[PATCH 5/5] net/virtio-user: support vDPA configuration callback

[skoteshwar]

From: Satha Rao <skotesh...@marvell.com>

Extended the vhost_vdpa_get_intr_fd API to create an event and
register for configuration callbacks with the vDPA backend. This
enhancement allows the virtio-user driver to handle configuration
changes more effectively.

Signed-off-by: Satha Rao <skotesh...@marvell.com>
---
 drivers/net/virtio/virtio_user/vhost_vdpa.c   | 18 ++++++++++--
 .../net/virtio/virtio_user/virtio_user_dev.c  | 29 +++++++++++++++++++
 .../net/virtio/virtio_user/virtio_user_dev.h  |  2 ++
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c 
b/drivers/net/virtio/virtio_user/vhost_vdpa.c
index e8aea54000..c9eaffce16 100644
--- a/drivers/net/virtio/virtio_user/vhost_vdpa.c
+++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c
@@ -9,6 +9,7 @@
 #include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <sys/eventfd.h>
 
 #include <rte_memory.h>
 
@@ -634,10 +635,21 @@ vhost_vdpa_update_link_state(struct virtio_user_dev *dev)
 }
 
 static int
-vhost_vdpa_get_intr_fd(struct virtio_user_dev *dev __rte_unused)
+vhost_vdpa_get_intr_fd(struct virtio_user_dev *dev)
 {
-       /* No link state interrupt with Vhost-vDPA */
-       return -1;
+       int fd;
+
+       if (dev->cfg_epfd)
+               return dev->cfg_epfd;
+
+       fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+       if (fd < 0) {
+               PMD_DRV_LOG(ERR, "failed to create fd error, %s", 
strerror(errno));
+               fd = -1;
+       }
+       dev->cfg_epfd = fd;
+
+       return fd;
 }
 
 static int
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c 
b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 91ad1312f7..ea00eb50f5 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -487,6 +487,21 @@ virtio_user_dev_get_speed_duplex_config(struct 
virtio_user_dev *dev, void *dst,
        return ret;
 }
 
+int
+virtio_user_dev_set_config_call(struct virtio_user_dev *dev, int fd)
+{
+       int ret = 0;
+
+       if (!dev->ops->set_config_call)
+               return -ENOTSUP;
+
+       ret = dev->ops->set_config_call(dev, fd);
+       if (ret)
+               PMD_DRV_LOG(ERR, "(%s) Failed to set config call in device", 
dev->path);
+
+       return ret;
+}
+
 static int
 virtio_user_dev_init_notify(struct virtio_user_dev *dev)
 {
@@ -769,6 +784,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char 
*path, uint16_t queues,
        dev->unsupported_features = 0;
        dev->backend_type = backend_type;
        dev->ifname = *ifname;
+       dev->cfg_epfd = 0;
 
        if (virtio_user_dev_setup(dev) < 0) {
                PMD_INIT_LOG(ERR, "(%s) backend set up fails", dev->path);
@@ -863,6 +879,15 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char 
*path, uint16_t queues,
                }
        }
 
+       /* vhost vdpa register valid fd to handle config callback */
+       if (dev->cfg_epfd) {
+               struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->hw.port_id];
+
+               if (rte_intr_efd_counter_size_set(eth_dev->intr_handle, 8))
+                       return -rte_errno;
+               virtio_user_dev_set_config_call(dev, dev->cfg_epfd);
+       }
+
        *ifname = NULL;
        return 0;
 
@@ -892,6 +917,10 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
 
        virtio_user_free_vrings(dev);
 
+       if (dev->cfg_epfd) {
+               close(dev->cfg_epfd);
+               dev->cfg_epfd = 0;
+       }
        free(dev->ifname);
 
        if (dev->is_server)
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h 
b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index 57d75d1c53..1ad93521e3 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -31,6 +31,7 @@ struct virtio_user_dev {
 
        int             *callfds;
        int             *kickfds;
+       int             cfg_epfd; /* config callback interrupt */
        int             mac_specified;
        uint16_t        max_queue_pairs;
        uint16_t        queue_pairs;
@@ -89,6 +90,7 @@ int virtio_user_dev_get_rss_config(struct virtio_user_dev 
*dev, void *dst, size_
                                   int length);
 int virtio_user_dev_get_speed_duplex_config(struct virtio_user_dev *dev, void 
*dst,
                                            size_t offset, int length);
+int virtio_user_dev_set_config_call(struct virtio_user_dev *dev, int fd);
 void virtio_user_dev_delayed_disconnect_handler(void *param);
 int virtio_user_dev_server_reconnect(struct virtio_user_dev *dev);
 extern const char * const virtio_user_backend_strings[];
-- 
2.25.1