Re: [dpdk-dev] [PATCH v3 1/9] vhost: provide helper for host notifier ctrl

[Maxime Coquelin]

On 12/13/18 11:09 AM, Xiao Wang wrote:

VDPA driver can decide if it needs to enable/disable the host notifier
mapping, so exposing a API can allow flexibility. A later patch will
base on this.

Signed-off-by: Xiao Wang <xiao.w.w...@intel.com>
---
v2:
* Reword the vdpa host notifier control API comment.
---
  drivers/net/ifc/ifcvf_vdpa.c           |  3 +++
  lib/librte_vhost/rte_vdpa.h            | 18 ++++++++++++++++++
  lib/librte_vhost/rte_vhost_version.map |  1 +
  lib/librte_vhost/vhost.c               |  3 +--
  lib/librte_vhost/vhost_user.c          |  7 +------
  5 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ifc/ifcvf_vdpa.c b/drivers/net/ifc/ifcvf_vdpa.c
index 97a57f182..e844109f3 100644
--- a/drivers/net/ifc/ifcvf_vdpa.c
+++ b/drivers/net/ifc/ifcvf_vdpa.c
@@ -556,6 +556,9 @@ ifcvf_dev_config(int vid)
        rte_atomic32_set(&internal->dev_attached, 1);
        update_datapath(internal);

+ if (rte_vhost_host_notifier_ctrl(vid, true) != 0)

+               DRV_LOG(NOTICE, "vDPA (%d): software relay is used.", did);
+
        return 0;
  }

diff --git a/lib/librte_vhost/rte_vdpa.h b/lib/librte_vhost/rte_vdpa.h

index a418da47c..fff657391 100644
--- a/lib/librte_vhost/rte_vdpa.h
+++ b/lib/librte_vhost/rte_vdpa.h
@@ -11,6 +11,8 @@
   * Device specific vhost lib
   */

+#include <stdbool.h>

+
  #include <rte_pci.h>
  #include "rte_vhost.h"

@@ -155,4 +157,20 @@ rte_vdpa_get_device(int did);

   */
  int __rte_experimental
  rte_vdpa_get_device_num(void);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Enable/Disable host notifier mapping for a vdpa port.
+ *
+ * @param vid
+ *  vhost device id
+ * @enable
+ *  true for host notifier map, false for host notifier unmap
+ * @return
+ *  0 on success, -1 on failure
+ */
+int __rte_experimental
+rte_vhost_host_notifier_ctrl(int vid, bool enable);
  #endif /* _RTE_VDPA_H_ */
diff --git a/lib/librte_vhost/rte_vhost_version.map 
b/lib/librte_vhost/rte_vhost_version.map
index ae39b6e21..22302e972 100644
--- a/lib/librte_vhost/rte_vhost_version.map
+++ b/lib/librte_vhost/rte_vhost_version.map
@@ -83,4 +83,5 @@ EXPERIMENTAL {
        rte_vhost_crypto_finalize_requests;
        rte_vhost_crypto_set_zero_copy;
        rte_vhost_va_from_guest_pa;
+       rte_vhost_host_notifier_ctrl;
  };
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 70ac6bc9c..e7a60e0b4 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -408,8 +408,7 @@ vhost_detach_vdpa_device(int vid)
        if (dev == NULL)
                return;

- vhost_user_host_notifier_ctrl(vid, false);

-
+       vhost_destroy_device_notify(dev);

It seems that is addition is not mentioned in the commit message.
Why is it needed now?

        dev->vdpa_dev_id = -1;
  }

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c

index 3ea64eba6..5e0da0589 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -2045,11 +2045,6 @@ vhost_user_msg_handler(int vid, int fd)
                if (vdpa_dev->ops->dev_conf)
                        vdpa_dev->ops->dev_conf(dev->vid);
                dev->flags |= VIRTIO_DEV_VDPA_CONFIGURED;
-               if (vhost_user_host_notifier_ctrl(dev->vid, true) != 0) {
-                       RTE_LOG(INFO, VHOST_CONFIG,
-                               "(%d) software relay is used for vDPA, performance 
may be low.\n",
-                               dev->vid);
-               }
        }

return 0;

@@ -2144,7 +2139,7 @@ static int 
vhost_user_slave_set_vring_host_notifier(struct virtio_net *dev,
        return process_slave_message_reply(dev, &msg);
  }

-int vhost_user_host_notifier_ctrl(int vid, bool enable)

+int rte_vhost_host_notifier_ctrl(int vid, bool enable)
  {
        struct virtio_net *dev;
        struct rte_vdpa_device *vdpa_dev;