From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Stefan Hajnoczi <stefanha@redhat.com>, dev@dpdk.org
Cc: Yuanhan Liu <yliu@fridaylinux.org>, Tetsuya Mukawa <mtetsuyah@gmail.com>
Subject: Re: [dpdk-dev] [PATCH] vhost: introduce rte_vhost_vring_call()
Date: Thu, 21 Dec 2017 22:30:56 +0100 [thread overview]
Message-ID: <95c9797f-3571-6843-0a79-7d3d1ed1a5c1@redhat.com> (raw)
In-Reply-To: <20171221164128.20001-1-stefanha@redhat.com>
Hi Stefan,
On 12/21/2017 05:41 PM, Stefan Hajnoczi wrote:
> +int
> +rte_vhost_vring_call(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;
> +
> + /* flush used->idx update before we read avail->flags. */
> + rte_mb();
> +
> + /* Kick the guest if necessary. */
> + if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
> + && (vq->callfd >= 0))
> + eventfd_write(vq->callfd, (eventfd_t)1);
> + return 0;
> +}
I think it may be better to have an internal function that just take the
vq as argument to avoid getting again the vq from the vid & vring index
in the hot path.
Also, this internal function could be tagged as always inlined.
Thanks,
Maxime
prev parent reply other threads:[~2017-12-21 21:31 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-21 16:41 Stefan Hajnoczi
2017-12-21 21:30 ` Maxime Coquelin [this message]
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