From: "Liu, Changpeng" <changpeng.liu@intel.com>
To: "Xia, Chenbo" <chenbo.xia@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>,
David Marchand <david.marchand@redhat.com>
Subject: RE: [PATCH v3] vhost: add new `rte_vhost_vring_call_nonblock` API
Date: Mon, 17 Oct 2022 07:50:59 +0000 [thread overview]
Message-ID: <PH0PR11MB5093EDBDF06A0BD9A74E4820EE299@PH0PR11MB5093.namprd11.prod.outlook.com> (raw)
In-Reply-To: <SN6PR11MB3504572FD5A8AF6DD469BE259C299@SN6PR11MB3504.namprd11.prod.outlook.com>
> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia@intel.com>
> Sent: Monday, October 17, 2022 3:40 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 v3] vhost: add new `rte_vhost_vring_call_nonblock` API
>
> Hi Changpeng,
>
> > -----Original Message-----
> > From: Liu, Changpeng <changpeng.liu@intel.com>
> > Sent: Monday, October 17, 2022 3:15 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 v3] 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>
> > ---
> > doc/guides/prog_guide/vhost_lib.rst | 6 ++++++
> > doc/guides/rel_notes/release_22_11.rst | 6 ++++++
> > lib/vhost/rte_vhost.h | 15 +++++++++++++
> > lib/vhost/version.map | 3 +++
> > lib/vhost/vhost.c | 30 ++++++++++++++++++++++++++
> > 5 files changed, 60 insertions(+)
> >
> > diff --git a/doc/guides/prog_guide/vhost_lib.rst
> > b/doc/guides/prog_guide/vhost_lib.rst
> > index bad4d819e1..52f0589f51 100644
> > --- a/doc/guides/prog_guide/vhost_lib.rst
> > +++ b/doc/guides/prog_guide/vhost_lib.rst
> > @@ -297,6 +297,12 @@ The following is an overview of some key Vhost API
> > functions:
> > Clear in-flight packets which are submitted to async channel in vhost
> > async data
> > path. Completed packets are returned to applications through ``pkts``.
> >
> > +* ``rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx)``
> > +
> > + Notify the guest that used descriptors have been added to the vring.
> > This function
> > + will return -EAGAIN when vq's access lock is held by other thread, user
> > should try
> > + again later.
> > +
> > * ``rte_vhost_vring_stats_get_names(int vid, uint16_t queue_id, struct
> > rte_vhost_stat_name *names, unsigned int size)``
> >
> > This function returns the names of the queue statistics. It requires
> > diff --git a/doc/guides/rel_notes/release_22_11.rst
> > b/doc/guides/rel_notes/release_22_11.rst
> > index 2da8bc9661..9b3783ffd8 100644
> > --- a/doc/guides/rel_notes/release_22_11.rst
> > +++ b/doc/guides/rel_notes/release_22_11.rst
> > @@ -236,6 +236,12 @@ New Features
> >
> > strings $dpdk_binary_or_driver | sed -n 's/^PMD_INFO_STRING= //p'
> >
> > +* **Added non-block notify API to the vhost library.**
> > +
> > + Added API to notify the guest that used descriptors have been added
> > + to the vring in non-block way, user should check the return value of
> > + this API.
> > +
>
> This may be better:
>
> * **Added non-blocking notify API to the vhost library.**
>
> Added ``rte_vhost_vring_call_nonblock`` API to notify the guest that used
> descriptors have been added to the vring in non-blocking way. User should
> check the return value of this API and try again if needed.
>
> And for new features, library should come before scripts, so you need to move
> this before ' Rewritten pmdinfo script. ' item.
Thanks Chenbo, applied them with v4.
>
> Thanks,
> Chenbo
>
> >
> > Removed Items
> > -------------
> > 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
next prev parent reply other threads:[~2022-10-17 7:51 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-06 2:22 [PATCH] vhost: use try_lock in rte_vhost_vring_call Changpeng Liu
2022-09-06 21:15 ` Stephen Hemminger
2022-09-07 0:40 ` Liu, Changpeng
2022-09-20 7:12 ` Maxime Coquelin
2022-09-20 2:24 ` Xia, Chenbo
2022-09-20 2:34 ` Liu, Changpeng
2022-09-20 2:53 ` Xia, Chenbo
2022-09-20 3:00 ` Liu, Changpeng
2022-09-20 7:23 ` Maxime Coquelin
2022-09-20 7:30 ` Maxime Coquelin
2022-09-20 7:19 ` Maxime Coquelin
2022-09-20 7:29 ` Liu, Changpeng
2022-09-20 7:34 ` Maxime Coquelin
2022-09-20 7:45 ` Liu, Changpeng
2022-09-20 8:12 ` Maxime Coquelin
2022-09-20 8:43 ` Liu, Changpeng
2022-09-21 9:41 ` Maxime Coquelin
2022-09-21 9:52 ` Liu, Changpeng
2022-10-11 11:56 ` Maxime Coquelin
2022-10-12 6:40 ` [PATCH v2] vhost: add new `rte_vhost_vring_call_nonblock` API Changpeng Liu
2022-10-13 7:56 ` Maxime Coquelin
2022-10-17 6:46 ` Xia, Chenbo
2022-10-17 7:17 ` Liu, Changpeng
2022-10-17 7:14 ` [PATCH v3] " Changpeng Liu
2022-10-17 7:39 ` Xia, Chenbo
2022-10-17 7:50 ` Liu, Changpeng [this message]
2022-10-17 7:48 ` [PATCH v4] " Changpeng Liu
2022-10-19 5:27 ` Xia, Chenbo
2022-10-26 9:24 ` Xia, Chenbo
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