[v2] vhost: add new `rte_vhost_vring_call_nonblock` API

Message ID 20221012064007.56040-1-changpeng.liu@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series [v2] vhost: add new `rte_vhost_vring_call_nonblock` API |

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ci/checkpatch success coding style OK

Commit Message

Liu, Changpeng Oct. 12, 2022, 6:40 a.m. UTC
  Vhost-user library locks all VQ's access lock when processing
vring based messages, such as SET_VRING_KICK and SET_VRING_CALL,
and the data processing thread may already be started, e.g: SPDK
vhost-blk and vhost-scsi will start the data processing thread
when one vring is ready, then deadlock may happen when SPDK is
posting interrupts to VM.  Here, we add a new API which allows
caller to try again later for this case.

Bugzilla ID: 1015
Fixes: c5736998305d ("vhost: fix missing virtqueue lock protection")

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
---
 lib/vhost/rte_vhost.h | 15 +++++++++++++++
 lib/vhost/version.map |  3 +++
 lib/vhost/vhost.c     | 30 ++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)
  

Comments

Maxime Coquelin Oct. 13, 2022, 7:56 a.m. UTC | #1
Hi Changpeng,

On 10/12/22 08:40, Changpeng Liu wrote:
> Vhost-user library locks all VQ's access lock when processing
> vring based messages, such as SET_VRING_KICK and SET_VRING_CALL,
> and the data processing thread may already be started, e.g: SPDK
> vhost-blk and vhost-scsi will start the data processing thread
> when one vring is ready, then deadlock may happen when SPDK is
> posting interrupts to VM.  Here, we add a new API which allows
> caller to try again later for this case.
> 
> Bugzilla ID: 1015
> Fixes: c5736998305d ("vhost: fix missing virtqueue lock protection")
> 
> Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> ---
>   lib/vhost/rte_vhost.h | 15 +++++++++++++++
>   lib/vhost/version.map |  3 +++
>   lib/vhost/vhost.c     | 30 ++++++++++++++++++++++++++++++
>   3 files changed, 48 insertions(+)
> 
> diff --git a/lib/vhost/rte_vhost.h b/lib/vhost/rte_vhost.h
> index bb7d86a432..d22b25cd4e 100644
> --- a/lib/vhost/rte_vhost.h
> +++ b/lib/vhost/rte_vhost.h
> @@ -909,6 +909,21 @@ rte_vhost_clr_inflight_desc_packed(int vid, uint16_t vring_idx,
>    */
>   int rte_vhost_vring_call(int vid, uint16_t vring_idx);
>   
> +/**
> + * Notify the guest that used descriptors have been added to the vring.  This
> + * function acts as a memory barrier.  This function will return -EAGAIN when
> + * vq's access lock is held by other thread, user should try again later.
> + *
> + * @param vid
> + *  vhost device ID
> + * @param vring_idx
> + *  vring index
> + * @return
> + *  0 on success, -1 on failure, -EAGAIN for another retry
> + */
> +__rte_experimental
> +int rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx);
> +
>   /**
>    * Get vhost RX queue avail count.
>    *
> diff --git a/lib/vhost/version.map b/lib/vhost/version.map
> index 7a00b65740..c8c44b8326 100644
> --- a/lib/vhost/version.map
> +++ b/lib/vhost/version.map
> @@ -94,6 +94,9 @@ EXPERIMENTAL {
>   	rte_vhost_async_try_dequeue_burst;
>   	rte_vhost_driver_get_vdpa_dev_type;
>   	rte_vhost_clear_queue;
> +
> +	# added in 22.11
> +	rte_vhost_vring_call_nonblock;
>   };
>   
>   INTERNAL {
> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
> index 8740aa2788..ed6efb003f 100644
> --- a/lib/vhost/vhost.c
> +++ b/lib/vhost/vhost.c
> @@ -1317,6 +1317,36 @@ rte_vhost_vring_call(int vid, uint16_t vring_idx)
>   	return 0;
>   }
>   
> +int
> +rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx)
> +{
> +	struct virtio_net *dev;
> +	struct vhost_virtqueue *vq;
> +
> +	dev = get_device(vid);
> +	if (!dev)
> +		return -1;
> +
> +	if (vring_idx >= VHOST_MAX_VRING)
> +		return -1;
> +
> +	vq = dev->virtqueue[vring_idx];
> +	if (!vq)
> +		return -1;
> +
> +	if (!rte_spinlock_trylock(&vq->access_lock))
> +		return -EAGAIN;
> +
> +	if (vq_is_packed(dev))
> +		vhost_vring_call_packed(dev, vq);
> +	else
> +		vhost_vring_call_split(dev, vq);
> +
> +	rte_spinlock_unlock(&vq->access_lock);
> +
> +	return 0;
> +}
> +
>   uint16_t
>   rte_vhost_avail_entries(int vid, uint16_t queue_id)
>   {

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime
  
Chenbo Xia Oct. 17, 2022, 6:46 a.m. UTC | #2
Hi Changpeng,

> -----Original Message-----
> From: Liu, Changpeng <changpeng.liu@intel.com>
> Sent: Wednesday, October 12, 2022 2:40 PM
> To: dev@dpdk.org
> Cc: Liu, Changpeng <changpeng.liu@intel.com>; Maxime Coquelin
> <maxime.coquelin@redhat.com>; Xia, Chenbo <chenbo.xia@intel.com>; David
> Marchand <david.marchand@redhat.com>
> Subject: [PATCH v2] vhost: add new `rte_vhost_vring_call_nonblock` API
> 
> Vhost-user library locks all VQ's access lock when processing
> vring based messages, such as SET_VRING_KICK and SET_VRING_CALL,
> and the data processing thread may already be started, e.g: SPDK
> vhost-blk and vhost-scsi will start the data processing thread
> when one vring is ready, then deadlock may happen when SPDK is
> posting interrupts to VM.  Here, we add a new API which allows
> caller to try again later for this case.
> 
> Bugzilla ID: 1015
> Fixes: c5736998305d ("vhost: fix missing virtqueue lock protection")
> 
> Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> ---
>  lib/vhost/rte_vhost.h | 15 +++++++++++++++
>  lib/vhost/version.map |  3 +++
>  lib/vhost/vhost.c     | 30 ++++++++++++++++++++++++++++++
>  3 files changed, 48 insertions(+)

For new API, we need to update release_22_11.rst and vhost_lib.rst.

You can refer to http://patchwork.dpdk.org/project/dpdk/patch/20221013092708.4922-2-xuan.ding@intel.com/

Thanks,
Chenbo

> 
> diff --git a/lib/vhost/rte_vhost.h b/lib/vhost/rte_vhost.h
> index bb7d86a432..d22b25cd4e 100644
> --- a/lib/vhost/rte_vhost.h
> +++ b/lib/vhost/rte_vhost.h
> @@ -909,6 +909,21 @@ rte_vhost_clr_inflight_desc_packed(int vid, uint16_t
> vring_idx,
>   */
>  int rte_vhost_vring_call(int vid, uint16_t vring_idx);
> 
> +/**
> + * Notify the guest that used descriptors have been added to the vring.
> This
> + * function acts as a memory barrier.  This function will return -EAGAIN
> when
> + * vq's access lock is held by other thread, user should try again later.
> + *
> + * @param vid
> + *  vhost device ID
> + * @param vring_idx
> + *  vring index
> + * @return
> + *  0 on success, -1 on failure, -EAGAIN for another retry
> + */
> +__rte_experimental
> +int rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx);
> +
>  /**
>   * Get vhost RX queue avail count.
>   *
> diff --git a/lib/vhost/version.map b/lib/vhost/version.map
> index 7a00b65740..c8c44b8326 100644
> --- a/lib/vhost/version.map
> +++ b/lib/vhost/version.map
> @@ -94,6 +94,9 @@ EXPERIMENTAL {
>  	rte_vhost_async_try_dequeue_burst;
>  	rte_vhost_driver_get_vdpa_dev_type;
>  	rte_vhost_clear_queue;
> +
> +	# added in 22.11
> +	rte_vhost_vring_call_nonblock;
>  };
> 
>  INTERNAL {
> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
> index 8740aa2788..ed6efb003f 100644
> --- a/lib/vhost/vhost.c
> +++ b/lib/vhost/vhost.c
> @@ -1317,6 +1317,36 @@ rte_vhost_vring_call(int vid, uint16_t vring_idx)
>  	return 0;
>  }
> 
> +int
> +rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx)
> +{
> +	struct virtio_net *dev;
> +	struct vhost_virtqueue *vq;
> +
> +	dev = get_device(vid);
> +	if (!dev)
> +		return -1;
> +
> +	if (vring_idx >= VHOST_MAX_VRING)
> +		return -1;
> +
> +	vq = dev->virtqueue[vring_idx];
> +	if (!vq)
> +		return -1;
> +
> +	if (!rte_spinlock_trylock(&vq->access_lock))
> +		return -EAGAIN;
> +
> +	if (vq_is_packed(dev))
> +		vhost_vring_call_packed(dev, vq);
> +	else
> +		vhost_vring_call_split(dev, vq);
> +
> +	rte_spinlock_unlock(&vq->access_lock);
> +
> +	return 0;
> +}
> +
>  uint16_t
>  rte_vhost_avail_entries(int vid, uint16_t queue_id)
>  {
> --
> 2.21.3
  
Liu, Changpeng Oct. 17, 2022, 7:17 a.m. UTC | #3
> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia@intel.com>
> Sent: Monday, October 17, 2022 2:47 PM
> To: Liu, Changpeng <changpeng.liu@intel.com>; dev@dpdk.org
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>; David Marchand
> <david.marchand@redhat.com>
> Subject: RE: [PATCH v2] vhost: add new `rte_vhost_vring_call_nonblock` API
> 
> Hi Changpeng,
> 
> > -----Original Message-----
> > From: Liu, Changpeng <changpeng.liu@intel.com>
> > Sent: Wednesday, October 12, 2022 2:40 PM
> > To: dev@dpdk.org
> > Cc: Liu, Changpeng <changpeng.liu@intel.com>; Maxime Coquelin
> > <maxime.coquelin@redhat.com>; Xia, Chenbo <chenbo.xia@intel.com>; David
> > Marchand <david.marchand@redhat.com>
> > Subject: [PATCH v2] vhost: add new `rte_vhost_vring_call_nonblock` API
> >
> > Vhost-user library locks all VQ's access lock when processing
> > vring based messages, such as SET_VRING_KICK and SET_VRING_CALL,
> > and the data processing thread may already be started, e.g: SPDK
> > vhost-blk and vhost-scsi will start the data processing thread
> > when one vring is ready, then deadlock may happen when SPDK is
> > posting interrupts to VM.  Here, we add a new API which allows
> > caller to try again later for this case.
> >
> > Bugzilla ID: 1015
> > Fixes: c5736998305d ("vhost: fix missing virtqueue lock protection")
> >
> > Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> > ---
> >  lib/vhost/rte_vhost.h | 15 +++++++++++++++
> >  lib/vhost/version.map |  3 +++
> >  lib/vhost/vhost.c     | 30 ++++++++++++++++++++++++++++++
> >  3 files changed, 48 insertions(+)
> 
> For new API, we need to update release_22_11.rst and vhost_lib.rst.
Thanks Chenbo, a new v3 is sent for review.
> 
> You can refer to
> http://patchwork.dpdk.org/project/dpdk/patch/20221013092708.4922-2-
> xuan.ding@intel.com/
> 
> Thanks,
> Chenbo
> 
> >
> > diff --git a/lib/vhost/rte_vhost.h b/lib/vhost/rte_vhost.h
> > index bb7d86a432..d22b25cd4e 100644
> > --- a/lib/vhost/rte_vhost.h
> > +++ b/lib/vhost/rte_vhost.h
> > @@ -909,6 +909,21 @@ rte_vhost_clr_inflight_desc_packed(int vid, uint16_t
> > vring_idx,
> >   */
> >  int rte_vhost_vring_call(int vid, uint16_t vring_idx);
> >
> > +/**
> > + * Notify the guest that used descriptors have been added to the vring.
> > This
> > + * function acts as a memory barrier.  This function will return -EAGAIN
> > when
> > + * vq's access lock is held by other thread, user should try again later.
> > + *
> > + * @param vid
> > + *  vhost device ID
> > + * @param vring_idx
> > + *  vring index
> > + * @return
> > + *  0 on success, -1 on failure, -EAGAIN for another retry
> > + */
> > +__rte_experimental
> > +int rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx);
> > +
> >  /**
> >   * Get vhost RX queue avail count.
> >   *
> > diff --git a/lib/vhost/version.map b/lib/vhost/version.map
> > index 7a00b65740..c8c44b8326 100644
> > --- a/lib/vhost/version.map
> > +++ b/lib/vhost/version.map
> > @@ -94,6 +94,9 @@ EXPERIMENTAL {
> >  	rte_vhost_async_try_dequeue_burst;
> >  	rte_vhost_driver_get_vdpa_dev_type;
> >  	rte_vhost_clear_queue;
> > +
> > +	# added in 22.11
> > +	rte_vhost_vring_call_nonblock;
> >  };
> >
> >  INTERNAL {
> > diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
> > index 8740aa2788..ed6efb003f 100644
> > --- a/lib/vhost/vhost.c
> > +++ b/lib/vhost/vhost.c
> > @@ -1317,6 +1317,36 @@ rte_vhost_vring_call(int vid, uint16_t vring_idx)
> >  	return 0;
> >  }
> >
> > +int
> > +rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx)
> > +{
> > +	struct virtio_net *dev;
> > +	struct vhost_virtqueue *vq;
> > +
> > +	dev = get_device(vid);
> > +	if (!dev)
> > +		return -1;
> > +
> > +	if (vring_idx >= VHOST_MAX_VRING)
> > +		return -1;
> > +
> > +	vq = dev->virtqueue[vring_idx];
> > +	if (!vq)
> > +		return -1;
> > +
> > +	if (!rte_spinlock_trylock(&vq->access_lock))
> > +		return -EAGAIN;
> > +
> > +	if (vq_is_packed(dev))
> > +		vhost_vring_call_packed(dev, vq);
> > +	else
> > +		vhost_vring_call_split(dev, vq);
> > +
> > +	rte_spinlock_unlock(&vq->access_lock);
> > +
> > +	return 0;
> > +}
> > +
> >  uint16_t
> >  rte_vhost_avail_entries(int vid, uint16_t queue_id)
> >  {
> > --
> > 2.21.3
  

Patch

diff --git a/lib/vhost/rte_vhost.h b/lib/vhost/rte_vhost.h
index bb7d86a432..d22b25cd4e 100644
--- a/lib/vhost/rte_vhost.h
+++ b/lib/vhost/rte_vhost.h
@@ -909,6 +909,21 @@  rte_vhost_clr_inflight_desc_packed(int vid, uint16_t vring_idx,
  */
 int rte_vhost_vring_call(int vid, uint16_t vring_idx);
 
+/**
+ * Notify the guest that used descriptors have been added to the vring.  This
+ * function acts as a memory barrier.  This function will return -EAGAIN when
+ * vq's access lock is held by other thread, user should try again later.
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @return
+ *  0 on success, -1 on failure, -EAGAIN for another retry
+ */
+__rte_experimental
+int rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx);
+
 /**
  * Get vhost RX queue avail count.
  *
diff --git a/lib/vhost/version.map b/lib/vhost/version.map
index 7a00b65740..c8c44b8326 100644
--- a/lib/vhost/version.map
+++ b/lib/vhost/version.map
@@ -94,6 +94,9 @@  EXPERIMENTAL {
 	rte_vhost_async_try_dequeue_burst;
 	rte_vhost_driver_get_vdpa_dev_type;
 	rte_vhost_clear_queue;
+
+	# added in 22.11
+	rte_vhost_vring_call_nonblock;
 };
 
 INTERNAL {
diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 8740aa2788..ed6efb003f 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -1317,6 +1317,36 @@  rte_vhost_vring_call(int vid, uint16_t vring_idx)
 	return 0;
 }
 
+int
+rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(vid);
+	if (!dev)
+		return -1;
+
+	if (vring_idx >= VHOST_MAX_VRING)
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (!vq)
+		return -1;
+
+	if (!rte_spinlock_trylock(&vq->access_lock))
+		return -EAGAIN;
+
+	if (vq_is_packed(dev))
+		vhost_vring_call_packed(dev, vq);
+	else
+		vhost_vring_call_split(dev, vq);
+
+	rte_spinlock_unlock(&vq->access_lock);
+
+	return 0;
+}
+
 uint16_t
 rte_vhost_avail_entries(int vid, uint16_t queue_id)
 {