From: "Wang, Yinan" <yinan.wang@intel.com>
To: "Hu, Jiayu" <jiayu.hu@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "Bie, Tiwei" <tiwei.bie@intel.com>,
"maxime.coquelin@redhat.com" <maxime.coquelin@redhat.com>,
"stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [dpdk-stable] [PATCH v2] vhost: fix interrupt suppression for the split ring
Date: Wed, 20 Mar 2019 00:45:55 +0000 [thread overview]
Message-ID: <E0CBA5A1980F1F408E1F28F9991B5B1D50E4E416@SHSMSX104.ccr.corp.intel.com> (raw)
In-Reply-To: <1552804712-9973-1-git-send-email-jiayu.hu@intel.com>
Test-by: Wang, Yinan <yinan.wang@intel.com>
Best Wishes,
Yinan
> -----Original Message-----
> From: Hu, Jiayu
> Sent: 2019年3月17日 14:39
> To: dev@dpdk.org
> Cc: Bie, Tiwei <tiwei.bie@intel.com>; maxime.coquelin@redhat.com; Wang,
> Yinan <yinan.wang@intel.com>; Hu, Jiayu <jiayu.hu@intel.com>;
> stable@dpdk.org
> Subject: [PATCH v2] vhost: fix interrupt suppression for the split ring
>
> The VIRTIO_RING_F_EVENT_IDX feature of split ring might be broken, as the
> value of signalled_used is invalid after live migration, start up and virtio driver
> reload.
> 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>
> ---
> change in v2:
> - fix virtio-net driver reload
>
> lib/librte_vhost/vhost.h | 12 ++++++++----
> lib/librte_vhost/vhost_user.c | 2 ++
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> f008ec4..e9138df 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) diff --git
> a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c index
> 36c0c67..01a8d80 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1298,6 +1298,8 @@ vhost_user_get_vring_base(struct virtio_net
> **pdev,
>
> vq->callfd = VIRTIO_UNINITIALIZED_EVENTFD;
>
> + vq->signalled_used_valid = false;
> +
> if (dev->dequeue_zero_copy)
> free_zmbufs(vq);
> if (vq_is_packed(dev)) {
> --
> 2.7.4
next prev parent reply other threads:[~2019-03-20 0:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-22 8:13 [dpdk-stable] [PATCH] " Jiayu Hu
2019-02-25 7:06 ` Tiwei Bie
2019-02-27 5:38 ` Hu, Jiayu
2019-02-27 10:55 ` Tiwei Bie
2019-03-17 6:38 ` [dpdk-stable] [PATCH v2] " Jiayu Hu
2019-03-20 0:45 ` Wang, Yinan [this message]
2019-03-20 4:56 ` Tiwei Bie
2019-03-20 7:36 ` Maxime Coquelin
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