[dpdk-dev] [PATCH 03/12] vhost: enable fds passing when sending vhost-user messages

[Maxime Coquelin]

Passing userfault fds to Qemu will be required for postcopy
live-migration feature.

Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index a07b26d99..a9b429598 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1171,6 +1171,7 @@ vhost_user_get_protocol_features(struct virtio_net *dev,
 
        msg->payload.u64 = protocol_features;
        msg->size = sizeof(msg->payload.u64);
+       msg->fd_num = 0;
 }
 
 static int
@@ -1442,13 +1443,13 @@ read_vhost_message(int sockfd, struct VhostUserMsg *msg)
 }
 
 static int
-send_vhost_message(int sockfd, struct VhostUserMsg *msg, int *fds, int fd_num)
+send_vhost_message(int sockfd, struct VhostUserMsg *msg)
 {
        if (!msg)
                return 0;
 
        return send_fd_message(sockfd, (char *)msg,
-               VHOST_USER_HDR_SIZE + msg->size, fds, fd_num);
+               VHOST_USER_HDR_SIZE + msg->size, msg->fds, msg->fd_num);
 }
 
 static int
@@ -1462,19 +1463,18 @@ send_vhost_reply(int sockfd, struct VhostUserMsg *msg)
        msg->flags |= VHOST_USER_VERSION;
        msg->flags |= VHOST_USER_REPLY_MASK;
 
-       return send_vhost_message(sockfd, msg, NULL, 0);
+       return send_vhost_message(sockfd, msg);
 }
 
 static int
-send_vhost_slave_message(struct virtio_net *dev, struct VhostUserMsg *msg,
-                        int *fds, int fd_num)
+send_vhost_slave_message(struct virtio_net *dev, struct VhostUserMsg *msg)
 {
        int ret;
 
        if (msg->flags & VHOST_USER_NEED_REPLY)
                rte_spinlock_lock(&dev->slave_req_lock);
 
-       ret = send_vhost_message(dev->slave_req_fd, msg, fds, fd_num);
+       ret = send_vhost_message(dev->slave_req_fd, msg);
        if (ret < 0 && (msg->flags & VHOST_USER_NEED_REPLY))
                rte_spinlock_unlock(&dev->slave_req_lock);
 
@@ -1659,6 +1659,7 @@ vhost_user_msg_handler(int vid, int fd)
        case VHOST_USER_GET_FEATURES:
                msg.payload.u64 = vhost_user_get_features(dev);
                msg.size = sizeof(msg.payload.u64);
+               msg.fd_num = 0;
                send_vhost_reply(fd, &msg);
                break;
        case VHOST_USER_SET_FEATURES:
@@ -1690,6 +1691,7 @@ vhost_user_msg_handler(int vid, int fd)
                        goto skip_to_reply;
                /* it needs a reply */
                msg.size = sizeof(msg.payload.u64);
+               msg.fd_num = 0;
                send_vhost_reply(fd, &msg);
                break;
        case VHOST_USER_SET_LOG_FD:
@@ -1731,6 +1733,7 @@ vhost_user_msg_handler(int vid, int fd)
        case VHOST_USER_GET_QUEUE_NUM:
                msg.payload.u64 = (uint64_t)vhost_user_get_queue_num(dev);
                msg.size = sizeof(msg.payload.u64);
+               msg.fd_num = 0;
                send_vhost_reply(fd, &msg);
                break;
 
@@ -1778,6 +1781,7 @@ vhost_user_msg_handler(int vid, int fd)
        if (msg.flags & VHOST_USER_NEED_REPLY) {
                msg.payload.u64 = !!ret;
                msg.size = sizeof(msg.payload.u64);
+               msg.fd_num = 0;
                send_vhost_reply(fd, &msg);
        } else if (ret) {
                RTE_LOG(ERR, VHOST_CONFIG,
@@ -1861,7 +1865,7 @@ vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t 
iova, uint8_t perm)
                },
        };
 
-       ret = send_vhost_message(dev->slave_req_fd, &msg, NULL, 0);
+       ret = send_vhost_message(dev->slave_req_fd, &msg);
        if (ret < 0) {
                RTE_LOG(ERR, VHOST_CONFIG,
                                "Failed to send IOTLB miss message (%d)\n",
@@ -1877,8 +1881,6 @@ static int 
vhost_user_slave_set_vring_host_notifier(struct virtio_net *dev,
                                                    uint64_t offset,
                                                    uint64_t size)
 {
-       int *fdp = NULL;
-       size_t fd_num = 0;
        int ret;
        struct VhostUserMsg msg = {
                .request.slave = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
@@ -1894,11 +1896,11 @@ static int 
vhost_user_slave_set_vring_host_notifier(struct virtio_net *dev,
        if (fd < 0)
                msg.payload.area.u64 |= VHOST_USER_VRING_NOFD_MASK;
        else {
-               fdp = &fd;
-               fd_num = 1;
+               msg.fds[0] = fd;
+               msg.fd_num = 1;
        }
 
-       ret = send_vhost_slave_message(dev, &msg, fdp, fd_num);
+       ret = send_vhost_slave_message(dev, &msg);
        if (ret < 0) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "Failed to set host notifier (%d)\n", ret);
-- 
2.17.1