[dpdk-dev] [PATCH] vchost: Notify application of ownership change
Tetsuya Mukawa
mukawa at igel.co.jp
Mon Oct 26 06:54:07 CET 2015
On 2015/10/25 2:16, Thomas Monjalon wrote:
> 2015-08-12 03:34, Xie, Huawei:
>> On 8/8/2015 1:21 AM, Jan Kiszka wrote:
>>> On VHOST_*_RESET_OWNER, we reinitialize the device but without telling
>>> the application. That will cause crashes when it continues to invoke
>>> vhost services on the device. Fix it by calling the destruction hook if
>>> the device is still in use.
> [...]
>>> --- a/lib/librte_vhost/virtio-net.c
>>> +++ b/lib/librte_vhost/virtio-net.c
>>> @@ -402,6 +402,9 @@ reset_owner(struct vhost_device_ctx ctx)
>>>
>>> ll_dev = get_config_ll_entry(ctx);
>>>
>>> + if ((ll_dev->dev.flags & VIRTIO_DEV_RUNNING))
>>> + notify_ops->destroy_device(&ll_dev->dev);
>> To me this patch makes sense here.
>> Whether RESET_OWNER is really needed is another question. Whenever the
>> vhost itself needs to process the vhost device, we need to notify the
>> switch application to remove it from data plane.
> Huawei,
> some patches have been accepted for RESET_OWNER management.
> Is this patch obsolete?
Hi Yuanhan and Huawei,
I also have the same question. Do we have a patch for this issue?
Today, I've download Yuanhan's multiple queues patches and applied it on
latest dpdk tree.
Then, tried to apply my vhost PMD patch on it.
When I check the patch, it seems I've faced this issue.
Here are steps to reproduce.
1. Start vhost-user backend application.
(In my case, testpmd using vhost PMD is the application)
2. Start a VM with vhost-user.
You can see below message from the backend application.
VHOST_CONFIG: read message VHOST_USER_SET_VRING_ENABLE
VHOST_CONFIG: set queue enable: 1 to qp idx: 0
(snip)
VHOST_CONFIG: read message VHOST_USER_SET_VRING_KICK
3. After booting Linux on guest, bind the virtio-net device to igb_uio.
Then below messages are shown.
VHOST_CONFIG: read message VHOST_USER_RESET_OWNER
VHOST_CONFIG: read message VHOST_USER_RESET_OWNER
VHOST_CONFIG: read message VHOST_USER_GET_VRING_BASE
The point is we will have VHOST_USER_RESET_OWNER before
VHOST_USER_GET_VRING_BASE.
Currently, in RESET_OWNER function, all virtio-net data is initialized.
As a result, we also initialize virtio-net flags.
When we get GET_VRING_BASE, we cannot call destroy callback handler
because RUNNING flag has been initialized already.
I guess when we get RESET_OWNER message, I don't need to do anything.
And all finalizations should be done in GET_VRING_BASE.
(Or some finalizations might be done when next SET_MEM_TABLE is called.)
Thanks,
Tetsuya
More information about the dev
mailing list