From: Jason Wang <jasowang@redhat.com>
To: Yongji Xie <xieyongji@bytedance.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Stefano Garzarella" <sgarzare@redhat.com>,
"Parav Pandit" <parav@nvidia.com>,
"Christoph Hellwig" <hch@infradead.org>,
"Christian Brauner" <christian.brauner@canonical.com>,
"Randy Dunlap" <rdunlap@infradead.org>,
"Matthew Wilcox" <willy@infradead.org>,
"Al Viro" <viro@zeniv.linux.org.uk>,
"Jens Axboe" <axboe@kernel.dk>,
bcrl@kvack.org, "Jonathan Corbet" <corbet@lwn.net>,
"Mika Penttilä" <mika.penttila@nextfour.com>,
"Dan Carpenter" <dan.carpenter@oracle.com>,
joro@8bytes.org,
virtualization <virtualization@lists.linux-foundation.org>,
netdev@vger.kernel.org, kvm <kvm@vger.kernel.org>,
linux-fsdevel@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace
Date: Thu, 27 May 2021 13:40:31 +0800 [thread overview]
Message-ID: <ee00efca-b26d-c1be-68d2-f9e34a735515@redhat.com> (raw)
In-Reply-To: <CACycT3ve7YvKF+F+AnTQoJZMPua+jDvGMs_ox8GQe_=SGdeCMA@mail.gmail.com>
在 2021/5/27 下午1:08, Yongji Xie 写道:
> On Thu, May 27, 2021 at 1:00 PM Jason Wang <jasowang@redhat.com> wrote:
>>
>> 在 2021/5/27 下午12:57, Yongji Xie 写道:
>>> On Thu, May 27, 2021 at 12:13 PM Jason Wang <jasowang@redhat.com> wrote:
>>>> 在 2021/5/17 下午5:55, Xie Yongji 写道:
>>>>> +
>>>>> +static int vduse_dev_msg_sync(struct vduse_dev *dev,
>>>>> + struct vduse_dev_msg *msg)
>>>>> +{
>>>>> + init_waitqueue_head(&msg->waitq);
>>>>> + spin_lock(&dev->msg_lock);
>>>>> + vduse_enqueue_msg(&dev->send_list, msg);
>>>>> + wake_up(&dev->waitq);
>>>>> + spin_unlock(&dev->msg_lock);
>>>>> + wait_event_killable(msg->waitq, msg->completed);
>>>> What happens if the userspace(malicous) doesn't give a response forever?
>>>>
>>>> It looks like a DOS. If yes, we need to consider a way to fix that.
>>>>
>>> How about using wait_event_killable_timeout() instead?
>>
>> Probably, and then we need choose a suitable timeout and more important,
>> need to report the failure to virtio.
>>
> Makes sense to me. But it looks like some
> vdpa_config_ops/virtio_config_ops such as set_status() didn't have a
> return value. Now I add a WARN_ON() for the failure. Do you mean we
> need to add some change for virtio core to handle the failure?
Maybe, but I'm not sure how hard we can do that.
We had NEEDS_RESET but it looks we don't implement it.
Or a rough idea is that maybe need some relaxing to be coupled loosely
with userspace. E.g the device (control path) is implemented in the
kernel but the datapath is implemented in the userspace like TUN/TAP.
Thanks
>
> Thanks,
> Yongji
>
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com>
To: Yongji Xie <xieyongji@bytedance.com>
Cc: "Jens Axboe" <axboe@kernel.dk>,
"Jonathan Corbet" <corbet@lwn.net>,
linux-kernel <linux-kernel@vger.kernel.org>,
kvm <kvm@vger.kernel.org>, "Michael S. Tsirkin" <mst@redhat.com>,
netdev@vger.kernel.org, "Randy Dunlap" <rdunlap@infradead.org>,
iommu@lists.linux-foundation.org,
"Matthew Wilcox" <willy@infradead.org>,
virtualization <virtualization@lists.linux-foundation.org>,
"Christoph Hellwig" <hch@infradead.org>,
"Christian Brauner" <christian.brauner@canonical.com>,
bcrl@kvack.org, "Al Viro" <viro@zeniv.linux.org.uk>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
linux-fsdevel@vger.kernel.org,
"Dan Carpenter" <dan.carpenter@oracle.com>,
"Mika Penttilä" <mika.penttila@nextfour.com>,
"Stefano Garzarella" <sgarzare@redhat.com>
Subject: Re: [PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace
Date: Thu, 27 May 2021 13:40:31 +0800 [thread overview]
Message-ID: <ee00efca-b26d-c1be-68d2-f9e34a735515@redhat.com> (raw)
In-Reply-To: <CACycT3ve7YvKF+F+AnTQoJZMPua+jDvGMs_ox8GQe_=SGdeCMA@mail.gmail.com>
在 2021/5/27 下午1:08, Yongji Xie 写道:
> On Thu, May 27, 2021 at 1:00 PM Jason Wang <jasowang@redhat.com> wrote:
>>
>> 在 2021/5/27 下午12:57, Yongji Xie 写道:
>>> On Thu, May 27, 2021 at 12:13 PM Jason Wang <jasowang@redhat.com> wrote:
>>>> 在 2021/5/17 下午5:55, Xie Yongji 写道:
>>>>> +
>>>>> +static int vduse_dev_msg_sync(struct vduse_dev *dev,
>>>>> + struct vduse_dev_msg *msg)
>>>>> +{
>>>>> + init_waitqueue_head(&msg->waitq);
>>>>> + spin_lock(&dev->msg_lock);
>>>>> + vduse_enqueue_msg(&dev->send_list, msg);
>>>>> + wake_up(&dev->waitq);
>>>>> + spin_unlock(&dev->msg_lock);
>>>>> + wait_event_killable(msg->waitq, msg->completed);
>>>> What happens if the userspace(malicous) doesn't give a response forever?
>>>>
>>>> It looks like a DOS. If yes, we need to consider a way to fix that.
>>>>
>>> How about using wait_event_killable_timeout() instead?
>>
>> Probably, and then we need choose a suitable timeout and more important,
>> need to report the failure to virtio.
>>
> Makes sense to me. But it looks like some
> vdpa_config_ops/virtio_config_ops such as set_status() didn't have a
> return value. Now I add a WARN_ON() for the failure. Do you mean we
> need to add some change for virtio core to handle the failure?
Maybe, but I'm not sure how hard we can do that.
We had NEEDS_RESET but it looks we don't implement it.
Or a rough idea is that maybe need some relaxing to be coupled loosely
with userspace. E.g the device (control path) is implemented in the
kernel but the datapath is implemented in the userspace like TUN/TAP.
Thanks
>
> Thanks,
> Yongji
>
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com>
To: Yongji Xie <xieyongji@bytedance.com>
Cc: "Jens Axboe" <axboe@kernel.dk>,
"Jonathan Corbet" <corbet@lwn.net>,
linux-kernel <linux-kernel@vger.kernel.org>,
kvm <kvm@vger.kernel.org>, "Michael S. Tsirkin" <mst@redhat.com>,
netdev@vger.kernel.org, joro@8bytes.org,
"Randy Dunlap" <rdunlap@infradead.org>,
iommu@lists.linux-foundation.org,
"Matthew Wilcox" <willy@infradead.org>,
virtualization <virtualization@lists.linux-foundation.org>,
"Christoph Hellwig" <hch@infradead.org>,
"Christian Brauner" <christian.brauner@canonical.com>,
bcrl@kvack.org, "Al Viro" <viro@zeniv.linux.org.uk>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
linux-fsdevel@vger.kernel.org,
"Dan Carpenter" <dan.carpenter@oracle.com>,
"Mika Penttilä" <mika.penttila@nextfour.com>
Subject: Re: [PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace
Date: Thu, 27 May 2021 13:40:31 +0800 [thread overview]
Message-ID: <ee00efca-b26d-c1be-68d2-f9e34a735515@redhat.com> (raw)
In-Reply-To: <CACycT3ve7YvKF+F+AnTQoJZMPua+jDvGMs_ox8GQe_=SGdeCMA@mail.gmail.com>
在 2021/5/27 下午1:08, Yongji Xie 写道:
> On Thu, May 27, 2021 at 1:00 PM Jason Wang <jasowang@redhat.com> wrote:
>>
>> 在 2021/5/27 下午12:57, Yongji Xie 写道:
>>> On Thu, May 27, 2021 at 12:13 PM Jason Wang <jasowang@redhat.com> wrote:
>>>> 在 2021/5/17 下午5:55, Xie Yongji 写道:
>>>>> +
>>>>> +static int vduse_dev_msg_sync(struct vduse_dev *dev,
>>>>> + struct vduse_dev_msg *msg)
>>>>> +{
>>>>> + init_waitqueue_head(&msg->waitq);
>>>>> + spin_lock(&dev->msg_lock);
>>>>> + vduse_enqueue_msg(&dev->send_list, msg);
>>>>> + wake_up(&dev->waitq);
>>>>> + spin_unlock(&dev->msg_lock);
>>>>> + wait_event_killable(msg->waitq, msg->completed);
>>>> What happens if the userspace(malicous) doesn't give a response forever?
>>>>
>>>> It looks like a DOS. If yes, we need to consider a way to fix that.
>>>>
>>> How about using wait_event_killable_timeout() instead?
>>
>> Probably, and then we need choose a suitable timeout and more important,
>> need to report the failure to virtio.
>>
> Makes sense to me. But it looks like some
> vdpa_config_ops/virtio_config_ops such as set_status() didn't have a
> return value. Now I add a WARN_ON() for the failure. Do you mean we
> need to add some change for virtio core to handle the failure?
Maybe, but I'm not sure how hard we can do that.
We had NEEDS_RESET but it looks we don't implement it.
Or a rough idea is that maybe need some relaxing to be coupled loosely
with userspace. E.g the device (control path) is implemented in the
kernel but the datapath is implemented in the userspace like TUN/TAP.
Thanks
>
> Thanks,
> Yongji
>
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-05-27 5:40 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 9:55 [PATCH v7 00/12] Introduce VDUSE - vDPA Device in Userspace Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-17 9:55 ` [PATCH v7 01/12] iova: Export alloc_iova_fast() Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-26 2:36 ` Jason Wang
2021-05-26 2:36 ` Jason Wang
2021-05-26 2:36 ` Jason Wang
2021-05-26 2:43 ` Yongji Xie
2021-05-26 2:43 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 02/12] file: Export receive_fd() to modules Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-20 6:18 ` Al Viro
2021-05-20 6:18 ` Al Viro
2021-05-20 6:18 ` Al Viro
2021-05-20 6:32 ` Yongji Xie
2021-05-20 6:32 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 03/12] eventfd: Increase the recursion depth of eventfd_signal() Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-17 9:55 ` [PATCH v7 04/12] virtio-blk: Add validation for block size in config space Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-19 13:39 ` Yongji Xie
2021-05-19 13:39 ` Yongji Xie
2021-05-19 14:42 ` Dan Carpenter
2021-05-19 14:42 ` Dan Carpenter
2021-05-19 14:42 ` Dan Carpenter
2021-05-20 5:25 ` Yongji Xie
2021-05-20 5:25 ` Yongji Xie
2021-05-20 5:43 ` Michael S. Tsirkin
2021-05-20 5:43 ` Michael S. Tsirkin
2021-05-20 5:43 ` Michael S. Tsirkin
2021-05-20 7:08 ` Yongji Xie
2021-05-20 7:08 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 05/12] virtio_scsi: Add validation for residual bytes from response Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-26 2:41 ` Jason Wang
2021-05-26 2:41 ` Jason Wang
2021-05-26 2:41 ` Jason Wang
2021-05-17 9:55 ` [PATCH v7 06/12] vhost-iotlb: Add an opaque pointer for vhost IOTLB Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-17 9:55 ` [PATCH v7 07/12] vdpa: Add an opaque pointer for vdpa_config_ops.dma_map() Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-17 9:55 ` [PATCH v7 08/12] vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap() Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-17 9:55 ` [PATCH v7 09/12] vdpa: Support transferring virtual addressing during DMA mapping Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-17 9:55 ` [PATCH v7 10/12] vduse: Implement an MMU-based IOMMU driver Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-17 9:55 ` [PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-20 6:28 ` Al Viro
2021-05-20 6:28 ` Al Viro
2021-05-20 6:28 ` Al Viro
2021-05-20 7:03 ` Yongji Xie
2021-05-20 7:03 ` Yongji Xie
2021-05-27 4:12 ` Jason Wang
2021-05-27 4:12 ` Jason Wang
2021-05-27 4:12 ` Jason Wang
2021-05-27 4:57 ` Yongji Xie
2021-05-27 4:57 ` Yongji Xie
2021-05-27 5:00 ` Jason Wang
2021-05-27 5:00 ` Jason Wang
2021-05-27 5:00 ` Jason Wang
2021-05-27 5:08 ` Yongji Xie
2021-05-27 5:08 ` Yongji Xie
2021-05-27 5:40 ` Jason Wang [this message]
2021-05-27 5:40 ` Jason Wang
2021-05-27 5:40 ` Jason Wang
2021-05-27 7:34 ` Yongji Xie
2021-05-27 7:34 ` Yongji Xie
2021-05-27 8:41 ` Jason Wang
2021-05-27 8:41 ` Jason Wang
2021-05-27 8:41 ` Jason Wang
2021-05-27 8:43 ` Jason Wang
2021-05-27 8:43 ` Jason Wang
2021-05-27 8:43 ` Jason Wang
2021-05-27 10:14 ` Yongji Xie
2021-05-27 10:14 ` Yongji Xie
2021-05-28 1:33 ` Jason Wang
2021-05-28 1:33 ` Jason Wang
2021-05-28 1:33 ` Jason Wang
2021-05-28 3:54 ` Yongji Xie
2021-05-28 3:54 ` Yongji Xie
2021-05-28 6:38 ` Jason Wang
2021-05-28 6:38 ` Jason Wang
2021-05-28 6:38 ` Jason Wang
2021-05-27 13:17 ` Yongji Xie
2021-05-27 13:17 ` Yongji Xie
2021-05-28 2:31 ` Jason Wang
2021-05-28 2:31 ` Jason Wang
2021-05-28 2:31 ` Jason Wang
2021-05-31 4:27 ` Yongji Xie
2021-05-31 4:27 ` Yongji Xie
2021-05-31 4:38 ` Jason Wang
2021-05-31 4:38 ` Jason Wang
2021-05-31 4:38 ` Jason Wang
2021-05-31 6:24 ` Yongji Xie
2021-05-31 6:24 ` Yongji Xie
2021-05-31 4:56 ` Greg KH
2021-05-31 4:56 ` Greg KH
2021-05-31 4:56 ` Greg KH
2021-05-31 6:19 ` Yongji Xie
2021-05-31 6:19 ` Yongji Xie
2021-05-31 6:32 ` Greg KH
2021-05-31 6:32 ` Greg KH
2021-05-31 6:32 ` Greg KH
2021-05-31 7:13 ` Yongji Xie
2021-05-31 7:13 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 12/12] Documentation: Add documentation for VDUSE Xie Yongji
2021-05-17 9:55 ` Xie Yongji
2021-05-20 6:06 ` [PATCH v7 00/12] Introduce VDUSE - vDPA Device in Userspace Michael S. Tsirkin
2021-05-20 6:06 ` Michael S. Tsirkin
2021-05-20 6:06 ` Michael S. Tsirkin
2021-05-20 9:06 ` Yongji Xie
2021-05-20 9:06 ` Yongji Xie
2021-05-25 6:40 ` Jason Wang
2021-05-25 6:40 ` Jason Wang
2021-05-25 6:40 ` Jason Wang
2021-05-25 6:48 ` Michael S. Tsirkin
2021-05-25 6:48 ` Michael S. Tsirkin
2021-05-25 6:48 ` Michael S. Tsirkin
2021-05-25 7:11 ` Jason Wang
2021-05-25 7:11 ` Jason Wang
2021-05-25 7:11 ` Jason Wang
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