vhost: support postcopy end request

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>

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 8890abb..0560f2f 100644 (file)
--- 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",
 };
 
 static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg);
@@ -1636,6 +1637,25 @@ 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 VH_RESULT_REPLY;
+}
+
 typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
                                        struct VhostUserMsg *msg,
                                        int main_fd);
@@ -1665,6 +1685,7 @@ 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,
 };
 
 

diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
index 55d8659..73b1fe2 100644 (file)
--- a/lib/librte_vhost/vhost_user.h
+++ b/lib/librte_vhost/vhost_user.h
@@ -52,7 +52,8 @@ typedef enum VhostUserRequest {
        VHOST_USER_CRYPTO_CLOSE_SESS = 27,
        VHOST_USER_POSTCOPY_ADVISE = 28,
        VHOST_USER_POSTCOPY_LISTEN = 29,
-       VHOST_USER_MAX = 30
+       VHOST_USER_POSTCOPY_END = 30,
+       VHOST_USER_MAX = 31
 } VhostUserRequest;
 
 typedef enum VhostUserSlaveRequest {