Hi,
On 7/11/23 11:25, Rma Ma wrote:
> Since backend and frontend message are synchronous in the same thread,
> there will be a probability of message deadlock.
> Consider each driver to determine whether to wait for response.
>
> Fixes: d90cf7d111ac ("vhost: support host notifier")
> Cc: maxime.coque...@redhat.com
> Signed-off-by: Rma Ma <rma...@jaguarmicro.com>
> ---
> v2 - fix format error in commit message
> v3 - add --in-reply-to
> ---
Hi Maxime,
This patch helps to fix vhost-user message deadlock, could you help
review it?
The patch introduces a new device op, but it is used nowhere in vDPA
drivers.
What vDPA driver is it going to be used with?
Regards,
Maxime
Thanks.
Best wishes,
Rma
------------------------------------------------------------------------
*发件人:* Rma Ma
*发送时间:* 2023年7月4日 10:52
*收件人:* dpdk-dev <dev@dpdk.org>
*抄送:* Maxime Coquelin <maxime.coque...@redhat.com>; Chenbo Xia
<chenbo....@intel.com>; Rma Ma <rma...@jaguarmicro.com>
*主题:* [PATCH v3] vhost: add notify reply ops to fix message deadlock
Since backend and frontend message are synchronous in the same thread,
there will be a probability of message deadlock.
Consider each driver to determine whether to wait for response.
Fixes: d90cf7d111ac ("vhost: support host notifier")
Cc: maxime.coque...@redhat.com
Signed-off-by: Rma Ma <rma...@jaguarmicro.com>
---
v2 - fix format error in commit message
v3 - add --in-reply-to
---
lib/vhost/vdpa_driver.h | 3 +++
lib/vhost/vhost_user.c | 23 ++++++++++++++++++-----
2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/lib/vhost/vdpa_driver.h b/lib/vhost/vdpa_driver.h
index 8db4ab9f4d..3d2ea3c90e 100644
--- a/lib/vhost/vdpa_driver.h
+++ b/lib/vhost/vdpa_driver.h
@@ -81,6 +81,9 @@ struct rte_vdpa_dev_ops {
/** get device type: net device, blk device... */
int (*get_dev_type)(struct rte_vdpa_device *dev, uint32_t *type);
+
+ /** Get the notify reply flag */
+ int (*get_notify_reply_flag)(int vid, bool *need_reply);
};
/**
diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 901a80bbaa..aa61992939 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -3365,13 +3365,14 @@ rte_vhost_backend_config_change(int vid, bool
need_reply)
static int vhost_user_backend_set_vring_host_notifier(struct
virtio_net *dev,
int index, int fd,
uint64_t offset,
- uint64_t size)
+ uint64_t size,
+ bool need_reply)
{
int ret;
struct vhu_msg_context ctx = {
.msg = {
.request.backend =
VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG,
- .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY,
+ .flags = VHOST_USER_VERSION,
.size = sizeof(ctx.msg.payload.area),
.payload.area = {
.u64 = index & VHOST_USER_VRING_IDX_MASK,
@@ -3388,7 +3389,13 @@ static int
vhost_user_backend_set_vring_host_notifier(struct virtio_net *dev,
ctx.fd_num = 1;
}
- ret = send_vhost_backend_message_process_reply(dev, &ctx);
+ if (!need_reply)
+ ret = send_vhost_backend_message(dev, &ctx);
+ else {
+ ctx.msg.flags |= VHOST_USER_NEED_REPLY;
+ ret = send_vhost_backend_message_process_reply(dev, &ctx);
+ }
+
if (ret < 0)
VHOST_LOG_CONFIG(dev->ifname, ERR, "failed to set host
notifier (%d)\n", ret);
@@ -3402,6 +3409,7 @@ int rte_vhost_host_notifier_ctrl(int vid, uint16_t
qid, bool enable)
int vfio_device_fd, ret = 0;
uint64_t offset, size;
unsigned int i, q_start, q_last;
+ bool need_reply;
dev = get_device(vid);
if (!dev)
@@ -3440,6 +3448,11 @@ int rte_vhost_host_notifier_ctrl(int vid,
uint16_t qid, bool enable)
if (vfio_device_fd < 0)
return -ENOTSUP;
+ if (vdpa_dev->ops->get_notify_reply_flag == NULL)
+ need_reply = true;
+ else
+ vdpa_dev->ops->get_notify_reply_flag(vid, &need_reply);
+
if (enable) {
for (i = q_start; i <= q_last; i++) {
if (vdpa_dev->ops->get_notify_area(vid, i,
&offset,
@@ -3449,7 +3462,7 @@ int rte_vhost_host_notifier_ctrl(int vid, uint16_t
qid, bool enable)
}
if
(vhost_user_backend_set_vring_host_notifier(dev, i,
- vfio_device_fd, offset, size) < 0) {
+ vfio_device_fd, offset, size,
need_reply) < 0) {
ret = -EFAULT;
goto disable;
}
@@ -3458,7 +3471,7 @@ int rte_vhost_host_notifier_ctrl(int vid, uint16_t
qid, bool enable)
disable:
for (i = q_start; i <= q_last; i++) {
vhost_user_backend_set_vring_host_notifier(dev, i, -1,
- 0, 0);
+ 0, 0, need_reply);
}
}
--
2.17.1
