[v2,14/17] vhost: add support to postcopy's end request
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Commit Message
The master sends this message before stopping handling
userfaults, so that the backend closes the userfaultfd.
The master waits for the slave to acknowledge the request
with an empty 64bits payload for synchronization purpose.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
lib/librte_vhost/vhost_user.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
Comments
On 02.10.2018 12:36, Maxime Coquelin wrote:
> The master sends this message before stopping handling
> userfaults, so that the backend closes the userfaultfd.
>
> The master waits for the slave to acknowledge the request
> with an empty 64bits payload for synchronization purpose.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
> lib/librte_vhost/vhost_user.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index b207de6e0..ee7337ac8 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -77,6 +77,7 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
> [VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
> [VHOST_USER_POSTCOPY_ADVISE] = "VHOST_USER_POSTCOPY_ADVISE",
> [VHOST_USER_POSTCOPY_LISTEN] = "VHOST_USER_POSTCOPY_LISTEN",
> + [VHOST_USER_POSTCOPY_END] = "VHOST_USER_POSTCOPY_END",
> };
>
> /* The possible results of a message handling function */
> @@ -1640,6 +1641,25 @@ vhost_user_set_postcopy_listen(struct virtio_net **pdev,
> return VH_RESULT_OK;
> }
>
> +static int
> +vhost_user_postcopy_end(struct virtio_net **pdev, struct VhostUserMsg *msg,
> + int main_fd __rte_unused)
> +{
> + struct virtio_net *dev = *pdev;
> +
> + dev->postcopy_listening = 0;
> + if (dev->postcopy_ufd >= 0) {
> + close(dev->postcopy_ufd);
> + dev->postcopy_ufd = -1;
> + }
> +
> + msg->payload.u64 = 0;
> + msg->size = sizeof(msg->payload.u64);
> + msg->fd_num = 0;
> +
> + return 0;
I think, it should return VH_RESULT_REPLY as the reply is
mandatory according to specification. In pair with change
in patch #1 this will not produce double replies.
> +}
> +
> typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> int main_fd);
> @@ -1669,6 +1689,7 @@ static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
> [VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
> [VHOST_USER_POSTCOPY_ADVISE] = vhost_user_set_postcopy_advise,
> [VHOST_USER_POSTCOPY_LISTEN] = vhost_user_set_postcopy_listen,
> + [VHOST_USER_POSTCOPY_END] = vhost_user_postcopy_end,
> };
>
>
>
@@ -77,6 +77,7 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
[VHOST_USER_POSTCOPY_ADVISE] = "VHOST_USER_POSTCOPY_ADVISE",
[VHOST_USER_POSTCOPY_LISTEN] = "VHOST_USER_POSTCOPY_LISTEN",
+ [VHOST_USER_POSTCOPY_END] = "VHOST_USER_POSTCOPY_END",
};
/* The possible results of a message handling function */
@@ -1640,6 +1641,25 @@ vhost_user_set_postcopy_listen(struct virtio_net **pdev,
return VH_RESULT_OK;
}
+static int
+vhost_user_postcopy_end(struct virtio_net **pdev, struct VhostUserMsg *msg,
+ int main_fd __rte_unused)
+{
+ struct virtio_net *dev = *pdev;
+
+ dev->postcopy_listening = 0;
+ if (dev->postcopy_ufd >= 0) {
+ close(dev->postcopy_ufd);
+ dev->postcopy_ufd = -1;
+ }
+
+ msg->payload.u64 = 0;
+ msg->size = sizeof(msg->payload.u64);
+ msg->fd_num = 0;
+
+ return 0;
+}
+
typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
struct VhostUserMsg *msg,
int main_fd);
@@ -1669,6 +1689,7 @@ static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
[VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
[VHOST_USER_POSTCOPY_ADVISE] = vhost_user_set_postcopy_advise,
[VHOST_USER_POSTCOPY_LISTEN] = vhost_user_set_postcopy_listen,
+ [VHOST_USER_POSTCOPY_END] = vhost_user_postcopy_end,
};