[dpdk-dev] [PATCH v4 5/8] virtio-user: add device emulation layer APIs

[Yuanhan Liu]

On Fri, Apr 29, 2016 at 01:18:33AM +, Jianfeng Tan wrote:
> +static int
> +kick_one_vq(struct virtio_user_hw *hw, struct virtqueue *vq,
> + unsigned queue_sel)

Firstly, "dev" is a more common word than "hw" here. So, name the struct
to "virtio_user_device", and name the var to "dev".

And you are still mixing virtio driver and virtio device emulation here.
Say, struct virtqueue should not be used here: it belongs to driver.
Instead, you should define your own. It could be fair simple that is
enough for current usage:

struct virtqueue {
uint32_t num;
uint64_t desc_addr;
uint64_t avail_addr;
uint64_t used_addr;
};

That could let us not depend on any structures (or just few if not
possible) from virtio PMD driver.

--yliu
> +{
> + int callfd, kickfd;
> + struct vhost_vring_file file;
> + struct vhost_vring_state state;
> + struct vhost_vring_addr addr = {
> + .index = queue_sel,
> + .desc_user_addr = (uint64_t)(uintptr_t)vq->vq_ring.desc,
> + .avail_user_addr = (uint64_t)(uintptr_t)vq->vq_ring.avail,
> + .used_user_addr = (uint64_t)(uintptr_t)vq->vq_ring.used,
> + .log_guest_addr = 0,
> + .flags = 0, /* disable log */
> + };

[dpdk-dev] [PATCH v4 5/8] virtio-user: add device emulation layer APIs

[Jianfeng Tan]

Two device emulation layer APIs are added for virtio driver to call:
  - virtio_user_start_device()
  - virtio_user_stop_device()

These APIs will get called by virtio driver, and they call vhost adapter
layer APIs to implement the functionality. Besides, this patch defines
a struct named virtio_user_hw to help manage the data stands for this
kind of virtual device.

  --
  | -- |
  | | virtio driver  | |
  | -- |
  | |  |
  | -- | -->  virtio-user PMD
  | | device emulate |-|> (virtio_user_dev.c, virtio_user_dev.h)
  | || |
  | | vhost adapter  | |
  | -- |
  --
|
|
|
   --
   | vhost backend  |
   --

Signed-off-by: Huawei Xie 
Signed-off-by: Jianfeng Tan 
Acked-By: Neil Horman 
---
 drivers/net/virtio/Makefile  |   1 +
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 168 +++
 drivers/net/virtio/virtio_user/virtio_user_dev.h |  59 
 3 files changed, 228 insertions(+)
 create mode 100644 drivers/net/virtio/virtio_user/virtio_user_dev.c
 create mode 100644 drivers/net/virtio/virtio_user/virtio_user_dev.h

diff --git a/drivers/net/virtio/Makefile b/drivers/net/virtio/Makefile
index c9f2bc0..68068bd 100644
--- a/drivers/net/virtio/Makefile
+++ b/drivers/net/virtio/Makefile
@@ -59,6 +59,7 @@ ifeq ($(CONFIG_RTE_VIRTIO_VDEV),y)
 SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost.c
 SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost_user.c
 SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost_kernel.c
+SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/virtio_user_dev.c
 endif

 # this lib depends upon:
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c 
b/drivers/net/virtio/virtio_user/virtio_user_dev.c
new file mode 100644
index 000..81f7f03
--- /dev/null
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -0,0 +1,168 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in
+ *   the documentation and/or other materials provided with the
+ *   distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ *   contributors may be used to endorse or promote products derived
+ *   from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#include 
+#include 
+
+#include "vhost.h"
+#include "virtio_user_dev.h"
+#include "../virtio_ethdev.h"
+
+static int
+kick_one_vq(struct virtio_user_hw *hw, struct virtqueue *vq,
+   unsigned queue_sel)
+{
+   int callfd, kickfd;
+   struct vhost_vring_file file;
+   struct vhost_vring_state state;
+   struct vhost_vring_addr addr = {
+   .index = queue_sel,
+   .desc_user_addr = (uint64_t)(uintptr_t)vq->vq_ring.desc,
+   .avail_user_addr = (uint64_t)(uintptr_t)vq->vq_ring.avail,
+   .used_user_addr = (uint64_t)(uintptr_t)vq->vq_ring.used,
+   .log_guest_addr = 0,
+   .flags = 0, /* disable log */
+   };
+
+   /* May use invalid flag, but some backend leverages kickfd and callfd as
+* criteria to judge if dev is alive. so finally we use real event_fd.
+*/
+   callfd = eventfd(0, O_CLOEXEC | O_NONBLOCK);
+   if (callfd < 0) {
+   PMD_DRV_LOG(ERR, "callfd error, %s\n", strerror(errno));
+   return -1;
+   }
+   kickfd = eventfd(0, O_CLOEXEC |