
> <amore...@redhat.com>
> Subject: [dpdk-dev] [PATCH v2 6/8] vhost: add support for virtio get status
> message
>
> This patch adds support to the new Virtio device get status Vhost-user
> message.
>
> The driver can send this new message to read the device status.
>
> One of the uses of this message is to ensure the feature negotiation has
> succeded. According to the virtio spec, after completing the feature
> negotiation,
> the driver sets the FEATURE_OK status bit and re-reads it to ensure the device
> has accepted the features.
>
> This patch also clears the FEATURE_OK status bit if the feature negotiation
> has
> failed to let the driver know about his failure.
>
> Signed-off-by: Adrian Moreno <amore...@redhat.com>
> ---
> lib/librte_vhost/vhost.h | 2 ++
> lib/librte_vhost/vhost_user.c | 32 ++++++++++++++++++++++++++++++++
> lib/librte_vhost/vhost_user.h | 1 +
> 3 files changed, 35 insertions(+)
>
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> 25d31c71b..e743821cc 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -32,6 +32,8 @@
> #define VIRTIO_DEV_BUILTIN_VIRTIO_NET 4
> /* Used to indicate that the device has its own data path and configured */
> #define VIRTIO_DEV_VDPA_CONFIGURED 8
> +/* Used to indicate that the feature negotiation failed */ #define
> +VIRTIO_DEV_FEATURES_FAILED 16
>
> /* Backend value set by guest. */
> #define VIRTIO_DEV_STOPPED -1
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index
> 8d3d13913..00da7bf18 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -88,6 +88,7 @@ static const char *vhost_message_str[VHOST_USER_MAX]
> = {
> [VHOST_USER_GET_INFLIGHT_FD] = "VHOST_USER_GET_INFLIGHT_FD",
> [VHOST_USER_SET_INFLIGHT_FD] = "VHOST_USER_SET_INFLIGHT_FD",
> [VHOST_USER_SET_STATUS] = "VHOST_USER_SET_STATUS",
> + [VHOST_USER_GET_STATUS] = "VHOST_USER_GET_STATUS",
> };
>
> static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg); @@ -339,6
> +340,9 @@ vhost_user_set_features(struct virtio_net **pdev, struct
> VhostUserMsg *msg,
> VHOST_LOG_CONFIG(ERR,
> "(%d) received invalid negotiated features.\n",
> dev->vid);
> + dev->flags |= VIRTIO_DEV_FEATURES_FAILED;
> + dev->status &= ~VIRTIO_DEVICE_STATUS_FEATURES_OK;
> +
> return RTE_VHOST_MSG_RESULT_ERR;
> }
>
> @@ -402,6 +406,7 @@ vhost_user_set_features(struct virtio_net **pdev, struct
> VhostUserMsg *msg,
> if (vdpa_dev)
> vdpa_dev->ops->set_features(dev->vid);
>
> + dev->flags &= ~VIRTIO_DEV_FEATURES_FAILED;
> return RTE_VHOST_MSG_RESULT_OK;
> }
>
> @@ -2458,6 +2463,22 @@ vhost_user_postcopy_end(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> return RTE_VHOST_MSG_RESULT_REPLY;
> }
>
> +static int
> +vhost_user_get_status(struct virtio_net **pdev, struct VhostUserMsg *msg,
> + int main_fd __rte_unused)
> +{
> + struct virtio_net *dev = *pdev;
> +
> + if (validate_msg_fds(msg, 0) != 0)
> + return RTE_VHOST_MSG_RESULT_ERR;
> +
> + msg->payload.u64 = dev->status;
> + msg->size = sizeof(msg->payload.u64);
> + msg->fd_num = 0;
> +
> + return RTE_VHOST_MSG_RESULT_OK;
> +}
> +
> static int
> vhost_user_set_status(struct virtio_net **pdev, struct VhostUserMsg *msg,
> int main_fd __rte_unused)
> @@ -2476,6 +2497,16 @@ vhost_user_set_status(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
>
> dev->status = msg->payload.u64;
>
> + if ((dev->status & VIRTIO_DEVICE_STATUS_FEATURES_OK) &&
> + (dev->flags & VIRTIO_DEV_FEATURES_FAILED)) {
> + VHOST_LOG_CONFIG(ERR, "FEATURES_OK bit is set but feature
> negotiation failed\n");
> + /*
> + * Clear the bit to let the driver know about the feature
> + * negotiation failure
> + */
> + dev->status &= ~VIRTIO_DEVICE_STATUS_FEATURES_OK;
> + }
> +
There's a coding style issue because of above '}' alignment. Could you fix this?
Another thing I'm not sure: if above condition happens, should it be treated
as err? If set status is with replay-ack (this will happen, right?), would QEMU
like to know this status is not set? As QEMU should know it during SET_FEATURES,
I'm not sure whether this will also need NACK when reply-ack enabled. What's
your opinion?
Thanks!
Chenbo
> VHOST_LOG_CONFIG(INFO, "New device status(0x%08x):\n"
> "\t-ACKNOWLEDGE: %u\n"
> "\t-DRIVER: %u\n"
> @@ -2527,6 +2558,7 @@ static vhost_message_handler_t
> vhost_message_handlers[VHOST_USER_MAX] = {
> [VHOST_USER_GET_INFLIGHT_FD] = vhost_user_get_inflight_fd,
> [VHOST_USER_SET_INFLIGHT_FD] = vhost_user_set_inflight_fd,
> [VHOST_USER_SET_STATUS] = vhost_user_set_status,
> + [VHOST_USER_GET_STATUS] = vhost_user_get_status,
> };
>
> /* return bytes# of read on success or negative val on failure. */ diff --git
> a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h index
> 82885ab5e..16fe03f88 100644
> --- a/lib/librte_vhost/vhost_user.h
> +++ b/lib/librte_vhost/vhost_user.h
> @@ -58,6 +58,7 @@ typedef enum VhostUserRequest {
> VHOST_USER_GET_INFLIGHT_FD = 31,
> VHOST_USER_SET_INFLIGHT_FD = 32,
> VHOST_USER_SET_STATUS = 39,
> + VHOST_USER_GET_STATUS = 40,
> VHOST_USER_MAX = 41
> } VhostUserRequest;
>
> --
> 2.26.2
