| Message ID | 1550823230-16809-1-git-send-email-jiayu.hu@intel.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | Maxime Coquelin |
| Headers | show |
| Series | vhost: fix interrupt suppression for the split ring | expand |
| Context | Check | Description |
|---|---|---|
| ci/checkpatch | success | coding style OK |
| ci/mellanox-Performance-Testing | success | Performance Testing PASS |
| ci/intel-Performance-Testing | success | Performance Testing PASS |
| ci/Intel-compilation | success | Compilation OK |
On Fri, Feb 22, 2019 at 04:13:50PM +0800, Jiayu Hu wrote: > The VIRTIO_RING_F_EVENT_IDX feature of split ring might > be broken, as the value of signalled_used is unpredictable > after live migration or start up. This patch fixes it by > using signalled_used_valid. Seems you also need to invalidate the signalled_used in e.g. set_vring_base, as signalled_used may not match last_used_idx anymore e.g. when guest driver is reloaded. > > In addition, this patch makes the VIRTIO_RING_F_EVENT_IDX > implementation of split ring match kernel backend to suppress > more interrupts. > > Fixes: e37ff954405a ("vhost: support virtqueue interrupt/notification suppression") > Cc: stable@dpdk.org > > Signed-off-by: Jiayu Hu <jiayu.hu@intel.com> > --- > lib/librte_vhost/vhost.h | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h > index fc31796..c4e5e34 100644 > --- a/lib/librte_vhost/vhost.h > +++ b/lib/librte_vhost/vhost.h > @@ -633,16 +633,20 @@ vhost_vring_call_split(struct virtio_net *dev, struct vhost_virtqueue *vq) > if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) { > uint16_t old = vq->signalled_used; > uint16_t new = vq->last_used_idx; > + bool signalled_used_valid = vq->signalled_used_valid; > + > + vq->signalled_used = new; > + vq->signalled_used_valid = true; > > VHOST_LOG_DEBUG(VHOST_DATA, "%s: used_event_idx=%d, old=%d, new=%d\n", > __func__, > vhost_used_event(vq), > old, new); > - if (vhost_need_event(vhost_used_event(vq), new, old) > - && (vq->callfd >= 0)) { > - vq->signalled_used = vq->last_used_idx; > + > + if ((vhost_need_event(vhost_used_event(vq), new, old) && > + (vq->callfd >= 0)) || > + unlikely(!signalled_used_valid)) > eventfd_write(vq->callfd, (eventfd_t) 1); > - } > } else { > /* Kick the guest if necessary. */ > if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT) > -- > 2.7.4 >
> -----Original Message----- > From: Bie, Tiwei > Sent: Monday, February 25, 2019 3:07 PM > To: Hu, Jiayu <jiayu.hu@intel.com> > Cc: dev@dpdk.org; maxime.coquelin@redhat.com; stable@dpdk.org > Subject: Re: [PATCH] vhost: fix interrupt suppression for the split ring > > On Fri, Feb 22, 2019 at 04:13:50PM +0800, Jiayu Hu wrote: > > The VIRTIO_RING_F_EVENT_IDX feature of split ring might > > be broken, as the value of signalled_used is unpredictable > > after live migration or start up. This patch fixes it by > > using signalled_used_valid. > > Seems you also need to invalidate the signalled_used in e.g. > set_vring_base, as signalled_used may not match last_used_idx > anymore e.g. when guest driver is reloaded. To handle the virtio device reload case, how about setting signalled_used_valid to false in get_vring_base()? Thanks, Jiayu > > > > > In addition, this patch makes the VIRTIO_RING_F_EVENT_IDX > > implementation of split ring match kernel backend to suppress > > more interrupts. > > > > Fixes: e37ff954405a ("vhost: support virtqueue interrupt/notification > suppression") > > Cc: stable@dpdk.org > > > > Signed-off-by: Jiayu Hu <jiayu.hu@intel.com> > > --- > > lib/librte_vhost/vhost.h | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h > > index fc31796..c4e5e34 100644 > > --- a/lib/librte_vhost/vhost.h > > +++ b/lib/librte_vhost/vhost.h > > @@ -633,16 +633,20 @@ vhost_vring_call_split(struct virtio_net *dev, > struct vhost_virtqueue *vq) > > if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) { > > uint16_t old = vq->signalled_used; > > uint16_t new = vq->last_used_idx; > > + bool signalled_used_valid = vq->signalled_used_valid; > > + > > + vq->signalled_used = new; > > + vq->signalled_used_valid = true; > > > > VHOST_LOG_DEBUG(VHOST_DATA, "%s: > used_event_idx=%d, old=%d, new=%d\n", > > __func__, > > vhost_used_event(vq), > > old, new); > > - if (vhost_need_event(vhost_used_event(vq), new, old) > > - && (vq->callfd >= 0)) { > > - vq->signalled_used = vq->last_used_idx; > > + > > + if ((vhost_need_event(vhost_used_event(vq), new, old) && > > + (vq->callfd >= 0)) || > > + unlikely(!signalled_used_valid)) > > eventfd_write(vq->callfd, (eventfd_t) 1); > > - } > > } else { > > /* Kick the guest if necessary. */ > > if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT) > > -- > > 2.7.4 > >
On Wed, Feb 27, 2019 at 01:38:28PM +0800, Hu, Jiayu wrote: > > -----Original Message----- > > From: Bie, Tiwei > > Sent: Monday, February 25, 2019 3:07 PM > > To: Hu, Jiayu <jiayu.hu@intel.com> > > Cc: dev@dpdk.org; maxime.coquelin@redhat.com; stable@dpdk.org > > Subject: Re: [PATCH] vhost: fix interrupt suppression for the split ring > > > > On Fri, Feb 22, 2019 at 04:13:50PM +0800, Jiayu Hu wrote: > > > The VIRTIO_RING_F_EVENT_IDX feature of split ring might > > > be broken, as the value of signalled_used is unpredictable > > > after live migration or start up. This patch fixes it by > > > using signalled_used_valid. > > > > Seems you also need to invalidate the signalled_used in e.g. > > set_vring_base, as signalled_used may not match last_used_idx > > anymore e.g. when guest driver is reloaded. > > To handle the virtio device reload case, how about setting > signalled_used_valid to false in get_vring_base()? Sounds good. > > Thanks, > Jiayu > > > > > > > > > In addition, this patch makes the VIRTIO_RING_F_EVENT_IDX > > > implementation of split ring match kernel backend to suppress > > > more interrupts. > > > > > > Fixes: e37ff954405a ("vhost: support virtqueue interrupt/notification > > suppression") > > > Cc: stable@dpdk.org > > > > > > Signed-off-by: Jiayu Hu <jiayu.hu@intel.com> > > > --- > > > lib/librte_vhost/vhost.h | 12 ++++++++---- > > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > > > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h > > > index fc31796..c4e5e34 100644 > > > --- a/lib/librte_vhost/vhost.h > > > +++ b/lib/librte_vhost/vhost.h > > > @@ -633,16 +633,20 @@ vhost_vring_call_split(struct virtio_net *dev, > > struct vhost_virtqueue *vq) > > > if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) { > > > uint16_t old = vq->signalled_used; > > > uint16_t new = vq->last_used_idx; > > > + bool signalled_used_valid = vq->signalled_used_valid; > > > + > > > + vq->signalled_used = new; > > > + vq->signalled_used_valid = true; > > > > > > VHOST_LOG_DEBUG(VHOST_DATA, "%s: > > used_event_idx=%d, old=%d, new=%d\n", > > > __func__, > > > vhost_used_event(vq), > > > old, new); > > > - if (vhost_need_event(vhost_used_event(vq), new, old) > > > - && (vq->callfd >= 0)) { > > > - vq->signalled_used = vq->last_used_idx; > > > + > > > + if ((vhost_need_event(vhost_used_event(vq), new, old) && > > > + (vq->callfd >= 0)) || > > > + unlikely(!signalled_used_valid)) > > > eventfd_write(vq->callfd, (eventfd_t) 1); > > > - } > > > } else { > > > /* Kick the guest if necessary. */ > > > if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT) > > > -- > > > 2.7.4 > > >
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index fc31796..c4e5e34 100644 --- a/lib/librte_vhost/vhost.h +++ b/lib/librte_vhost/vhost.h @@ -633,16 +633,20 @@ vhost_vring_call_split(struct virtio_net *dev, struct vhost_virtqueue *vq) if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) { uint16_t old = vq->signalled_used; uint16_t new = vq->last_used_idx; + bool signalled_used_valid = vq->signalled_used_valid; + + vq->signalled_used = new; + vq->signalled_used_valid = true; VHOST_LOG_DEBUG(VHOST_DATA, "%s: used_event_idx=%d, old=%d, new=%d\n", __func__, vhost_used_event(vq), old, new); - if (vhost_need_event(vhost_used_event(vq), new, old) - && (vq->callfd >= 0)) { - vq->signalled_used = vq->last_used_idx; + + if ((vhost_need_event(vhost_used_event(vq), new, old) && + (vq->callfd >= 0)) || + unlikely(!signalled_used_valid)) eventfd_write(vq->callfd, (eventfd_t) 1); - } } else { /* Kick the guest if necessary. */ if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
The VIRTIO_RING_F_EVENT_IDX feature of split ring might be broken, as the value of signalled_used is unpredictable after live migration or start up. This patch fixes it by using signalled_used_valid. In addition, this patch makes the VIRTIO_RING_F_EVENT_IDX implementation of split ring match kernel backend to suppress more interrupts. Fixes: e37ff954405a ("vhost: support virtqueue interrupt/notification suppression") Cc: stable@dpdk.org Signed-off-by: Jiayu Hu <jiayu.hu@intel.com> --- lib/librte_vhost/vhost.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)